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1.1 Turbine

1.1.1 Gas Turbine

In This Process, a gas turbine is used as utility to produce electricity and supply

power to for generator. For the utility and sizing we leave it to the vendor. The

methane gas is leaving the combustion with 1039,5 kg/day.

For gas turbine specification, methane data must be completed.

Specification of methane gas

LHV : 940 (Btu/scf)

Equipment Specification

Equipment Name Siemens Gas Turbine SST5-4000

Turbine Series

High-pressure (H) modules

and combined intermediate-pressure / low-pressure (IL)

modules for 50 Hz

Equipment Code SGT4-4000F

Function Decreasing the gas pressure and produce electricity

Number of stages 4

Fuel Natural Gas

Drive Cold end, direct coupled

Dimension

Quantity 1

Equipment Type Gas Turbine

Weight package 312000 kg

Blade Diameter 311.9 mm

Package Height 4.9 m

Package Widht 4.9 m

Package Lenght 11 m

Operating Condition

Flow rate (m /hr) 573.5

Power (MW) 210


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Heat Rate(kj/kWh) 9,001

Rotor Speed 3000 rpm

Efficiency 40%

Turbine DataPressure Ratio 2,416x10

Inlet Pressure (kPa) 2662

Outlet Pressure (kPa) 0.6432

Power (MW) 210

Exhaust Flow (kg/s) 723

Exhaust Temperature 579

1.2 Pumps

Both of in natural gas combined cycle power plant and acid plant needs pump to

increase the pressure of the fluid. It essentially needs to flow the fluid from higher

pressure to the lower pressure

Table 1. 1Specification of Pump J-101

J-101

Function Pumping water from water tank to HRSG

Type Single Stage Centrifugal Pump

Impeller Francis Vane

Material Stainless Steel

Pressure ratio 15.2

Flow (m3/s) 0.0266

Efficiency 75%

Suction Pressure (kPa) 6.895

Discharge Pressure

(kPa)

104.8

Head 32.709 ft

BHP 4.6 HP

(Source: Authors Personal Data)


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J-102

Function As the backup of main pump J-101 which

serves to pumping water from water tank

to HRSG


Impeller Francis Vane


Pressure ratio 15.2

Flow (m3/s) 0.0266

Efficiency 75%

Suction Pressure (kPa) 6.895

Discharge Pressure

(kPa)

104.8

Head 32.709 ft

BHP 4.6 HP



J-201

Function Pumping sulfuric acid to electrolytic cell


Impeller Mixed Flow


Flow (m3/s) 0.001

Efficiency 75%

Pressure Difference (kPa) 96,526

Head 17.576 ft

BHP 4.57 HP

(Source: AuthorsPersonal Data)


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Table 1. 6Specification of Pipes in Acid Plant

PipeNominal Pipe

Size (in)ID (in) OD (in) Length (ft)

Pipe for Water

Utility3 3.068 3.5 100

Pipe for Water

Utility2 1/2 2.469 2.88 100

Pipe for SO2 to

Converter12 12.09 12.75 80

Pipe for O2 to

Converter12 12.09 12.75 80

Pipe for SO3 to

absorber12 12.09 12.75 100


Air Separation Plant Piping Selection

Table 1. 7Specification of Pipes in Air Separation Plant

PipeNominal Pipe

Size (in)ID (in) OD (in) Length (ft)

Pipe for Air to

Hydroylone12 12.09 312.75 80

Pipe for

Condensate3 3.068 23.5 120

Pipe for Air to

Adsorber12 12.09 12.75 60

Pipe for Air to

Adsorber12 12.09 12.75 60

Pipe for N2 12 12.09 12.75 100

Pipe For O2 12 12.09 12.75 100



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APPENDIX

A.7 Pump Calculation

The following are the steps performed in determining the design and sizing on each

pump:

1. Determine the type and materials used by the pump fluid properties

2. Calculate the pressure difference () on the suction and discharge

3. Calculate the density of the flow at the pump

4. Calculate the total head at each pump

5. Determine the type of impeller used based on specific speed of each pump

()()

[()]

Figure A. 1Impeller shapes related to specific speed

6. Determining pump power used


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Below is just a calculation to pump J-401 that we display. For other pumps we

just attach Specification table for each pump based on the calculation that we have

done based on those steps above

J-101

1. Determining the type of pump and Material

The pump used is a type of centrifugal pumps and the material is stainless

steel

2. Calculation

14.2 psi

Mass Flow = 9.566 x 104kg/h

Flowrate = 95.39 m3/h = 419.98 GPM

Efficiency = 75%

1800 rpm

()()

[()]


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Figure A. 2Impeller shapes related to specific speed

From Figure above, it can be seen thay type of impeller for this pump is the

Francis Vane.

Pump Horsepower

BHP = 4.638 hp

WHP = 3.479 hp

Figure A. 3Pump J-101(Source: Authors Personal Data)

Acid Plant Piping Selection

The materials of construction for piping are dependent on fluid flow velocities

and quality concerns. In general, seamless carbon steel piping is used for flow

velocities between 1-3 feet per second (fps). 316 SS is acceptable for flow velocities

of 0-8 fps. Alloy 20 works for flow velocities of 0-20 fps, and Teflon-lined pipe

works for all ranges of fluid velocity. If iron contamination is a concern for the

process, stay away from carbon steel. These recommendations assume ambient

temperatures. All metal piping should be welded per "ANSI B31.3 - Normal Service"

specifications. Screwed fittings are discouraged. PVC and CPVC piping is

recommended for vent/vapor lines only. They are not recommended for liquid service.

The "Rules of Thumb" for flow limitation when designing piping system at

ambient temperatures are:

Carbon Steel: 1-3 feet per second (fps)

304 and 304L stainless steel: 0-6 fps


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316 and 316L stainless steel: 0-8 fps

Alloy 20: 0-20 fps

Teflon and Kynar lined: 0-50 fps

Based on the rules of thumb above we choose 304 and 304L stainless steel for piping

material.

Two shortcut rules have been derivied by Peters and Timmerhaus (1980) for

optimum diameters of steel pipes of 1-in size or greater, for turbulent and laminar

flow:

, turbulent flow

, laminar flow

a.

Pipe for Water Utilty

()()

()()

From Appendix A5 (Stanley M. Walas,), we choose commercial steel pipe with

specification below:

Nominal Size = 3 in

Schedule Number = 40

Inside Diameter (ID) = 3.068 in

Outside Diam. (OD) = 3.5 in

Inside Sec. Area = 0.804 ft2

Length = 100 ft


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()()

()()



Nominal Size = 2 1/2 in

Schedule Number = 40




Length = 100 ft

b. Pipe for SO2 to Converter

()()

()()



Nominal Size = 12 in





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Length = 100 ft

c. Pipe for O2 to Converter

()()

()()



d. Nominal Size = 12 in

e. Inside Diameter (ID) = 12.09 in

f. Outside Diam. (OD) = 12.75 in

g. Inside Sec. Area = 3.17 ft2

h. Length = 80 ft

i. Pipe for SO3 to Absorber

()()

()()


specification below: Nominal Size = 12 in




Length = 100 ft

In general, piping is formally externally inspected visually every five years,and ultrasonic thickness tested biennially. Again, actual plant experience may dictate


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an increase or decrease in this schedule. Extra attention should be paid to elbows,

tees, valves and any other places in the piping where flow disturbances (and

erosion/corrosion) could occur. Use API 570, Class II piping standards for guidance.

Air Seperation Plant Piping Selection

The metals from which an ASU is manufactured have several requirements.

Carbon steel is used for most warm equipment and piping. The cryogenic portion of

the plant must be capable of withstanding temperatures down to 77K while still

being economic. Almost all parts of the ASU will see enriched oxygen, either during

normal operation or upsets. Copper, aluminum, and stainless steel are all good for the

cryogenic temperatures.

Table Piping Materials for Air Separation Unit

Carbon Steel Copper Alumunium Stainless Steel

Suitable for

Low Temps

N Y Y Y

Relative

Strength

2 4 3 1

Cost Low Very High Moderate High

Ignitability

with O2

Moderate N/A Low Low

Intensity of

Burning

Moderate N/A High Moderate

(Source : www. Gasin.com)

Notes:

(a) This is a relative measure of the strength of the materials, 1=highest, 4=lowest

(b) Difficulty of initiating combustion of the metal with O2

(c) Copper is not flammable in O2

The ignitability of any material is a function of the O2 purity, O2 pressure,

and material geometry. Ignitability generally increases with higher pressure, higher


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purity, and thinner materials. Aluminum in particular is very sensitive to O2 purity,

with just fractions of percent impurities decreasing the ignitability very significantly.

A three-tier methodology is used to select a material for a given O2 service and to

minimize the risk to personnel:

If possible, all ignition sources are removed. Without ignition, the material cannot

combust. A good example of this is the careful cleaning of carbon steel pipe in

high pressure O2 pipelines. By eliminating the ignition source, carbon steel is an

acceptable material.

In some cases, it is not possible to remove all ignition sources. However, the

material may still be used safely, if it is used where the combustion will not

propagate. An example of this is aluminum pipe. Aluminum/O2 ignition is not

completely understood, so it is difficult to eliminate all ignition sources. However,

by only using aluminum pipe in services where propagation does not occur, it is

possible to safely use aluminum pipe, as the long history of safe service of

aluminum pipe has shown. (Note that when aluminum is used in O2 service, it is

cleaned to eliminate as many ignition sources as possible.)

Based on the considerations above we choose stainless steel as piping material in Air

Separation Unit.

Two shortcut rules have been derivied by Peters and Timmerhaus (1980) for optimum

diameters of steel pipes of 1-in size or greater, for turbulent and laminar flow:

, turbulent flow

, turbulent flow

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