Multiphase Membrane Reactors for Separating Stereoisomers

López, Jorge L.; Wald, Stephen A.; Matson, Stephen L.; Quinn, John A.

doi:10.1111/j.1749-6632.1990.tb18156.x

Cited by 31 publications

(17 citation statements)

References 6 publications

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“…Because of the importance of the aqueous pH, sodium hydroxide solution was frequently added to the aqueous phase during TSP-EMR runs to maintain buffer condition. 56,85,86 Albeit phosphate buffers were a good aqueous phase, they occasionally could not be used to provide a proper aqueous environment. As in hydrolysis of the racemic methyl-methoxy phenylglycidate (MMPG), the phosphate buffer led to base-catalysed hydrolysis of the substrate to form aldehyde by-product, which inhibited enzyme activity; hence in MMPG hydrolysis, researchers used a bisulphite solution to prevent aldehyde contamination.…”

Section: Fluids Characteristicsmentioning

confidence: 99%

“…For example, ethyl butyrate was hydrolysed by porcine liver esterase in several hours at the reaction rate of 9600 µ min −1 . 56 Hydrolysis of oils also proceeded in a no-solvent system. 76,77 The increase of olive oil concentrations led to the increase of catalytic efficiency.…”

Section: Dissolved-or No-solvent Operationmentioning

confidence: 99%

“…Transport could be achieved using hydrophobic membranes and positive pressure on the aqueous side or hydrophilic membranes and positive pressure on the organic side. 50,56 Use of HFM to house the enzymes has advantages over conventional enzymes immobilization methods. Large exchange surface per unit volume is provided by these membranes.…”

Section: Tsp-emr: Basic Needsmentioning

confidence: 99%

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Enzymatic membrane reactors: the determining factors in two separate phase operations

Agustian¹,

Kamaruddin²,

Bhatia³

2011

J of Chemical Tech & Biotech

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A two separate phase-enzymatic membrane reactor is an attractive process since it has a large interfacial area and exchange surfaces, simultaneous reaction and separation and other benefits. Many factors influence its successful operation, and these include characteristics of the enzyme, membrane, circulating fluids and reactor operations. Although the operating conditions are the main factor, other factors must be considered before, during or after its application. At the initial stage of reactor development, the solubility of substrates and products, type of operation, membrane material and size, enzyme preparation and loading procedure, and cleanliness of the recirculated fluids should be specified. The immobilization site, reactor arrangement, dissolved or no-solvent operation, classic or emulsion operation and immobilized or suspended enzyme(s) are determined later. Some factors still need further studies. Utilization of the technology is described for use from multigram-to plant-scale capacity to process racemic and achiral compounds. The racemates were resolved primarily by kinetic resolution, but dynamic kinetic resolution has been exploited. The technology focused on hydrolytic reactions, but esterification processes were also exploited.

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Section: Fluids Characteristicsmentioning

confidence: 99%

Section: Dissolved-or No-solvent Operationmentioning

confidence: 99%

Section: Tsp-emr: Basic Needsmentioning

confidence: 99%

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Enzymatic membrane reactors: the determining factors in two separate phase operations

Agustian¹,

Kamaruddin²,

Bhatia³

2011

J of Chemical Tech & Biotech

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“…Since enzymes generally operate in aqueous solutions and not organic solvents, it has proven difficult to facilitate the enzymecatalyzed bioconversion and subsequent separation of poorly water-soluble optical isomers. Multiphase (biphasic) membrane reactors offer many advantages in managing these sorts of reactions [127,128,134]. Typically, the membrane immobilized enzyme preferentially converts one reactive stereoisomer in a racemic (R and S) feed mixture of water-insoluble feed isomers to a water-soluble product isomer of altered chemical composition.…”

Section: Applicationmentioning

confidence: 99%

“…Instead of trapping the organic phase in one membrane (ILM) and using a bilayer membrane sandwich to separate two aqueous solutions, in biphasic (multiphase) membrane reactors a single hydrophilic, enzyme-activated porous membrane is used to separate immiscible aqueous and organic streams [97,127,128]. By virtue of the hydrophilicity of the membrane and the slight organic-to-aqueous-phase pressure difference imposed across the membrane, the aqueous/organic interface is fixed at that side of the membrane that is in contact with the organic stream.…”

Section: Biphasic (Multiphase) Membrane Bioreactors 281 Conceptmentioning

confidence: 99%

Biocatalytic membrane reactors (BMR)

Vladisavljević

2016

Physical Sciences Reviews

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Extraordinary enantiospecificity of lipase catalysis in organic media induced by purification and catalyst engineering

Tsai

Dordick

2000

Biotechnol. Bioeng.

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A purified lipase preparation from Candida rugosa was compared to its crude counterpart in anhydrous and slightly hydrated hydrophobic organic solvents. The purified lipase preparation was less active than the crude enzyme in dry n‐heptane, whereas the presence of small concentrations of added water dramatically activated the purified enzyme but not the crude enzyme. Thus, in the presence of as little as 0.25 μL/mL of added water in n‐heptane, the purified enzyme is over 230‐fold more active and 6‐fold more enantioselective than the dry enzyme suspension in the esterification of racemic 2‐(4‐chlorophenoxy)propionic acid with n‐butanol. The reactivity and selectivity of this biocatalyst, however, was affected by coalescence of the enzyme preparation suspended in the wet organic solvent. Engineering the biocatalyst environment by dissolving the purified lipase in aqueous buffer and then adding this solution to n‐heptane resulted in a precipitated enzyme preparation with smaller particle sizes that did not coalesce severely. In the presence of 5 μL/mL of water added with the enzyme, this pretreatment resulted in an activation over the dry, purified enzyme preparation of over 1800‐fold and nearly enantiospecific catalysis (E > 100). Hence, by simply modifying the way enzymes are hydrated, dramatic activation of catalytic competency can be achieved. © 1996 John Wiley & Sons, Inc.

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Multiphase Membrane Reactors for Separating Stereoisomers

Cited by 31 publications

References 6 publications

Enzymatic membrane reactors: the determining factors in two separate phase operations

Enzymatic membrane reactors: the determining factors in two separate phase operations

Biocatalytic membrane reactors (BMR)

Extraordinary enantiospecificity of lipase catalysis in organic media induced by purification and catalyst engineering

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