Hadi ApriliawanHadi ApriliawanAdelya Desi KAdelya Desi K

Rhytia AyuRhytia Ayu

1Food Technology and Science

2

Supercritical extraction is a free radical degradation process in low pressure and high temperature

Hot compresed water is water on the nearcritical (hydrothermal) and supercritical area, the temperature is higher than 200°C and have high pressure

Supercritical Supercritical Fluid Fluid

Density

Viscosity & Diffusivity

liquid

Gas

High mass transfer rate

Solvent can be

controlledChanges:1.Temperature 2.Pressure

4

5

6

7

8

9

Penggunaan fluida superkritis (atau mendekati superkritis), yaitu gas atau cairan di atas titik kritis

Untuk memisahkan campuran banyak komponen dengan memanfaatkan perbedaan:◦ volatilitas komponen (seperti pada distilasi)◦ Interaksi spesifik antar komponen (kelarutan)

Menarik karena:◦ Banyak gas-gas menunjukkan daya larut yang hebat bila

dikompres melebihi titik kritisnya◦ Energi yang digunakan pada distilasi semakin mahal◦ Peraturan yang mendorong penggunaan bahan ramah

lingkungan serta tidak beracun (mereduksi penggunaan hidrokarbon terklorinasi). Cth: CO2 sbg solven

10

t1

Su

hu

t2

t3

t4

t1

t2

t3

t4

11

Dalam produksi bahan bakar pada industri nuklir, proses cairan-cairan coal tar, dan terutama pada pemisahan hidrokarbon pada industri petrokimia

Pemisahan aromatik dari minyak bakar berbasis kerosin untuk meningkatkan kualitas pembakaran

Pemisahan aromatik dari senyawaan parafin atau nafta untuk meningkatkan karakter viskositas-suhu suatu minayk pelumas

Pengambilan senyawa relatif murni seperti benzena, toluen dan xylene dari reformat yang dihasilkan secara katalitis pada industri

Produksi asam asetat anhidrat

Ekstraksi phenol dari larutan coal tar

Pemurnian penicilin (dari senyawaan lain sebagai hasil fermentasi yang sangat kompleks)

12

Qunsheng Li, Zeting Zhang, Chongli Zhong, Yancheng Liu, Qingrong Zhou

It has a great application potential in many separation

and purification processes

Since the solubility of solids can be easily tuned with solvent density near the

solvent critical point

it makes supercritical fluids (SCFs) attractive solvent candidates for separating

heavy compounds

CO2CO2

CO2CO2

it is an easy gas to handle, it is inert, nontoxic and

nonflammable, and it has a convenient critical

temperature.

it is an easy gas to handle, it is inert, nontoxic and

nonflammable, and it has a convenient critical

temperature.

it has some limitations because of its lack of polarity and the

capacity to form specificsolvent–solute interactions

it has some limitations because of its lack of polarity and the

capacity to form specificsolvent–solute interactions

the addition of a small amount of suitable cosolvent can greatly enhance its solvent power (great incentive to improve its great incentive to improve its

polaritypolarity)

to measure the solubilityof solid solutes, in CO2 with

and without cosolvents

Anthracene and 2-naphthol,

polar (ethanol andacetone) and nonpolar

(cyclohexane)

the present work caninvestigate the effects of both the concentration

and the functionality of the cosolvents

This work is an important step in our long-term objective to predict the solution properties of multi-component supercritical fluid mixtures based on the

molecular interactions.

This work is an important step in our long-term objective to predict the solution properties of multi-component supercritical fluid mixtures based on the

molecular interactions.

It will provide a basis for future attempts to demonstrate that a multicomponent supercritical

solvent mixture can be highly selective for particular solutes due to specific interactions.

Rational utilization of these cosolvents could improve

the existing and newly proposed processes, particularly for those compounds with extremely

limited solubility in pure fluids.

1. CO2 syringe pump2. Cosolvent pump3. Thermometer4. Preheater coil5. Equilibrium cell6. Waterbath

1. CO2 syringe pump2. Cosolvent pump3. Thermometer4. Preheater coil5. Equilibrium cell6. Waterbath

7. 8.9.10. Tubes11. Wet gas meter12. Analitic scale

7. 8.9.10. Tubes11. Wet gas meter12. Analitic scale

The equilibrium cell was packed with solid solute, 2-naphthol or anthracene, and each end was plugged with glass wool to

prevent the fine solid powder from plugging the smaller 1/6 in. i.d. interconnecting stainless steel tubing.

The equilibrium cell was packed with solid solute, 2-naphthol or anthracene, and each end was plugged with glass wool to

prevent the fine solid powder from plugging the smaller 1/6 in. i.d. interconnecting stainless steel tubing.

CO2 and cosolvent from vessels were compressed into the mixer, then through the connecting tube heated by electricity coil, they were put into the equilibrium cell from the bottom.

CO2 and cosolvent from vessels were compressed into the mixer, then through the connecting tube heated by electricity coil, they were put into the equilibrium cell from the bottom.

In the equilibrium cell, the solvent and solute reached equilibrium through mass transfer. The fluid phase reached

equilibrium flowed from the top of the cell through a decompress valve into two U type tubes in turn.

In the equilibrium cell, the solvent and solute reached equilibrium through mass transfer. The fluid phase reached

equilibrium flowed from the top of the cell through a decompress valve into two U type tubes in turn.

The solid solute was settled and weighed up by an analysis scale with an accuracy of ±0.05mg after drying. The volume was measured by the wet gas meter with an accuracy of ±1%.

The solid solute was settled and weighed up by an analysis scale with an accuracy of ±0.05mg after drying. The volume was measured by the wet gas meter with an accuracy of ±1%.

We started the measurements at a flow rate of 100 l/h, then reduced the flow rate until the solubility measured did not change with further decreasing the flow rate.

By this way, we determined the suitable flow rate is 40 l/h to ensure that the solid and fluid reach equilibrium in the equilibrium cell.

To make sure that all the precipitated solute was collected, two U type tubes were used in turn. From experimental observation, nearly all the solute was collected in the first U type tube, and very little precipitated in the second U type tube.

The experimental error for the solute solubility is estimated to be ±2%.

2 Naphthol

Anthracene

The addition of a cosolvent to increase the bulk density contribute to solubility enhancement

A large variation in density would be expected close to thecritical point where the isothermal compressibility is largest

the solubility of solutes increases with increasing density in general

4,0 mol % aceton

3,6 mol % cyclohexan

The effect factor of cosolvent can be defined as:

y2cosolvent

y2 puree=

e = effect factor of cosolventy2

cosolvent = solubility of solids in SCF with

cosolventy2

pure = solubility of solids in pure SCF

enhancement solubility by the addition of a cosolvent is mainly caused by the formation of special interactions between the solute and cosolvent molecules

the largest cosolvent effect on polar solute, 2-naphthol, is from ethanol ethanol has the strongest interactions with the solute

the largest cosolvent effect comes from the nonpolar solvent, cyclohexane

In this case, the interactions between the solute and cosolvent molecules come mainly from the dispersion force

Hadi ApriliawanHadi ApriliawanAdelya Desi KAdelya Desi K

Rhytia AyuRhytia Ayu

30

Food Technology and Science