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Page 1: Acetone Production Report
Page 2: Acetone Production Report

SUMMARY

The process purpose is to produce acetone from isopropyl alcohol (IPA) at the given

conditions. This report is formed, some properties, manufacturing process of acetone. In

manufacturing process, feed drum, vaporizer, heater, reactor, furnace, cooler, condenser,

flash unit, scrubber, acetone and IPA columns are used.

This profile envisages the establishment of a plant for the production of acetone with a

capacity of 100 tons per annum.

The present demand for the proposed product is estimated at 70 tons per annum. The demand

is expected to reach at 137.7 tones by the year 2017.

The plant will create employment opportunities for 20 persons.

The total investment requirement is estimated at Birr 6.17 million, out of which Birr 2.84

million is required for plant and machinery.

The project is financially viable with an internal rate of return (IRR) of 14 % and a net

present value (NPV) of Birr 1.71 million, discounted at 8.5%.

Page 3: Acetone Production Report

NOMENCLATURE

MW=Molecular Weight [kg/kmol]

N = mole [mol/h]

Y = mol or mass fraction of gas stream

X = mol or mass fraction of liquid stream

P Tn = Total Pressure [bar]

Pi*n= Vapour Pressure of Component [bar]

Pv* = Vapour Pressure [bar]

F = Feed Flow Rate [k mol/h]

V = Flow Rate of Vapour [kmol/h]

L = Flow Rate of Liquid [kmol/h]

T = Temperature [° C]

∆ Hvap = Latent Heat of Vaporization [kJ/kg]

TC = Critical Temperature [° C]

PC = Critical Pressure [bar]

Tb = Normal Boiling Point [° C]

Q = Heat [kJ]

M = Mass Flow Rate [kg/h]

K = Activity Coefficient

Page 4: Acetone Production Report

Introduction:-

Acetone is the organic compound with the formula (CH3)2CO, a colorless, mobile, flammable

liquid, the simplest example of the ketones. Acetone is miscible with water and serves as an

important solvent in its own right, typically as the solvent of choice for cleaning purposes in

the laboratory. About 6.7 million tons were produced worldwide in 2010, mainly for use as a

solvent and production of methyl methacrylate and bisphenol A. Familiar household uses of

acetone are as the active ingredient in nail polish remover and as paint thinner. It is a

common building block in organic chemistry.

Acetone is naturally produced and disposed of in the human body as a result of normal

metabolic processes. It is normally present in blood and urine. Diabetic people produce it in

larger amounts. Reproductive toxicity tests show that it has low potential to cause

reproductive problems. In fact, the body naturally increases the level of acetone in pregnant

women, nursing mothers and children because their higher energy requirements lead to

higher levels of acetone production. Ketogenic diets that increase acetone in the body are

used to reduce epileptic attacks in infants and children who suffer from recalcitrant refractory

epilepsy. Acetone (dimethyl ketone, 2-propane, CH3COCH3) formulation weight 58,079 is

the simplest and the most important of the ketones. It is a colorless, mobile, flammable liquid

with a mildly pungent and somewhat aromatic odour. It is miscible in all proportions with

water and with organic solvents such as ether, methanol, ethyl alcohol, and esters.

Acetone is used as a solvent for cellulose acetate and nitrocellulose, as a carrier for acetylene

And as a raw material for the chemical synthesis of a wide range of products such as ketene,

Methyl methacrylate, bisphenol A, diacetone alcohol mesityl oxide, methyl isobutyl ketone,

Hexylene glycol (2-methyl-2, 4-pentanediol), and isophorone.

Acetone is produced in various ways;

1. The Cumene Hydro peroxide Process for Phenol and Acetone

2. Isopropyl Alcohol Dehydrogenation

3. Direct Oxidation of Hydrocarbons to a Number of Oxygenated Products Including

Acetone

4. Catalytic Oxidation of Isopropyl Alcohol

5. Acetone as a By-Product of the Propylene Oxide Process Used by Oxirane

6. The p-Cymene Hydro peroxide Process for p Cresol and Acetone

7. The Diisopropylbenzene Process for Hydroquinone (or Resorcinol) and Acetone

In this report isopropyl alcohol dehydrogenation was investigated.

Page 5: Acetone Production Report

PHYSICAL AND CHEMICAL PROPERTIES:

Appearance: - Liquid. Clear.

Molecular wt.:- 58.079

Colour: - Colourless.

Density/specific gravity (g/ml):- 0.79 Temperature (°C): 20

Melting Point -94.60C

Boiling Point 56.130C (at 760 mm Hg)

Vapour Pressure: - 24 .7 KP at Temperature (°C):

20Evaporation Rate: - .6

Volatile by vol. (%):- 10

Solubility description: - Miscible with water.

Solubility Value (g/100g H 2O20°C ):- 100

Auto Ignition Temp. (°C):- 540

Flammability limit (lower) (%):- 2.1

Flammability limit (upper) (%):- 13.0

Stability and Reactivity:

Stability: - Stable under normal conditions of use.

Conditions to avoid: - Avoid contact with: Strong oxidising agents. Avoid

Contact with acids. Avoid heat, flames and other .

. Sources of ignition

Materials to avoid: - Potassium sulphate, sodium hydroxide, sulphuric acid,

Nitric acid, hydrogen peroxide, chloroform, activated

Carbon, Bromine.

Hazardous Decomp.Product - Thermal decomposition or burning may release oxides

Of carbon and other hazardous gases or vapours

Page 6: Acetone Production Report

Uses-:

About a third of the world's acetone is used as a solvent, and a quarter is consumed as a

precursor to methyl methacrylate.

Solvent use:

Acetone is a good solvent for most plastics and synthetic fibers including those used in

laboratory bottles made of polystyrene, polycarbonate and some types of polypropylene. It is

ideal for thinning fibreglass resin, cleaning fiberglass tools and dissolving two-part epoxies

and superglue before hardening. It is used as a volatile component of some paints and

varnishes. As a heavy-duty degreaser, it is useful in the preparation of metal prior to painting;

it also thins polyester resins, vinyl and adhesives. It is also useful for high reliability

soldering applications to remove solder rosin after soldering is complete. This helps to

prevent the Rusty bolt effect from occurring due to dirty solder contacts.

Storage of acetylene

Although flammable itself, acetone is also used extensively as a solvent for the safe

transporting and storing of acetylene, which cannot be safely pressurized as a pure

compound. Vessels containing a porous material are first filled with acetone followed by

acetylene, which dissolves into the acetone. One litter of acetone can dissolve around 250

litters of acetylene.

Methyl methacrylate

This application begins with the initial conversion of acetone to acetone cyanohydrins:

(CH3)2CO + HCN → (CH3)2C (OH) CN

In a subsequent step, the nitrile is hydrolyzed to the unsaturated amide, which is esterified:

(CH3)2C (OH) CN + CH3OH → CH2= (CH3) CCO2CH3 + NH3

The third major use of acetone (about 20%) entails its condensation with phenol to give

bisphenol A

(CH3)2CO + 2 C6H5OH → (CH3)2C (C6H4OH) 2 + H2O

Page 7: Acetone Production Report

Bisphenol A is a component of many polymers such as polycarbonates, polyurethanes, and

epoxy resins.

Medical and cosmetic uses

Acetone is used in a variety of general medical and cosmetic applications and is also listed as

a component in food additives and food packaging.

Acetone is commonly used in chemical peeling. Common agents used today for chemical peels

are salicylic acid, glycolic acid, 30% salicylic acid in ethanol, and trichloroacetic acid (TCA).

Prior to chemexfoliation, the skin should be cleaned properly and excess fat removed. This

process is known as defatting. Acetone, Septisol, or a combination of these agents is

commonly used in this process.

Laboratory uses

In the laboratory, acetone is used as a polar aprotic solvent in a variety of organic reactions,

such as SN2 reactions. The use of acetone solvent is also critical for the Jones oxidation. It is a

common solvent for rinsing laboratory glassware because of its low cost and volatility. H\

however, it does not form an azeotrope with water (see azeotrope (data)). Despite its common

use as a supposed drying agent, it is not effective except by bulk displacement and dilution.

Acetone can be cooled with dry ice to −78 °C without freezing; acetone/dry ice baths are

commonly used to conduct reactions at low temperatures. Acetone is fluorescent under

ultraviolet light, and its vapour may be used as a fluorescent tracer in fluid flow experiments.

Domestic and other niche uses

Acetone is often the primary component in cleaning agents such as nail polish remover. Ethyl

acetate, another organic solvent, is sometimes used as well. Acetone is a component of

superglue remover and it easily removes residues from glass and porcelain.

It can be used as an artistic agent; when rubbed on the back of a laser print or photocopy

placed face-down on another surface and burnished firmly, the toner of the image transfers to

the destination surface. Make-up artists use acetone to remove skin adhesive from the netting

of wigs and moustaches by immersing the item in an acetone bath, then removing the oftened

glue residue with a stiff brush.

Page 8: Acetone Production Report

MARKET TREND -:

Past Supply and Present Demand

The country's requirement for acetone is totally met through import. Data obtained from the

Ethiopian Customs Authority with regard to import of acetone for the period covering 1997 -

2011 is given in Table-

IMPORTANCE OF ACETONE YEAR QUANTITY(Mt.Tons)

1997 41.6

1998 90.6

1999 52.7

2000 24.7

2001 154.3

2002 34.0

2003 34.3

2004 57.7

2005 47.5

2006 84.2

2007 70.5

2008 74.9

2009 80.2

2010 85.8

2011 91.8

Page 9: Acetone Production Report

Projected Demand -: Acetone is used as a solvent in the production of paint, varnish,

lacquer, cellulose acetate, potassium iodide and permanganate. It is also used to clean dry

parts of precision equipments, delusterant for cellulose acetate fibre and specification testing

of vulcanized rubber products. This clearly indicates that demand for acetone is directly

related with the development of the industrial sector. Taking this in consideration, annual

average growth of 7% is applied to forecast the future demand. The forecasted demand up to

the year 2017 is given in Table 3.2. 55-6 import figures were much higher than the imports in

the following years. In 1998, the import figure was about 90.6 tonnes while in the following

years, i.e., 1999 and 2000 the import figure dropped to 52.7 tonnes and 24.7 tonnes

respectively. Similarly, import figure in the year 2001 was about 154 tones while in the

following four consecutive years, i.e., from 2002 - 2005 import ranges from only 34 tonnes to

about 58 tonnes. This probably indicates that the high imports in some years were used as

buffer stocks for the following years. Hence, some portions of the imports were distributed

among the subsequent years in which recorded import figures were found to be

comparatively low.

By looking to the above argument, the present effective demand is estimated using the

following methodology.

The average import figures in the recent past six years, i.e., 2001- 2006 is taken as an

effective demand for the year 2007 since the product is directly related with the growth of the

manufacturing sector, an annual average growth rate of 7% (which is recorded by the

industrial sector in the past) is applied to arrive at the current (year 2007) demand.

PROJECT DEMAND OF ACETONE YEAR QUANTITY(Mt.Tons)

2012 98.2

2013 105.1

2014 112.4

2015 120.3

2016 128.7

2017 137.7

Page 10: Acetone Production Report

METHODS OF PRODUCTION:-

(a) Catalytic Dehydrogenation of Isopropanol

(b) Oxidation of Isopropyl benzene

(c) Co product of Glycerine- H2O2 process

(d) Oxidation of Butanol

(e) Oxidation of Propylene

(a) Acetone by oxidation of Propylene: A process for acetone production by direct

oxidation of propylene using air. In this process the catalysis consists of a solution of

copper chloride containing small quantities of palladium chloride.

The overall reaction is as follows

C3H6+1/2O2 CH3COCH3

(b) Oxidation of Butanol:

Catalytic oxidation of n butane using either cobalt or manganese acetate produces

acetic acid at 75-80% yield. By products of commercial value are obtained in

variable amounts. In the Celanese process the oxidation reaction is performed at a

temperature range 150-2250C and pressure of approx 505 atm.

CH3CH2CH2CH3 + O2 CH3COOH + CH3COCH3

(c) Co product of Glycerine- H2O2 process:

When Glycerine is produced from propylene via acrolein then acetone is produced as

a by product.

CH3CH═CH2 + H2O CH3CHOHCH3 + O2 CH3COCH3 + H2O2

(d) Oxidation of Isopropyl Benzene (Cumene):Cumene is synthesised from propylene

and benzene, followed by oxidation for the formation of hydro peroxide and splitting

the same into acetone and phenol. The crude products are then fractionated to get

pure acetone and phenol.

Page 11: Acetone Production Report

(e) Dehydrogenation of Isopropanol: Acetone is produced from catalytic

dehydrogenation of isopropanol. The catalyst used in this process is ZNO.The crude

product obtained from this process is fractioned and pure product is obtained.

  (CH3)2CHOH (CH3)3CO + H2

The acetone produced in the reactor passes into a phase separator and then into a separation

system that includes one stripping and two distillation columns. A recycle stream takes a

mixture of unreacted isopropyl alcohol and water, with a trace amount of acetone, back into a

mixer that feeds the reaction system. Using the catalyst which will be employed throughout

this analysis, the reaction is first order with respect to the concentration of isopropanol and

has an Arrhenius dependence on temperature with E=72.38 MJ/kmol and k=351,000 cubic m

gas/cubic m reactor sec.

Reason for selecting the process: (Catalytic dehydrogenation of

Isopropanol): Acetone production from Cumene process is a serious competitor for the

isopropanol dehydrogenation process. Catalytic dehydrogenation of isopropanol can be

chosen as a synthetic route when high-purity acetone is required, such as in biomedical

applications. In this process 88% of isopropanol is recycled so this process is cost effective.

Catalytic dehydrogenation of isopropanol gives approx 99% pure product.

Catalytic dehydrogenation of isopropanol: In the simplified process, an aqueous solution

of isopropyl alcohol is fed into the reactor, where the stream is vaporized and reacted over a

solid catalyst at 2 atm. The reactions occurring within the reactor are as follows:

CH3-CHOH-CH3 CH3-CO-CH3 + H2

Isopropyl alcohol (IP) Acetone (AC) Hydrogen (HY)

CH3-CHOH-CH3 + ½ O2 CH3-CO-CH3 + H2O

IP Acetone Water

Page 12: Acetone Production Report

Flow Sheet of Acetone Production

Page 13: Acetone Production Report

Process Description:

Feed drum is a kind of tank used for the mixing of the recycle stream and feed stream.

Recycle stream concentration was assumed to be same with the feed stream. The temperature

of the feed stream is assumed to be 250C at 2 bar pressure, which is assumed to be constant.

The temperature of recycle stream was calculated as 111.50C. The temperature of the leaving

stream was calculated as 32.890C, by the energy balance around feed drum. In the vaporizer

molten salt was used for heating. The temperature at the entrance of the unit is the

temperature of the mixture leaving the feed drum, which is 32.890C. And the leaving

temperature is the bubble point temperature of the mixture, which is 109.50C. The pressure is

2 bars, and assumed to be constant. Since the temperature leaving the vaporizer is not enough

for the reaction a pre-heat was used. The unit is working at 2 bars, and assumed to be

constant. The entrance and leaving temperatures are 109.50 C and 3250 C. The reactor was the

starting point for the calculations. The temperature values for the entering and leaving

streams were found from literature, which are 3250C and 3500C, respectively. The reaction

taken place inside is endothermic, for this reason the reactor has to be heated. For heating,

molten salt was used. The pressure is 1.8 bar, and assumed to be constant. The entrance

temperature of the cooler is 350 0C and leaving is 94.70C. For cooling, water was used.

Instead of water a refrigerant may be used. Better results may get. But since it costs too

much, it wasn’t chosen as the cooling material. From the temperature values it’s easily seen

that the load is on the cooler not on the condenser, for this process. But in reality the unit

cannot cool that much, and the load is mostly on the condenser. In this process, the mixture

cooled down to its dew point. The pressure is 1,5 bar, and assumed to be constant.- 5 - The

temperature of the entering stream is the dew point and the leaving temperature is the bubble

point of the mixture. In the condenser water was used as cooling material. In the calculation

of the dew and bubble points Antoine Equation was used. Trial and error was used with the

help of Excel. The mixture includes acetone, i- propyl -alcohol, water and hydrogen. But

hydrogen was not taken into consideration in the calculations. Since the condensation

temperature of hydrogen is very low, it is not condense in the condenser. It stays in the for

this reasons it has no affect on bubble and dew point calculations. Also since it does not

affect the temperature calculations it’s not taken into consideration on mole and mass fraction

calculations. The leaving and entering temperatures are 94.70 0C and 81 0C, respectively. The

pressure is 1.5 bar, and assumed to be constant. Flash unit was assumed to be isothermal, for

this reason temperature was not changed. It is 81 0C in the entrance and exit. The pressure is

1.5 bar, and assumed to be constant. By trial and error method, (V / F) value was found to be

Page 14: Acetone Production Report

0.2. The entrance temperature of the unit is the bubble point of the mixture, but if it was its

dew point the (V/F) value would be much higher. Scrubber was assumed to be adiabatic. The

temperature of water entering the unit was assumed to be 25 0C. The temperature of the off

gas, including hydrogen and a very little amount of acetone, was assumed to 70 0C. But this

assumption is too high, a lower temperature should have been assumed, since a lot of water is

used in the unit. It should have been around 40 0C – 50 0C. The temperature of the leaving

stream was found to be 28.1 0C.The pressure of the unit is 1.5 bar, and assumed to be

constant

Raw Material

Propylene or ISO-propyl alcohol is the only raw material used for manufacturing of acetone in the presence of a catalyst. Packaging materials are required for delivering this product. The annual materials requirement and cost of the plant is given in Table 4.1.

ANNUAL CONSUMPTION OF RAW MATERIALS AND COST

ANNUAL CONSUMPTION OF RAW MATERIALS AND

COST Description

Unit of meas.

Qty. Cost in '000 Birr

F.C L.C T.C Propylene tonnes 120 918 162 1080 Catalyst (silver or copper) " 0.5 17 3 20 Water m3 80 - 0.26 0.26

Packaging Barrel 625 - 188 188Total 935 353.26 1288.26

Page 15: Acetone Production Report

7.2 MATERIAL BALANCE:

7.2.1 Material Balance on Reactor:

CONVERSION = 90%

Nacetron5= 100*0.9 =90kmole/hr

Nh25 =100*0.9 =90 kmole/hr

NH2o 5 =49.25kmole/hr

Nipa =100*0.1= 10 kmole/hr

Ntotal= naceton +nh2o + nh2 5 +nipa =239.25kmole/hr

Yacetone =90/239.25= 0.376

Yh2 5=90/239.25 =.376

YH2o= 49.25/239.25= o.206

yipa=10/239.25 =0.042

Page 16: Acetone Production Report

7.2.2 Material Balance on Flash Unit:

It is assume that there is no change at temp. and pressure.

Ki == pi*/pp= yi/xi (at bubble point = 810c)

For Acetone

Logp*aceton =7.0947 – 1161/ (224+81)

P*aceton= 1651.6mmHg

Kaceton =1651.6/ ((1.5/1.013)*760) = 1.467

For IPA

Log p*= 8.37895- 1788.02/ (227.438+81)

P*ipa =381`.89 mmHg

Kipa = 381.89/1125.092 =0.339

For H2O

Log p*H2O = 7.96681 – 1668.21/ (228+81)

P*H2O = 369.89

Page 17: Acetone Production Report

KH2O = 369.89/1125.092 = 0.328

For Trail error

F/V = 0.2

Ft= nacetone +nH2O + nipa =149.25

F = V + L

V/F =0.2

Solving

V = 29.85kmole/hr , L= 119.4 Kmole/ hr

YV = K * xl

F*ZF = Vx *yv + z* xl

For Acetone

Yv = 1.467 * xL

90=29.85 yv + 119.4* xL

After solving

Xl=0.551

Yv = 0.809

For IPA

Yv = 0.339 * xL

10= 29.85 * yv + 119.4 * xl

After solving

Xl ==0.077 Yv = 0.026

For water

Yv = 0.328 *xl

49.25 = 29.85 * yv + 119.4 * xl

X l = o.381

Yv = o.125

Page 18: Acetone Production Report

At Stream 8:

V= 29.85 kmol/hr.

Yacetone= 0.809

Nacetone8= (0.809)*(29.85) = 24.148 kmol/hr

Yipa= 0.026

Nipa8= 0.026*29.85= 0.766 kmol/hr

YH2O =0.125

NH2O= (0.125)*(29.85) =3.731kmol/hr

At Stream 9

L= 119.4kmol/hr

Xacetone=0.551 nacetone= (0.551)*(119.4) = 65.789 kmol/hr

Xipa=0.077 nipa9= (0.077)*(119.4) = 9.149 kmol/hr

Xwater=0.381 nacetone= (0.381)*(119.4) = 45.491 kmol/hr

Page 19: Acetone Production Report

7.2.3 Material balance for Scrubber:

T=(81oC) = 354.15 K, P=1.5bar

Assume: 1/1000 of inlet acetone is off gas.

Nacetone12= 0.024148 kmol/hr

Nacetone10=24.148-0.024148=24.124kmol/hr

Ntotal= nacetone+nH2,8+nH2O+nipa 24.148+90+3.731+0.776 = 118.655 kmol/hr

nacetone12= nacetone12+nH2,12 0.024148+90 = 90.024kmol/hr

Yacetone=0.024148/90.024= 2.68*10-4

Yacetone8= 24.148/118.655 =0.203

Yacetone12/ Yacetone8=1-A/1-A6 Where A =L11/m* V8

M= e (10.92-3598/T)/P take P=1.48 T=354.15

Page 20: Acetone Production Report

M= 1.445

Yacetone12/ Yacetone8=2.68*10-4/0.203 = 1.320*10-3= 1-A/1-A6

From trial error A is found is 3.523

L11= m*A*V8= 1.445*3.523*118.655 = 604.041 kmol/hr

NH2O10= nH2O8+ nH2O11 3.731+604.041 =607.772 kmol/hr

Ntotal10= nacetone10+nH2,10+nipa10 24.124+607.772+0.776= 632.6724 kmol/hr

7.2.4 Material balance for Acetone Column

Nacetone13= Nacetone9+nacetone10= 65.789+24.124= 89.913kmol/hr

Nipa13= Nipa9+ Nipa10= 9.194+0.776 = 9.97 kmol/hr

NH2o13= NH2o9+ NH2o10= 45.491+607.772=653.263 kmol/hr

Assume: 1/1000 of acetone is in bottom product.

Nacetone15=89.913/1000= 0.089kmol/hr

Nacetone14= 89.913-0.089= 89.824kmol/hr

Since acetone purity is 99%.

Nipa14=89.824*(0.01/.99)= 0.907kmol/hr

Nipa15=nipa13-nipa14=9.97-0.907=9.063kmol/hr

Page 21: Acetone Production Report

NH2O15=nH2o13=653.263kmol/hr

7.2.5 Material Balance for IPA column:

All the ipa is at the top product Nipa17 = nipa 15 = 9.063 kmole/hr

Nacetone17 = nacetone15 = 0.089kmole/hr

Assume the composition of the recycle stream is as feed stream so that

Yacetone = 0.33 yipa =o.67

N H2O 17 = 9.063 * 0.33/o.67 = 4.469kmole/hr

nwater = nwater - nwater = 653.263 - 4.464 = 648.729kmole/hr

7.2.6 Material Balance for Feed Drum:

INPUT = OUTPUT

Nipa 12 = nipa - nipa 17

= 100 - 9.063 = 90.933kmole/hr

NH2O = nH2O + nh2o 17

NH2O = 49.25 - 4.464 = 44.786kmole/hr

Sience 115000tonns/day acetone is wanted to produce all of these calculation should be

correlated as this amount, these new value are shown in lable

Amount = 89.824 kmole/hr * 58.08 kg/1 * 1 ton/1000 * 8760/1 yr

Page 22: Acetone Production Report

= 45700.726 tpy

Scale factor

Sf = (115000ton/yr)/ 45700.726 = 2.516

7.3 ENERGY BALANCE

7.3.1 For Feed Drum

MH2O=2029.966kg/hr 1

T=250C

Mipa=13749.785kg/hr 2

T=32.890C

Mipa=15120.159kg/hr

Mwater=2232.293kg/hr

3

Mipa=1370.369kg/hr Mwater=202.326kg/hr

Tref =250C Cp.pia=2497kj/kg Cp.water=4178kj/kg

For stream 1,2 and 17 calculate Cpmix

Cpmix = (2497*0.87)+(4178*0.13) =2715 kj/kg

Mtotal1=13749.785+2029.966= 15779.75 kg/hr

Mtotal2=15120.154+2232.293=17352.447kg/hr

Feed Drum

Page 23: Acetone Production Report

Mtotal3=1370.369+202.326= 1572.695 kg/hr

Qin=Qout

15779.75*2.715*(25-25) +1572.695*2.715*(111.5-25) = 17352.447*2.715*(T-25)

T=32.830C

7.3.2 For Vaporiser:

T=32.830C

MIPA =15120.15kg/hr

MH2O =2232.293kg/hr

T =109.50C

Mipa=15120.154 Kg/hr

Mwater = 2232.293kg/hr

At 32.83 0c

Cpipa = 145kj/kmole K = 2.413 kj/kg K

CpH2o = 4.179 kj/kg K

For Water

Tc = 508.3 K

Tb = 394.399K

ΔHf = 39838 kj/kmole

ΔHvap ,H2O = H [(Tc-T)/(Tc-Tb)]o.38

= 41370.970 kj/kmole

= 2296.4731 kj/kg

Page 24: Acetone Production Report

For IPA

Tc = 647.3 K

Tb = 375K

ΔHf = 40683kj/kmole

ΔH vap , ipa = 40683[(647.3k-382.5k)/(647.3k-375k)]0.38

=40253.505 kj/kmol = 66982kj/kg

Q = (mipa * Cpipa * Δ T) + ( mwater * Cpw * ΔT) + (mw *Δ H vep, wat) + (mpipa * ΔHvap ,ipa)

= 9.652 * 106 kj

Molten Salt:

We assume

Δ T = 20

Q = m * Cpmolt.salt * Δ T

9.652*10^6 kj = 156 kj/kg * m * (20)

M = 309.358 tons

7.3.3 Pre Heater:

T=109.50C T=3250C

Mwater=2232.253kg/hr Mwater=15120.154kg/hr

Mipa=15120.154kg/hr Mipa=2232.293kg/hr

Tref=109.50C Cp,pia=24.6kj/kgk CpH2O=2019kj/kgk

Heater

Page 25: Acetone Production Report

Q=(mwater*Cpwater*∆T)+(mipa*Cpipa*∆T) =[(2232.293*2.468*(325-

109.5)+(15120.154*2.019*215.5)]

= 1.845*106 kj

Molten Salt: We assume ∆T= 1500C

Q=m*Cp molten salt*∆T= 1.845*106=156*m*150

M=7.855 ton

7.3.4 For Reactor:

(CH3)2CHOH (CH3)2CO+ H2

COMPOUN

D

Nin kmol/hr Hf kj/kmol Nout kmol/hr

(CH3)2CHOH 251.6 -272.290 25.16

CH3)2CO 0 -216.685 226.44

H2 0 0 226.44

T=3250C T=3500C

MH2=435.144kg/hr

M ipa

=1512.015kg/hr

Mipa=15120.154kg/hr

Mwater=2232.293kg/hr

Mwater= 2232.293kg/hr

Macetone=13151.635kg/hr

Reactor

Page 26: Acetone Production Report

∆Hin ipa= -272.29+25∫325(32.427+1.886*10-1T+6.405*10-5T2-9.261*10-8T5)dT

∆Hin ipa= -272.29+20.104 = -252186 kj/mol

∆Hout ipa= -27229+25∫350(32.427+1886*10-1T+6405*10-5T2-9261*10-8T3)dT

∆Hout ipa= -249.691 kj/kmol

∆Hout acetone= -216.685+25∫350(71.96+20.1*10-2T+12.78*10-5T2+3.476*10-8T3)dT

∆Hout acetone= -182.745 kj/mol

∆Hout H2= 25∫350(28.84*10-3+0.3288*10-8T2+0.00765*10-5T-0.8698*10-12T3)dT

∆Hout H2=9.466 kj/kmol

∆Hr0=(-216.685kj/kmol)-(-272.29)kj/kmol

∆Hr0= 55.605kj/kmol

∆Hr=226.44*55.685/1 =12591kj

Q= ∑outniHi - ∑inniHi+∆Hr

Q= [ 25.16( -249.691)+226.44(-182.745)+226.44(9.466)] – [252.6(-252.106)] +2591.196

Q=30521.67 kj

Molten Salt

Cp(molten salt b/w 3600C- 4100C) = 156kj/kg

Q=m*Cp*∆T

30521.67=156*m*50

M=391.300kg/hr

Page 27: Acetone Production Report

7.3.5 For Cooler

T = 3500C

MIPA = 1512.015kg/hr

MH2O = 2232.293kg/hr T= 94.70c ,

Macetone = 13151.635kg/hr mipa =1512.015kg/hr

MH2 = 455.144kg/hr m H2O =2232.293

kg/hr

M acetone =13151.635

kg/hr

M H2 =

455.144kg/hr

Tref = 94.70c

CpH2 = 12.608 kj/kg K

CpH2O= 2.035 kj/kg K

Cpipa =2.536kj/kg K

Cpacetone = 1.096 kj/kg K

We know

Q =[(mH2 *CpH2) + (mH2O * CpH2O) + (mipa * Cpipa) + (macetone * Cpacetone)] * del T

Q = - 10.123 * 106 kj

Water

Δ T water = 35- 20 =20

CpH2O =4.179 kj/hr

Page 28: Acetone Production Report

Q = m * CpH2o * Δ T

10.123 *106kg = 4.179kj/kg * m * 20 m = 121.117 ton/hr

7.3.6 For Condencer:

T = 94.70C

T = 81 0c

MIPA =1512.O15Kg/hr

MH2O =2232.293 kg/h mh2o= 2232.293kg/hr

Macetone = 1315.635kg/hr m acetone

=13151.635kg/hr

Mh2= 455.144 kg/hr mH2 = =455.444k/hr

Log P* = a – b/(c+Tdp)

Assumption = PT = 1.5 bar = 1125 mmHg

[(yacetone * pt )/(p*acetone * Tdp)] + [(yh2o * pt )/(p*

water *Tdp)] + [(yipa * pt)/( pipa* * Tdp)] +

[(yH2 *pt)/(pH2* * Tdp)] = 1

From Literature :

For acetone

A = 7.02447 B = 1161 C = 224

For H2O

A = 7.96681 B = 1668.21 C = 228

For IPA

Page 29: Acetone Production Report

A = 8.3789 B = 1788.02 C = 227.938

Using yaceton = 0.6 yH2o = 0.33 yipa = 0.07

By trial error Tdp = 94.7 0C

For aceton

At 14.70C & 1.5 bar

Cpacetone = 1.297 kg /K

Qacetone== m * Cp * del T

= 13151.6322 * 1.297 [(81+273.15) - (943.7 +273.15)]

= - 233.690 * 10-6 kj

Δ Hvep = Δ Hf [(Tc - T)/(Tc-Tb)]0.38

= 29140 kj/kmole

Tc 508.1 K Tb= 341.5 K

Δ Hvap = =28289.029kj/kmole = 487.07 kj/ kg

For IPA

At 94.70c & 1.5 bar

Cpipa = 1.761 kj / g KS

Cpipa = 1.761 kj.kg K

Qipa = =1512.015 * 1.761 *(354.15-367.85)

= -36.487 * 10^-3 Kj

∆ H vep =delHf [(Tc -T)/(Tc –Tb)]0.38

∆HF = 39850 kj/kmole

Tc =508.3K Tb = 366.6K

∆Hvap = 4116935kg/kmole

Page 30: Acetone Production Report

∆Hvap = 685128 kj/kg

For H2O

At 94.7 oC & 1.50bar

CpH2o = 1.898 kj/kgK

QH2o = 2232.293 *1898 *(354.15 -367.85)

= -58.045 *10^3 kj

∆Hvap = 40683 kj/kmole

Tc = 647.3 K Tb = 385.106K

∆HVAP = 40683 * [(6473-354)/(6473-385.126)].38

= 42442.0561 kj/kmole

=2356845 kj/lg

For H2

At 94.70c & 1.5 bar

CpH2 = 13.255 kj/kg K

QH2 = 435.144 kg * 13225 * (354.15 – 367.85)

= -82.464 * 103 kj

∑ m.Cp .∆ T = -410.677 *103 kg

∑mi ∆Hvap =12.702 * 106 kg

QTOTAL = ∑mi CP,t ∆T + ∑mi . ∆Hvap

= 12.3 *10^6

For H2O

∆T for water = (35-15)= 20

Cpwater =40182 kj/lg

Page 31: Acetone Production Report

Q = m*Cpwater *∆ T

682691.799kj = 40182 kj/kg * m *20

m=147.038 ton/day

∆H vap == 40683 *[(647.3 -354)/(647.3 -385.186)]0.38

=2356.845 kj/kgmole

7.3.7 For Scrubber:

Qin = Qout

Tref = 250C

455.144 * 14.419 *(81-25)+ 3528.708 *1.259*(81- 25) + 169.107 * 4.193 *(81-25) +

117.307 * 1.716 *(81-25) = 455.144 *14.401 *(70-25) + 3.485 *1229*(70-25) +

35.25.224 * 1249 *(T-25) + 27547.709 *4.183 *(T -25) + 117.307 * 1710 * (T-25)

4222.8319 = 18777.661 + (T-25)*755114.9

T = 28.10C

7.3.8 For Acetone column:

∆ Hvap = ∆Hf[(Tc -T)/(Tc- Tb)]0.38

Befor the application the boiling temp (Tb) for each of the component must be find at 1.1 bar

pressur.

For the boiling point calculation,

ln psat = A - (B/T ) will be used

Condenser:

For Acetone - Pc= 47 bar Tc= 508.1K P= 1.0133 bar T= 329.2K

Page 32: Acetone Production Report

ln1.0133= A-B/329.2 ln47= A-B/508.1

then A=10.91 B= 3587.3

At 1.1 bar pressure boiling point is- ln1.1= 10.91-(3587.3/Tb)

Tb= 331.706K

For ipa

Pc=47.6 bar Tc=508.3K

P= 1.0133 bar T= 355.35K

ln1.0133= A-(B/355.35)

ln47.6= A-(B/508.3) A=12.807 B= 4546.375

At 1.1 bar pressure boiling point is

ln1.1 = 12.807-(4546.375/ Tb) Tb= 357.653K

Substituting the result to the first equation:

∆Hacetone= 29140*[(508.1-375.3) / (508.1-331.706) ]0.38 = 26160195 kj/ kmol

∆Hipa= 39858*[(508.3-375.3) / (508.3-357.653) ]0.38

∆Hipa= 38014 kj/kmol

For the mixture:

∆Hmix= 450.417*0.99+632.618*0.01 = 452.24 kj/kg

MT=13263.045kg

For the energy balance of the mixture:

Q= mT*∆Hmix= 6*106 kj

For Water:

Pc= 220.5 bar Tc= 647.3K P= 1.0133 bar T= 373.15K

ln1.0133= A-(B/373.15)

Page 33: Acetone Production Report

ln220.5= A-(B/647.3) then A=12.72 B= 4743.39

At 1.1 bar pressure boiling point

ln1.1= 12.72-(4743.39/Tb) Tb=375.723K

Reboiler:

∆Hvap, aceton =29140 *[(508.1-378)/(508.1-331.706)]0.38

=25956.795 kj/kmole

=446.951 kj/kg

FOR H2O

∆Hvap,H2O = 40683*[ (647.3-378)/(647.1-375.723)] 0.38

∆Hvap, H2O = 40533.043kj/kgmole = 474.872

∆Hvap, ipa = 39838 *[(508.3-378)/(508.3-337.653)]0.38

= 627.722 kj/kmole

Yacetone = 4.364 * 10-4 yH2O = 0.955 yipa =0.045

∆H vap,mix= 446915 *6364 *10-4 + 674872 * 0.955 + 627.722*0.045

=672.945 kj/kg

Balance;

Q = mt . ∆ x vap mix

= 30993.013*672.945

=20.86*106kj

7.3.9 IPA Column

Tb ipa = 84.6530C TbH2o = 102.7230C

Page 34: Acetone Production Report

∆Hf,H2o =40683kj/kmole del Hf,ipa =39858kg/kmole

∆Hf,aceton = 29140 kj/kmole

∆Hvap,h2o =40294.194 kj/kmole= 2236.081kj/kg

∆Hvap,ipa = 38014 kj/kmole = 632.618kj/kg

∆Hvap,acetone = 26160.195 kj/kmole

sience aceton is neglected

YH2O = 0.13 Yipa = 0.87

∆Hvap,mix =2236.081*632.618

= 841.068 kj/kg

For the energy balance for mixing

Q = mT. ∆Hmix = 1941.326*841.068 =1.633 *106kj

Reboiler:

ΔHvap, water = 40683 * [(647.3-384.5)/(647.1-375.723)]0.38

=40179.523 kj/kmole

=2230.892kj/kg

Q = mT.ΔH.vap,water = 2230.892*29407.290

= 65.604 *106kj

Page 35: Acetone Production Report

Preliminary equipment summary table for acetone process

Equipment P-401 A/B P-402 A/B V-401 V-402MOC Carbon Steel Carbon

steelCarbon steel

Carbon steel

POWER(Shaft)(KW)

0.43 1.58 _ _

Efficiency 40% 50% _ _

Type/Drive Centrifugal/Electric

Centifugal/Electric

_ _

Op.Temreperatu(0C)

32 360 32 20

Pressure In(bar)

1.25 1.90 _ _

Pressure Out(bar)

3.10 3.30 _ _

Diameter(m) _ _ 0.80 0.75

Height/Length (m)

_ _ 2.40 2.25

Orietionnt _ _ Horizontal Horizontal

Intenals _ _ _ SS Demister

Op. Pressure(bar)

_ _ 1.0 1.63

Maximum Allowable Op.Prs.(bar)

_ _ 3.0 3.2

Page 36: Acetone Production Report

Preliminary equipment summary table for acetone process (cont’d)

Equipment T-401 H-401 R-401

MOC Corban steel Carbon steel Carbon steel

Diameter 0.32 _ Width=4.57m

Height/Length(m) 3.20 _ Depth=6.10m Height=5m

Orientation vertical _

Vertical

Internals 2.5m of packing (1”Ceremic Rashing Rings)

_

Fluidized bed Containing 7.5m3 of catalyst+7.8m3 of inert particleHTA=188m2

Op. Pressure(bar)

1.6 3.0 Tube side

2.16 in bed 2.70 in tube

Maximum Allowable Op.prs.(bar)

3.2 4.0 3.2 in bed 4.0 in bed

Type _ Fired heat _

Design Duty(Mj/h)

_ 3436 3436

Maximum Duty (Mj/h)

_ 3800 _

Area Radiant(m2)

_ 13.0 _

Area Convectiv(m2)

_ 37.0 _

Page 37: Acetone Production Report

Design Calculations

Vertical Tube Vaporizer

Conditions

Vapor leaves at 2.16 bar and 101C (saturated vapor). The shell side is assumed to be well

mixed and at 101C.

Heat Transfer Calculations

1. Regulate steam pressure to give a 10C temperature driving force T sat = 111C which

corresponds to a P sat = 1.48 bar.

2. Heat Duty = 2850 MJ/h , Cpl = 2880 J/kgºC

3. Limiting heat transfer resistance is on boiling organic side, shell = 1000 W/m2 shell C.

Uh shell = 1000 W/m2C

Tln = T = 10C

Page 38: Acetone Production Report

A=Q/U•Tlm (F=1)

= 285010 6 /3600/1000/10 = 79.2 m2

1110c

1010c

T

320c

Lenth along tubes

Note: over the range of ∆T = 7 to 250c it is known that hT 1/3 for boiling isopropanol.

Shell side well mixed

Page 39: Acetone Production Report

Reactor

Heat Transfer Calculations

Assume that the fluidized bed is well mixed, thus the feed gas immediately heats to the

reactor temperature of 350C. The molten salt approach temperature is 10C and therefore the

molten salt temperature leaving the reactor is 360C. The temperature vs. Q diagram is shown

below:

Tin

3600c

3500c 3500c

1010c

Length of reactor

Q=3436 MJ/h

Cp,gas = 1780 J/kgºC (inlet) and 2500 J/kgºC (outlet)

Use Hi TecTM molten salt with the following average physical properties:

C p = 1.72 kJ/kg K, = 1980 kg/m3, = 2.1 cP,

Maximum operating temperature = 1000C

Use a T = 50C for the circulating salt Tin = 410C

Tlm= (410-360)/ln[(410-350)/(360-350)] = 27.9C

Page 40: Acetone Production Report

Energy balance on molten salt

Q=MCpT 3436106 = (M)(1720)(50)

M = 39,950 kg/h = 11.10 kg/s

Vol flow of salt = M/ = 11.10/1980=5.60510-3 m3 /s

Evaluation of U

Fluidized Bed to tube wall, ho = 200 W/m2C

[this will not change much with fluidization velocity in the range of 2 – 5 umf ]

Inside heat transfer coefficient [molten salt to wall], h i = ?

Assume that the velocity in the tubes is 2 ft/s = 0.61 m/s

Use ½” diameter tube 18 BWG with inside diameter = 0.01021 m

Re = (0.61)(0.01021)(1980)/(0.0021) =5872

Nu = 0.023Re 0.8 Pr 0.33 = (.023)(5872) 0.8 (17200.0021/0.606) 0.33 = 42.9

(actually Seider-Tate is only good for Re>10,000 - check this later)

hi = Nu[k/d] = (42.9)(0.606)/(.01021) = 2546 W/m2C

Below 500C molten salt should not foul so h f = very large Overall heat transfer coefficient,

U = [d0/(dihi) + 1/ho]-1 = [1.244/2546+1/200]-1 = 182 W/m2C

Heat transfer area, Ao = Q/Uo T lm = (343610)/[(3600)(182)(27.9)] = 188 m2

Check tube arrangement and molten salt velocity

Page 41: Acetone Production Report

External surface area of 20 ft tubes =•doL = (3.142)(0.0127)(20)(0.3048) = 0.243 m2

Number of tubes = (188)/(0.243) = 773

Use 110 parallel sets of 7 tubes piped in series

Cross sectional area (csa) for flow of molten salt = (110)(3.142)(0.01021)2/4 = 0.0090 m2

Velocity of molten salt in tubes = 5.60510-3/0.0090 = 0.622 m/s

This gives Re = 5988 and Nu = 43.6 and hi = 2588 and U = 182 W/m 2C no change

For Re<10,000 we should use correlation from Walas [1]:

Nu0.012[Re 0.87 280]Pr 0.4 [1-(d/L)2/3]

This gives Nu = 41.1 and h = 2438, thus U = 181 W/m 2 C same as before.

Arrangement of tubes in Fluidized Bed

110 parallel banks of 7 tubes in Fluidized Bed Reactor

Height of Catalyst and Filler in Bed

Page 42: Acetone Production Report

Use a square tube pitch of 1.5 inches

Dimensions of tube bank are 1101.5/12 by 71.5/12 by 20 ft = 13.75 by 0.875 by 20 ft

Assume bed width and depth of 15 by 20 ft respectively

Volume of solids to just cover the tubes, assuming bottom row of tubes is 6” from distributor

plate and 6” of solids above tube bank = Vsol

V sol = (15)(20)(1+0.875) – volume occupied by tubes

= 562.5 – (770)(20)(•)(0.5)2 /(4144) = 541.5 ft 2 = 15.3 m3

Calculate the amount of catalyst required for 90% conversion

For a first order, isothermal, irreversible reaction at constant pressure we have the following

expression for the conversion of component A,XA :

Kτ = (1+ԑA)ln (1/1-XA)-ԑAXA

From the kinetics expression, at a reactor temperature of 350C, we have:

k=k0exp[-Ea/RT] =3.51×105exp[72,380/ (8.314)(273+350)]

=0.2996m3gas/m3bulk catalyst

ԑA= (number of mole if completely reacted – number of moles initially)/ number of moles

initially

= (96.48-57.84)/(57.84)=0.668

Using above values and 90% conversion we get:

Kτ = (1+0.668)ln (1/1-0.9)-(0.668)(0.9)=3.2395

τ =(3.2395)/(0.2996) =10.813 m3bulk catalyst s/ m3gas

Vcatalyst =υgas τ

Page 43: Acetone Production Report

Now the volumetric flow rate of gas, υgas =0.696 m3/s

Vcatalyst = (0.696)(10.83) =7.5 m3bulk catalyst

Amount of catalyst required is 7.5 m3, therefore we must add 7.8 m3 of inert filter to give a

total of 15.3 m3 of bed solids. This will give a slumped bed height approximately 6 above the

top of the tube bank.

Check minimum fluidizing velocity

Cross sectional area (csa) of bed = 300 ft2 = 27.9 m2

Properties of gas flowing through fluidized bed:

= 1.067 kg/m3, = 18.210-6 kg/m.s

flow of gas = 2670 kg/h

vol flow of gas = (2670)/[(1.067)(3600)] = 0.696 m3 /s

Superficial gas velocity, u = (0.696)/(27.9) = 0.0250 m/s

catalyst particles are approximately 100 •m in diameter, and have a density of 2500 kg/m 3

and bulk density of 1200 kg/m3 . Calculate minimum fluidizing velocity using the correlation

due to Wen and Yu [2]

Repmf = [33.72 + 0.0408Ar]1/2-33.7 where Ar = dp3ρg(ρs-ρg)g/µ2

Ar = (10-4 )3 (1.067)(2500 – 1.067)(9.81)/(18.210-6 ) 2 = 78.97

Re pmf = [33.72 +0.0408(78.97)] 1/2– 33.7 = 0.0478

umf = (0.0478)(18.210-6 )/[(1.067)(10-4)] = 0.00815 m/s

u/u mf = 0.0250/0.00815 = 3.06 O.K.

Cyclones can handle solids and gas in the range 1< u/u mf <5

Pressure Drop Across Fluidized Bed

Page 44: Acetone Production Report

Height of solids in fluidized bed = 1.875 ft = 0.57 m

Pbed = =hbulkg = (0.57)(1200)(9.81) = 6727 Pa = 0.067 bar

Distributor loss = 0.6 Pbed = 0.040 bar

Internal cyclone losses = 0.14 bar

(The design of the cyclones has been based on a maximum superficial gas velocity of 5umf )

Total loss across bed = 0.067 + 0.040 + 0.14 0.25 bar

Use a reactor height of 5.0 m to accommodate solids bed, plenum, freeboard, and cyclones.

Pressure Drop of Molten Salt through Heat Transfer Tubes

Re for molten salt flow = 5988

Roughness of drawn tubes, e = 0.0015 mm

e/d = 0.0015/10.21 = 0.00015

f = 0.0087

d = 0.01021 m

= 1980 kg/m3

Leq = length of tube + equivalent length of 12-90 bends = (7)(20)(.3048) + (12)(30d)

= 46.3m

Pf = 2fLequ 2/d = (2)(1980)(0.0087)(46.3)(0.622) 2 /(0.01021) = 60443 Pa = 60.4 kPa

UTILITIES

Page 45: Acetone Production Report

Utilities required for manufacturing acetone include electric power, potable and cooling

water, and steam.

Electricity

The power required for electrochemical processes; motor drives, lighting, and general use,

may be generated on site, but will more usually be purchased from the local supply company

(the national grid system in the UK). The economics of power generation on site are

discussed by Caudle (1975). The voltage at which the supply is taken or generated will

depend on the demand. For a large site the supply will be taken at a very high voltage,

typically 11,000 or 33,000 V.

Transformers will be used to step down the supply voltage to the voltages used on the site. In

the United Kingdom a three-phase 415-V system is used for general industrial purposes, and

240-V single-phase for lighting and other low-power requirements. If a number of large

motors is used, a supply at an intermediate high voltage will also be provided, typically 6000

or 11,000 V.

A detailed account of the factors to be considered when designing electrical distribution

systems for chemical process plants, and the equipment used (transformers, switch gearand

cables), is given by Silverman (1964).

Water:

Cooling water

Natural and forced-draft cooling towers are generally used to provide the cooling water

required on a site; unless water can be drawn from a convenient river or lake in sufficient

quantity. Sea water, or brackish water, can be used at coastal sites, but if used directly

will necessitate the use of more expensive materials of construction for heat exchangers

Water for general use

The water required for general purposes on a site will usually be taken from the local

mains supply, unless a cheaper source of suitable quality water is available from a river,

lake or well.

Demineralised water

Demineralised water, from which all the minerals have been removed by ion-exchange,

Page 46: Acetone Production Report

is used where pure water is needed for process use, and as boiler feed-water. Mixed and

Multiple-bed ion-exchange units are used; one resin converting the cations to hydrogen

and the other removing the acid radicals. Water with less than 1 part per million of

dissolved solids can be produced.

ANNUAL CONSUMPTION OF UTILITIES AND COST

Description Unit of

Measure

Qty. Cost in '000 Birr

Electricity kWh 33,100 16

Furnace oil m3 140 757

Water m3 15,040 83

Total 856

Control and instrumentation

Instrumentation is provided to monitor the key process variables during the plant operations.

They may be incorporated in automatic control loops, or used for the manual monitoring of

the process operation. They may also be part of an automatic computer data logging system.

Instruments monitoring critical process variables will be fitted automatic alarms to alert the

operations to critical and hazardous situation.

It is desirable that the process variable to be monitored be measured directly ; often however,

this is impractical and some dependent variables, i.e. easier to measure, is monitored in its

place for example, in the control of the distillation columns the continuous , online analysis

of the overhead product is desirable but difficult and expensive to achieve reliably, so

temperature is often monitored as an indication of composition . The temperature instrument

may form a part of a control loop controlling, say reflux flow; with the composition of the

overhead checked frequently by sampling and laboratory analysis.

Instrumentation and Control Objectives

Page 47: Acetone Production Report

The primary objectives of the designer when specifying instrumentation and control

objectives are;

1. Safe Plant Operation:

To keep the process variables within known safe operating limits.

To detect dangerous situations as they develop and to provide alarms and automatic

shutdown systems.

To provide interlocks and alarms to prevent dangerous operating procedures.

2. Production Rate:

To achieve the design product output.

3. Product Qualities:

To maintain the product composition within the specified quality standards.

4. Costs:

To operate at the lowest production cost, commensurate with the other objectives.

These are not separate objectives and must be considered together.

The order in which they are listed is not mean to employ the precedence of any objective over

another, other than that of putting safety first.

Product quality, production rate and the cost of production will be dependent on sale

requirement. For example, it may be better strategy to produce a better quality product at a

higher cost in a typical chemical processing plant these objectives are achieved by a

combination of automatic control , manual monitoring and laboratory analysis .

Automatic Control System:

The detail design and specification of the automatic control schemes for a large product is

usually done by specialists.

Guide Rule:

The following procedure can be used when drawing up preliminary P&I DIAGRAM:

Page 48: Acetone Production Report

1. Identify and draw in those control loops that are obviously needed for steady state plant

operation such as:

Level control

Flow control

Pressure control

Temperature control

2. Identify the key process variables that need to be controlled to be achieved the specified

product quality. Include control loops using direct measurement of the controlled variable,

where possible; if not practicable, select a suitable dependent variable.

3. Identify and include those additional control loops required for safe operation.

4. Decide and show those ancillary instruments needed for the monitoring of the plant

operation by operators; and for trouble shooting and plant development .It is well worthwhile

including additional connection for instruments which may be needed for future trouble

shooting and plant development, even if the instruments are not installed permanently. This

would include: extra thermo wells, pressure tapings, orifice flanges, and extra sample points.

5. Decide on the location of the sample points.

6. Decide on the need for recorders and the location of the read out points, local or control

rooms. This step would be done in conjunctions with step 1 to 4.

7. Decide on the alarms and interlocks needed; this would be done in conjunction with step 3.

9.3 Typical Control System:

Level Control:

In any equipment where an interface exists between two phase (e.g. liquid –vapour), some

means of maintaining the interface at required level must be provided. This may be

incorporated in the design of the equipment. Figure shows a typical arrangement, as is usually

done for the decanters by automatic control of the flow from the equipment.

Page 49: Acetone Production Report

Level control arrangement finds position at the base of column. The control valve should be

placed on the discharge line from the pump.

Pressure Control:

Pressure control will be necessary for the most systems handling vapour of gas. The method

of control will depend on the nature of the process. Typical schemes are proposed. When

vented gas was toxic, or valuable. In these circumstances the vent should be taken to a vent

recovery system, such as scrubber.

Flow Control:

Flow control is usually associated with inventory control in a storage tank or other

equipment. There must be a reservoir to take up the charge ion flow rate.

To provide flow control on a compressor or pump running at a fixed speed and supplying a

near constant column output ,a by pass control would we used.

Heat exchangers:

In the simplest arrangement, the temperature being controlled by varying the flow of the

cooling and heating medium. If the exchange is between two process streams whose flow are

fixed, by-pass control will have to be used.

Condenser Control:

Temperature control is unlikely to be effective for condensers, unless the liquid streams are

sub cooled. Pressure control is often used or control an be based on the outlet coolant

temperature.

Reboiler And Vaporizer:

As with condensers, temperature control is not effective as the saturated vapour temperature

is constant at constant pressure. Level control is often used for vaporizers ; the controller

controlling the stream supply to the heating surface , with the liquid feed to vaporizer on flow

control. An increase in the feed results in an automatic increases in stream to the vaporizer

the increased flow and maintains the level constant.

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Cascade Control:

With this arrangement, the output of one controller is used to adjust the set point .cascade

control can give smoother control in situation by direct control of the variable would lead to a

unstable operation. The “Slave” controller can be used to compensate for any short –term

variations in, say, a service. Stream flow, which would offset the controlled variable; the

primary (master) controller long term variations.

Ratio Control:

Ratio control can be used for it is used where it is desired to maintain two flows at a constant

ratio; for example, Reactor feeds and distillation column reflux.

Distillation Column Control:

The primary objective of distillation column control is to maintain the specified composition

the top and bottom products, and any side streams; correcting for the effects of disturbances

in:

. Feed flow rate, composition and temperature.

. Stream supply pressure

. Cooling water pressure and heater temperatures.

. Ambient composition, which cause changes in internal reflux.

The compositions are controlled by regulating reflux flow and boil up. The column overall

material balance must be controlled; distillation column has little surge capacity (hold up)

and the flow of distillate and bottom product (and side streams). Must match the feed flows.

A variety of control schemes has been devised for distillation column control. Column

pressure is normally controlled at a constant value.

The feed flow –rate is often set by the level controller on a preceding column. it can be

independently controlled if the column is fed from a storage or surge tank. feed temperature

is not normally controlled, unless a feed preheated is used.

Temperature is often as an indication of composition. The temperature sensor should be

located at the position in the column where the rate of change of temperature with change in

composition of the key component is maximum. Near top and bottom of the column the

change is usually small .with multicomponent systems, temperature is not unique function of

the composition. Top temperature is usually controlled by varying the reflux ratio, the bottom

temperature by varying the boil-up rate. If reliable on-line analyzers are variables they can be

incorporated in the control loop, but more complex equipment will be needed.

Differential pressure control is often used on packed columns to ensure the packing operates

at the correct loading.

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Addition temperature indication or recording points should be included up the column for

monitoring column performance and for troubleshooting.

Reactors Control:

The schemes used for reactor control depend on the process and the type of reactor. If reliable

on-line analyzer is available, and the reactor dynamics are suitable, the product composition

can be Monitored continuously and the reactor conditions and feed flows controlled

automatically to maintain the desired product composition and yield.

Reactor temperature will normally be controlled by regulating the flow of heating or cooling

medium. Pressure is usually held constant. Material balance control will be necessary to

maintain the correct flow of reactants to the reactor and the flow of products and unreacted

materials from reactor.

Alarms, Safety Trips and Interlocks

Alarm:

Alarms are used to alert operators of serious and potentially hazardous deviations in process

conditions. Key instrument are filled with switches and relays to operate audible and visual

alarms on the control panels and enunciators panels, where delay or lack of response, by the

operator is likely to lead to the rapid development of a hazardous situations, the instrument

would be fitted with a trip system to pumps, closing valves, operating emergency systems.

The basic components of the automatic control system are:

1. A sensor to monitor control variable and to provide an output signal when a preset

value is exceeded.

2. A link to transfer the signal to the actuator, usually consisting of a system of

pneumatic or electrical relays

3. An actuator to carry out the required action; close or open a valve, switch off a motor

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Safety:

A safety trip can be incorporated in a control loop. In this system, high temperature alarm

operates a solenoid valve, releasing the air on the pneumatic activator, closing the valve on

high temperature. However the safe operation of such a system will be dependent on the

reliability of the control equipment, and for potentially hazardous situation it is better practice

to specify a separate trip system. Provision must be made for the periodic checking of the trip

system to ensure that the system operates when needed.

Interlocks:

Where it is necessary to follow a fixed sequence of operations for example, during a plant

start-up and shut-down , or in batch operations interlocks are included to prevent operators,

departing from the required sequence. They may be incorporated in the control system design

as the pneumatic or electric relays, or may be mechanical interlocks. Special locks with

various properties and key system are available.

Computers and microprocessors an Process Control

Computers are being increasingly used for data logging, process monitoring and control.

They have largely superseded the strip charts and analog controllers seen in the older plants.

The long instrument panels and “mimic” flow charts displays have been replaced by

intelligent video displays units. These provide a window on the process. Operators and

technical supervisors can call up and display any section of the process to review the

operating parameters and adjust control settings. Abnormal and alarm situation are

highlighted and displayed.

Historical operating data is retained in the computer memory. Averages and trends can be

displayed, for plant investigation and trouble shooting.

Software to continuously update and optimize plant performance can be incorporated in the

computer control systems. Programmable logic controllers (PLC’s) are used for the control

and interlocking of the processes where a sequential operating steps has to be carried out,

such as in the batch processes and in the start-up and shut-down of the continuous process.

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SAFETY DATA SHEET

ACETONE

1. IDENTIFICATION OF THE SUBSTANCE/PREPARATION AND THE

COMPANY:

PRODUCT NAME: ACETONE

CHEMICAL NAME 2 : PROPAN-2-ONE

2 HAZARDS IDENTIFICATION:

Highly flammable. Irritating to eyes. Repeated exposure may cause skin dryness or

Cracking. Vapours may cause drowsiness and dizziness.

3. FIRST AID MEASURES:

GENERAL: IN ALL CASES OF DOUBT OR WHEN SYMPTOMS PERSIST, ALWAYS

SEEK MEDICAL ATTENTION

IN HALATION: Move affected person to fresh air. If recovery not rapid, seek medical

attention. If breathing stops, provide artificial respiration. Keep affected person warm and at

rest.

IN GESTION: Only when conscious, rinse mouth with plenty of water and give plenty of

water to drink - (approx 500ml). DO NOT INDUCE VOMITING. In case of spontaneous

Vomiting, be sure that vomit can freely drain because of danger of suffocation. Keep

patient at rest and obtain medical attention.

SKIN: Remove contaminated clothing. Wash affected area with plenty of soap and water.

Obtain medical attention.

EYES: Rinse immediately with plenty of water for at least 5 minutes while lifting the eye

lids.

Seek medical attention. Continue to rinse.

4. FIRE FIGHTING MEASURES:

EXTINGUISHING MEDIA: Water spray, fog or mist. Dry chemicals, sand, dolomite etc.

Halon. Powder, foam or CO2.

SPECIAL FIRE FIGHTING

PROCEDURES:

Move container from fire area if it can be done without risk. Take measures to retain water

used for extinguishing. Do not release contaminated water into drains, soil and surface water.

Dispose of contaminated water and soil according to local regulations.

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UNUSUAL FIRE & EXPLOSION

HAZARDS:

Forms explosive mixtures with air. Extremely flammable. May explode in a fire. Vapour may

travel considerable distance to source of ignition and flash back.

HAZARDOUS COMBUSTION

PRODUCTS:

Burning may release oxides of carbon and other hazardous gases or vapours.

PROTECTIVE MEASURES IN FIRE: Fire fighters should wear self-contained breathing

apparatus.

6. ACCIDENTAL RELEASE MEASURES:

PERSON AL PRECAUTION IN SPILL: Avoid direct contact with skin, eyes and clothing.

Do not breathe vapour or fumes.

PRECAUTIONS TO PROTECT ENVIRONMENT:

Prevent contamination of soil, drains and surface water.

SPILL CLEAN UP METHOD S: Accidental release measures - avoid ignition sources.

Take-up spillage with absorbent, inert material and place in a suitable and closable labelled

container for recovery or disposal. Wash the area clean with water and detergent, observing

environmental requirements. Absorb small quantities with paper towels or other inert material

and allow to evaporate in safe place (fume hood/cupboard).

7. HANDLING AND STORAGE:

USAGE PRECAUTIONS: HANDLING - Product should be used in accordance with good

industrial principles for handling and storing of hazardous chemicals. Avoid vapour

inhalation, skin and eye contact. Do not use contact lenses. Avoid vapour formation and

ignition sources.

Ensure good ventilation and local exhaust extraction in work place. (engineering controls

must be to explosion/flameproof standard). Earth container and transfer equipment to

eliminate accumulation of static charge.

STORAGE PRECAUTIONS: Avoid direct sunlight. Store in a cool, dry, well ventilated

place, in securely closed original container.

STORAGE CRITERIA: Flammable liquid storage.

8. EXPOSURE CONTROLS AND PERSONAL PROTECTION:

INGREDIENT NAME: CAS No.: STD LT EXP 8 Hrs ST EXP 15 Min

ACETONE 67-64-1 OES 750 ppm 1500 ppm

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INGREDIENT COMMENTS: Refer to the current edition of HSE Guidance Note EH

40/200* for occupational exposure limits;

VENTILATION: Work in fume cupboard. Respiratory protection required in insufficiently

ventilated woking areas.

RESPIRATORS: For short periods of work, a suitable RPE fitted with a combination

charcoal or organic vapour cartridge is recommended.

PROTECIVE GLOVES: Use impervious gloves made of butyl rubber of PTFE (teflon).

EYE PROTECTION: Contact lenses should not be worn when working with this chemical!

Where the potential for eye contact exists, splash-proof goggles or face shield must be worn.

OTHER PROTECTION: Wear protective clothing and closed footwear. Wear personal

protective equipment appropriate to the quantity of material handled.

HYGIENIC WORK PRA CTIC ES: DO NOT SMOKE IN WORK AREA!

SKIN PROTECTION - use appropriate barrier cream to prevent defatting and cracking of

skin.

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Safety

Flammability

The most common hazard associated with acetone is its extreme flammability. It auto-ignites

at a temperature of 465 °C (869 °F). At temperatures greater than acetone's flash point of −20

°C (−4 °F), air mixtures of between 2.5% and 12.8% acetone, by volume, may explode or

cause a flash fire. Vapors can flow along surfaces to distant ignition sources and flash back.

Static discharge may also ignite acetone vapors.

Health information

Acetone has been studied extensively and is generally recognized to have low acute and

chronic toxicity if ingested and/or inhaled. Inhalation of high concentrations (around 9200

ppm) in the air caused irritation of the throat in humans in as little as 5 minutes. Inhalation of

concentrations of 1000 ppm caused irritation of the eyes and of the throat in less than 1 hour;

however, the inhalation of 500 ppm of acetone in the air caused no symptoms of irritation in

humans even after 2 hours of exposure. Acetone is not currently regarded as a carcinogen, a

mutagenic chemical or a concern for chronic neurotoxicity effects.

Acetone can be found as an ingredient in a variety of consumer products ranging from

cosmetics to processed and unprocessed foods. Acetone has been rated as a GRAS (Generally

Recognized as Safe) substance when present in beverages, baked foods, desserts, and

preserves at concentrations ranging from 5 to 8 mg/L. Additionally, a joint U.S-European

study found that acetone’s "health hazards are slight.

Toxicology

Acetone is believed to exhibit only slight toxicity in normal use, and there is no strong

evidence of chronic health effects if basic precautions are followed.

At very high vapour concentrations, acetone is irritating and, like many other solvents, may

depress the central nervous system. It is also a severe irritant on contact with eyes, and a

potential pulmonary aspiration risk. In one documented case, ingestion of a substantial

amount of acetone led to systemic toxicity, although the patient eventually fully recovered.

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Some sources estimate LD50 for human ingestion at 1.159 g/kg; LD50 inhalation by mice is

given as 44 g/m3, over 4 hours.

Acetone has been shown to have anticonvulsant effects in animal models of epilepsy, in the

absence of toxicity, when administered in mill molar concentrations. It has been hypothesized

that the high-fat low-carbohydrate ketogenic diet used clinically to control drug-resistant

epilepsy in children works by elevating acetone in the brain.

EPA EPCRA Delisting (1995). EPA removed acetone from the list of “toxic

chemicals” maintained under Section 313 of the Emergency Planning and Community

Right to Know Act (EPCRA). In making that decision, EPA conducted an extensive

review of the available toxicity data on acetone and found that acetone “exhibits acute

toxicity only at levels that greatly exceed releases and resultant exposures,” and

further that acetone “exhibits low toxicity in chronic studies.”

Genotoxicity. Acetone has been tested in more than two dozen in vitro and in vivo

assays. These studies indicate that acetone is not genotoxic.

Carcinogenicity. EPA in 1995 concluded, “There is currently no evidence to suggest a

concern for carcinogenicity.”(EPCRA Review, described in Section 3.3). NTP

scientists have recommended against chronic toxicity/carcinogenicity testing of

acetone because “the prechronic studies only demonstrated a very mild toxic response

at very high doses in rodents.”

Neurotoxicity and Developmental Neurotoxicity. The neurotoxic potential of both

acetone and isopropanol, the metabolic precursor of acetone, have been extensively

studied. These studies demonstrate that although exposure to high doses of acetone

may cause transient central nervous system effects, acetone is not a neurotoxicant. A

guideline developmental neurotoxicity study has been conducted with isopropanol,

and no developmental neurotoxic effects were identified, even at the highest dose

tested.

Environmental. When the EPA exempted acetone from regulation as a volatile

organic compound (VOC) in 1995, EPA stated that this exemption would “contribute

to the achievement of several important environmental goals and would support

EPA’s pollution prevention efforts.” 60 Fed. Reg. 31,634 (June 16, 1995). 60 Fed.

Reg. 31,634 (June 16, 1995). EPA noted that acetone could be used “as a substitute

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for several compounds that are listed as hazardous air pollutants (HAP) under section

112 of the [Clean Air] Act.

Environmental effects

Acetone evaporates rapidly, even from water and soil. Once in the atmosphere, it is degraded

by UV light with a 22-day half-life. Acetone dissipates slowly in soil, animals, or waterways

since it is sometimes consumed by microorganisms, but it is a significant groundwater

contaminant due to its high solubility in water. The LD50 of acetone for fish is 8.3 g/l of water

(or about 0.8%) over 96 hours, and its environmental half-life is about 1 to 10 days. Acetone

may pose a significant risk of oxygen depletion in aquatic systems due to the microbial

activity consuming it.

Acetone peroxide

When oxidized, acetone forms acetone peroxide as a by-product, which is a highly unstable

compound. It may be formed accidentally, e.g. when waste hydrogen peroxide is poured into

waste solvent containing acetone. Acetone peroxide is more than ten times as sensitive to

friction and shock as nitro-glycerine. Due to its instability, it is rarely used, despite its easy

chemical synthesis

Potential Health Effects

Inhalations

Inhalation of vapors irritates the respiratory tract. May cause coughing, dizziness, dullness,

and headache. Higher concentrations can produce central nervous system depression,

narcosis, and unconsciousness.

Ingestion:

Swallowing small amounts is not likely to produce harmful effects. Ingestion of larger

amounts may produce abdominal pain, nausea and vomiting. Aspiration into lungs can

produce severe lung damage and is a medical emergency. Other symptoms are expected to

parallel inhalation.

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Skin Contact:

Irritating due toe defatting action on skin. Causes redness, pain, drying, and cracking of the

skin.

Eye Contact:

Vapors are irritating to the eyes. Splashes may cause severe irritation, with stinging, tearing,

redness and pain.

Chronic Exposure:

Prolonged or repeated skin contact may produce severe irritation or dermatitis.

Aggravation of Pre-existing conditions

Use of alcoholic beverages toxic effects. Exposure may increase the toxic protentian of

chlorinated hydrocarbons, such as chloroform, trichloroethane

First Aid Measures

Inhalation

Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult,

give oxygen. Get medical attention.

Ingestion

Aspiration hazard. If swallowed, vomiting may occur spontaneously, but DO NOT INDUCE.

If vomiting occurs, keep head below hips to prevent aspiration into lungs. Never give

anything by mouth to an unconscious person. Call a physician immediately.

Skin Contact

Immediately flush skin with plenty of water for at least 15 minutes. Remove

contaminated clothing and shoes. Get medical attention. Wash clothing before reuse.

Thoroughly clean shoes before reuse.

Eye Contact

Immediately flush eyes with plenty of water for at least 15 minutes, lifting upper and lower

eyelids occasionally. Get medical attention.

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Fire Fighting Measures

Fire

Flash point: -20oC (-4F) CC

Auto ignition temperature: 465oC (869 F)

Flammable limits in air % by volume:

Lel : 2,5; uel : 12,8

Extremely flammable liquid and vapor! vapor may cause flash fire

Explosion

Above flash point, vapor-air mixtures are explosive within flammable limits noted above.

Vapors can flow along surfaces to distant ignition source and flash back. Contact with string

oxidizer may cause fire. Sealed containers may rupture when heated. This material may

produce a floating fire hazard. Sensitive to static discharge.

Fire Extinguishing Media

Dry chemical, alcohol foam or carbon dioxide. Water may be ineffective. Water spray may

be used to keep fire exposed containers cool, dilute spills to nonflammable mixtures, protect

personnel attempting to stop leak and disperse vapors.

Special information

In the event of a fore, wear full protective clothing, such as breathing apparatus with full face

piece operated in the pressure demand or other positive pressure mode.

Handling and Storage

Protect against physical damage. Store in a cool, dry well-ventilated location, away from any

area where the fire hazard may be a cute. Outside or detached stroge s preferred. Separate

from incompatibles. Containers should be bonded and grounded for transfers to avoid static

sparks. Storage and use areas should be NO SMOKING AREA. Use non-sparking type tools

and equipment, including explosion proof ventilation. Containers of this material may be

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hazardous when empty since they retain product residues (vapors, liquid); observe all

warning and precautions listed for the product.

Exposure Controls/Personal Protection

Ventilation system

A system of local and/or general exhaust is recommended to keep employee exposures below

the airborne exposure limits. Local exhaust ventilation is generally preferred because it can

control the emissions of the contaminant at its source, preventing dispersion of it into the

general work area.

Personal respirators

If the exposure limit is exceeded and engineering controls are not feasible, a half-face organic

vapor respirator may be worn up to ten times the exposure limit, or the maximum use

concentration specified by the appropriate regulatory agency or respirator supplier, whichever

is lowest. A full face-piece organic vapor respirator may be worn up to 50 times the exposure

limit, or the maximum use concentration specified by the appropriate regulatory agency or

respirator supplier, whichever is lowest. For emergencies or instances where the exposure

levels are not known, use a full-face piece positive-pressure, air-supplied respirator.

WARNING: air-purifying respirators do not protect workers in oxygen-deficient

atmospheres

Skin Protection

Wear impervious protective clothing, including boots, gloves, lab coat, apron or coveralls, as

appropriate, to prevent skin contact.

Eye contact

Use chemical safety goggles and/or a full face shield where splashing is possible. Maintain

eye wash fountain and quick-drench facilities in work area.

Stability and Reactivity

Stability

Stable under ordinary conditions of use and storage.

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Hazardous Decomposition Products:

Carbon dioxide and carbon monoxide may form when heated to decomposition.

Hazardous Polymerization:

Will not occur.

Incompatibilities:

Concentrated nitric and sulfuric acid mixtures, oxidizing materials, chloroform, alkalis,

chlorine compounds, acids, potassium t-butoxide.

Conditions to Avoid:

Heat, flames, ignition sources and incompatibles

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PLANT LOCATION

The geographical location of the final plant can have strong influence on the success of an

industrial venture. Considerable care must be exercised in selecting the plant site, and many

different factors must be considered. Primarily, the plant should be located where the

minimum cost of production and distribution can be obtained, but other factors, such as room

for expansion and safe living conditions for plant operation as well as the surrounding

community, are also

important.

A general consensus as to the plant location should be obtained before a design project

reaches the detailed estimate stage, and a firm location should be established upon

completion of the detailed-estimate design. The choice of the final site should first be based

on a complete survey of the advantages and disadvantages of various geographical areas and,

ultimately, on the advantages and disadvantages of available real estate. The following

factors should be considered in selecting a plant site:

1. Raw materials availability

2. Markets

3. Energy availability

4. Climate

5. Transportation facilities

6. Water supply

7. Waste disposal

8. Labor supply

9. Taxation and legal restrictions

10. Site characteristics

11. Flood and fire protection.

12. Community factors

PLANT DESIGN AND ECONOMICS FOR CHEMICAL ENGINEERS

The factors that must be evaluated in a plant-location study indicate the need for a vast

amount of information, both quantitative (statistical) and qualitative. Fortunately, a large

number of agencies, public and private, publish useful information of this type greatly

reducing the actual original gathering of the data.

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Raw materials availability.

The source of raw materials is one of the most important factors influencing the selection of a

plant site. This is particularly true if large volumes of raw materials are consumed, because

location near the raw-materials source permits considerable reduction in transportation and

storage charges. Attention should be given to the purchased price of the raw materials,

distance from the source of supply, freight or transportation expenses, availability and

reliability of supply, purity of the raw materials, and storage requirements.

Markets

The location of markets or intermediate distribution centers affects the cost of product

distribution and the time required for shipping. Proximity to the major markets is an

important consideration in the selection of a plant site, because the buyer usually finds it

advantageous to purchase from nearby sources. It should be noted that markets are needed for

by-products as well as for major final products.

Energy availability

Power and steam requirements are high in most industrial plants, and fuel is ordinarily

required to supply these utilities. Consequently, power and fuel can be combined as one

major factor in the choice of a plant site. Electrolytic processes require a cheap source of

electricity, and plants using electrolytic processes are often located near large hydroelectric

installations. If the plant requires large quantities of coal or oil, location near a source of fuel

supply may be essential for economic operation. The local cost of power can help determine

whether power should be purchased or self-generated.

Climate

If the plant is located in a cold climate, costs may be increased by the necessity for

construction of protective shelters around the process equipment, and special cooling towers

or air-conditioning equipment may be required if the prevailing temperatures are high.

Excessive humidity or extremes of hot or cold weather can have a serious effect on the

economic operation of a plant, and these factors should be examined when selecting a plant

site.

Transportation facilities

Water, railroads, and highways are the common means of transportation used by major

industrial concerns. The kind and amount of products and raw materials determine the most

suitable type of transportation facilities. In any case, careful attention should be given to local

freight rates and existing railroad lines. The proximity to railroad centers and the possibility

of canal, river, lake, or ocean transport must be considered: Motor trucking.

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GENERAL DESIGN CONSIDERATIONS

facilities are widely used and can serve as a useful supplement to rail and water facilities. If

possible, the plant site should have access to all three types of transportation, and, certainly,

at least two types should be available. There is usually need for convenient air and rail

transportation facilities between the plant and the main company headquarters, and effective

transportation facilities for the plant personnel are necessary.

Water supply

The process industries use large quantities of water for cooling, washing, steam generation,

and as a raw material. The plant, therefore, must be located where a dependable supply of

water is available. A large river or lake is preferable, although deep wells or artesian wells

may be satisfactory if the amount of water required is not too great. The level of the existing

water table can be checked by consulting the state geological survey, and information on the

constancy of the water table and the year-round capacity of local rivers or lakes should be

obtained. If the water supply shows seasonal fluctuations, it may be desirable to construct a

reservoir or to drill several standby wells. The temperature, mineral content, silt or sand

content, bacteriological content, and cost for supply and purification treatment must also be

considered when choosing a water supply.

Waste disposal

In recent years, many legal restrictions have been placed on the methods for disposing of

waste materials from the process industries. The site selected for a plant should have

adequate capacity and facilities for correct waste disposal. Even though a given area has

minimal restrictions on pollution, it should not be assumed that this condition will continue to

exist. In choosing a plant site, the permissible tolerance levels for various methods of waste

disposal should be considered carefully, and attention should be given to potential

requirements for additional waste-treatment facilities.

Labor supply

The type and supply of labor available in the vicinity of a proposed plant site must be

examined. Consideration should be given to prevailing pay scales, restrictions on number of

hours worked per week, competing industries that can cause dissatisfaction or high turnover

rates among the workers, and variations in the skill and productivity of the workers.

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Taxation and legal restrictions

State and local tax rates on property income, unemployment insurance, and similar items

vary from one location to another. Similarly, local regulations on zoning, building codes,

nuisance aspects, and transportation facilities can have a major influence on the final choice

of a plant site. In fact, zoning difficulties and obtaining the many required permits can often

be much more important in terms of cost and time delays than many of the factors discussed

in the preceding sections.

Site characteristics

The characteristics of the land at a proposed plant site should be examined carefully. The

topography of the tract of land and’ the soil

PLANT DESIGN AND ECONOMICS FOR CHEMICAL ENGINEERS

structure must be considered, since either or both may have a pronounced effect on

construction costs. The cost of the land is important, as well as local building costs and living

conditions. Future changes may make it desirable or necessary to expand the plant facilities.

Therefore, even though no immediate expansion is planned, a new plant should be

constructed at a location where additional space is available.

Flood and fire protection

Many industrial plants are located along rivers or near large bodies of water, and there are

risks of flood or hurricane damage. Before selecting a plant site, the regional history of

natural events of this type should be examined and the consequences of such occurrences

considered.

Protection from losses by fire is another important factor in selecting a plant location. In case

of a major fire, assistance from outside fire departments should be available. Fire hazards in

the immediate area surrounding the plant site must not be overlooked.

Community factors

The character and facilities of a community can have quite an effect on the location of the

plant. If a certain minimum number of facilities for satisfactory living of plant personnel do

not exist, it often becomes a burden for the plant to subsidize such facilities. Cultural

facilities of the community are important to sound growth. Churches, libraries, schools, civic

theaters, concert associations, and other similar groups, if active and dynamic, do much to

make a community progressive. The problem of recreation deserves special consideration.

The efficiency, character, and history of both state and local government should be evaluated.

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The existence of low taxes is not in itself a favorable situation unless the community is

already well developed and relatively free of debt.

Selection of the Plant Site

The major factors in the selection of most plant sites are (1) raw materials, (2) markets,

(3) energy supply, (4) climate, (5) transportation facilities, and (6) water supply. For a

preliminary survey, the first four factors should be considered. Thus, on the basis of raw

materials, markets, energy supply, and climate, acceptable locations can usually be reduced to

one or two general geographical regions. For example, a preliminary survey might indicate

that the best location for a particular plant would be in the south-central or south-eastern part

of the United States. In the next step, the effects of transportation facilities and water supply

are taken into account. This permits reduction of the possible plant location to several general

target areas. These areas can then be reduced further by considering all the factors that have

an influence on plant location. As a final step, a detailed analysis of the remaining sites can

be made. Exact data on items such as freight rates, labor conditions, tax rates, price of land,

and general local conditions can be obtained. The various sites can be

GENERAL DESIGN CONSIDERATIONS

Inspected and appraised on the basis of all the factors influencing the final decision. Many

times, the advantages of locating a new plant on land or near other facilities already owned

by the concern that is building the new plant outweigh the disadvantages of the particular

location. In any case, however, the final decision on selecting the plant site should take into

consideration all the factors that can affect the ultimate success of the overall operation.

PLANT LAYOUT

After the process flow diagrams are completed and before detailed piping, structural, and

electrical design can begin, the layout of process units in a plantand the equipment within

these process units must be planned. This layout can play an important part in determining

construction and manufacturing costs, and thus must be planned carefully with attention

being given to future problems that may arise. Since each plant differs in many ways and no

two plant sites are exactly alike, there is no one ideal plant layout. However, proper layout in

each case will include arrangement of processing areas, storage areas, and handling areas in

efficient coordination and with regard to such factors as:

1. New site development or addition to previously developed site

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2. Type and quantity of products to be produced

3. Type of process and product control

4. Operational convenience and accessibility

5. Economic distribution of utilities and services

6. Type of buildings and building-code requirements

7. Health and safety considerations

8. Waste-disposal requirements

9. Auxiliary equipment

10. Space available and space required

11. Roads and railroads

12. Possible future expansion

Preparation of the Layout

Scale drawings, complete with elevation indications can be used for determining the best

location for equipment and facilities. Elementary layouts are developed first. These show the

fundamental relationships between storage space and operating equipment. The next step

requires consideration of the safe operational sequence and gives a primary layout based on

the flow of materials, unit operations, storage, and future expansion. By analyzing all the

factors that are involved in plant layout, a detailed recommendation can be presented, and

drawings and elevations, including isometric drawings of the piping systems, can be

prepared.

Page 69: Acetone Production Report

FINANCIAL ANALYSIS

The financial analysis of the acetone project is based on the data presented in the previous chapters and the following assumptions:-

Construction period 1 year

Source of finance 30 % equity

70 % loan

Tax holidays 3 years

Bank interest 8%

Discount cash flow 8.5%

Accounts receivable 30 days

Raw material local 30 days

Raw material, import 90 days

Work in progress 5 days

Finished products 30 days

Cash in hand 5 days

Accounts payable 30 days

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A. TOTAL INITIAL INVESTMENT COST

The total investment cost of the project including working capital is estimated at Birr 6.17

million, of which 27 per cent will be required in foreign currency.

The major breakdown of the total initial investment cost is shown in Table 7.1.

Table 7.1

INITIAL INVESTMENT COST

Sr

No.

Cost Items Total Cost (‘000

Birr)

1 Land lease value 700.0

2 Building and Civil Work 1,500.0

3 Plant Machinery and

Equipment

2,841.2

4 Office Furniture and

Equipment

100.0

5 Vehicle 250.0

6 Pre-production Expenditure* 440.9

7 Working Capital 342.0

Total Investment cost 6,174.2

Foreign Share 27

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PRODUCTION COST

The annual production cost at full operation capacity is estimated at Birr 3.29 million (see

Table 7.2). The material and utility cost accounts for 65.16 per cent, while repair and

maintenance take 3.45 per cent of the production cost.

ANNUAL PRODUCTION COST AT FULL CAPACITY ('000 BIRR)

Items Cost %

Raw Material and Inputs 1,288.26 39.15

Utilities 856 26.01

Maintenance and repair 113.65 3.45

Labour direct 147.24 4.47

Factory overheads 49.08 1.49

Administration Costs 98.16 2.98

Total Operating Costs 2,552.39 77.57

Depreciation 484.12 14.71

Cost of Finance 254.09 7.72

Total Production Cost 3,290.60 100

FINANCIAL EVALUATION

1. Profitability

According to the projected income statement, the project will start generating profit in the first year of operation. Important ratios such as profit to total sales, net profit to equity (Return on equity) and net profit plus interest on total investment (return on total investment) show an increasing trend during the life-time of the project.

The income statement and the other indicators of profitability show that the project is viable.

Break-even Analysis

The break-even point of the project including cost of finance when it starts to operate at full capacity (year 3) is estimated by using income statement projection.

BE = Fixed Cost / (Sales-Variable Cost) = 24 %

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3. Pay Back Period

The investment cost and income statement projection are used to project the pay-back period. The project’s initial investment will be fully recovered within 6 years.

4. Internal Rate of Return and Net Present Value

Based on the cash flow statement, the calculated IRR of the project is 14 % and the net present value at 8.5% discount rate is Birr 1.71 million.

D. ECONOMIC BENEFITS

The project can create employment for 20 persons. In addition to supply of the domestic needs, the project will generate Birr1.2 million in terms of tax revenue. The establishment of such factory will have a foreign exchange saving effect to the country by substituting the current imports.

Equipment

Heat Exchanger (E-401):

This unit heats, vaporizes, and superheats the feed to 235°C at 2.2 bar. A pump, which is not shown and which you do not have to be concerned with this semester, increases the pressure of the feed to the indicated pressure.

Reactor (R-401):

Following development of a new catalyst, only the following reaction occurs:

CH 3 CHOHCH3 → CH 3 COCH 3 + H2

IPA acetone (1)

The reaction occurs at 350°C, and the conversion at this temperature is 90%. The reactor exit pressure is 1.9 bar. The reaction is endothermic with heat being supplied by hot molten salt.

Fired Heater (H-401):

This unit heats the molten salt that provides heat to the reactor. Energy is supplied by combustion of natural gas, which may be assumed to be pure methane. The molten salt enters the fired heater at 360°C (Stream 3) and leaves the fired heater at 410°C (Stream 4). The heat capacity of molten salt is 1.56 J/g K.

Page 73: Acetone Production Report

Heat Exchanger (E-402):

This unit cools and partially condenses the reactor effluent. None of the hydrogen condenses. The exit pressure may be at any pressure below 1.6 bar and any temperature below 50°C that can be achieved by using cooling water (cw) or refrigerated water (rw) is possible.

Separation Vessel (V-401):

This unit disengages the vapor and liquid effluent from E-402. In this separator, all hydrogen in the feed enters the vapor phase, Stream 7. All other components distribute according to Raoult’s Law at the temperature and pressure of E-402. The combination of E-402 and V-401 is often called a flash operation.

Absorber (T-401):

Here, additional acetone is recovered by absorption into pure process water. The absorber operates at the same temperature and pressure as V-401 Stream 11 contains all of the hydrogen and the acetone and water which are not in Stream 10. Stream 10 contains all of the IPA in Stream 7, 95% of the water in Streams 7 and 9. The amount of acetone in Stream 10 can be calculated from:

ystream 11

ystream 7

= 1−A1−A6

(2)

Where y is the mole fraction of acetone,

A= LmV (3)

L is the total molar flowrate of liquid in Stream 9, and V is the total molar flowrate of liquid in Stream 7. The parameter m is an equilibrium constant that is a function of temperature and pressure

m=exp (10 . 92−3598

T )P (4)

where T is in Kelvin and P is in atm.

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Distillation Column (T-402):

In this distillation column, the acetone, IPA, and water in Stream 12 are separated. The column operates at 1.4 bar. Specifications are as follows. The acetone must be 99.9 mol% pure and 99.5 mol% of the acetone in the feed must be recovered in Stream 13. Stream 14 contains most of the water and IPA from Stream 12.

Heat Exchanger (E-403):

In this heat exchanger, the contents of Stream 13 are condensed from saturated vapor to saturated liquid at a rate three times the flow of Stream 13. The cost is for the amount of cooling water needed to remove the necessary energy.

Heat Exchanger (E-404):

In this heat exchanger, you may assume that one-half of the flow of Stream 14 is vaporized from saturated liquid to saturated vapor at 1.4 bar and is returned to the column. The cost is for the amount of low-pressure steam needed to supply the necessary heat.

An additional distillation column (T-403):

You may choose to add an additional distillation column to process Stream 14 further. This column can recover a near azeotropic mixture of water and IPA (88 wt% IPA – with all of theacetone remaining in Stream 14) out of the top, with residual water and IPA out the bottom. If you choose to do this, you must recycle the IPA/water top product to the beginning of the process. The bottom product goes to waste water treatment. This distillation column needs two heat exchangers with similar energy specifications to E-403 and E-404. This distillation column operates at 1.2 bar. You should only include this column if you decide it to be economically attractive

Other Equipment

It is required for two streams that mix to be at identical pressures. Pressure reduction may be accomplished by adding a valve. These valves are not shown on the attached flowsheet, and it may be assumed that additional valves can be added as needed at no cost. Flow occurs from higher pressure to lower pressure. Pumps increase the pressure of liquid streams, and compressors increase the pressure of gas streams. You may assume that a pump exists where ever you need one. For this semester only, there is no cost for pumps.

Equipment Costs

Page 75: Acetone Production Report

The equipment costs for the acetone plant are given below. Each cost is for an individual piece of equipment, including installation.

Equipment Installed Cost

in millions of $

Reactor, R-401 1.5

Absorber, T-401 0.03

Acetone distillation column T-402

including reboiler and condenser

2.8

IPA distillation column T-403 (if added)

including reboiler and condenser

0.1

Vessel, V-401 0.07

Any heat exchanger 0.05

Fired heater installed cost in dollars:

11×10x

where

x=2 .5+0 .8 log10Q

where Q is the heat duty in kW

Utility Costs

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Low-Pressure Steam (446 kPa, saturated) $5.00/1000 kg

Medium-Pressure Steam (1135 kPa, saturated) $7.31/1000 kg

High-Pressure Steam (4237 kPa, saturated) $8.65/1000 kg

Natural Gas or Fuel Gas (446 kPa, 25C) $3.00/GJ

Electricity $0.05/kW h

Boiler Feed Water (at 549 kPa, 90C) $2.54/1000 kg

Cooling Water $0.16/GJ

available at 516 kPa and 30C

return pressure ³ 308 kPa

return temperature should be no more than 15C above the inlet temperature

Refrigerated Water $1.60/GJ

available at 516 kPa and 10C

return pressure ³ 308 kPa

return temperature is no higher than 20C

Process Water $0.04/1000 kg

available at 300 kPa and 25°C

Data

Page 77: Acetone Production Report

Use data from Reference [1] or from any handbook (such as Reference [2]). The following data are not readily available in these references.

Liquid Heat Capacity

For IPA: 145 J/mole K

Vapor Heat Capacity

for IPA: 27.87 + 0.176 + 2.1210-4T 2 - 4.0910-7T 3 J/mole K T (K)

Vapor Pressures – Antoine’s Equation constants

ln p¿=A− BT +C (5)

(p* in mm Hg, T in K)

A B C

IPA 17.664 3109.3 -73.546

acetone 16.732 2975.9 -34.523

Normal heat of vaporization

for IPA: 56,900 kJ/kmole

Economic Analysis

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When evaluating alternative cases, the following objective function should be used. It is the

equivalent annual operating cost (EAOC), and is defined as

EAOC = -(product value - feed cost - other operating costs - capital cost annuity)

A negative EAOC means there is a profit. It is desirable to minimize the EAOC; i.e., a large

negative EAOC is very desirable.

The cost for acetone is $0.88/kg. The cost for IPA is $0.72/kg IPA in the feed solution. The

value for hydrogen is $35/1000 std m3.

Other operating costs are utilities, such as steam, cooling water, natural gas, and electricity.

The capital cost annuity is an annual cost (like a car payment) associated with the one-time,

fixed cost of plant construction. A list of capital costs for all pieces of equipment will be

provided by early March.

The capital cost annuity is defined as follows:

Capital cost annuity = 0.2(capital cost)

Cost Data

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Raw Materials

Isopropanol (88 – 91 wt%) see Chemical Marketing Reporter

Utility Costs

Low Pressure Steam (618 kPa saturated) $6.62/1000 kg

Medium Pressure Steam (1135 kPa saturated) $7.31/1000 kg

High Pressure Steam (4237 kPa saturated) $8.65/1000 kg

Natural Gas (446 kPa, 25C) $3.00/GJ

Fuel Gas (use this price for fuel gas credit) $2.75/GJ

Electricity $0.06/kW h

Boiler Feed Water (at 549 kPa, 90C) $2.54/1000 kg

Cooling Water available at 516 kPa and 30C $0.16/GJ

return pressure ³ 308 kPa

return temperature is no more than 15C above the inlet temperature.

Refrigerated Water available at 516 kPa and 10C $1.60/GJ

return pressure ³ 308 kPa

return temperature is no higher than 20C.

Deionized Water available at 5 bar and 30°C $1.00/1000 kg

Waste Treatment of Off-Gasincinerated - incinerated-take fuel credit

Equipment Costs (Purchased)

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Piping $/m = 5.0 (diameter, in)

Valves $100 (flow diameter, in) 0.8 for control valve with orifice plate, double the price

Pumps $630 (power, kW) 0.4

Heat Exchangers $1030 (area, m 2 ) 0.6 add 25% additional for boilers or evaporators

Compressors $770 (power, kW) 0.96 + $400 (power, kW) 0.6 assume 70% efficiency

Turbine $2.18•10 5 (power output, MW) 0.6 assume 65% efficiency

Fired Heater $635 (duty, kW) 0.8 assume 80% thermal efficiency assume can be designed to use any organic compound as a fuel

Vessels $[1.67(0.959 + 0.041P - 8.3•10-6 P 2 )]•10 z z = (3.17 + 0.2D + 0.5 log 10 L + 0.21 log 10 L) D = diameter, m 0.3 m < D < 4.0 m L = height, m 3 < L/D < 20 P = absolute pressure, bar

Reactor assume to be $1 million

Equipment Cost Factor:

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Pressure Factors

Pressure <10 atm,0.0 Does not apply to turbines,

(absolute) 10-20 atm,0.6

compressor,vessels,packing

20-40 atm,3.0 trays or catalysts, since

their 40-50 atm,5.0 cost equations

includepressure

50-100 atm,10 effects.

Material factors

Carbon steel -0.0

Stainless steel- 4.0

Total installed cost=Purchased cost(4+material factor+pressure factor )

Heat Exchangers:

For heat exchangers that do not have to be designed in detail, use the following

approximation for heat transfer coefficients to allow you to determine the heat transfer area

and heat exchanger cost.

SITUATION h(w/m2c 0)

Condensing Steam 6000

Condensing Organic 1000

Boiling Water 7500

Boiling Organic 1000

Flowing Liquid 600

Flowing Gas 60

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