Additive manufacturing process for producing packing material and rotating packed bed apparatus utilizing the same

Abstract

The present disclosure relates generally to methods and apparatus for large- or commercial-scale process intensification and, more particularly, to additive manufacturing processes for producing packing material and rotating packed bed apparatus utilizing the same.

Description

PATENT APPLICATION ADDITIVE MANUFACTURING PROCESS FOR PRODUCING PACKING MATERIAL AND ROTATING PACKED BED APPARATUS UTILIZING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 729,026, filed December 6, 2024, entitled “ADDITIVE MANUFACTURING PROCESS FOR PRODUCING PACKING MATERIAL AND ROTATING PACKED BED APPARATUS UTILIZING THE SAME”, which is incorporated herein by reference in its entirety for all purposes.TECHNICAL FIELD

[0002] The present disclosure relates generally to methods and apparatus for commercial-scale process intensification and, more particularly, to additive manufacturing processes for producing packing material and rotating packed bed apparatus utilizing the same.BACKGROUND

[0003] One of the key topics in contemporary process engineering is the idea of process intensification (PI), which comprises techniques leading to improvements in process performance through higher efficiency, lower energy consumption and capital costs, decrease in equipment size, or reduction in waste formation. Traditional countercurrent equipment, such as stationary packed columns, uses gravity as the primary force for phase contact. High Gravity (HiGee) equipment, which is one of the leading examples of PI, replaces gravity with a much higher centrifugal force. The idea of HiGee was then developed into a device for gas-liquid contact known as the rotatingpacked bed (RPB) apparatus. RPBs can be used for the separation of mixtures, for which innovative packings are developed, designed and characterized, including those produced by additive manufacturing techniques. Such techniques, however, are limited to packings for laboratory and pilot plant scales, whose performance characteristics cannot be extrapolated to large-scale, commercial RPB applications.SUMMARY

[0004] Additive manufacturing has been used in the prototyping of packing materials for RPBs for several years, but several challenges persist which have prevented the successful scale up of the technology from becoming a commercially viable solution. Such challenges include printer resolution, build-time, post-processing requirements, and computing time for both model build and printer. As packing volumes continue to increase to handle commercial and industrial scale projects, for example, the reduction in material waste and post-processing time is critical. Yet, existing additive manufacturing techniques fail to address these challenges and shortcomings.

[0005] In view of the shortcomings of conventional additive manufacturing techniques for producing rotating packed bed (RPB) packings and the packings produced thereby, the present disclosure provides additive manufacturing processes for producing novel RPB packings with controlled dimensionality, material, and structural characteristics that advantageously permit highly efficient and effective use in large- scale, industrial, or commercial environments.

[0006] As such, one aspect of the present disclosure can include an additive manufacturing process for producing a packing material adapted for use in a RPB apparatus at a commercial scale. The process can include the steps of: (a) producingand saving a three-dimensional (3D) model in an electronic file format for use in operating an additive build platform; (b) loading one or more precursor materials into at least one reservoir associated with the additive build platform; (c) calibrating the additive build platform; (d) operating the additive build platform to obtain a packing material; and (e) optionally, performing post-processing of the packing material obtained in step (d).

[0007] Another aspect of the present disclosure can include a packing material adapted for use in a RPB apparatus at a commercial scale. The packing material can be produced by a process comprising the steps of: (a) producing and saving a 3D model in an electronic file format for use in operating an additive build platform; (b) loading one or more precursor materials into at least one reservoir associated with the additive build platform; (c) calibrating the additive build platform; (d) operating the additive build platform to obtain a packing material; and (e) optionally, performing postprocessing of the packing material obtained in step (d).

[0008] Another aspect of the present disclosure can include a RPB apparatus comprising a packing material. The packing material can be produced by a process comprising the steps of: (a) producing and saving a 3D model in an electronic file format for use in operating an additive build platform; (b) loading one or more precursor materials into at least one reservoir associated with the additive build platform; (c) calibrating the additive build platform; (d) operating the additive build platform to obtain a packing material; and (e) optionally, performing post-processing of the packing material obtained in step (d).

[0009] Another aspect of the present disclosure can include a method of using a RPB apparatus to transfer mass between a sorbent and a gas at a commercial scale.The method can comprise: receiving, by the RPB apparatus, a flow of gas; receiving, by the RPB apparatus, a flow of sorbent; wherein the RPB apparatus comprises a packing material produced by a process comprising the steps of: (a) producing and saving a 3D model in an electronic file format for use in operating an additive build platform; (b) loading one or more precursor materials into at least one reservoir associated with the additive build platform; (c) calibrating the additive build platform; (d) operating the additive build platform to obtain a packing material; and (e) optionally, performing post-processing of the packing material obtained in step (d); and providing a cross-flow of the received sorbent and received gas in a region of mass transfer of the RPB apparatus, thereby obtaining a loaded sorbent and a treated gas.

[0010] Another aspect of the present disclosure can include a method of using a RPB apparatus to degass a liquid. The method can comprise the steps of: causing a rotatable element within the RPB apparatus to spin at a tangential velocity; wherein the RPB apparatus comprises a packing material produced by a process comprising the steps of: (a) producing and saving a 3D model in an electronic file format for use in operating an additive build platform; (b) loading one or more precursor materials into at least one reservoir associated with the additive build platform; (c) calibrating the additive build platform; (d) operating the additive build platform to obtain a packing material; and (e) optionally, performing post-processing of the packing material obtained in step (d); infusing a liquid containing a gas into the RPB apparatus; applying a vacuum to an interior region of the RPB apparatus; and generating a liquid substantially free of the gas.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The foregoing and other features of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates upon reading the following description with reference to the accompanying drawings, in which:

[0012] Fig. 1 is a process flow diagram illustrating an additive manufacturing process for producing a packing material adapted for use in a rotating packed bed (RPB) apparatus at a commercial scale according to one aspect of the present disclosure;

[0013] Fig. 2 is an image showing the results of computer-based modeling whereby initial patterns and parameters of defined test cubes of 4”x4” were used to evaluate volumetric parameters (e.g., cell sizes, volume fraction percentage, and surface area-to- volume ratio) of a RPB packing material;

[0014] Figs. 3A-B are graphs showing how packing materials produced by the present disclosure compare to an idealized material of 45 PPI and very low VFD (Fig.3A - Fixed SLPM at 500: Varying High Gravity Force; Fig. 3B - Fixed High Gravity Force at 98.05: 400-700 SLPM);

[0015] Fig. 4 is an image showing Voronoi packing structures (400 micron strut on left, 300 micron on right); and

[0016] Figs. 5A-B are a series of graphs showing constant RPM test comparing DMLS to binderjet and RVC foams (Fig. 5A) and constant gas flow test comparing DMLS to binderjet and RVC foams (Fig. 5B).DETAILED DESCRIPTION

[0017] Definitions

[0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the present disclosure pertains.

[0019] Throughout the description and claims of this specification, the word “comprise” and variations of the word, such as “comprising” and “comprises,” means “including but not limited to,” and is not intended to exclude, for example, other additives, components, integers or steps. In particular, in methods stated as comprising one or more steps or operations it is specifically contemplated that each step comprises what is listed (unless that step includes a limiting term such as “consisting of”), meaning that each step is not intended to exclude, for example, other additives, components, integers or steps that are not listed in the step.

[0020] In the context of the present disclosure, the term “about”, when expressed as from “about” one particular value and / or “about” another particular value, also specifically contemplated and disclosed is the range from the one particular value and / or to the other particular value unless the context specifically indicates otherwise. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another, specifically contemplated embodiment that should be considered disclosed unless the context specifically indicates otherwise. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint unless the context specifically indicates otherwise. Finally, it should be understood that all of the individual values and sub-ranges of values contained within an explicitly disclosed range are also specifically contemplated and should beconsidered disclosed unless the context specifically indicates otherwise. The foregoing applies regardless of whether in particular cases some or all of these aspects are explicitly disclosed.

[0021] Optionally, in some aspects, when values or characteristics are approximated by use of the antecedents “about,” “substantially,” or “generally,” it is contemplated that values within up to 15%, up to 10%, up to 5%, or up to 1 % (above or below) of the particularly stated value or characteristic can be included within the scope of those aspects.

[0022] As used herein, phrases such as “between X and Y” and “between about X and Y” can be interpreted to include X and Y.

[0023] As used herein, phrases such as “between about X and Y” can mean “between about X and about Y”.

[0024] As used herein, phrases such as “from about X to Y” can mean “from about X to about Y”.

[0025] It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0026] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms can encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features.

[0027] As used herein, the terms “first,” “second,” etc. should not limit the elements being described by these terms. These terms are only used to distinguish one element from another. Thus, a “first” element discussed below could also be termed a “second” element without departing from the teachings of the present disclosure. The sequence of operations (or acts / steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

[0028] As used herein, the terms “optionally” and “optional” can mean that the subsequently described event, circumstance, or material may or may not occur or be present, and that the description includes instances where the event, circumstance, or material occurs or is present and instances where it does not occur or is not present.

[0029] As used herein, the terms “rotating packed bed apparatus” or “RPB apparatus” can refer to a device capable of generating a high gravity field to affect mass transfer between at least two liquids and / or gases. The high gravity field is the result of a centrifugal force field generated by rotation of packed beds in the RPB apparatus. The phrase “high gravity field” means that liquid and / or gas reactants are introducedinto the high gravity field and react while they are moved centrifugally; or the liquid reactant is moved from the center of the RPB apparatus centrifugally and the gas reactant is introduced oppositely with respect to the liquid reactant along the radial direction when the packed bed is rotating. In general, the reaction represented by the phrase “under high gravity” can be carried out in any RPB apparatus or any other similar high gravity field reactor.

[0030] As used herein, the term “commercial scale” can refer to a capture scale of about 10 tons per day (TPD) to about 100,000 TPD or greater of a target gas or sorbent by a RPB apparatus. In one example, “commercial scale” can include about 10 TPD to about 100,000 TPD e.g., about 10 TPD to about 100 TPD), about 100 TPD to about 1 ,000 TPD, about 1 ,000 TPD to about 10,000 TPD, about 10,000 TPD to about 20,000 TPD, about 20,000 TPD to about 30,000 TPD, about 30,000 TPD to about 40,000 TPD, about 40,000 TPD to about 50,000 TPD, about 50,000 TPD to about 60,000 TPD, about 60,000 TPD to about 70,000 TPD, about 70,000 TPD to about 80,000 TPD, about 80,000 TPD to about 90,000 TPD, or about 90,000 TPD to about 100,000 TPD. It will be appreciated that the term does not refer to, or include, small-scale testing (e.g., bench top) and research applications, e.g., operating at a capture scale of less than about 5 TPD, e.g., less than about 1 TPD.

[0031] As used herein, the term “additive build platform” can refer to any device (e.g., printer) that creates physical objects from 3D digital models by joining material or materials incrementally on top of each other. Non-limiting types of such devices can include selective laser sintering (SLS) printers, digital light process (DLP) printers, multijet fusion (MJF) printers, PolyJet printers, direct metal laser sintering (DMLS) printers, and electron beam melting (EBM) lasers.

[0032] Improved Additive Manufacturing Process for Producing RPB Packing Material

[0033] One aspect of the present disclosure can include an additive manufacturing process 10 (Fig. 1 ) for producing a packing material (e.g., non-metal foams) adapted for use in a RPB apparatus at a commercial scale. Traditional manufacturing of foams for RPB packing material is a complex and less refinable process. Advantageously, the process 10 of the present disclosure provides a highly controllable method for obtaining a RPB packing material with precise specifications (e.g., pore size, pore density, surface area-to-volume ratio) for superior process intensification not possible with traditional manufacturing techniques. Using traditional manufacturing techniques, for example, large blank pieces are created. These large blank pieces are then postprocessed into final shapes, which creates scrap waste as well as added cost. The large blank pieces are like a slug or ingot of raw material, which then must be cut into a desired shape (e.g., adapted for a RPB rotor) and necessarily creates a waste product, i.e., the discarded parts of that initial blank. In the process 10 of the present disclosure, however, the part produced is the end-product and thereby significantly reduces waste as well as cost, e.g., the process of the present disclosure produces the final part, which fits directly into a RPB rotor and does not create additional waste product(s).Additionally, the process 10 of the present disclosure provides flexibility to select packing material properties for specific process conditions and environments, which is not feasible in traditional manufacturing methods. Finally, the process 10 improves theaccuracy of enhanced computational fluid dynamics (CFD) simulation, which further improves design cycle efficiencies and reduces the need for iterative testing plans.

[0034] As shown in Fig. 1 , one step of the process 10 can include producing and saving a three-dimensional (3D) model in an electronic file format for use in operating an additive build platform (Step 12).

[0035] A packing material adapted for use in a RPB apparatus at a commercial scale can be prepared using one or a combination of additive build platforms and associated 3D printing processes including, but not limited to, digital light processing (DLP), direct metal laser sintering (DMLS), laser powder bed fusion (LPBF), laser metal jetting (LMJ), multi jet fusion (MJF), and binder jetting.

[0036] In one embodiment, a packing material adapted for use in a RPB apparatus at a commercial scale can be prepared using an additive manufacturing process other than fused deposition modeling (FDM) or stereolithography (SLA). For example, a packing material adapted for use in a RPB apparatus at a commercial scale using one or a combination of additive build platforms and associated 3D printing processes including, but not limited to, digital light processing (DLP), direct metal laser sintering (DMLS), laser powder bed fusion (LPBF), laser metal jetting (LMJ), multi jet fusion (MJF), and binder jetting, but not using FDM. In another example, a packing material adapted for use in a RPB apparatus at a commercial scale using one or a combination of additive build platforms and associated 3D printing processes including, but not limited to, digital light processing (DLP), direct metal laser sintering (DMLS), laser powder bed fusion (LPBF), laser metal jetting (LMJ), multi jet fusion (MJF), and binder jetting, but not using SLA.

[0037] In one example, a packing material adapted for use in a RPB apparatus at a commercial scale can be prepared using DLP. One advantage of using DLP is the speed at which packing layers can be built. By exposing an entire layer of material to cure at the same time a complex packing structure can be built much faster than a traditional SLA laser needing to travel a specific path. This wholistic building of layers also reduces the computer processing required to validate production paths.

[0038] In another example, a packing material adapted for use in a RPB apparatus at a commercial scale can be prepared using DMLS. DMLS as an additive manufacturing technology offers many advantages when scaling packing production for RPBs. First, the fine resolution of the laser production method allows for the creation of small features in the production part. Strut thicknesses are viable as low as 100 microns. This fine resolution affords the modeling of packing structures with much higher surface area to volume ratios while reducing the overall density to as low as .01 lb / in3for 316 stainless steel. This directly reduces the overall mass of material usage and cost of the final packing in both material usage as well as production time. This significant reduction in density opens the possibility of utilizing normally stronger heavier materials like stainless steel or nickel. These metals have historically been used as foams, but they are much denser, and more difficult to produce at scales required for commercial RPBs.

[0039] A second benefit of DMLS (as well as DLP) is the ability to produce packing structures with significant overhang of about 45 degrees, without the need for internal support structures. As effective RPB packings are composed of small porous cells the ability to remove internal support structures becomes increasingly difficult as youincrease the volume of printed material, so necessarily removing the need for these structures increases production times as well as ability to scale.

[0040] Advantageously, DMLS and DLP can be used for commercial-scale RPB packing production because each of these additive manufacturing techniques offer large printing platforms, the ability to print without internal support structure, high resolution which reduces part density, and the ability to rapidly render layers.

[0041] In one aspect, the 3D model can be created using known software, such as SolidWorks (Dassault Systemes SolidWorks Corporation, Waltham, MA) with parametric patterning performed in nTop (nTopology Inc., New York, NY). It will be appreciated, however, that any 3D modeling and parametric software package that can output .STL files can be used to generate the 3D model.

[0042] At Step 12, an initial RPB rotor size can be determined based on one or more of the following physical characteristics: expected gas to be treated; expected liquid required to treat the gas; plant space requirements; plant power limitations; and the like. The initial RPB rotor size can be modeled in SolidWorks or another 3D modeling software as a solid volume representing the intended final packing material.

[0043] A plan for the physical characteristics of the packing material (e.g., pore size, pore shape, density, linkage thickness, relative void space, effective area, etc.) can be determined to meet the efficiency characteristics of the particular 3D printing process. Using a parametric modeling software such as nTop, for example, a 3D model of the prospective packing material geometry can be modeled in a representative cube. The representative cube can be iterated as needed to produce the desired geometry.

[0044] Once acceptable, the representative cube geometry can be applied to the initial RPB rotor model. This can be achieved directly by importing the original solid model into nTop software, for example, by applying the cube geometry as a pattern to the original solid model; or other means of combining the geometric structure with the planned volume of packing material. At this stage, consideration can be made as to how the final packing material will be printed, installed, and supported inside the RPB rotor. A small print bed size, for example, can necessitate multiple sections and final installation around support rods can necessitate stress reduction features or holes to be included in the 3D model. Ultimately, Step 12 can produce a 3D model that can be converted to an .STL format for use in the process 10.

[0045] An .STL file can be evaluated for printing viability based on a number of variables including, but not limited to, model size, triangle count, minimum detail size, and complexity. Most of these variables are objective and their impact on printing viability can be influenced by the functional ability of the additive build platform and / or the processing computer being used to create the packing material.

[0046] Once the 3D model is deemed viable, it is uploaded to an additive build platform, which can parse the .STL file into executable commands and provide the additive build platform with fabrication instructions. At this point, the decision can be made as to which printing technology will be used based, at least in part, on the following criteria: material requirements (e.g., strength, corrosion properties, density, etc.); part resolution; and expected post-processing requirements (if any).

[0047] Configuring the additive build platform will depend upon the particular 3D printing process used to produce the final packing material; although, those skilled inthe art will appreciate that several common steps are shared when configuring various additive build platforms. An initial step, for example, can include identifying the packing material based, e.g., on certain parameters (e.g., density, overall weight, volume, stiffness, corrosion resistance, effective area, need for post processing, etc.) deemed important to achieving desired RPB apparatus performance. Material selection can also affect which printing process is most feasible as some materials are only available on select additive build platforms.

[0048] Next, at Step 14, one or more materials (e.g., precursor materials) can be loaded into at least one reservoir associated with the additive build platform. This can be done after selecting the desired type of printing process and the associated material(s). An appropriate methodology, such as loading spools for LMJ, resins for DLP, etc., or powders and binders for DMLS, LPBF, Binderjet and MJF, etc., can be employed.

[0049] At Step 16, once the material(s) has been loaded, the additive build platform can be calibrated, e.g., as per the manufacturer’s recommended procedure to hold the tightest print tolerance. Those skilled in the art will appreciate that any preparation of the additive build platform or the area surrounding the platform can be performed at Step 16. After this has been performed, the previously created .STL file / s can be uploaded for printing to a printer controller. Many printer control software programs provide built-in controls to evaluate the .STL for print viability, material usage, support needs, and location as well as process controls (e.g., head speed, head temperature and resolution). These parameters can be set, and preferably verified, with test builds of smaller and possibly simpler representations of the packing material. When thefile(s) is / are loaded and properly set up, the file(s) can be sent to the additive build platform for printing.

[0050] At Step 18, the additive build platform can be operated to obtain the packing material. Depending on the particular 3D printing process employed and the complexity or size of the packing or packing segment, Step 18 can take hours or days to complete.

[0051] Step 20 can include optionally performing post-processing of the packing material obtained in Step 18. For example, one or more post-processing steps may be needed to ready the packing material or part for final installation in the RPB apparatus. For FDM, for example, there may be a need to remove support structures. This can be done by physical removal or potentially a soak in a NaOH solution with a rinse bath in sterile water. For many resin-based processes, such as SLA, SLS and DLP, there may be a need for a final cure in a specialized UV or infrared oven to fully set all of the polymer chains, often followed by a cleaning rinse. For other 3D printing processes, such as binder jetting or MJF, a curing stage can be employed where the packing material or part is placed in a controlled oven that fully sets the binder material and is also, or optionally, under a vacuum to help remove the support structure (which should not be bonded). This material can often be re-used in future prints, which advantageously helps to reduce waste. Lastly, a final packing segment of any material can be sent for mechanical post-processing where final machining steps are performed (e.g., such as adding additional holes or mounting features or modifying of the printed product) to conform to specific mechanical tolerances for final assembly.

[0052] Another aspect of the present disclosure can include a packing material adapted for use in a RPB apparatus at a commercial scale and being produced by the process 10.

[0053] Yet another aspect of the present disclosure can include a RPB apparatus comprising a packing material produced by the process 10. In one example, the RPB apparatus comprising a packing material produced by the process 10 can comprise a RPB apparatus as disclosed in any one of U.S. Patent No. 7,537,644, U.S. Patent No. 7,326,283, and U.S. Patent Application Publication No. 2007 / 0034565.

[0054] Methods

[0055] Another aspect of the present disclosure can include a method of using an RPB apparatus, which comprises a packing material produced by the process 10, to transfer mass between a sorbent and a gas at a commercial scale. The method can include the steps of: receiving, by the RPB apparatus, a flow of gas; receiving, by the RPB apparatus, a flow of sorbent; and providing a cross-flow of the received sorbent and received gas in a region of mass transfer of the RPB apparatus, thereby obtaining a loaded sorbent and a treated gas.

[0056] In one example, the treated gas is free of, or substantially free of, one or more gases selected from the group consisting of carbon dioxide, mercaptans, hydrogen sulphide, and carbonyl sulphide. The term “substantially free of”, as used in this context, can mean having a trivial amount of, such that a treated gas contains about 0 wt % to about 5 wt % of the one or more gases (e.g., carbon dioxide, mercaptans, hydrogen sulphide, and carbonyl sulphide), or about 0 wt % to about 1 wt %, or about 5 wt % or less, or less than, equal to, or greater than about 4.5 wt %, 4, 3.5, 3.2.5, 2, 1 .5,1 , 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 , 0.01 , or about 0.001 wt % or less, or about 0 wt %.

[0057] In another example, the method can be performed for the purpose of carbon capture. Using a RPB apparatus that includes a packing material produced by the process 10, a liquid sorbent and a gas containing carbon can be mixed. In the RPB, mass transfer occurs in the packing material when rotated. Due to the artificial gravity that is introduced by the rotation, the effective contact area between the gas and sorbent is increased without causing early flooding. Advantageously, the method can reduce the concentration of at least one gas in a mixture of gasses, such as a flue gas, so that the concentration of carbon dioxide in the flue gas is reduced before it is released into the atmosphere. Alternatively, where the gas mixture is a mixture of hydrogen and carbon dioxide (e.g., as may be generated by a reforming process), the method of the present disclosure can reduce the concentration of carbon dioxide in the gas mixture to generate substantially pure hydrogen.

[0058] In yet another example, carbon capture can be accomplished using a RPB apparatus, which includes a packing material produced by the process 10 of the present disclosure, in combination with the methods described in PCT Pub. No. WO 2019 / 057932.

[0059] Another aspect of the present disclosure can include a method of using a RPB apparatus, which includes a packing material produced by the process 10 of the present disclosure, to degass a liquid (e.g., water, malt beverages, alcohol and nonalcohol beverages or liquids, and fruit juices) containing a target gas containing at least one atom selected from the group consisting of O, N, S, H, and C (e.g., air, oxygen,carbon dioxide, nitrogen). The method can comprise the steps of: causing a rotatable element within the RPB apparatus to spin at a tangential velocity; infusing a liquid containing a gas into the RPB apparatus; applying a vacuum to an interior region of the RPB apparatus; and generating a liquid substantially free of the target gas. The term “substantially free of”, as used in this context, can mean having a trivial amount of, such that the treated liquid contains about 0 wt % to about 5 wt % of the target gas, or about 0 wt % to about 1 wt %, or about 5 wt % or less, or less than, equal to, or greater than about 4.5 wt %, 4, 3.5, 3.2.5, 2, 1 .5, 1 , 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 , 0.01 , or about 0.001 wt % or less, or about 0 wt %.

[0060] In one example, the method can be performed using a RPB apparatus ( / .e., comprising a packing material produced by the process 10) as described in U.S. Patent No. 7,537,644.

[0061] Exemplary Aspects

[0062] In view of the described compositions, devices, and methods and variations thereof, herein below are certain more particularly described aspects of the present disclosure. These particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein, or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language literally used therein.

[0063] Aspect 1 : An additive manufacturing process for producing a packing material adapted for use in a rotating packed bed (RPB) apparatus at a commercial scale, the process comprising the steps of: (a) producing and saving a three- dimensional (3D) model in an electronic file format for use in operating an additive buildplatform; (b) loading one or more precursor materials into at least one reservoir associated with the additive build platform; (c) calibrating the additive build platform; (d) operating the additive build platform to obtain a packing material; and (e) optionally, performing post-processing of the packing material obtained in step (d).

[0064] Aspect 2: The process of Aspect 1 , being performed as part of a 3D printing process selected from the group consisting of digital light processing, binder jetting, multi jet fusion, liquid metal jetting, laser powder bed fusion, and direct metal laser sintering or others.

[0065] Aspect 3: The process of any one of Aspects 1 -2, wherein the 3D printing process comprises the additional step of: performing post-processing of the packing material obtained in step (d); wherein performing post-processing includes a curing step in which a binder material is fused to create the obtained packing material.

[0066] Aspect 4: A packing material adapted for use in a RPB apparatus at a commercial scale and being produced by the method of any one of Aspects 1 -3.

[0067] Aspect 5: A RPB apparatus comprising the packing material of Aspect 4.

[0068] Aspect 6: A method of using the RPB apparatus of Aspect 5 to transfer mass between a sorbent and a gas at a commercial scale, the method comprising: receiving, by the RPB apparatus, a flow of gas; receiving, by the RPB apparatus, a flow of sorbent; and providing a cross-flow of the received sorbent and received gas in a region of mass transfer of the RPB apparatus, thereby obtaining a loaded sorbent and a treated gas.

[0069] Aspect 7: The method of Aspect 6, wherein the treated gas is free of, or substantially free of, one or more gases selected from the group consisting of carbon dioxide, mercaptans, hydrogen sulphide, and carbonyl sulphide.

[0070] Aspect 8: A method of using the RPB apparatus of Aspect 5 to degass a liquid, the method comprising: causing a rotatable element within the RPB apparatus to spin at a tangential velocity; infusing a liquid containing a gas into the RPB apparatus; applying a vacuum to an interior region of the RPB apparatus; and generating a liquid substantially free of the gas.

[0071] Aspect 9: The method of Aspect 8, wherein the liquid includes water.

[0072] Aspect 10: The method of any one of Aspects 8-9, wherein the gas is selected from the group consisting of air, oxygen, carbon dioxide, and nitrogen.

[0073] The following Examples are for the purpose of illustration only and are not intended to limit the scope of the claims, which are appended hereto.Example 1

[0074] To test the ability to generate, manufacture, and evaluate a packing material for a RPB apparatus, the following process was performed using digital light processing (DLP).

[0075] First, a stand-in model of the total volume of packing material was created in SolidWorks to represent the volume of packing with respective mounting features. For this bench-scale mockup, the inner diameter was 3.5 inches and the outer diameter was 1 1 .75 inches. There were six 0.525-inch diameter by 0.52-inch-long slots evenly spaced around the outside diameter of the volume to act as mounting points. Thismodel served as a stand-in to evaluate dynamic forces in the rotor and a starting point for modeling the final packing.

[0076] The next step in the process was to define the criteria that would form the basis of the packing material. We defined a matrix of potential designs, which included the parameters indicated in Table 1.Table 1 - Selected Parameters of Packing Material

[0077] Initial modeling to create the above structures in nTop was started and four cell structures were identified to potentially act as the periodic pattern: Weaire-Phelan; Fluorite; Octet; and Kelvin. The nTop software can also generate randomized foam-like structures when given a set of parameters to follow. For this, we defined certain features as fixed values so we could directly compare the options. First, beam thickness was fixed at 1 mm for all patterns, which was done to ensure viability of printing in a technology agnostic scenario. Second, the patterns were defined to produce an open cell structure to ensure gas and liquid could freely flow through thepacking. Finally, there was an effort to maintain a constant pore size between the variations as closely tied to the target as possible (some of the periodic patterns created geometries with multiple openings of different size, so as with the random structure an average was used).

[0078] After the initial patterns and parameters were defined, test cubes of 4”x4” were modeled and used to evaluate for volumetric parameters, such as cell sizes, volume fraction percentage, and surface area-to-volume ratio (Fig. 2). These results were compared and used to select for candidates to move forward for evaluation. A voronoi pattern was selected for the randomized structure and the fluorite was chosen for the periodic owing, in part, to a higher liklihood higher printing fidelity.

[0079] After selecting the above patterns, the initial stand-in model from SolidWorks was imported into nTop for an application of the parameters to a representative volume of the final packing. As shown in Table 2, eight (8) model iterations (indicated by shaded rows) of these models were generated and exported as .STL files.Table 2 - Representative Model Iterations

[0080] When attempting to export as an .STL file, the model is broken into small triangles, which replace the surface of the solid model and which surface information is translated to the printer. The eight (8) model iterations were evaluated for number of triangles and processing power required to print. The models for all random-styled packing processed without issue; however, the 0.4 mm and 0.7 mm pore-sized periodic prints created over 34 billion triangles, which limited the processing capabilities of the computer creating the files.

[0081] After the .STL files were exported, they were sent to a computer connected to a DLP printer. The .STL models were arranged such that they would print in a vertical orientation to fit all eight (8) models into one print run. This was done to reduce the associated cost and also to assess the limits of the printer’s resolution and fidelity. The DLP printer, like most additive manufacturing processes, required calibration and filling with a printing material. To do this, the manufacturer’s process was followed. Thematerial selected for this print run was Evonik 6100L; although, alternative materials may need to be used for specific processes as compatibility issues may exist. The packing files were then printed (the total run took approximately 12 hours). After the print was completed, the packing samples were removed from the DLP printer and rinsed to remove excess material and sent to a curing station. There, the packing samples were exposed to UV light to fully harden the material and improve the strength and finish of the final product.

[0082] The final parts were then installed into the test RPB system and run to evaluate their efficacy compared to traditional packing materials. After curing and cleaning, it was determined that the 0.4 mm structured pore size packing did not have sufficient openings to merit testing, so it was omitted from the test. Figs. 3A-B illustrate how the packing samples compared to an idealized material of 45 PPI and very low VFD. As is shown, the 3D packing materials, especially the 2 mm pore sized samples, unexpectedly approximated the efficacy of the 45 PPI ideal.Example 2

[0083] An exemplary application of the process described herein using binder jetting for scaled-up production of a RPB packing material is described below.

[0084] A packing design is scaled from a benchtop sample (such as in Example 1 ) to an industrial scale by following the three additional steps: segmenting the stand-in packing model into printable pieces; creating a means to join those packing segments effectively; and employing multiple printers to maintain feasible timelines and costs.

[0085] A stand-in model is created in SolidWorks for an industrial scale rotor packing, which is 3.5 m OD, 3 M ID and 2.4 m tall. Such packing does not fit anycommercially available 3D printer with a fine enough resolution to recreate the 2 mm pore size structured packing (from Example 1 ) and, as such, is divided into smaller segments for printing. These smaller segments are divided equally into 36, 10-degree segments which are 0.1 m tall, which allows them to fit within the build platform of our binder jet printer. Symmetrical but opposite dovetail features are added to the segmented shape, with a negative half circle on one edge and a positive half circle on the opposite. These mating features provide a positive alignment feature in the final rotor assembly.

[0086] This smaller segment model is imported into the nTop software where the 2 mm pore pattern (e.g., from Example 1 ) can be applied to the volume to create the final packing model. This final packing model is exported as a .STL file for uploading to the binder jet printer, which is calibrated per the manufacturer’s instructions and loaded with a nickel-based alloy powder and a binding agent. The .STL file is loaded and printed on a bank of available binder jet printers, each of which has been programmed to run the required 900 segmented pieces. Following their respective print times, each piece is cleaned of excess powder and moved to a sintering furnace where a final curing fuses the alloy particles together creating a solid and stable packing segment. These pieces are all joined together during the assembly phase of the rotor where it is ready for installation into an industrial-scale RPB.Example 3

[0087] In an effort to scale up additive manufacturing of RPB packing utilizing DMLS, an experiment was run to compare the performance to existing stainless steel foam as well as other commercially available foams. The first step was creating a packingstructure in CAD software which is suitable for DMLS manufacture, for this case Ntop was used. In an attempt to minimize the overall density of the part by maximizing void percentage and reducing print material, two strut thicknesses were modeled and test printed. For the purpose of this Example, a strut thickness of 300 microns and 400 microns was modeled on a 1 -inch cube test sample (Fig. 4). The modeled pattern was a Voronoi style foam which was chosen for its similarity to production stainless steel foams and previous internal testing performed on additive packings. After successfully test printing the sample cubes the model packing structure was applied to a test volume of ID 3.0” OD 11 .75” and thickness 1 .0” the chosen strut thickness was 400 micron.

[0088] This full volume packing was printed in 316 stainless steel material on a Farsoon DMLS printer. The packing was used in a test RPB set up which has been used to previously characterize both traditional stainless-steel foam as well as binderjet and DLP printed materials. The RPB was run at both constant RPMs with varied gas flow as well as fixed gas flow and varied RPMs to evaluate the effective area (Figs. 5A- B), which allowed for a quick comparison of the effectiveness of packings.

[0089] In view of the foregoing results, it is evident that the DMLS exceeds the interfacial area of the traditionally manufactured foams in both a fixed rpm as well as a fixed gas flow test case. The DMLS printed packing, though made of traditionally heavy stainless steel material, had a density of -0.016 lb / in3which is still considerably heavier than a typical RVC of 0.002 lb / in3but carries the unexpected benefit of increased strength and ductility.

[0090] From the above description of the present disclosure, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes,and modifications are within the skill of those in the art and are intended to be covered by the appended claims. All patents, patent applications, and publications cited herein are incorporated by reference in their entirety.

Claims

CLAIMSThe following is claimed:1 . An additive manufacturing process for producing a packing material adapted for use in a rotating packed bed (RPB) apparatus at a commercial scale, the process comprising the steps of:(a) producing and saving a three-dimensional (3D) model in an electronic file format for use in operating an additive build platform;(b) loading one or more precursor materials into at least one reservoir associated with the additive build platform;(c) calibrating the additive build platform;(d) operating the additive build platform to obtain a packing material; and(e) optionally, performing post-processing of the packing material obtained in step (d).

2. The process of claim 1 , being performed as part of a 3D printing process selected from the group consisting of digital light processing, binder jetting, multi jet fusion, liquid metal jetting, laser powder bed fusion, and direct metal laser sintering.

3. The process of any one of claims 1 -2, further comprising the step of: performing post-processing of the packing material obtained in step (d); whereinperforming post-processing includes a curing step in which a binder material is fused to create the obtained packing material.

4. A packing material adapted for use in a RPB apparatus at a commercial scale and being produced by the process of any one of claims 1 -3.

5. A RPB apparatus comprising the packing material of claim 4.

6. A method of using the RPB apparatus of claim 5 to transfer mass between a sorbent and a gas, the method comprising: receiving, by the RPB apparatus, a flow of gas; receiving, by the RPB apparatus, a flow of sorbent; and providing a cross-flow of the received sorbent and received gas in a region of mass transfer of the RPB apparatus, thereby obtaining a loaded sorbent and a treated gas.

7. The method of claim 6, wherein the treated gas is free of, or substantially free of, one or more gases selected from the group consisting of carbon dioxide, mercaptans, hydrogen sulphide, and carbonyl sulphide.

8. A method of using the RPB apparatus of claim 5 to degass a liquid, the method comprising: causing a rotatable element within the RPB apparatus to spin at a tangential velocity; infusing a liquid containing a gas into the RPB apparatus; applying a vacuum to an interior region of the RPB apparatus; and generating a liquid substantially free of the gas.

9. The method of claim 8, wherein the liquid includes water.

10. The method of any one of claims 8-9, wherein the gas is selected from the group consisting of air, oxygen, carbon dioxide, and nitrogen.

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