Catalytic membrane reactor

Abstract

The invention relates to reactors comprising at least three flow regions arranged concentrically around one another or in layers on top of one another, each separated from one another by membranes, comprising at least two fluid supply devices and at least two fluid discharge devices, wherein the reactor is configured such that the flow direction in a first region arranged between two other regions is the same as or opposite the flow direction in the two other regions, a fluid supply device and a fluid discharge device are connected to the first region, and the other fluid supply devices and fluid discharge devices are connected to the other regions, and immobilised catalyst particles are arranged in the first region arranged between the two other regions. The invention also relates to reactor systems, methods and uses based on this principle.

Description

[0001] CATALYTIC MEMBRANE REACTOR

[0002] All documents cited in the present application are incorporated by reference in their entirety into the present disclosure.

[0003] The present invention relates to reactors with several flow zones separated from each other by membranes, their use and processes for the catalytic conversion of substrates.

[0004] State of the art:

[0005] In the context of the bioeconomy, enzymatic biosyntheses are becoming increasingly important for industrial applications. Important applications include the food industry, the synthesis of fine chemicals, and the pharmaceutical industry. The reactions are usually carried out in a cyclic process in a conventional batch reactor. In this conventional process, the enzyme is usually lost at the end of the reaction. To avoid this, the basic concept of the enzyme membrane reactor (EMR) was developed approximately 50 years ago. An EMR combines a membrane separation process with an enzymatic reaction. The selective membrane serves to separate the biocatalyst from the reaction products. The main goal of the EMR is to ensure the complete separation of the enzyme to maintain full activity within the reaction volume.Depending on the design, the enzyme molecules can circulate freely on the retentate side or be immobilized on the membrane surface or within its porous structure.

[0006] In the case of an EMR with free, dissolved enzymes, the biocatalyst is retained by an ultrafiltration membrane, while the product can pass through this membrane. If the EMR is operated as a dead-end filtration, the enzyme rapidly accumulates above the membrane surface, leading to concentration polarization and potential fouling. Furthermore, the corresponding depletion of the enzyme in the bulk volume of the reactor leads to reduced conversion rates and yields / space-time-yield STY. Cross-flow operation of the EMRs and recycling of the reaction solution in a loop reduces concentration polarization; however, the concept is only partially suitable for the realization of continuous-flow enzyme cascades, especially when the substrates and products involved are of comparable size.In the case of EMR with enzyme immobilized in the membrane matrix, no concentration polarization occurs. However, the contact time between the substrate passing through the membrane and the immobilized enzyme is very short in continuous single-pass systems, which reduces the achievable throughputs and yields. Therefore, most scientific and industrial EMR applications use systems of the first type with free enzymes. A combination of continuously stirred tank reactors (CSTRs) and commercial membrane filtration units is commonly used, but such a combination is far from an optimal EMR unit with integrated product purification and / or buffer exchange.

[0007] A prior art document concerning a form of EMR in which substrate, product, and dissolved enzyme circulate is WO 2021 / 186148 A1. US 2015 / 0118118 A1 discloses reactors in which exactly two areas are separated by a membrane. Further prior art documents include US 4,786,597, WO 2006 / 034100 A1, WO 2004 / 022480 A2, US 7,537,738 B2, and US 5,449,848.

[0008] There is still potential for further improvement based on the known state of the art; in particular, the current state of the art does not allow for the implementation of complex, particularly multi-stage reactions in a satisfactory manner.

[0009] The object of the present invention was therefore to provide improved reactors for catalytic reactions with regard to the state of the art, with which the disadvantages of the state of the art can be avoided and particularly good results can be achieved.

[0010] Further tasks for the specialist arise from the following description.

[0011] These and other objects are achieved within the scope of the present invention by the subject matter of the independent claims.

[0012] Preferred embodiments emerge from the dependent claims and the following description. Within the scope of the present invention, the term "comprise" also includes "consisting of" as a particularly preferred embodiment; this means that a corresponding list may contain (=comprise) further elements in addition to the explicitly mentioned elements, or it may contain precisely these elements (=consist of) (whereby non-essential elements such as screws, markings, etc. are not taken into account).

[0013] For relative information such as top, bottom, left, right or similar, the reference system used in the present invention is an observer standing upright on the ground in front of the object in question.

[0014] In the context of the present invention, the term "and / or" means that both elements mentioned in the context are included individually as well as the combination of the elements mentioned in the context.

[0015] In the context of the present invention, all quantities are to be understood as weights unless otherwise stated.

[0016] For the purposes of the present invention, the term "ambient temperature" means a temperature of 20°C. Unless otherwise stated, temperatures are in degrees Celsius (°C).

[0017] Unless otherwise stated, the reactions or process steps mentioned are carried out at atmospheric pressure, ie at approximately 1013 kPa.

[0018] Firstly, the subject of the present invention is a reactor comprising, or in variants consisting of, at least three, or in variants even more than three, for example four, five, six, seven or even more, flow regions arranged concentrically around one another or in layers one above the other, which are each separated from one another by membranes, preferably semipermeable membranes.

[0019] In variants of the present invention, it is preferred if the reactor has exactly three regions.

[0020] Furthermore, in variants of the present invention, it is preferred if the regions are arranged in layers one above the other.

[0021] Semipermeable membranes are membranes whose pores are permeable to only a portion of the substances flowing into the membranes, meaning that only molecules below a certain molecular weight, or colloids or particles below a certain size, are allowed to pass through. In the case of nanofiltration membranes, the electrical charge of the molecules and their hydrophilic or hydrophobic character also play a role in the retention by the membranes. In the simplest case, this means that the respective membrane allows the solvent to pass through, but not the dissolved substance. This principle is well known to those skilled in the art. Therefore, the selection of appropriate membranes by the skilled person, possibly depending on the desired reactions to be carried out in the reactor according to the invention, is clear to the skilled person and requires no further explanation.

[0022] Examples of suitable membranes include nanofiltration membranes made of polyamide thin-film composites with a molecular weight cutoff (MWCO) of, for example, 150, 300, or 700 Daltons (Da). Other common nanofiltration membranes consist of, for example, polypiperazinamide or cellulose acetate, also with MWCO values ​​between 150 and 1000 Daltons. Suitable ultrafiltration membranes include those made of polyamide thin-film composites, polyethersulfones, or polyacrylonitrile with MWCO values ​​of 1000 Da, 2000 Da, 3000 Da, 5000 Da, up to 50,000 Da or more.

[0023] In some preferred variants of the present invention, the membranes used are therefore selected from the group consisting of

[0024] Nanofiltration membranes consisting of polyamide thin film composites with a molecular weight cut-off size of 150, 300 or 700 Dalton, nanofiltration membranes made of polypiperazinamide with MWCO values ​​between 150 and 1000 Dalton,

[0025] Nanofiltration membranes made of cellulose acetate with MWCO values ​​between 150 and 1000 Dalton,

[0026] Ultrafiltration membranes made of polyamide thin film composites with MWCO values ​​of 1000 Da, 2000 Da, 3000 Da, 5000 Da up to 50000 Da, or ultrafiltration membranes made of polyamide thin film composites with MWCO values ​​of more than 50000 Da,

[0027] Ultrafiltration membranes made of polyethersulfones with MWCO values ​​of 1000 Da, 2000 Da, 3000 Da, 5000 Da up to 50000 Da, or ultrafiltration membranes made of polyethersulfones with MWCO values ​​of more than 50000 Da, and

[0028] Ultrafiltration membranes made of polyacrylonitrile with MWCO values ​​of 1000 Da, 2000 Da, 3000 Da, 5000 Da up to 50000 Da, or ultrafiltration membranes made of polyacrylonitrile with MWCO values ​​of more than 50000 Da.

[0029] The respective membranes can be the same or different. In some embodiments of the present invention, it is preferred if the membranes between the first region and the two adjacent regions are the same. In some other embodiments of the present invention, it is preferred if the membranes between the first region and the two adjacent regions are different, particularly if no reversal of the flow direction through the membrane is planned during operation.

[0030] In some preferred embodiments of the present invention, the first membrane serves for the controlled supply of an exchange solution into the first (middle) region (flow channel), in which the immobilized catalyst (the immobilized enzyme) is located and in which the catalytic conversion (reaction of the substrate to the product) takes place. The second membrane in these embodiments of the present invention serves for the simultaneous, controlled removal of solvent from the first (middle) region (flow channel). At the same time, the membrane retains the product. This also applies to an intermittent change of the supply from the second to the third region (or vice versa), except that in this case the flow direction is simply reversed transversely to the flow direction through the first region, and the two membranes swap roles.

[0031] The reactor according to the invention further comprises at least two fluid supply devices and at least two fluid discharge devices, wherein one fluid supply device and one fluid discharge device are connected to the first region, which in the preferred embodiments has three regions located between the other regions, and the further fluid supply devices and fluid discharge devices are connected to the other regions.

[0032] It should be noted that the respective fluid supply or discharge devices within the scope of the present invention can consist of several individual channels / tubes, etc. Furthermore, each of these devices can have control and / or throttle valves. This allows the supplied or discharged fluid quantities to be regulated even more precisely (in addition to control via pressure, etc.) and, if necessary, simplifies the mixing of individual components.

[0033] Within the scope of the present invention, it is also possible in some preferred variants for each region to have more than one fluid supply device or fluid discharge device.

[0034] In preferred variants of the present invention, the reactor according to the invention has at least one fluid supply device per region and at least one fluid discharge device per region.

[0035] Furthermore, the reactor according to the invention is configured such that the flow direction in a (the) first region arranged between (the) two other regions is in cocurrent with or opposite to the flow direction in the two other regions.

[0036] A further essential feature of the present invention is that immobilized catalyst particles are arranged in the first region of the reactor according to the invention, which is arranged between the two other regions.

[0037] In the context of the present invention, the fluids supplied and discharged are preferably liquids, i.e. substances or mixtures of substances which are liquid under the respective operating conditions of the reactor, for example an operating temperature between 5°C and 80°C and atmospheric pressure.

[0038] However, within the scope of the present invention, it is in principle also possible to use gaseous fluids (at atmospheric pressure or higher or lower pressure or higher or lower temperatures).

[0039] Particularly preferably, the fluids added and supplied in the context of the present invention are aqueous solutions.

[0040] As shown, the reactor according to the invention has at least two supply and discharge devices for fluids.

[0041] In some variants of the present invention, in which the reactor according to the invention has three zones, it is preferred if the reactor according to the invention has at least one fluid supply device per zone and at least one fluid discharge device per zone. This allows particularly good mixing of the substances passing through the membranes to be achieved, particularly in countercurrent flow, i.e., when the flow direction in the first zone located between the other zones is opposite to that of the two outer zones.

[0042] In other variants of the present invention, in which the reactor according to the invention has three regions, it is preferred if the reactor according to the invention has a fluid supply device and a fluid discharge device for the first region located between the other regions, and has a fluid supply device for the upper region (but no fluid discharge device) and a fluid discharge device for the lower region (but no fluid supply device). Accordingly, in yet other variants of the present invention, in which the reactor according to the invention has three regions, it is preferred if the reactor according to the invention has a fluid supply device and a fluid discharge device for the first region located between the other regions, and has a fluid supply device for the lower region (but no fluid discharge device) and a fluid discharge device for the upper region (but no fluid supply device).These variants are particularly suitable for uniform flow, as they maintain a constant flow direction through the membranes during operation. The membrane-permeable substances then enter the upper or lower region, pass through the first membrane into the first region, and later through the other membrane into the lower or upper region, from where they are discharged from the reactor. Alternatively, to implement these two variants, it is possible to use a reactor according to the invention that has at least one fluid supply device per region and at least one fluid discharge device per region; in this case, only one supply device or discharge device would be unused and closed accordingly.

[0043] Analogously, even with more than three zones, either all zones can have fluid supply and discharge devices, or only some of them. The only essential factor is that the fluid or fluids in a first zone located between two other zones can be mixed with substances passing through the membranes from at least one other zone (by diffusing in and / or out, or in particular, by convective transport with the solvent passing through the membrane).

[0044] With the reactor according to the invention, during operation, i.e., when fluids are passed through the first region and the adjacent regions, a volume flow of a solution enters the first region through a membrane due to pressure differences from an adjacent region, and simultaneously exits the first region through another membrane into another adjacent region. This enables a modification of the solution in the first region, regardless of the main flow direction, which is defined by the fluid supply device and fluid discharge device of the first region.

[0045] Although it is preferred in variants of the present invention if the flow direction in the first region is opposite to the flow direction in the adjacent regions, this is not absolutely necessary within the scope of the present invention, and in other (less preferred) variants of the present invention, it may be preferred if the flow directions are the same. This is because there are cases in which the flow direction is irrelevant or in which a cocurrent flow is more advantageous, for example, if a change in the flow direction through the membranes is omitted.

[0046] The fact that the catalyst particles are immobilized means that they are not freely mobile in the first region. There are various possibilities for immobilization that are known to those skilled in the art. For example, the catalyst particles do not necessarily have to be arranged on a framework; they can also be fixed to support particles and then arranged in the first region in the form of a bed or suspension.

[0047] In variants of the present invention, the catalysts are immobilized on support materials, preferably selected from the group consisting of fibers, particles, in particular microparticulate particles, lattice structures, or combinations thereof. Microparticulate particles, which can also be referred to as microparticles, preferably mean that the particles have a size in the micrometer range, in particular in the range from 0.5 pm to 500 pm, preferably 2 pm to 300 pm.

[0048] The term "lattice structures" refers to structures that have a grid-like or sieve-like structure. The respective webs of the grids or sieves are not limited in their dimensions, except that the resulting grid or sieve structure must not be too large for arrangement in the first region and that, after immobilization of the catalyst particles, sufficient free volume must remain for fluid flow. In this respect, the person skilled in the art can simply select the applicable grid structures based on their general technical knowledge.

[0049] Although in principle all known techniques can be used for immobilization, the following possibilities for immobilization are preferred within the scope of the present invention: covalent immobilization on carrier particles by chemical bonding, for example (preferably) via l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) or glutaraldehyde (GA);

[0050] Immobilization via tagged enzymes and corresponding ligands on the carrier particles, for example (preferably) His-tagged enzymes and particles with imminodiacetic acid ligands or enzymes and particles that form a covalent bond during immobilization via the so-called spytag / spycatcher technology;

[0051] Immobilization by adsorptive binding to carrier particles;

[0052] Inclusion immobilization in particles such as (preferably) hydrogel particles; particulate enzyme immobilizates that can be synthesized by cross-linking the enzymes, e.g., cross-linked enzyme aggregates (CLEAs).

[0053] In principle, all known carrier particles are suitable as carrier particles for the first three variants mentioned. In particular, they can be both porous and non-porous. Their chemical nature can be polymer-based, mineral-based, or a combination of these.

[0054] In some preferred variants, the carrier particles are selected from the group consisting of carriers made of agarose, dextran, chitosan, gelatin, alginate, polyethylene glycol, polyvinyl alcohol, polymethyl methacrylate, polystyrene, silica, iron oxides, aluminum oxides, organometallic cage compounds or mixtures thereof.

[0055] In preferred variants of the present invention, the immobilized catalysts are biocatalysts, in particular enzymes.

[0056] In principle, any enzymes can be used within the scope of the present invention. In some preferred embodiments, the enzymes are selected from the group consisting of oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases, translocases, and mixtures thereof.

[0057] Accordingly, the reactors according to the invention are particularly preferably enzyme membrane reactors; however, the present invention is not limited thereto.

[0058] In preferred variants of the present invention, the first region arranged between the two other regions has retaining devices, preferably frits, for the catalyst particles on its fluid supply devices and fluid discharge devices.

[0059] In further preferred variants of the present invention, these retaining devices can be openable or replaceable. This allows, for example, catalyst beds to be easily removed and replaced, for example, with new but identical, new but different, or even regenerated catalyst beds.

[0060] In preferred variants of the present invention, the respective fluid supply devices and the respective fluid discharge devices are further configured to be switched and controlled independently of one another. This enables particularly good control of the flows. For example, this can prevent the end facing away from the inflow from "running dry" if the inflow into an upper region is too low, or it can ensure that a sufficiently high supply pressure in a lower region ensures good flow all the way to the upper region, or other effects can be achieved. Combined effects can also be achieved. In preferred variants of the present invention, it is possible to arrange flow-influencing fittings, such as baffles or support grids, in the various regions, each independently of other regions.This can, for example, further improve or regulate the mixing of fluid components.

[0061] A preferred embodiment of the present invention relates to an enzyme membrane reactor comprising or consisting of, a) three flow zones arranged in layers one above the other, which are each separated from one another by semipermeable membranes, b) at least one fluid supply device per zone, c) at least one fluid discharge device per zone, wherein the reactor is configured such that the flow direction in the first zone arranged between the two other zones is opposite to the flow direction in the other two zones, characterized in that in the first zone arranged between the two other zones, immobilized enzymes are arranged as immobilized catalyst particles on support materials, preferably selected from the group consisting of fibers, particles, in particular microparticulate particles, lattice structures or mixtures thereof.

[0062] In preferred variants of the present invention, the fluid supply devices and the fluid discharge devices are mounted at the respective ends of the regions of the reactor.

[0063] In some preferred variants of the present invention, the reactors according to the invention or their components are manufactured by 3D printing. In variants, the reactor housing and / or the support for immobilizing the catalyst particles are manufactured by 3D printing, and corresponding semipermeable membranes not manufactured by 3D printing are inserted into the housing.

[0064] In some preferred variants of the present invention, the reactors according to the invention each have one or more additional feed devices to all or some, preferably all, of the regions adjacent to the first region. Fluids can then also be fed via these additional feed devices. These fluids can each be independent of one another, the same fluids as those mentioned in the other feed devices, or different fluids.

[0065] Their supply can also be carried out independently of the other supplies.

[0066] In preferred variants of the present invention, these additional feeds are arranged upstream of the discharge of the first region. In variants of the present invention, the reactor is designed such that downstream of the additional feeds, as seen in the flow direction of the first region, a region is provided that is free of immobilized catalyst. For this purpose, appropriate retention devices for the immobilized catalyst can be provided in the first region.

[0067] In preferred variants of the present invention, all feeds to the reactors according to the invention are configured such that they can be switched (used) independently of the other feeds, as well as independently of the discharges.

[0068] In preferred variants of the present invention, at least two reactors according to the invention are connected in series. This allows the reactions carried out to be made even more effective, for example.

[0069] In further preferred variants of the present invention, conventional apparatus, such as preferably fluid washing devices, fluid separators, heat exchangers or the like, can be arranged between each two reactors according to the invention.

[0070] The feed devices to the respective reactors can be identical or different and can feed identical or different fluids. In this way, it is also possible to easily carry out staged reactions separately by stage using several reactors according to the invention connected in series, which results in a significant increase in controllability.

[0071] In this way, cascades of reactors according to the invention are possible. In other preferred variants of the present invention, at least two reactors according to the invention are connected in parallel. This allows, for example, the throughput to be made even more effective / increased.

[0072] Here, too, in further preferred variants of the present invention, conventional equipment, such as fluid washing devices, fluid separators, heat exchangers, or the like, can be arranged between each two reactors according to the invention. Here, too, the feed devices to the respective reactors can be the same or different and can stir the same or different fluids. In this way, it is also possible to carry out step reactions in a simple manner, separated by stages, using several reactors according to the invention connected in series, which results in a significant increase in controllability.

[0073] Of course, it is also possible within the scope of the present invention to combine series and parallel circuits of reactors according to the invention.

[0074] It is of course also possible to connect reactors according to the invention with reactors not according to the invention, even if several reactors according to the invention are connected in series and / or parallel.

[0075] In this respect, it is possible within the scope of the present invention to create reactor fields with which high conversions can be achieved both qualitatively and quantitatively.

[0076] Series and / or parallel connections of reactors according to the invention, as well as combinations of reactors according to the invention with reactors not according to the invention, are also subject matter of the present invention. These combinations are occasionally also referred to as reactor systems according to the invention.

[0077] A further subject of the present invention is an automated reactor system comprising at least two reactors according to the invention and at least one control and monitoring device; the automated reactor system of the present invention thus differs from the other reactor systems according to the invention, in which the control (and monitoring) is carried out manually, by virtue of the control and monitoring device(s).

[0078] Analogous to the reactor systems according to the invention, the aforementioned series connections, parallel connections, and / or combinations with non-inventive reactors can be used. The various aforementioned combinations of several reactors according to the invention, optionally with non-inventive reactors, reactor systems according to the invention, and automated reactor systems according to the invention are particularly suitable as or for enzyme cascades with continuous buffer exchange between individual reactors.

[0079] A special feature of the reactor systems and automated reactor systems according to the invention is that buffer changes can take place simultaneously with the reaction along the flow path in the middle (first) region directly in the reactor.

[0080] By connecting two or more reactors in series according to the invention, which are filled with different catalysts, particularly advantageous combinations of effects can be achieved.

[0081] A further subject of the present invention is a process for the catalytic conversion of a substrate, wherein as the first fluid a substrate solution is passed into a reactor in and through a first region arranged between two other regions, independently of fluid supplies into the other regions, preferably uniformly and continuously, and as the second and third fluid a solution is introduced alternately into the other regions, with the same or opposite flow direction to the first fluid, which solution is based on the same solvent as the substrate solution or is miscible with this solvent.

[0082] In this process, it is essential that an immobilized catalyst is arranged in the first region and that the first region is separated from the other regions by membranes, preferably semipermeable membranes, and that the membranes are configured to be impermeable to the substrate, the main product and the catalyst.

[0083] Within the scope of the present invention, it is preferred that excipients and unwanted byproducts be able to pass through the membranes. The term "second and third fluid" refers to the fact that these fluids are directed into a second and third region. The second and third fluids can be the same or different.

[0084] Within the scope of the present invention, it is possible in one variant to cyclically switch the flow direction through the membrane and thereby utilize a second and third inlet to the areas adjacent to the first area. The same (second) fluid can be switched to either inlet via a valve (e.g., a multiport or multi-way valve), so that no third fluid is used in a reactor in this variant.

[0085] In the context of the present invention, the term "miscible with this solvent" means that the solution is miscible with the solvent in the first region at least in a ratio of 1:2 without phase separation or precipitation occurring.

[0086] In some preferred variants of the present invention, the fluid supply into the first region takes place in countercurrent to the flow direction in the two adjacent regions.

[0087] The statements made above with regard to the reactors also apply mutatis mutandis to the process according to the invention.

[0088] In some preferred variants of the process according to the invention, the reaction (of the respective reactants) is carried out in a reactor according to the invention, a reactor system according to the invention or an automated reactor system according to the invention.

[0089] The precise conditions that must be set and / or maintained in the respective reactors, particularly pressure, temperature, and flow rates, depend on the desired reaction, i.e., in particular, the reactants, catalysts, and any auxiliary materials such as cofactors, cocatalysts, and the like. These will be selected or adjusted by the person skilled in the art depending on the planned reaction.

[0090] In some preferred variants of the process according to the invention, immobilized enzymes are used as catalyst in the first region arranged between two other regions.

[0091] In some preferred variants of the process according to the invention, the second and third supplied fluids are the same or the same and pure solvent, or contain one or more elements selected from the group consisting of the same or different solvent as the solvent in the first region, excipients, buffers, cocatalysts, cofactors, further reactants, other reactants and mixtures thereof.

[0092] In some preferred variants of the method according to the invention, a buffered enzymatic reaction takes place in the first zone. Buffer solution, preferably containing additional substances, is replenished via the inlets of the other zones, and any depleted buffer solution is removed via the outlets of the other zones. It is further preferred if all zones are filled with fluid during operation.

[0093] In some preferred variants of the present invention, the fluid supply is effected alternately into the two regions adjacent to the first region (i.e., the (two) adjacent regions are alternately supplied with or not supplied with fluid). The alternating supply can be effected by switching the supply at a predetermined interval, for example, every 30 seconds or every 5 minutes, or can be triggered by measured values, for example, a decreasing or increasing pH value, or can also be performed manually.

[0094] In preferred variants of the process according to the invention, a solution exchange via the semipermeable membranes is carried out in parallel with an enzymatic reaction taking place in the first zone. In further preferred variants of the process according to the invention, an auxiliary stream is additionally supplied to all or individual zones, preferably all zones adjacent to the first zone, at a further location. This additional auxiliary stream can be the same as or different from the other auxiliary streams.

[0095] This additional supply makes it possible, for example, to achieve further dilution or purification downstream (seen in the flow direction of the stream in the first area).

[0096] In some preferred variants of the present invention, these additional feed devices can be used to supply, for example, exchange buffers with an auxiliary agent for the reaction in the central region (the first region), while the feeds arranged at the ends of the reactor according to the invention can be used to supply, for example, exchange buffers or even just solvents for product purification and formulation in the product outlet region (the product discharge). Downstream of the additional feeds (viewed in the flow direction of the first region), a section can be provided in the central (first) region of the reactor according to the invention in which no immobilized catalyst is present, preferably no catalyst, especially if this configuration / process control is intended to purify the product in this section.For this purpose, a retaining device for the (immobilized) catalyst can be used in the first area, in particular at the level of the additional feed devices.

[0097] Last but not least, the present invention also relates to uses of the reactors according to the invention, the reactor systems according to the invention and the automated reactor systems according to the invention.

[0098] These uses preferably relate to the use for biocatalytic reactions, in particular for the production of products which require further reactants in addition to the main substrate, or products which are produced via an enzyme cascade with disturbing by-products.

[0099] The present invention makes it possible to selectively add additional reactants, which then pass through the semipermeable membrane into the reaction zone, or to remove byproducts that are transported out of the reaction zone through the semipermeable membranes. It should be noted that, while the term diffusion is occasionally used in the context of the present invention with reference to substances and their passage through the semipermeable membranes, this also includes flow-induced material flow (convective material flow), which incidentally generally accounts for the majority of the excipients or byproducts passing through the membranes.

[0100] Some preferred variants of the present invention relate to the use for the production of fine chemicals, preferably caprolactone by oxidation of cyclohexanone.

[0101] Further preferred variants of the present invention relate to the use for the production of oligosaccharides, in particular enzymatic production of oligosaccharides, glycans, glycoconjugates, therapeutic glycoproteins or hyaluronic acids.

[0102] Still other preferred variants of the present invention relate to the use for enzymatic reactions utilizing H2O2, in particular hydroxylations, epoxidations, halogenations or Baeyer-Villiger oxidations.

[0103] The present invention makes it possible to connect one or more reactors, in particular enzyme membrane reactors, sequentially with each other and thus to continuously carry out complex, multi-stage enzymatic cascades and thus to optimally synthesize new, sophisticated products.

[0104] The present invention makes it possible to obtain an EMR system that optimally fulfills the partial functions of enzyme immobilization and integrated product purification with continuous flow.

[0105] The advantages achievable with the present invention are achieved in some variants by

[0106] (i) the enzyme immobilisation takes place in / on / on particulate or fibrous support materials that can be pumped in the enzyme membrane reactor (EMR), and

[0107] (ii) by using the membrane module according to the invention with two parallel membranes. Accordingly, in some variants, this arrangement allows for the simultaneous, continuous supply of reactant streams and, decoupled therefrom, of auxiliary streams for product purification and / or the gradual variation of the reaction conditions over the length of the reactor.

[0108] A further advantage of the present invention is that additional purification, concentration or rebuffering of the product of enzymatic reactions can be carried out.

[0109] A further advantage of the present invention, particularly in the operation of reactor cascades, is that the buffer exchange required for optimal operation of a downstream reactor in a reactor cascade can be achieved in the discharge area of ​​an upstream reactor by adding an auxiliary material. This means that the intermediate product discharged from the upstream reactor can be adjusted by appropriately adding auxiliary materials so that it is already present in the optimal buffer (range) for the reaction in the next reactor and can be introduced directly into this reactor.

[0110] An advantage of the present invention is that, via a rinsing solution which is supplied to a second or third region, cofactors necessary for the reaction (further reactants for the reaction, such as oxygen or hydrogen peroxide) can be supplied to the (reaction) system and, in addition, components can be removed from the respective third or second region.

[0111] A further advantage of the present invention is that three flow zones are used. This makes it possible to feed the reactants into the first zone and convert them into product using an immobilized catalyst. From a second zone, components of a rinsing solution can, for example, pass through the membrane into the reaction zone in order to, for example, supply auxiliary substances or to bring about a change in the reaction medium. Undesired substances that have passed through the membrane can then, for example, be removed via a third zone. For example, one zone (the second) can be responsible for feeding in an auxiliary substance and another zone (the third) for removing the used auxiliary substance or contaminants. This was not possible with prior art reactors. In contrast to the prior art, where there were only two flow channels or-areas are used, three different flow zones are provided within the scope of the present invention. This enables, in addition to product formation in the first zone, a simultaneous, controlled supply and removal of an exchange solution for the metered provision of required additional reactants or for the conversion of the reaction solution in order to achieve optimal conditions for the necessary subsequent reactions in a reaction cascade, which was not possible in the prior art.

[0112] In other words, a particularly preferred embodiment of the present invention can also be described as follows:

[0113] The reactor according to the invention, which can also be referred to as a reactor module according to the invention or simply as a module according to the invention, comprises two side parts and a central part, all of which have a channel structure through which solutions can flow; the side parts and the central part are the regions defined above, with the central part being the first region. A membrane is arranged between each of the side parts and the central part, i.e. the module according to the invention has two parallel membranes that delimit the central channel (first region) at the top and bottom. The support materials with the immobilized catalysts, in particular enzymes, are located in this central channel. In addition, the feed solution with the dissolved substrate (reactant) enters the region of this central channel at one end, and the optionally purified product solution exits at the other end of the central channel.As they flow through the central channel (the first region), the supplied substrate molecules are continuously converted into the desired product by the immobilized catalysts, particularly enzymes. At the same time, the buffer (the buffer solution) of the central channel is replaced by new buffer (new buffer solution), which is also continuously supplied through a membrane bounding the central channel. This buffer originates from the fluid supply to one of the adjacent regions (into one of the side sections). The original buffer of the central channel region to be exchanged is simultaneously removed via the second bounding membrane (into the third region or the other side section). This results in an integrated, gradual exchange of the solution buffer in the central channel, in addition to product formation.In preferred variants, the gradual buffer exchange allows for the continuous addition of auxiliary substances which, for example, if added directly to the incoming substrate stream, would be harmful to the catalyst, especially an enzyme, due to their high local concentration (e.g., hydrogen peroxide in connection with the use of peroxygenases). Another important possibility of gradual buffer exchange within the scope of the present invention is the removal of undesirable reaction by-products (if they occur), which enables the target product to leave the reactor according to the invention already purified in an exchange buffer that is optimal for storage or a subsequent reaction.

[0114] In preferred variants of the present invention, the set (continuous) substrate flow in the first region (the middle channel) and the volume flow of the exchange buffer passing through the membranes are completely independent of each other and freely selectable; moreover, the volume flow exiting via the second membrane can be greater than the volume flow of new buffer entering through the first membrane, whereby, in addition to an exchange of the buffer solution, there is also a concentration of the product formed in the first region (the middle channel), which can often be advantageous.

[0115] A very great advantage of the present invention is that by using a countercurrent principle within the scope of the present invention, the buffer exchange process achieves very good efficiencies, i.e. the required quantities of new buffer for an exchange of more than 99% are only in the range of 2 to 5 times the volume flow of the middle channel (the first region). The countercurrent principle is achieved in that the exchange buffer enters at the end of the reactor according to the invention (module end) at which the solution exits the middle channel (the first region). As a result, in this variant of the present invention, the end of the middle flow channel is in contact with the inlet of the pure exchange buffer, which allows, for example, the last remnants of the unwanted by-product to be flushed out.

[0116] Another very advantageous feature of the reactor according to the invention (membrane module according to the invention) and its mode of operation, i.e., the process according to the invention, is the option of using an alternating flow direction through the membranes during continuous operation. Due to the orthogonal flow through the central channel by the incoming exchange buffer, an accumulation of particles (for example, incompletely fixed enzyme carriers or aggregates of substances) can occur on one side of the channel. To limit this accumulation and achieve a good distribution of the particles throughout the central channel, the system can cyclically switch the flow direction through the membrane without having to interrupt the pumping flow of the central channel.The switching can be done, for example, using multi-port valves, whereby the inflow, for example of exchange buffer, can be directed either to the upper or the lower part of the module (the areas adjacent to the first area).

[0117] In preferred embodiments, the reactor system according to the invention or the automated reactor system according to the invention comprises devices for independently controlling the substrate flow into the central flow region (the first region), the product flow exiting this region, and the volume flow of the exchange buffer (which would be directed into at least one adjacent region). Optionally, the flow direction (for example, switching from top to bottom to bottom) through the two membranes, and thus their respective roles (see above), can be switched during the process or during operation. This prevents the permanent formation of a concentration polarization or fouling layer due to substances accumulated on the membrane surface, such as in particular product and / or enzyme carrier particles.

[0118] An essential feature of the present invention is that the catalysts, in particular enzymes, are not fixed in or on the membranes (semipermeable membranes) (as in the case of the bi- or trilayer membranes of the prior art).

[0119] In particularly preferred embodiments of the present invention, i.e. the reactors according to the invention, the reactor systems according to the invention, the automated reactor systems according to the invention, the processes according to the invention, the catalysts, in particular enzymes, are not immobilized on or in the membranes, in particular semipermeable membranes.

[0120] It should be noted that this does not mean that the membranes cannot retain mobile catalyst particles (enzyme particles), especially if they are supported—because such particles can accumulate in front of / at the respective membrane during sustained flow—but rather that the catalyst particles are not bonded to the membrane, so that the particles detach from the respective membrane when the flow ceases or the flow direction reverses. In the context of the present invention, the catalyst particles, especially enzymes, are immobilized in the first region (i.e., the middle region / channel in the case of three layers arranged one above the other).

[0121] In preferred variants of the present invention, they are immobilized on (micro)particulate supports, also called microparticles, which are pumped as a suspension into the reactor according to the invention in a separate step. For this purpose, the reactor according to the invention then preferably has retention devices at its ends that retain the immobilized particles inside the first region. This variant enables a quick and uncomplicated replacement of the catalyst particles / enzyme supports when the catalysts / enzymes become increasingly inactive over the course of their operating life. For this purpose, the module does not have to be disassembled and no membranes have to be replaced. Additional structures, such as grid or sieve structures, can also be arranged in the first region to further immobilize the supported catalyst particles.

[0122] The possibility of a gradual exchange of the solution in which a catalytic, particularly enzymatic, reaction or reaction cascade takes place (i.e. by supplying solution / solvent into the areas adjacent to the first area and thus then through the membranes into the first area) has several advantages:

[0123] (i) For reactions that require additional excipients in addition to the substrate, such as cofactors or hydrogen peroxide, this excipient can be continuously added at exactly the required concentration. This is particularly important for substances that are toxic at higher concentrations or that inhibit enzymes. The possibility of continuous addition, independent of the substrate flow, is also advantageous in the case of poorly soluble excipients. Since an equivalent amount of excipient-depleted solution is simultaneously removed from the central channel region (the first region), the continuous addition of the exchange solution containing the excipient does not lead to a dilution of the product flow.

[0124] (ii) In addition to the supply of excipients, the product can be purified from impurities and converted into a desired solution for storage or subsequent reactions by supplying exchange solution in the product outlet area and simultaneously removing the original solution from the middle channel (the first area) into an adjacent area.

[0125] (iii) The independent control of the volume flows in the individual areas or for the individual areas makes it possible to remove more solution from the middle channel (the first area) than to supply it. This allows for an additional concentration (of the product flow) in addition to the solution exchange. For example: 1 ml / min is pumped into the middle channel (first area) and 1 ml / min of new buffer solution penetrates into the middle channel via the first membrane. At the same time, 1.5 ml / min is withdrawn via the second membrane. In this example, these 1.5 ml / min then contain 1 ml / min of used buffer solution as well as 0.5 ml / min of the solvent originally flowing in via the substrate solution. The product formed, however, is retained by the membrane. Due to the mass balance, the volume flow of the effluent product is reduced to 0.5 ml / min (1 + 1 - 1.5). From a substrate flow with, for example,According to this example, a 1 mol / L feed concentration results in a product stream with a concentration of 2 mol / L at a complete 1:1 conversion to product, since the solvent volume flowing out of the middle channel has been halved.

[0126] For example, the reactor module according to the invention can be configured in three parts, including two side parts through which, for example, a diafiltration buffer or permeate flows, and a central part containing the feed inlet and the retentate outlet. Each of the parts can have a flat flow channel (= area) with a cross-section that is optionally filled with a (3D-printed) grid that supports the membrane and guides the flow.

[0127] Depending on the particular application, the reactors according to the invention can have different dimensions; thus, the present invention is not limited to specific reactor sizes.

[0128] The present invention can be used or applied to all products produced biocatalytically. In particular, products that require additional reactants in addition to the main substrate, as well as products produced via enzyme cascades with disruptive byproducts. The individual components of the devices / systems according to the invention interact with one another in a conventional and known manner.

[0129] The various embodiments of the present invention, for example - but not exclusively - those of the various dependent claims or individual embodiments described in the figures, can be combined with one another in any desired manner, provided that such combinations do not contradict one another.

[0130] The embodiments of the present invention explained in more detail below with reference to the figures represent various preferred embodiments. Many of the features or embodiments shown in individual figures below can be combined with features and embodiments shown in other figures or the rest of the description, particularly where the features are described accordingly. Furthermore, the figures are not to be interpreted in a limiting manner and are not true to scale. Furthermore, the figures do not contain all features that conventional devices / systems have, but are reduced to the features essential to the present invention and its understanding. For example, screws, hoses, brackets, etc. are not shown or not shown in detail.

[0131] The same reference symbols / numbers mean the same or equivalent device parts.

[0132] Figure 1 illustrates a membrane reactor R according to the invention. This figure shows a variant according to the invention in which three fluid channels or regions 2, 2a, 3 are arranged one above the other. (Semipermeable) membranes 1, 1a are arranged between these. The immobilized catalyst, preferably enzyme, is arranged in the central region 3. Furthermore, flow directions for the individual streams are indicated (which do not necessarily follow the direction shown in all variants of the invention). In this figure, a substrate or substrate mixture stream S is fed in from the left, flows to the right through region 3 and leaves the reactor on the right as the product P- is discharged; here, as with the other streams in the figures, the plus sign indicates a feed and the minus sign indicates a discharge.A first auxiliary stream B, which can be a buffer solution, for example, is fed into the upper section 2 from the right; this is illustrated by the arrow with the solid line. The auxiliary stream B, or parts of it, flows through the semipermeable membrane 1 into the middle section 3 and then through the second semipermeable membrane 1a into the lower section 2a, from where the auxiliary stream exits the reactor to the left B-. The arrows shown with solid lines illustrate that these are the switched (used) inlets and outlets. The arrows shown with dashed lines mean alternative inlets and outlets. These can be switched (used) alternately with the others (with the solid lines). This means that auxiliary streams can be fed via the two sections 2 and 2a at different times. The respective supplied streams can be the same or different.It is therefore possible to either maintain a switching position and thus a flow direction through the membranes throughout the entire operation, or to change them during operation, especially cyclically.

[0133] Figure 2 shows a reactor R according to Figure 1, but here the flow path SW of an auxiliary stream B' is illustrated in a highly schematic manner, as it arises when the switching position for the feeds is cyclically changed during operation. As can be clearly seen, the auxiliary material B' initially flows to the left into region 2a. It then passes over the membrane 1a into the middle region 3 and is pushed back to the right by the opposite flow of the product stream S. However, since B' continues to be added, the flow of B', which is orthogonal to the flow from P, is not zero, so that B' reaches the other semipermeable membrane 1 and enters region 2. If the feed from B' to the lower region 2a is then stopped and switched to the upper region 2 instead, B' is essentially entrained and flows to the left again. When membrane 1 is reached, the process takes place in the opposite direction.A substance fed in with the second auxiliary stream B' will therefore follow a serpentine flow path SW in a process with alternating feed of B' into zones 2 and 2a until it exits on the left side of the reactor. Although this figure shows the exit in the other zone, this is not mandatory; the exit from the reactor can also occur in the same zone or in both zones 2 and 2a. Figure 3 shows the pH and UV signal curve plotted against the volume passed through in the outlet of the middle channel according to Example 1. The volume passed through the first zone (middle channel) (right axis) is plotted against the measured UV signal (vertical axis, left) or the simultaneously measured pH value (vertical axis, right).In the upper part of the diagram, the flow rates Q for the substrate flow (QF) and the buffer flow (QP) are each indicated by double arrows, which illustrates the range in which the given flow rate is present.

[0134] Figure 4 shows the pH and UV signal curve plotted against the volume passed through in the middle channel according to Example 2 and corresponds in principle, except for the data, to the diagram in Figure 3 (Example 1).

[0135] Figure 5 schematically shows the interconnection of two reactors R according to the invention to form a reactor system RS, in particular for an enzyme cascade. Substrate (mixture) S is fed from the left into the central region with immobilized catalyst 3 of the left-hand reactor Rimks. The product discharged from the first (left-hand) reactor is fed as new substrate (mixture) into the central region with immobilized catalyst 3 of the right-hand reactor R. reChts (for the sake of clarity, shown in the figure only as an arrow, without labeling) and then discharged as the final product P from the right reactor Rrechts to the far right. From the right, auxiliary materials B' are fed to the right reactor Rrechts and in the same way to the left reactor Ri in ks between the two reactors, the auxiliary materials B are fed in analogously. To the far left, waste (products / solution) W is discharged from the left reactor Rimks. Undesired by-products BP flushed out from the right reactor Rrechts can also be discharged between the reactors. The respective feed devices for the auxiliary materials to the reactor Ri inks and Rrechts each comprise (multiport) valves V, with which the supply to the upper and / or lower regions 2, 2a can be regulated, so that auxiliary materials can be metered into either the upper region, the lower region, or both regions; the discharge devices can also be equipped with such valves (shown in the figure only for the waste W but not for the by-products BP). Figure 6 shows a further variant of the reactors R according to the invention. The reactor R shown corresponds to the reactor R shown in Figure 2, with the difference that two further feed devices are provided, via which the auxiliary material streams B" and B'" can be fed.The flow path SW, which is already shown very schematically, does not change fundamentally; however, it can be somewhat "flattened" or "depressed" in the area of ​​the additional feeds, since the streams B" and B'" exert a certain counterpressure / lateral pressure; however, this is not illustrated for the sake of simplicity. These additional feed devices can be used to supply, for example, exchange buffers with an auxiliary substance B" for the reaction in the middle area (the first area), while the feeds for B and B' arranged at the ends of the reactor R can supply, for example, exchange buffers or even just solvents for product purification and formulation in the area of ​​the product outlet (the product discharge).Although it is not shown here in the figure for the sake of simplicity, a section can be provided to the right of the further feeds for B" or B'" in the middle (first) region of the reactor R in which no immobilized catalyst is present, preferably no catalyst, in particular if this constellation / process control is intended to purify the product in this section.

[0136] List of reference symbols:

[0137] R reactor according to the invention

[0138] RS reactor system

[0139] B (first) auxiliary material (stream) (solvent / diluent / buffer / co-

[0140] factors etc.)

[0141] B' second auxiliary substance (stream) (solvent / diluent / buffer / co-

[0142] factors etc.)

[0143] B" third auxiliary material (stream) (solvent / diluent / buffer / co-

[0144] factors etc.)

[0145] B'" fourth auxiliary material (stream) (solvent / diluent / buffer / co-

[0146] factors etc.)

[0147] S Substrate or substrate mixture (-stream)

[0148] P reaction product or conversion product (-stream)

[0149] BP Byproduct W Waste

[0150] V (multiport) valve / flow diverter

[0151] + in connection with a material flow means supply of a

[0152] Stream in connection with a material stream means the discharge of a stream, possibly depleted in (individual) ingredients and possibly enriched with other ingredients / conversion products from another stream

[0153] 1,1a (semipermeable) membrane

[0154] 2.2a Fluid channel (area)

[0155] 3 Fluid channel (area) with immobilized catalyst (enzyme)

[0156] QF flow rate product stream (feed)

[0157] Q P Flow rate buffer current

[0158] SW flow path auxiliary material

[0159] Example:

[0160] The invention will now be further explained with reference to the following non-limiting examples.

[0161] EXAMPLE 0 - REACTOR

[0162] A reactor module according to the invention was manufactured from essentially three parts, including a central part (corresponding to the first area) and two side parts (the other two areas). Each of the parts had a flat flow channel (= area) with a cross-section of approximately 2 x 20 mm 2 These channels were filled with (3D-printed) grids that supported the membranes and guided the flow. The grids had anisotropic structures, where in the x-direction (if the reactor is placed in a Cartesian coordinate system), the fluid flow passed through approximately 80 cubic chambers of approximately 3 x 3 x 2 mm.3 with narrow windows of about lxl mm 2 in the walls between the chambers; and the grid had short, completely open, square channels in the y-direction, with no obstacles to the fluid flow.

[0163] Between the central and adjacent parts (areas) were two membranes of the same type, both facing the central channel (first area) with their selective layer. Due to size exclusion, the protein entering with the feed could only move within the channel defined by the central part and the adjacent membranes (i.e., through the first area). Each membrane had an effective area of ​​2972 ​​mm. 2with a flow path length of 24.5 cm. For operation, the module was integrated into an FPLC system (Äkta Purifier UPC 10, GE Healthcare, Uppsala, Sweden) with an additional sampling pump and online detectors for UV / Vis adsorption, conductivity, and pH.

[0164] EXAMPLE 1 - ENZYME REACTION WITH CONTINUOUS ADDITION AND DISCHARGE OF AUXILIARY SOLUTIONS

[0165] In this example, the continuous enzymatic hydrolysis of an ester compound (para-nitrophenyl octanate - pNPA) to octanoic acid and para-nitrophenol was investigated using an esterase immobilized on microparticles. The hydrolysis of the ester produced an acid, which, at higher feed concentrations of the ester and only weakly buffered solutions, led to a pH reduction along the reactor during the reaction, which negatively affected enzyme activity. It was also shown that the direct addition of a high buffer concentration directly into the starting solution also had a negative impact on the productivity of the system.

[0166] Therefore, the possibility of a distributed buffer supply throughout the reactor with simultaneous removal of used buffer was demonstrated using the reactor according to the invention (a novel enzyme membrane reactor). Here, an inventive (enzyme) membrane reactor module was manufactured using 3D printing for the laboratory scale. The module consisted of a central section (the first area) and two side sections (the adjacent areas), each containing a flow channel measuring 50 x 20 x 2 mm, as shown in Fig. 1. 3Within the flow channels was a permeable support structure. Between the central section and the side sections was a semipermeable membrane, which separated the flow channels (areas) from each other. The support structure within the channels served not only to guide the flow but also to mechanically support the two membranes. The central channel of the module was filled with 0.2 g of enzyme-loaded microparticles (diameter approximately 30 pm) with an esterase loading of 20 mg enzyme per gram of microparticle (esterase of EC number 3.1.1.1 on PureCube Ni-IDA MagBeads).

[0167] For operation, the described inventive module was connected to an FPLC system (ÄKTA purifier UPC 10, GE Healthcare, Uppsala, Sweden). Additional sensors were also installed to measure pressure and accumulated masses of the inlet and outlet streams. This combination enabled detailed and precise control of the operating conditions as well as online monitoring of the key process parameters. The three piston pumps of the FPLC system guaranteed pressure-independent control of the inlet flow of the substrate solution, the outlet flow of the formed product, and the inlet flow of the fresh buffer solution for pH control. The outlet flow of the used buffer was determined automatically by the incompressibility of the aqueous medium and the mass balance.The sensors of the FPLC system also enabled online monitoring of the pH value and, via UV adsorption of para-nitrophenol, monitoring of the product concentration in the module effluent.

[0168] For continuous flow catalysis, a solution of 4 mM pNPA in TBS buffer (100 mM, pH 7.8) was first continuously pumped through the middle channel (first section) of the enzyme membrane reactor at a flow rate (QF) of 1 ml / min. Simultaneously, the product solution was also discharged at a flow rate (QP) of 1 ml / min via the outlet (fluid discharge device) of the middle channel. For continuous replenishment of the buffer substance, a TBS buffer solution (500 mM, pH 7.8) was pumped into the upper side section at 0.3 ml / min, and used buffer solution was discharged from the lower side section at the same volume flow rate. The flow direction of the buffer solution in the side sections was countercurrent to the flow direction of substrate and product in the middle channel (the first section) of the (enzyme membrane) reactor.

[0169] Fig. 3 shows the pH and UV signal curve plotted against the flow volume in the outlet (fluid discharge) of the middle channel (the first zone). After a calibration phase of 10 ml, the feed was switched to the substrate solution (pNPA) and simultaneously the buffer feed into the side panel (an adjacent zone) was started. As can be seen, after a start-up phase of approximately 10 minutes caused by the residence time in the reactor (and the feed line tubing), there was an increase in the product concentration, which was initially accompanied by a steep drop in pH. The reason for the initial pH drop is the lower flow rate and therefore the longer residence time of the buffer solution. However, approximately 15 ml after the start of the substrate feed, the buffer solution had displaced the water initially located in the tubing and side panels (adjacent zones) and penetrated through the membranes into the reaction zone.As a result, the desired pH increase occurred in this range until, at a throughput volume of about 33 ml, the optimal pH value of 7.8 for the reaction was reached again.

[0170] At a flow volume of 33 ml, the flow rate of the substrate supply (Q F ) was reduced to 0.75 ml / min in order to achieve higher substrate conversions and thus higher product concentrations through a slightly longer residence time. As expected, the reduction in the flow rate led to a significant increase in the UV signal. The higher substrate conversions led to a slight decrease in pH due to increased acid formation. However, the continuous supply of fresh buffer solution possible in the (enzyme membrane) module according to the invention enabled continuous operation in the optimal pH range of 7.8 even under these conditions.

[0171] EXAMPLE 2 - ENZYME REACTION WITH CONTINUOUS DEPLENISHMENT OF A BY-PRODUCT

[0172] In a further experiment, the continuous depletion of a contamination produced as a by-product was demonstrated. For this purpose, the inventive (enzyme membrane) reactor was first operated with the same substrate and buffer solutions at a flow rate of the substrate solution (Q F ) of 1 ml / min and a flow rate of the buffer solution (Q P) of 0.3 ml / min. The UV and pH curve initially resembles that described in Example 1 (a corresponding diagram is shown in Fig. 4). At the beginning of product formation, there was a brief pH reduction, which was quickly compensated for by the buffer flow fed through the membrane. As the reaction progressed, the para-nitrophenol formed along with octanoic acid was considered an undesirable by-product. In order to continuously remove this from the middle reaction zone (the first zone), the buffer solution to substrate feed volume flow ratio was increased to a value of 2 starting at a throughput volume of 33 ml. For this purpose, the flow rate of the substrate solution (Q F ) to 0.5 ml / min, which is the buffer solution (Q P), however, was increased to 1 ml / min. As expected, the countercurrent principle implemented within the (enzyme) reactor and the simultaneous addition and removal of fresh or contaminant-enriched buffer solution via two separate membranes resulted in the desired significant depletion of the model contaminants in the effluent, evident from the rapid and significant decrease in the UV signal. The decrease in the UV signal far exceeded what would result from simply diluting the para-nitrophenol by adding the buffer solution in the specified ratio.

[0173] It was shown by means of the examples that advantageous effects can be achieved with the reactors according to the invention or with the process according to the invention and that the objects underlying the present invention can be achieved.

Claims

Claims:

1. Reactor comprising or consisting of a) at least three flow regions arranged concentrically around each other or in layers one above the other, each separated from the other by membranes, b) at least two fluid supply devices, c) at least two fluid discharge devices, wherein the reactor is configured such that the flow direction in a first region arranged between two other regions is in the same direction as or opposite to the flow direction in the two other regions, wherein a fluid supply device and a fluid discharge device are connected to the first region, and the further fluid supply devices and fluid discharge devices are connected to the other regions, characterized in that immobilized catalyst particles are arranged in the first region arranged between the two other regions and the catalysts are enzymes.

2. Reactor according to claim 1, characterized in that the membranes are semipermeable membranes.

3. Reactor according to claim 1, characterized in that it has b) at least one fluid supply device per area, c) at least one fluid discharge device per area.

4. Reactor according to one of claims 1 to 3, characterized in that the catalysts are immobilized on support materials preferably selected from the group consisting of fibers, particles, in particular microparticulate particles, lattice structures, or combinations thereof. Reactor according to any one of claims 1 to 4, characterized in that the first region arranged between the two other regions has retention devices, preferably frits, for the catalyst particles at its fluid supply and discharge devices, wherein the retention devices are optionally openable or replaceable. Reactor according to any one of claims 1 to 5, characterized in that the respective fluid supply devices and the respective fluid discharge devices are configured to be switched and controlled independently of one another. Reactor system comprising at least two reactors according to any one of claims 1 to 6 and optionally at least one control device, in particular as or for an enzyme cascade.with a continuous buffer exchange between the reactors. A method for the catalytic conversion of a substrate in a reactor according to one of claims 1 to 6 or an automated reactor system according to claim 7, wherein, as a first fluid, a substrate solution is introduced into a reactor in and through a first region arranged between two other regions, independently of the fluid supplies to the other regions, preferably uniformly and continuously, and as a second and third fluid, a solution is introduced alternately into the other regions, with the same or opposite flow direction to the first fluid, which is based on the same solvent as the substrate solution or is miscible with this solvent, characterized in that an immobilized catalyst is arranged in the first region and the first region is separated from the other regions by membranes, preferably semipermeable membranes.which are impermeable to the substrate and the catalyst, are separated, and immobilized enzymes are used as catalysts in the first area arranged between two other areas.

9. The method according to claim 8, characterized in that the second and third supplied fluids are the same and are pure solvent, or contain one or more elements selected from the group consisting of the same or different solvent as the solvent in the first region, auxiliary substances, buffers, cofactors, cocatalysts, further reactants, other reactants and mixtures thereof.

10. Method according to one of claims 8 or 9, characterized in that a buffered enzymatic reaction takes place in the first area, buffer solution, preferably containing further substances, is supplied via the feeds of the other areas and optionally depleted buffer solution is removed via the discharges of the other areas, wherein, further preferably, all areas are filled with fluid during operation.

11. Method according to one of claims 8 to 10, characterized in that fluid is supplied alternately to a first region and to a second region adjacent to the first region.

12. Use of a reactor according to any one of claims 1 to 6 or of an automated reactor system according to claim 7 for biocatalytic reactions, preferably for the production of products that require additional reactants besides the main substrate, or products that are produced via an enzyme cascade with interfering byproducts, in particular i) for the production of fine chemicals, preferably caprolactone by Oxidation of cyclohexanone, ii) for the production of oligosaccharides, glycans, glycoconjugates, therapeutic glycoproteins or hyaluronic acids, or iii) for enzymatic reactions utilizing H2O2, in particular Hydroxylations, epoxidations, halogenations or Baeyer-Villiger oxidations.

Images