Trickle Bed Reactor

Abstract

The trickle bed reactor comprises a plurality of catalyst beds connected in series, each with a gradually increasing catalyst mass from upstream to downstream, and a plurality of heat exchangers, each disposed between two of the catalyst beds, and the heat exchangers do not exchange heat with the exterior surface of the vessel housing the catalyst beds.

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 032,780, entitled "Trickle Bed Reactor," filed June 1, 2020, the entire contents of which are incorporated herein by reference for all purposes.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable

[0003] Field The present disclosure relates to trickle bed reactors.

[0004] background A trickle bed reactor is a solid-liquid-gas contactor in which a liquid stream flows downward through a catalyst bed with a pressure differential acting as the driving force. The fluid flows between the catalyst particles, forming a thin film, rivulets, or droplets. A gas stream either co-flows with the liquid or counter-flows through the catalyst bed. Trickle bed reactors are primarily operated in continuous mode, but are also sometimes used in semi-batch processes.

[0005] Trickle bed reactors (TBRs) are named for their operation in trickle flow mode, which is characterized by a steady, continuous flow of liquid and gas through the catalyst bed, similar to laminar flow in single-phase systems. The mode in which the system operates depends on the velocities of the liquid and gas flows. Trickle bed reactors can also operate in pulsating, droplet, or bubble flow modes, depending on the application.

[0006] Three-phase reactions are commonly carried out using continuous stirred tank reactors designed in either a continuous stirred tank or plug flow reactor configuration and operated as plug flow or slurry reactors. Trickle bed reactors are typically the least expensive, most scalable, and best-performing systems known. The plug flow reactor configuration is also superior to the continuous stirred tank reactor configuration, allowing for high conversions with high selectivity and minimal reactor operating volume. Summary of the Invention

[0007] Disclosed herein is a trickle-bed reactor comprising a plurality of catalyst beds connected in series, each having a catalyst mass gradually increasing from upstream to downstream, and a plurality of heat exchangers, each disposed between two catalyst beds, each of which does not exchange heat with the exterior surface of the vessel housing the catalyst beds.

[0008] Also disclosed herein is a method of operating a trickle-bed reactor, comprising passing one or more reactants through a plurality of catalyst beds connected in series and having a gradually increasing mass of catalyst from upstream to downstream. The trickle-bed reactor has a plurality of heat exchangers, each disposed between two catalyst beds. Each heat exchanger does not exchange heat with the exterior surface of the vessel containing the catalyst beds. [Brief explanation of the drawings]

[0009] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following brief description taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals refer to like parts, and wherein:

[0010] [Figure 1] FIG. 1 is a schematic diagram of a reactor configuration according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of a reactor configuration according to one embodiment of the present disclosure. [Figure 3] FIG. 3 is a graph showing conversion versus reactor length for the kinetic modeling performed in Examples 1-3. [Figure 4] FIG. 4 is a graph showing reactor length versus productivity in the kinetic modeling performed in Examples 1-3. DETAILED DESCRIPTION OF THE INVENTION

[0011] Conventional fixed-bed reactors for exothermic three-phase reactions consist of dozens to hundreds of 1- to 2-inch-diameter parallel tubes surrounded by a pressurized shell containing a heat transfer fluid. This configuration has high capital costs, does not perform well for three-phase reactions, and is challenging to control for three-phase reactions that exhibit significant exothermic or endothermic properties. Minute differences in tube-to-tube solid packing density result in uneven distribution of continuous gas and dispersed liquid flow rates through each parallel tube, especially when more tubes are added in parallel to enlarge the reactor. This can result in dead zones where less productive catalysts exist and hot zones where more productive catalysts exist. In addition, poorly dispersed liquid flow can affect catalyst selectivity and stability. Because each tube is surrounded by a shell containing a heat transfer fluid, it is impractical to introduce gas or liquid into the tubes along the reaction axis, especially when there are dozens or hundreds of tubes. Furthermore, shell-and-tube designs are very expensive in terms of total installed capital. Therefore, an improved reactor configuration is currently needed.

[0012] Apparatus and method aspects are disclosed herein that enable relatively low-cost trickle-bed reactors operating in trickle-flow mode (e.g., continuous gas, dispersed liquid) to adequately handle the exothermic or endothermic heat of a reaction without the use of parallel tubes packed with particles and coated with a shell of heat transfer fluid. Such advantages are realized while accommodating reactions that involve continuous or periodic introduction of gaseous and / or liquid additives at different locations in the reaction coordinate system.

[0013] As used herein, the terms "line," "conduit," and "stream" refer to a physical structure (e.g., piping) through which gases, liquids, solids, or combinations thereof flow, and are used interchangeably.

[0014] As used herein, the term "reaction coordinate" refers to the reaction path along which a reaction mixture flows in the disclosed apparatus and methods. A point on the reaction coordinate may have a reaction mixture with a specific composition that differs from other points. For example, the starting point of the reaction coordinate may contain 100% reactants, inert transport materials, or both, while the end point of the reaction coordinate may contain products, unreacted reactants, by-products, inert transport materials, or combinations thereof. Alternatively, the starting point of the reaction coordinate may contain reactants, inert transport materials, recycled products from a previous reaction, or combinations thereof.

[0015] As used herein, the term "reaction mixture" refers to a composition contained in an apparatus or process at a particular location within the apparatus or at a particular point in the reaction coordinate. For example, the reaction mixture upon entering the apparatus or process may contain 100% reactants, inert transport materials, or both, and the reaction mixture upon exiting the apparatus or process may contain products, unreacted reactants, by-products, inert transport materials, or combinations thereof.

[0016] FIG. 1 shows a process flow diagram of one embodiment of a trickle bed apparatus 100. The reaction mixture enters apparatus 100 via line 110a. Typically, the reaction mixture flows through lines 110a-g, 111a-g, and 112a-f, catalyst beds 120a-g, and heat exchangers 113a-g. That is, gas, liquid, and solids flow simultaneously through apparatus 100. For exothermic reactions, heat exchangers 113b-g are configured to cool the reaction mixture therethrough. For endothermic reactions, heat exchangers 113b-g are configured to heat the reaction mixture therethrough. In one embodiment, heat exchanger 113a regulates the temperature of the reaction mixture so that the reaction begins in the initial catalyst bed 120a. For various reactions, this may involve heating or cooling the reaction mixture to the desired reaction temperature at the inlet leading to the reactor. The liquid additive flows through line 130, which splits into lines 130a-f to introduce the liquid additive into lines 111a-f, respectively. The gaseous additive flows through line 140, which splits into lines 140a-f to introduce the gaseous additive into lines 110b-g, respectively. The liquid and gas addition rates in these lines are automatically controlled by various measurements. The reaction mixture, including products, unreacted reactants, inerts, and by-products, exits apparatus 100 through line 111g.

[0017] In FIG. 1 , gaseous additives are selectively introduced into one or more lines 110b-g via lines 140a-f at positions between heat exchangers 113b-g and corresponding catalyst beds 120b-g. The amount of gas selectively introduced via lines 140a-f may be the same for each line or may be selectively varied depending on the user and / or the objectives of the process. Liquid additives are selectively introduced into corresponding lines 111a-f via one or more lines 130a-f at positions between catalyst beds 120a-g and corresponding heat exchangers 113b-g (e.g., upstream of the heat exchangers), e.g., for exothermic reactions. Alternatively, liquid additives are contemplated to be selectively introduced into lines 110b-g via one or more lines 130a-f at positions between heat exchangers 113b-g and corresponding catalyst beds 120b-g (e.g., downstream of the heat exchangers), e.g., for endothermic reactions. The amount of liquid additive selectively introduced via lines 130a-f may be the same for each line or may be selectively varied by introduction location depending on the user and / or process objectives.

[0018] As shown in Figure 1, there are seven catalyst beds 120a-g connected in series. The amount of catalyst in catalyst bed 120a is less than the amount of catalyst in catalyst bed 120b, which is less than the amount of catalyst in catalyst bed 120c, which is less than the amount of catalyst in catalyst bed 120d, which is less than the amount of catalyst in catalyst bed 120e, which is less than the amount of catalyst in catalyst bed 120f, which is less than the amount of catalyst in catalyst bed 120g. That is, the mass of catalyst gradually increases downstream in catalyst beds 120a-g. In general, the mass of catalyst in catalyst beds 120a-g gradually increases downstream by any method. For example, using a larger diameter vessel to house the catalyst beds while maintaining the same bed lengths (e.g., catalyst bed 120b has the same length as catalyst bed 120a but a larger diameter than catalyst bed 120a), using longer catalyst beds while maintaining the same diameter (e.g., catalyst bed 120b has the same diameter as catalyst bed 120a but is longer than catalyst bed 120a), decreasing the amount of inert solid material mixed with the solid catalyst downstream in catalyst beds that all have the same dimensions (e.g., catalyst beds 120a and 120b have the same dimensions, but catalyst bed 120a contains 90 wt. % inert solid material mixed with the solid catalyst and 10 wt. % catalyst, while catalyst bed 120b contains 80 wt. % inert solid material mixed with the solid catalyst and 20 wt. % catalyst), or combinations thereof. Other suitable techniques for increasing the mass of catalyst downstream relative to the flow of the reaction mixture can also be used. In some embodiments, the amount of catalyst in the catalyst bed is from about 1% to about 85%, or from about 1% to about 70%, or from about 75% to about 85%, or about 85%, based on the total weight of the catalyst. In one or more embodiments, the amount of catalyst increases between about 100 kg and about 1,000,000 kg.

[0019] Although FIG. 1 illustrates seven reactor vessels, catalyst beds 120a-g may be implemented as fixed catalyst beds contained in any number of reactor vessels, for example, 1, 2, 3, 4, 5, 6, 7 or more vessels.

[0020] Heat removal using trickle-bed reactors of the type disclosed herein can be accomplished by heat exchangers 113a-g fluidly connected to the catalyst beds 120a-g. This mechanism of heat removal is distinctive to trickle-bed reactor configurations that include a single shell containing a heat transfer fluid that surrounds a vessel containing the catalyst. In some embodiments, the catalyst beds 120a-g can be adiabatic reactor sections in which heat exchange occurs only between the catalyst beds 120a-g.

[0021] FIG. 2 shows another process flow diagram of one embodiment of a trickle bed apparatus 200. In FIG. 2, there are nine catalyst beds 120a-120i. Six catalyst beds 120a-f are contained in a fixed bed configuration within a first vessel 201, and three catalyst beds 120g-i are contained in a fixed bed configuration within a second vessel 202. The second vessel 202 is located downstream from the first vessel 201, with the inlet of the second vessel 201 fluidly connected to the outlet of the first vessel 201. While shown with two vessels 201 and 202, generally any number of vessels can be used. Furthermore, while shown with a total of nine catalyst beds, more or fewer catalyst beds can be used as needed to meet one or more user and / or process objectives.

[0022] In vessels 201 and 202, the catalyst beds are spaced apart from one another in a vertical arrangement. Typically, the space between adjacent catalyst beds can be any suitable length. The gas phase flows downstream between the catalyst beds in vessels 201 and 202 and into the next catalyst bed, while liquid is removed from each catalyst bed 120a-120h in a corresponding line 111a-h. Between each catalyst bed, the liquid is cooled in the case of an exothermic reaction or heated in the case of an endothermic reaction.

[0023] In FIG. 2 , gaseous additives are selectively introduced into first vessel 201 via lines 140a-f located between two of catalyst beds 120a-f. The amount of gas selectively introduced via lines 140a-f may be the same for each line or may be selectively varied depending on the user and / or process objectives. During operation, the amount of gas added to these lines may be automatically controlled based on online process measurements. For example, in the case of an exothermic reaction, liquid additives are selectively introduced into corresponding lines 111a-e via lines 130a-e at a location between catalyst bed 120a-f and the corresponding heat exchanger 113b-f (e.g., upstream of the heat exchanger). Alternatively, for example, in the case of an endothermic reaction, liquid additives are selectively introduced into corresponding lines 110b-f via lines 130a-e at a location between heat exchanger 113b-f and the corresponding catalyst bed 120b-f (e.g., downstream of the heat exchanger). The amount of liquid additive selectively introduced via lines 130a-e may be the same for each line or may be selectively varied at different points depending on the user and / or process objectives. During operation, the amount of liquid added to these lines may be automatically controlled based on online process measurements.

[0024] In some embodiments, the gaseous additive may not be introduced into second vessel 202. For example, in the case of an exothermic reaction, the liquid additive may be selectively introduced into corresponding line 111g-h via line 130g-h at a location between catalyst bed 120g-f and corresponding heat exchanger 113h-i (e.g., upstream of the heat exchanger). Alternatively, it is understood that for example, in the case of an endothermic reaction, the liquid additive may be selectively introduced into corresponding line 110g-h via line 130g-h at a location between heat exchanger 113h-i and corresponding catalyst bed 120h-i (e.g., downstream of the heat exchanger).

[0025] 2 illustrates the flow of the reaction mixture from first vessel 201 to second vessel 202 via gas product line 203a and liquid / solid product line 203b. Pump 115 may be used to provide the motive force for the liquid flow from first vessel 201 to second vessel 202. Pump 115 may be disposed along liquid / solid product line 203b. A liquid additive is introduced into liquid / solid product line 203 via line 130f, forming line 203c. The combined liquid line 203c is then heat exchanged (heated in the case of an endothermic reaction or cooled in the case of an exothermic reaction) in heat exchanger 113g. The gas product in gas product line 203a is optionally compressed in compressor 204 and then combined with combined liquid line 203c to form inlet line 203d containing the gas / solid / liquid reaction mixture for introduction into second reactor vessel 202.

[0026] When two vessels 201, 202 are used, liquid additive line 130 initially splits into two sections 130x, 130y, with section 130x splitting into lines 130a-f for liquid introduction as described above and section 130y splitting into lines 130g-h for liquid introduction as described above.

[0027] It is understood that embodiments of the disclosed trickle-bed reactor configurations can also be used for exothermic or endothermic chemical reactions that have a large heat output or endothermic capacity. In one aspect, a trickle-bed reactor of the type disclosed herein is used to carry out a liquid-phase hydrogenation or liquid-phase oxidation. In another aspect, a trickle-bed reactor of the type disclosed herein is used to carry out a series of reactions in sequence or succession. For example, a trickle-bed reactor of the type disclosed herein may be used to carry out a dehydrogenation reaction followed by an oxidation reaction.

[0028] In trickle-bed reactors of the type disclosed herein, the gas phase may contain air or hydrogen, and the liquid phase may be aqueous or non-aqueous. In some embodiments, the solid phase contains catalyst particles having a particle size of about 0.4 mm to about 2 mm, or about 0.6 mm to about 1.8 mm, or about 0.8 mm to about 1.6 mm. In some embodiments, reactions carried out in trickle-bed reactors of the type disclosed herein have an exothermic or endothermic value greater than or less than about 100 kJ / mol. In some embodiments, the products of reactions in trickle-bed reactors are intermediates in the reaction coordinate, and gas and / or liquid additives are added along the reaction coordinate. The rates of liquid and gas additives along the reaction coordinate can be varied based on online process measurements such as pH or gas consumption.

[0029] One example is the exothermic catalytic oxidation of sodium gluconate to sodium glucarate. In such reactions, trickle-bed reactors of the type disclosed herein (e.g., trickle-bed reactor 100 or 200) are one or more vertically oriented vessels with catalyst beds stacked on top of each other and increasing in size downstream. Operating pressures for trickle-bed reactors of the type disclosed herein range from about 50 PSI to about 100,000 PSI.

[0030] In another embodiment, the operating pressure of a trickle-bed reactor of the type disclosed herein is from about 500 psig to about 1000 psig, or from about 600 psig to about 900 psig, or from about 700 psig to about 800 psig. In a further embodiment, the operating temperature for each catalyst bed in a trickle-bed reactor of the type disclosed herein ranges from about 25° C. to about 350° C., or from about 60° C. to about 120° C., or from about 80° C. to about 110° C., or from about 90° C. to about 100° C. In one embodiment, the temperature is controlled by external heat exchangers 113a-g (FIG. 1) or 113a-i (FIG. 2). A feed of sodium gluconate, water, and dissolved air may be preheated in heat exchanger 113a and fed to the top of first catalyst bed 120a.

[0031] The reactor configurations described herein offer the potential for improved reactant conversion and selectivity while suppressing potential by-products. This occurs, at least in part, due to the design's ability to increase productivity in the early catalyst beds, where reactants are primarily present and no products are present, while reducing productivity in the later catalyst beds, where side reactions between reactants and products may occur. It should also be appreciated that, as described herein, this result can be achieved without the need for external cooling jackets or shell and piping designs. Thus, the configuration and design embodiments described herein improve conversion and selectivity within the reactor with a relatively simple reactor design.

[0032] In some embodiments, the reactor system of the type disclosed herein is a trickle-bed reactor that does not have a shell-and-tube design. Compared to trickle-bed reactors with a shell-and-tube design, trickle-bed reactors of the type disclosed herein have lower operating costs. In some embodiments, trickle-bed reactors of the type disclosed herein allow for easy introduction of gases and / or liquids along the length of the reactor. In such embodiments, the introduced gases and / or liquids are uniformly mixed before introduction. In some embodiments, trickle-bed reactors of the type disclosed herein can control the exothermicity of the reaction without covering the reactor during the reaction. In such embodiments, control of the exothermicity of the reaction may be achieved by an external heat exchanger. In some embodiments, trickle-bed reactors of the type disclosed herein have improved conversion efficiencies of about 5% to about 99% compared to trickle-bed reactors with a core-shell configuration. In some embodiments, trickle-bed reactors of the type disclosed herein have improved selectivity of about 20% to about 90% compared to trickle-bed reactors with a core-shell configuration.

[0033] In certain embodiments, trickle bed reactors of the type disclosed herein are readily scalable. For example, a trickle bed reactor of the type disclosed herein can be used to produce approximately one kiloton (kt / a) per year. )mosquito Approximately 100,000 kt a、or from about 10 kJ / mol to about 1,000 kJ / mol, or from about 100 kJ / mol to about 500 kJ / mol of reactant material. The apparatus and methods disclosed herein are suitable for three-phase reactions with large exothermic or endothermic values. For example, the exothermic or endothermic value is about 100 kJ / mol or less, or from about 10 kJ / mol to about 400 kJ / mol, or from about 10 to about 200 kJ / mol, or from about 200 to about 400 kJ / mol. In other embodiments, the exothermic or endothermic value is about 100 kJ / mol or more, or from about 10 kJ / mol to about 400 kJ / mol, or from about 10 to about 200 kJ / mol, or from about 200 to about 400 kJ / mol. In yet other embodiments, the output of a trickle-bed reactor is an intermediate in a reaction coordinate. In some embodiments, trickle-bed reactors of the type disclosed herein can introduce gaseous and / or liquid additives into the pathway of the reaction coordinate. For example, liquid additives such as acids, bases, or buffer compositions can be administered after each reaction zone to control the operating pH, thereby controlling the pH along the reaction coordinate and improving overall reactivity. Gas additives can also be automatically added after each zone to control reactivity along the reaction coordinate.

[0034] Additional Disclosures The following is provided as additional disclosure for combinations of features and aspects of the present disclosure.

[0035] The first embodiment is a trickle-bed reactor comprising a plurality of catalyst beds connected in series, each having a catalyst mass gradually increasing from upstream to downstream, and a plurality of heat exchangers, each of which is disposed between two catalyst beds, and which does not exchange heat with the exterior surface of the vessel housing the catalyst beds.

[0036] A second embodiment is the trickle bed reactor of the first embodiment, wherein the multiple catalyst beds are not in a shell-and-tube heat exchange configuration.

[0037] A third embodiment is the trickle bed reactor of any of the first to third embodiments, further comprising a gaseous additive line in fluid communication with at least one catalyst bed or a liquid additive line in fluid communication with at least one catalyst bed.

[0038] A fourth embodiment is the trickle bed reactor of any of the first to third embodiments, wherein the productivity of the multiple catalyst beds gradually decreases from upstream to downstream, and the initial productivity of the first catalyst bed is 5 to 10 times the final productivity of the last catalyst bed.

[0039] A fifth embodiment is the trickle bed reactor of any of the first to fourth embodiments, further comprising a first reactor vessel containing a first group of catalyst beds and a second reactor vessel containing a second group of catalyst beds, the inlet of the second reactor vessel being fluidly connected to the product outlet of the first reactor vessel.

[0040] A sixth embodiment is the trickle bed reactor of the fifth embodiment, wherein the product outlet of the first reactor vessel has a gas outlet line and a liquid outlet line, and the trickle bed reactor further comprises a compressor disposed along the gas outlet line for compressing the gas product discharged from the first reactor vessel, and a pump disposed along the liquid outlet line for pumping the liquid product discharged from the second reactor vessel to the second reactor vessel, wherein the compressed gas product is mixed with the liquid product before the liquid product and the gas product are introduced into the second reactor vessel.

[0041] A seventh embodiment is the trickle bed reactor of any of the first to sixth embodiments, further comprising a feed line containing reactants and fluidly connected to a first catalyst bed of the plurality of catalyst beds, the plurality of catalyst beds being configured to convert the reactants to one or more products, and a discharge line fluidly connected to a last catalyst bed of the plurality of catalyst beds.

[0042] An eighth embodiment is a method of operating a trickle bed reactor, the method comprising passing one or more reactants through a plurality of catalyst beds connected in series and having a gradually increasing mass of catalyst from upstream to downstream, the trickle bed reactor having a plurality of heat exchangers, each heat exchanger being disposed between two respective catalyst beds, and each heat exchanger not exchanging heat with an exterior surface of a vessel containing the catalyst beds.

[0043] A ninth embodiment is the method of the eighth embodiment, wherein the trickle bed reactor has a gas additive line fluidly connected to at least one of the plurality of catalyst beds or a liquid additive line fluidly connected to at least one of the plurality of catalyst beds.

[0044] A tenth embodiment is the method of the eighth or ninth embodiment, wherein the reactants comprise sodium gluconate and the catalyst bed comprises an oxidation catalyst.

[0045] An eleventh embodiment is the method of the tenth embodiment, wherein at least a portion of the reactants form an oxidation product.

[0046] A twelfth embodiment is the method of the eleventh embodiment, wherein the oxidation product comprises sodium glucarate.

[0047] A thirteenth embodiment is the method of any of the eighth through twelfth embodiments, including introducing additional sodium gluconate into the trickle-bed reactor via the liquid additive line.

[0048] A fourteenth embodiment is the process of any of the eighth to thirteenth embodiments, wherein the trickle bed reactor does not have a core-shell configuration.

[0049] A fifteenth embodiment is the method of any of the eighth through fourteenth embodiments, wherein the mass of the catalyst increases by between about 100 kg and about 1,000,000 kg.

[0050] A sixteenth embodiment is the method of any of the eighth through fifteenth embodiments, wherein the operating pressure of the trickle bed reactor is from about 50 PSI to about 100,000 PSI.

[0051] A seventeenth embodiment is the method of any of the eighth to sixteenth embodiments, wherein the operating temperature of the trickle bed reactor is from about 25°C to about 350°C.

[0052] An eighteenth embodiment is the method of any of the eighth to seventeenth embodiments, wherein the trickle bed reactor has an improved conversion efficiency of about 5% to about 99% compared to a trickle bed reactor with a core-shell configuration.

[0053] A nineteenth embodiment is the process of any of the eighth to eighteenth embodiments, wherein the trickle bed reactor has an improvement in selectivity of about 20% to about 90% compared to a trickle bed reactor of core-shell configuration.

[0054] A twentieth aspect is the method of any of the eighth to nineteenth aspects, wherein the trickle bed reactor has a production rate of about one kilogram per year. Hmm? For about 100,000 years, In be. [Example]

[0055] Having generally described the invention of this disclosure, the following examples are presented to illustrate specific embodiments of the invention and to demonstrate its practice and advantages. It is understood that the examples are presented for illustrative purposes and are not intended to limit the scope of the specification or claims in any aspect.

[0056] To demonstrate the benefits of the trickle-bed reactor configuration of the present disclosure, a kinetic model was developed for the liquid-phase oxidation of sodium gluconate, calcium gluconate, glucoheptonic acid, sucrose, maltose, fructose, glucuronic acid, guluronic acid, glucose, glucodialdose, and other similar organic compounds using air and water over a core-shell Au / C extrudate catalyst. The initial reaction mixture was mixed with a gas phase of compressed air (16% oxygen by volume) and contained a liquid-phase composition of 20% organic compounds by weight and 80% water by weight. The reaction is highly exothermic (approximately 500 kJ / mol) and requires intermediate dosing of caustic (NaOH) to drive the reaction along the desired reaction coordinate. The caustic addition rate can be preset or automatically controlled depending on the pH of the process fluid based on the desired reaction scheme. 50 g of Au / C catalyst (0.3 wt. % loading on 1.5 × 3 mm trilobal carbon extrudates) was loaded into the catalyst bed of a downflow trickle-bed reactor in 3 / 4-inch OD tubing. Glass spheres with diameters of 200 μm or less were used to fill the space between the reactor wall and the extrudates. Kinetic models were constructed by conducting metal oxidation of these organic compounds at different reactant concentrations, flow rates, conversions, O2 to organic compound feed ratios, O2 to N2 ratios, temperatures, pressures, and excess caustic concentrations. The equation of state for dissolved oxygen concentration was taken from Desmond Tromans, Hydrometallurgy 48 (1998) 327-342.

[0057] The total catalyst charge in each of the following examples is equivalent to an ideal trickle bed reactor and a trickle bed reactor with the same amount of catalyst in each catalyst bed, as compared to the inventive trickle bed reactor configuration disclosed herein.

[0058] Example 1 Example 1 is a kinetic model of an idealized isothermal fixed-bed plug flow reactor in which caustic and ambient air are continuously introduced at infinitesimal points along the reaction coordinate. While such an idealized plug flow reactor cannot be constructed in practice, it is useful for comparison with the trickle-bed configuration of the invention disclosed herein. The design equations used in the kinetic model of the idealized isothermal plug flow reactor are as follows:

number

[0059] Example 2 Example 2 is a kinetic model of five catalyst beds connected in series with a total catalyst load equal to that of Example 1, with cooling of the reaction mixture between the catalyst beds. The design equations used for the kinetic model of this comparative trickle-bed reactor are as follows:

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number

number

[0060] Example 3 Example 3 is an associated kinetic model of nine catalyst beds connected in series with cooling of the reaction mixture between the catalyst beds, a configuration similar to that shown in apparatus 100 of FIG. 1, except that there are nine catalyst beds in Example 3 instead of the seven catalyst beds shown in FIG. 1. The catalyst beds in Example 3 have successively increasing catalyst masses from upstream to downstream, similar to the pattern shown in catalyst beds 120a-g in FIG. 1. The total catalyst loading in Example 3 is equal to the catalyst loading in Examples 1 and 2. The design equations used in the kinetic model of the trickle-bed reactor of the present invention are as follows:

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number

number

[0061] 3 is a graph of conversion versus reactor length for the kinetic models implemented in Examples 1 to 3. Curve 301 is the ideal isothermal plug flow reactor of Example 1, curve 302 is the trickle bed reactor with five equal-sized catalyst beds of Example 2, and curve 303 is the trickle bed reactor with nine catalyst beds of Example 3.

[0062] Curve 301 for an ideal isothermal plug flow reactor is not feasible and is a theoretical setup, but the theoretical setup is useful for comparison with the conventional trickle-bed reactor configuration of Example 2 and the trickle-bed reactor configuration according to the present invention of Example 3.

[0063] Curve 302 includes five smaller curves 302a-e, one for each of the five equal-sized catalyst beds in the conventional trickle-bed reactor of Example 2. The low conversion in curves 302a-b is due to the fact that the first two catalyst beds in the reactor are too large to handle the heat generated by the reaction. Therefore, the first two catalyst beds must operate at a lower temperature than ideal to prevent the cumulative heat generation from causing thermal runaway. In other words, the tradeoff for being able to operate five equal-sized catalyst beds without causing runaway reactions in the upstream catalyst beds is that the catalyst beds must be run at a lower temperature, sacrificing conversion. The gap between curve 302 and the ideal curve 301 represents the difference between the conversion actually achievable using a trickle-bed reactor loaded with the same amount of catalyst and the ideal setting.

[0064] Curve 303 includes nine smaller curves 303a-i, one for each of the nine catalyst beds in the inventive trickle-bed reactor of Example 3. Curves 303a-i show that the first small catalyst beds in the reactor (e.g., curves 303a-f) have higher conversion rates than the conventional trickle-bed reactor configuration of curve 302. The upstream catalyst beds were able to operate at higher temperatures while controlling the exothermic heat of the reaction. The higher the operating temperature of the upstream catalyst beds, the higher the conversion rate, which is closer to that of an ideal isothermal plug flow reactor, curve 301. The gap between curve 303 and the ideal curve 301 indicates that the conversion rate actually achievable using the inventive trickle-bed configuration disclosed herein is closer to the ideal setting than that of a conventional trickle-bed reactor configuration. Considering the need for ideal operation, the conversion rate achievable with the inventive catalyst bed configuration is an advantage over the conventional catalyst bed configuration.

[0065] 4 is a graph of reactor length versus productivity for the kinetic models implemented in Examples 1 to 3. Curve 401 is for the ideal isothermal plug flow reactor of Example 1. Curves 402a-e correspond to each of the five equal-sized catalyst beds in a conventional trickle-bed reactor of Example 2. Curves 403a-i correspond to each of the nine catalyst beds in a trickle-bed reactor according to the invention of Example 3.

[0066] The ideal isothermal plug flow reactor curve 401 is not realizable and is a theoretical design, but the theoretical design is useful for comparison with the conventional trickle-bed reactor configuration of Example 2 and the trickle-bed reactor configuration according to the present invention of Example 3.

[0067] Curves 402a-e show the productivity of each of the five equal-sized catalyst beds in the conventional trickle-bed reactor of Example 2. The low productivity in curves 402a-b is due to the fact that the first two catalyst beds in the reactor are too large to handle the heat generated by the reaction. Therefore, the first two catalyst beds must operate at a lower temperature to prevent the cumulative heat generation from causing thermal runaway. In other words, the tradeoff for being able to operate five equal-sized catalyst beds without causing runaway reactions in the upstream catalyst beds is the need to operate at a lower temperature, resulting in a sacrifice in productivity. The gap between curves 402a-e and the ideal curve 401 represents the difference between the ideal setup and the productivity that can actually be achieved using a trickle-bed reactor loaded with the same amount of catalyst. 0 g of productivity converted g -1 metal h -1 The periodic drop to corresponds to cooling between catalyst beds.

[0068] Curves 403a-i show the productivity of each of the nine catalyst beds in the trickle-bed reactor configuration of Example 3 according to the present invention. Curves 403a-i show that the first small catalyst beds in the reactor (e.g., curves 403a-e) have higher productivity than curves 402a-b of the conventional trickle-bed reactor configuration. The upstream catalyst beds were able to operate at higher temperatures while controlling the exothermic heat of the reaction. The higher operating temperatures for the upstream catalyst beds resulted in higher productivity, which intersected with the productivity of the ideal isothermal plug flow reactor, curve 401. The higher productivity of the conventional catalyst beds, curves 402c-e, cannot offset the lower productivity of the first catalyst beds, curves 402a-b. This is because the higher productivity of the downstream catalyst beds in Example 2, shown by curves 402c-e, resulted in more unwanted reaction by-products, and therefore the productivity of the downstream catalyst beds was wasted on producing undesired products. In contrast, the productivity of the upstream catalyst beds in Example 3 is highest, as shown by curves 403a-f and further down the reaction coordinate, and the productivity of the downstream catalyst beds, as shown by curves 403g-i, is low, resulting in less unwanted by-products in the inventive configuration. converted g -1metal h -1 The periodic drop to corresponds to cooling between catalyst beds.

[0069] While embodiments of the presently disclosed invention have been shown and described, those skilled in the art can make modifications thereto without departing from the spirit and teachings of the invention. The embodiments described herein are merely exemplary and are not intended to be limiting. Numerous variations and modifications of the invention disclosed herein are possible and fall within the scope of the disclosed invention. When a numerical range or numerical limitation is expressly stated, it should be understood that such an expressed range or limitation includes all iterative ranges or limitations of the same order that fall within the expressly stated range or limitation (e.g., about 1 to about 10 includes 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). The use of the term "optionally" with respect to an element in a claim means that the subject element is required or is not required. Both alternatives are intended to be within the scope of the claim. The use of broad terms such as having, including, and comprising should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and substantially being.

[0070] Accordingly, the scope of protection is not limited by the above description, but is limited only by the following claims, which scope includes all equivalents of the claimed invention. Each and every claim is introduced into the specification as an embodiment of the present disclosure. As such, the claims are further description and additional embodiments of the present invention. The discussion of any reference herein, especially any reference having a publication date after the priority date of this application, is not an admission that it is prior art to the invention(s) of the present disclosure. The disclosures of all patents, patent applications, and publications cited herein, to the extent that they provide exemplary, procedural, or other details supplementary to those set forth herein, are hereby incorporated by reference.

Claims

1. A trickle bed reactor comprising: a plurality of catalyst beds connected in series, the mass of catalyst gradually increasing from upstream to downstream; a plurality of heat exchangers, each of which is disposed between two of the catalyst beds, and which do not exchange heat with an exterior surface of a vessel containing the catalyst beds; a first reactor vessel containing a first group of said catalyst beds; a second reactor vessel containing a second group of catalyst beds of the catalyst beds, wherein the inlet of the second reactor vessel is fluidly connected to a product outlet of the first reactor vessel, the product outlet of the first reactor vessel having a gas outlet line and a liquid outlet line; a compressor disposed along the gas outlet line for compressing gas product discharged from the first reactor vessel; a pump disposed along the liquid outlet line for pumping the liquid product discharged from the first reactor vessel to the second reactor vessel; and The compressed gaseous product is mixed with the liquid product before the liquid product and the gaseous product are introduced into the second reactor vessel.

2. 2. The trickle bed reactor of claim 1, The catalyst bed is not a shell-and-tube heat exchange configuration.

3. 2. The trickle bed reactor of claim 1, a gaseous additive line in fluid communication with at least one of the catalyst beds; a liquid additive line in fluid communication with at least one of said catalyst beds; It further has:

4. 2. The trickle bed reactor of claim 1, The productivity of the catalyst bed gradually decreases from upstream to downstream, The productivity of the first catalyst bed is 5 to 10 times higher than the productivity of the last catalyst bed.

5. 2. The trickle bed reactor of claim 1, having a feed line and a discharge line; the feed line contains reactants and is fluidly connected to a first one of the catalyst beds; the catalyst bed is configured to convert the reactants to one or more products; The discharge line contains the product and is fluidly connected to the last of the catalyst beds.

6. 1. A method of operating a trickle bed reactor, comprising: passing one or more reactants through a plurality of catalyst beds connected in series and having a gradually increasing mass of catalyst from upstream to downstream; converting the reactants to one or more products by passing them through the catalyst bed; Including, The trickle bed reactor comprises a plurality of heat exchangers; each of the heat exchangers is disposed between two of the catalyst beds; The heat exchanger does not exchange heat with the exterior surface of the vessel containing the catalyst bed. the productivity of the product in each of the catalyst beds gradually decreases from upstream to downstream; The productivity of the first catalyst bed is 5 to 10 times higher than the productivity of the last catalyst bed.

7. 7. The method of claim 6, The trickle bed reactor further comprises a gaseous additive line in fluid communication with at least one of the catalyst beds or a liquid additive line in fluid communication with at least one of the catalyst beds.

8. 8. The method of claim 7, the reactants include sodium gluconate; The catalyst bed comprises an oxidation catalyst.

9. 9. The method of claim 8, The products include oxidation products.

10. 10. The method of claim 9, The oxidation products include sodium glucarate.

11. 9. The method of claim 8, introducing additional sodium gluconate into the trickle-bed reactor via the liquid additive line.

12. 7. The method of claim 6, The trickle bed reactor does not have a shell-and-tube heat exchange configuration.

13. 7. The method of claim 6, The catalyst mass gain is from 100 kg to 1,000,000 kg.

14. 7. The method of claim 6, The trickle bed reactor has an operating pressure of 50 PSI to 100,000 PSI.

15. 7. The method of claim 6, The trickle bed reactor has an operating temperature of 25°C to 350°C.

16. 7. The method of claim 6, The trickle bed reactor has a production capacity of 1 to 100,000 kilotonnes per year.

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