Biochemical Product Separation

8/9/2019 Biochemical Product Separation

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Novel product separations

Separation Applications in

downstream processing



Pervaporation,

Membrane distillation,

Vapor permeation and Gas permeation,

Membrane distillation,

Vapor permeation and Gas permeation

Contents



Pervaporation

Pervaporation is a membrane process, in

which a liquid mixture is brought in contact

with a membrane at the upstream side and the

permeate is removed as a vapor at thepermeate side. The driving force for the

process is established by reducing the relative

pressure at the downstream side by either the

use of an inert carrier gas or an appliedvacuum. The vapor is usually obtained as a

liquid in a condenser.



vapor

non condensables

feed retentate

membrane module

vacuum pump

condensed permeate

condenser

feed retentate

membrane module

condensed permeate

condenser

blower

carrier gas recycle

vacuum

pervaporation

carrier gas

pervaporation

Fig. 1: Schematic representation

of pervaporation processes



Types of industrial applications of

pervaporation

The dehydration of water-organic liquid

azeotropes and

The extraction of volatile trace organics

contained in aqueous mixtures.

In every case, pervaporation is combined

with distillation and is mainly used to

pass over the azeotropic composition.



applications for pervaporation …

Dehydration of organic solvents

Removal of dilute organics from

aqueous streams

Continuous extraction of products and

inhibitory by-products in biological and

food processes

Separation of organic mixtures



Membrane distillation (MD)-1

Membrane distillation is a distillation process,

in which two aqueous solutions with different

temperatures are separated by a microporous

hydrophobic membrane. In this process the pores of the microporous

membrane, which are not wetted by the liquid

mixtures at the feed side or the permeate side,

act as the vapor phase.



Module of membrane distillation.



Membrane distillation (MD)-2

The vapor pressure difference, resulting

usually from the temperature difference

across the membrane, causes vapor

molecules to be transported from thewarm feed side to the cold permeate

side.





industrial applications of

membrane dist i l lat ion

Due to very low entrainment of droplets

through the microporous membrane, the

production of utrapure low conductivity water

seems to be an interesting application. Also, the production of potable water from salt

containing water in arid regions (e.g. Australia)

by membrane distillation using solar energy

has been commercialized.



characteristics of a membrane

distillation process

The characteristics of a membrane

distillation process can be reduced to

one important point: the permeant is

t ranspo rted as a vapo r through the

pores o f a porous membrane, which

is at least at one side in d irect contact

w i th the l iqu id [Franken (1988)].



Vapor and Gas Permeation

compounds that are condensable

at standard conditions

so-called permanent gases



Vapor permeation (VP)

Vapor permeation denotes the transport of

matter through a membrane from a vapor

feed mixture to a vapor permeate. It is

related closely to gas permeation differing onlyin that a vapor mixture contains compounds

that are condensable at standard conditions (1

bar and 0°C), whereas a gas mixture contains

only so-called permanent gases [Cen andLichtenthaler (1995)].



Comparison of VP (vapor permeation) and PV

(pervaporation):

VP

+ no phase change

+ no heat of vaporization necessary

+ no severe concentration polarization problem

+ suitable for several hybrid processes (e.g.purification of top stream of rectification columns)

PerVap

- strong dependence of separation characteristics

on the feed pressure - sensitivity to friction losses in the feed stream

- possibility of condensation



Gas permeation (GP)

A gas separation membrane process comprises the transport of gases through amembrane. A gas separation membranepreferentially removes one or morecomponents of a gas mixture that is passedacross a membrane surface.

Usually, the feed gas mixture is pressurized toincrease the partial pressure differencebetween feed side and permeate side and,therefore, to increase mass transfer.



gas separation membranes :

Asymmetric polymer membranes

consisting of a highly permeable,

permselective and dense polymer film

fixed to a porous support.

Membrane polymers should have both

high solubility and high diffusivity of

gases as well as easy membraneformation properties.



Classes of gases that are separated

by membranes:

(significance of the development of gas

separation membranes varies with the type

of mixed gas)

1 The property and the molecular size of thecomponent gases in the gas mixture are

similar. Typical examples of the separation of

such mixed gases are O2/N2 separation and

alkane/alkene separation (same number ofcarbon atoms).



Classes of gases….

2 One component (e.g. SO2, CO2, NH3 or Cl2)in the gas mixture has a much largersolubility coefficient than other components.

A typical case is CO2/CH4 or CO2/COseparation.

3 One component in the gas mixture - such asH2 or He - has a small molecular diameterand low molecular weight. A typical exampleis the separation of H2/CO, H2/N2, or theseparation of He from natural gas.



Application of gas permeation

processes



Literature-1

Baker, R.W.: Recovering organic vapors from air. USPat. 4,553,983 (1985).

Beaumelle, D.; Marin, M.; Gibert, H.: Pervaporationwith Organophilic Membranes: State of the Art. Trans.

IChemE Part C, 71 (1993), 77-89. Belafi-Bakó, K.; Harasek, M.; Friedl, A.: Product

removal in ethanol and ABE fermentations. Hung. J.Ind. Chem., 23 (1995), 309-319.

Bengtsson, E.; Trägårdh, G.; Hallström, B.: Recoveryand Concentration of Apple Juice Aroma Compoundsby Pervaporation. J. Food Eng., 10 (1989), 65-71.



Literature-1a

Bennett, M.: Pervaporation Using ModifiedPolysiloxanes: Removal of Priority OrganicContaminants from Aqueous Streams. PhD thesis,University of Bath, United Kingdom (1996).

Blume, I.; Baker, R.W. (Membrane Technology &Research, Inc.): Process for recovering organiccomponents from liquid streams. US Pat. 5,030,356(1991).

Brüschke, H.E.A.: Multilayered membrane and its use

in separating liquid mixtures by the pervaporationmethod. DE Pat. 3 220 570 (1983).



Literature-2

Brüschke, H.E.A.; Schneider, W.; Tusel, G.F.:Verfahren zur Reduktion des Alkoholgehaltes vonalkoholischen Getränken. EP 0 332 738 (1988).

Cen, Y.; Lichtenthaler, R.N.: Vapor permeation. In:

Membrane Separations Technology – Principles and Applications. Membrane Science and TechnologySeries, 2 (1995), 85-112.

Franken, T.: Membrane distillation: a new approachusing composite membranes. PhD thesis, University of

Twente, The Netherlands (1988).



Literature-3

Friedl, A.; Windsperger, A.M.; Minkov, S.:Inertgasstrippen als Produktabtrennung beider Aceton-Butanolgärung und derEthanolgärung. Zuckerind., 114 (1989), 216-221.

Friedl, A.; Harasek, M.; Schmidt, A.:Concentration of hydrochloric acid and sulfuricacid by pervaporation and membranedistillation. Proceedings of Euromembrane´95, Bath (UK), 18-20 Sept. 1995, Volume II,198-203.



Literature-4

Geng, Q.; Park, C.-H.: Pervaporative ButanolFermentation by Clostridium acetobutylicum B18.Biotechnol. Bioeng., 43 (1994), 978-986.

Groot, W.J.; den Reyer, M.C.H.; Baart de la Faille, T.;

van der Lans, R.G.J.M.; Luyben, K.Ch.A.M.:Integration of pervaporation and continuous butanolfermentation with immobilized cells. I: Experimentalresults. Chem. Eng. J., 46 (1991), B1-B10.

Gudernatsch, W.; Chmiel, H.: Verfahren zur selektiven

An- oder Abreicherung flüchtiger Bestandteile einesFluidgemisches. DE Pat. 39 40 520 (1989).



Literature-5

Gudernatsch, W.; Kimmerle, K.: New Capillary

Modules for Pervaporation. Proc. 5th Int. Conf.

on Pervap. Proc. in Chem. Ind., Heidelberg

(Germany), 1991, R.Bakish (Ed.), BakishMaterials Corporation, Englewood (NJ, USA),

259-271.

Gupta, B.D.; Mukherhee, A.K.: Separation of

Liquid Mixtures by Pervaporation. Poly.-Plast.Technol. Eng., 29(4), 299-337 (1990).



Literature-6

Harasek, M.: Pervaporation and Membrane Distillation for the

Removal of Organic Compounds from Aqueous Mixtures. PhD

thesis, Vienna University of Technology (1997).

Henis, J.M.S.; Tripodi, M.K.: Multicomponent membranes for

separation of gases. US Pat. 4,230,463 (1978).

Karlsson, H.O.E.; Trägårdh, G.: Pervaporation of dilute organic-

water mixtures. A literature review on modelling studies andapplications to aroma compound recovery. J. Membr. Sci., 76

(1993), 121-146.



Literature-7

Karlsson, H.O.E.; Trägårdh, G.: Aroma

compound recovery with pervaporation -

the effect of high ethanol concentration.

J. Membr. Sci., 91 (1994), 189-198.

Kober, P.A.: Pervaporation, perstillation

and percrystallisation. J. Am. Chem.

Soc., 39 (1917), 944-948.



Literature-8

Meckl, K.; Lichtenthaler, R.N.: HybridProcesses Including Pervaporation for theRemoval of Organic Compounds from Processand Waste Waters. Proc. 6th Int. Conf. on

Pervap. Proc. in Chem. Ind., Ottawa (Canada),1992, R.Bakish (Ed.), Bakish MaterialsCorporation, Englewood (NJ, USA), 476-483.

Néel, J.: Pervaporation. In: MembraneSeparation Technology, Membrane Scienceand Technology Series, 2, edited byR.D.Noble and S.A.Stern, Elsevier,

Amsterdam (1995), 143-211.



Literature-9

Noezar, L.; Nguyen, Q.T.; Clément, R.; Néel,J.: High Performance Polymer BlendMembranes for Alcohol - Ether Separation.Proc. 7th Int. Conf. on Pervap. Proc. in Chem.

Ind., Reno (NV/USA), 1995, R.Bakish (Ed.),Bakish Materials Corporation, Englewood (NJ,USA), 45-51.

Pinnau, I.; Koros, W.J.: Relationship betweenSubstructure Resistance and Gas SeparationProperties of Defect-Free Integrally Skinned

Asymmetric Membranes. Ind. Eng. Chem.Res., 30 (1991), 1837-1840.



Literature-10

Rautenbach, R.; Klatt, S.; Vier, J.: State of the Art ofPervaporation, 10 Years of Industrial PV. Proc. 6th Int.Conf. on Pervap. Proc. in Chem. Ind., Ottawa(Canada), 1992, R.Bakish (Ed.), Bakish MaterialsCorporation, Englewood (NJ, USA), 2-15.

Schofield, R.W.; McCray, B.; Ray, R.J.; Newbold,D.D.: Opportunities for Pervaporation in the WaterTreatment Industry. Proc. 5th Int. Conf. on Pervap.Proc. in Chem. Ind., Heidelberg (Germany), 1991,R.Bakish (Ed.), Bakish Materials Corporation,

Englewood (NJ, USA), 409-420. Scott, K.: Handbook of Industrial Membranes. Elsevier

Advanced Technology (1995), ISBN 1-85617-233-3.



Literature-11

Pinnau, I.; Wind, J.; Peinemann, K.-V.:Ultrathin Multicomponent Poly(ether sulfone)Membranes for Gas Separation Made byDry/Wet Phase Inversion. Ind. Eng. Chem.

Res., 29 (1990), 2028-2032. Qureshi, N.; Maddox, I.S.; Friedl, A.:

Application of Continuous Substrate Feedingto the ABE Fermentation: Relief of ProductInhibition Using Extraction, Perstraction,Stripping and Pervaporation. Biotechnol.Prog., 8 (1992), 382-390.



Literature-12

Strathmann, H.; Bell, C.-M.; Gudernatsch, W.;Kimmerle, K.: Die Entwicklung vonLösungsmittel-selektiven Membranen und ihre

Anwendung für die Gastrennung und

Pervaporation. Chem.-Ing.-Tech., 60 (1988),590-603.

Strathmann, H.; Bell, C.-M.; Kerres, J.: GasSeparation and Pervaporation: Membrane andModule Development. Desalination, 77 (1990),259-278.



Literature-13

Streicher, C.; Kremer, P.; Tomas, V.; Hubner, A.; Ellinghorst, G.:

Development of new pervaporation membranes, systems and

processes to separate alcohols/ethers/hydrocarbons mixtures.

Proc. 7th Int. Conf. on Pervap. Proc. in Chem. Ind., Reno

(NV/USA), 1995, R.Bakish (Ed.), Bakish Materials Corporation,Englewood (NJ, USA), 297-309.

Udriot, H.; Araque, A.; von Stockar, U.: Azeotropic mixtures may

be broken by membrane distillation. Chem. Eng. J., 54 (1994),

87-93. Ward, R.R.; Chang, R.C.; Danos, J.C.; Carden, J.A.: Processes

for coating bundles of hollow fiber membranes. US Pat.

4,214,020 (1980).

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Biochemical Product Separation