sc fluid presentation

7/21/2019 Sc Fluid Presentation

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Properties and

Applications ofSupercritical uids

Presented by: Guided by:

Jadhav Manasvi Prof .S.P. Dabke



When a gas or liquid is compressed(underpressure) and heated past its criticalpoint, it enters a phase called“supercritical phase” and is referred as“supercritical fluid”

The density of both liquid and gas areidentical in this phase.

The critical pressure and criticaltemperature at which this happens are

unique to each substance.

What is a supercritical uid?

PHASE DAIGRAM

Tehno!o"y #ath$%o!&'$issue ($)u!y '**+



Comparison of Gases, Supercritical Fluids and Liquids

,ro,erties of -iuid

Density !"#m$% &iscosity 'Pa(s% Di)usi*itymm+#s%

Gases ( (* (&(*

SupercriticalFluids

(**&(*** +*&(** *.*(&*.(

Liquids (*** +**&(*** *.**(

Su,erritia! /uids have ,ro,erties bet#een those of "as and !iuid.



Supercritical fluids have no surface tension because they are not subject to the vapor-liquid boundary so no molecules have the attraction to the interior of the liquid.

The density of supercritical fluid approches density of liquid phase,which helps toimprove its solvating properties.

The other properties like diffusivity and viscosity approches to that of gas,whichenhances the transport properties of supercritical fluid and helps it to penetrate intoporous solid material more liquid solvent resulting in rapid masstransfer and extraction.

or supercritical fluids the heat of vapouri!ation is !ero at and beyond the critical point ,so for this there is no distinction between the phases.

"ts isothermal compressibility tends to infinity ,thus its density changes dramatically.

The dependency of solubility to the specific density is give by empirical correlationproposed by #hrastil as follows

# $ %density&k . exp 'a(T ) b*

where # is the solute concentration, a, b and k empirical constants

Properties of supercritical uids

http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Intermolecular_Forces/Surface_Tension





Graphs sho-in" chan"e in solu.ility of /aphthalene -ith respect to density

Sol*ent po-er of a SCF increases -ith density at "i*en temperature

Sol*ent po-er of a SCF increases -ith temperature at a "i*en density

Su,erritia! 0!uid E1tration by Mark MHu"h 2%a!3rukonis



There are 4any other advanta"es of su,erritia! /uid as so!vent instead of usin"

or"ani so!vent

5o residua! so!vent

Su,erritia!/uid as so!vent



APPL0CA102/S 2F S3P45C5010CAL FL30DS

Due to the s,eia! so!vent ,ro,erties of su,erritia! /uid it has no# beo4e a,art of 4any industria! ,ratie.

(6 Reation7ata!ysis:

) +se of S# # to replace traditional solvents has the benefit of increasing and controlling the

reaction kinetics by altering the pressure.

) asy separation of reaction product and removal of solvent from the system by simpledepressuri!ation.

) /pplication0biochemistry,polymerchemistry and environmental science.

'6 Parti!e 0or4ation:) +se in the production of powders or microparticles with possible use in pharmaceutical industry.

) "t increases the bio availability of poorly soluble molecules.

) 1y rapid depressuri!ing materials dissolves in #,microparticals are thus produced with drugs

embedded in substrate.

86 9!eanin":) ffective solvent for cleaning many kinds of delicate parts,electronics,plastics,parts having small

opening or porous material.

) "t enhances the wetting and diffusion properties of solvent also removes oils,fats,waxes withoutcausing any damage to matrix.



6 E!etroni hi, 4anufaturin":) lectronic chip manufacturing creats a large amount of environmental burden by

consuming large amount of chemicals,energy and water for cleaning.

) #- with appropriate detergents eliminates need for water

) 2educes energy consumption.) 3ue to low surface tension of S# the cleaning of finer surface features can be done

without any damage.

+6 9hro4ato"ra,hy:)

"t is the technique use to separate the chemical mixures into separate componenets.) #- replaces the mobile phase in 456#.

) "t helps to improve the performance of the separation column by giving higherresolution and faster separation.

;6 In)etion 4o!din" and e1trusion:) # melt in plastic melt lowers its viscosity thereby decreasing the injection pressure

required or decreasing ingection time.

) Thus it increases life of moulding equipmennt and production rate.

) 3ecrease in melt temperature can be used for moulding the thermally labile compound.



<6 0rationation:) S# are used to fractionate low vapor pressure oils and polymers.

) "t takes the advantage of very high selectivity of S#.

) This fractionation is difficult to achieve in simple distillation as the impurities have thesame volatility as the primary compound reducing selectivity.

) +se to fractionate the synthetic or natural oils such as siliconses,flouroethers,copolymersetc.

=6 Po!!ution abate4ent:) Substitution of organic solvent by S# in painting industry, polymer foaming, cleaning and

degreasing, dry cleaning, recycling processes.) Substitution to water and air polluting processes.

) 7ater stream polluted with water can be treated with # in order to recover the pollutants

prior to water disposal.

>6 E1tration:)

S is an alternative to liquid extraction using solvents such as hexane or dichloromethane.) #arbon dioxide %#& is the most used supercritical fluid, sometimes modified by co-

solvents such as ethanol or methanol.

) # is easy to remove simply by reducing the pressure, leaving almost no trace.

) 5roperties of a supercritical fluid can be altered by varying the pressure and temperature,allowing selective extraction.



Apllication of supercritical uid C26% in e7traction



P52C4D354 F25 S3P45C5010CAL FL30D4815AC102/

The !iuid ?S906 is ,u4,ed to a heatin" @one$ #here it is heated to su,erritia! onditions. It then ,asses into the e1tration vesse!$ #here it ra,id!y diuses into the so!id

4atri1 2 disso!ves the 4ateria! to be e1trated. The disso!ved 4ateria! is s#e,t fro4 the e1tration e!! into a se,arator at !o#er

,ressure$ and the e1trated 4ateria! sett!es out. The 9B' an then be oo!ed$ re&o4,ressed and rey!ed$ or dishar"ed to

at4os,here.

( 9ondensation' Pu4,in"8 Heatin" E1tration+ Deso4,ression; Se,aration



3ue to many special solvent properties of supercritical fluid, it has now become a part

of many industrial processes. "t has replace many organic solvents like hexane due to the increasing pressure of

global warming and o!one depletion. Thus S# have a great future ahead .

1ut the supercritical fluid processes are not always the best answers, but should beconsidered as alternatives among others, with their own advantages an limitations.

19A/: ;23

Conclusion

sc fluid presentation

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