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CN-122028977-A - Direct exchange of sorbent agglomerates

CN122028977ACN 122028977 ACN122028977 ACN 122028977ACN-122028977-A

Abstract

An improved process for making an ion exchange adsorbent product having sufficient mechanical strength for use in an industrial scale gas separation or gas purification adsorber. The shaped adsorbent particles are directly subjected to an ion exchange step without first performing a high temperature calcination step. After the ion exchange step is completed, the resulting ion exchanged adsorbent particles are subjected to a high temperature calcination step.

Inventors

  • PONTONIO STEVEN JOHN
  • BARRETT PHILIP A.
  • K. Hurd

Assignees

  • 普莱克斯技术有限公司

Dates

Publication Date
20260512
Application Date
20241106
Priority Date
20231109

Claims (16)

  1. 1. A direct ion exchange process for preparing an adsorbent product from a plurality of green adsorbent agglomerates having a predefined size, wherein the green adsorbent agglomerates comprise at least one active adsorbent material, at least one binder material, and optionally an inert core having a porosity of about 0% to about 10% as measured by mercury porosimetry and a volumetric heat capacity greater than about 0.8J/cm 3 - °k, wherein the process comprises: a) Curing the green sorbent agglomerates to form cured agglomerates, B) Subjecting the solidified agglomerates to an ion exchange step to form ion exchanged agglomerates, C) Calcining the ion exchanged agglomerates to form an adsorbent product, and D) Recovering the adsorbent product.
  2. 2. The method of claim 1, wherein the ion exchanged agglomerates have a crush strength of greater than 5N as measured by a single particle crush test method prior to calcining step c).
  3. 3. The method of claim 1, wherein the adsorbent product comprises a weight ratio of binder material and active adsorbent material of about 2/98 to about 12/88.
  4. 4. The method of claim 1, wherein the green sorbent agglomerates are core-shell sorbents comprising the inert core surrounded by a sorbent shell comprising the at least one active sorbent material and the at least one binder material.
  5. 5. The method of claim 4, wherein the inert core is coated with a binder selected from one or more of clay, alumina, silica, silicone-derived materials, alumina-silica reagents, and mixtures thereof.
  6. 6. The method of claim 1, wherein the curing step comprises one or more of the following: i) A low temperature heating step for driving off volatiles, wherein the green agglomerates are heated to a temperature of about 50 ℃ to 95 ℃ for a period of about 1 hour to about 4 hours, Ii) an aging treatment step wherein the green agglomerates are maintained in a hydrated state at a pressure of from about ambient to about 5 bar and a temperature of less than about 100 ℃ for a period of from 0.5 days to about 10 days, Iii) A chemical curing step wherein the green agglomerates are contacted with at least one compound to shape the curable components in the green agglomerates by either undergoing a chemical reaction or by contributing to a chemical reaction to form cured agglomerates meeting minimum 5N crush strength criteria.
  7. 7. The method of claim 1, wherein the ion exchange step comprises a batch process or a column process, wherein the composition of the active sorbent material is altered to form an active ion exchange sorbent material, and the composition of the ion exchanged agglomerates is distinguishable from the green agglomerate composition by cation exchange to an equivalent extent.
  8. 8. The method of claim 1, wherein calcining the ion exchanged agglomerates is performed under a predefined temperature-time curve, the agglomerates being heated to a temperature of about 450 ℃ to about 700 ℃ while being maintained at the predefined temperature for a period of at least 30 minutes.
  9. 9. The method of claim 1, wherein the adsorbent comprises one or more of zeolite, molecular Organic Framework (MOF), zinc silicate, titanosilicate, binder material, and mixtures thereof.
  10. 10. The method of claim 1, wherein the adsorbent comprises a zeolite selected from X, LSX, Y, A, L, ZSM-5, mordenite, clinoptilolite, chabazite, and mixtures thereof.
  11. 11. The method of claim 10, wherein the zeolite has a SiO 2 /Al 2 O 3 ratio of about 1.9 to 10, and wherein the zeolite comprises cations exchanged with one or more cations selected from H, li, na, K, mg, ca, sr, ba, ag, cu and mixtures thereof to produce an ion-exchanged zeolite.
  12. 12. The method of claim 11, wherein the ion exchange adsorbent is LiX or LiLSX, wherein the extent of Li exchange is greater than or equal to 90% on an equivalent basis.
  13. 13. A process for preparing an ion exchange adsorbent product for use in a gas separation or gas purification adsorber, the process comprising feeding agglomerates to an ion exchange step prior to subjecting an aggregate of the agglomerates to a calcination step, wherein the agglomerates after ion exchange have a crush strength of at least 5N and subsequently undergo a calcination step to obtain the ion exchange adsorbent product.
  14. 14. The method of claim 13, wherein the aggregate of agglomerates fed to the ion exchange step is formed by feeding an aggregate of green agglomerates to a curing step, wherein the curing step comprises one or more of the following: i) A low temperature heating step for driving off volatiles, wherein the green agglomerates are heated to a temperature of about 50 ℃ to 95 ℃ and maintained for a period of 1 hour to about 4 hours, Ii) an aging treatment step wherein the green agglomerates are maintained in a hydrated state at a pressure of from about ambient to about 5 bar and a temperature of less than about 100 ℃ for a period of from 0.5 days to about 10 days, Iii) A chemical curing step wherein the green agglomerates are contacted with at least one compound to shape the curable components in the green agglomerates by either undergoing a chemical reaction or by contributing to a chemical reaction to form cured agglomerates meeting minimum 5N crush strength criteria.
  15. 15. A process for preparing an ion exchange core-shell adsorbent product for use in a gas separation or gas purification adsorber, the process comprising feeding an aggregation of core-shell agglomerates to an ion exchange step prior to subjecting the agglomerates to a calcination step, wherein the agglomerates after ion exchange have a crush strength of at least 5N and subsequently to a calcination step to obtain the ion exchange adsorbent product.
  16. 16. The method of claim 16, wherein the aggregate of agglomerates fed to the ion exchange step is formed by feeding an aggregate of core shell green agglomerates to a curing step, wherein the curing step comprises one or more of the following steps: i) A low temperature heating step for driving off volatiles, wherein the green agglomerates are heated to a temperature of about 50 ℃ to 95 ℃ and maintained for a period of 1 hour to about 4 hours, Ii.) an aging treatment step wherein the green agglomerates are maintained in a hydrated state at a pressure of from about ambient to about 5 bar and a temperature of less than about 100 ℃ for a period of from 0.5 days to about 10 days, Iii.) a chemical curing step wherein the green agglomerates are contacted with at least one compound to shape the curable components in the green agglomerates by undergoing a chemical reaction or by facilitating a chemical reaction to form cured agglomerates meeting minimum 5N crush strength criteria.

Description

Direct exchange of sorbent agglomerates RELATED APPLICATIONS The present application claims the benefit of U.S. provisional application serial No. 63/597,504 filed on day 2023, 11, 9, which is incorporated herein by reference. Technical Field The present invention relates to a process for the manufacture of ion exchange adsorbents and adsorbent formulations having sufficient mechanical strength to be used in industrial scale gas separation or gas purification adsorbers. Background There are manufacturing processes by which an ion exchange step is performed on the adsorbent material to alter the composition of the original adsorbent material. In some process schemes, the adsorbent powder is subjected to an ion exchange step prior to forming shaped particles (such as beads, pellets, extrudates, etc.) for use in industrial scale adsorption gas separation systems. In some other process schemes, the ion exchange step is performed on shaped adsorbent particles formed using an adsorbent material and at least one binder material. The invention relates to the latter type of manufacturing process scheme. In batch or column ion exchange processes, when the calcined and rehydrated agglomerated adsorbent particles are subjected to an ion exchange step, the loss of adsorbent product yield from the ion exchange step can be excessive, thus compromising the manufacture and cost of the adsorbent. Agglomerated sorbent particles containing low binder content (e.g., binder content 10 wt.%) and/or core-shell formulations containing low binder content may have lower particle crush strength and/or attrition resistance. This typically means high yield losses in the operation of the ion exchange unit, which in turn affects the cost of manufacturing such products. It is generally seen that the crush strength (a measure of particle integrity) decreases from a higher value after calcination to a lower value before and after liquid phase ion exchange. Without wishing to be bound by theory, it is believed that this weakening of the particles prior to liquid phase ion exchange from the conventional process is one reason for yield problems in this part of the manufacturing process. The present invention is a direct exchange process that involves fewer manufacturing steps and can be performed on conventional adsorbent materials, where yield loss during ion exchange is not a problem. The improved yield loss and fewer manufacturing steps of the present invention may lead to savings in productivity. In a conventional manufacturing process scheme, the ion exchange steps are performed in a particular order as shown in fig. 1 and 2. In the process scheme shown in fig. 1, the adsorbent powder is ion exchanged and then calcined at an elevated temperature (e.g., 450 ℃ to 700 ℃). In the process scheme shown in fig. 2, the agglomerated particles of the adsorbent material are ion exchanged after calcination at high temperature. After ion exchange, the agglomerated particles are treated in an activation step that requires heating of the ion exchanged agglomerates to reduce the moisture content to about 1% by weight or less. The temperature requirement for activation is a temperature requirement that is capable of reducing the moisture content to the value to be achieved. For zeolitic materials, the activation temperature is typically in the range of 300 ℃ to 450 ℃. As disclosed in us patent No. 5,932,509, there is also a mixing process in which the powder is subjected to some ion exchange, followed by some ion exchange of the agglomerated material after calcination. As explained in us patent No. 6,649,556, it is important to ion exchange with expensive cations (such as lithium) in a manner that minimizes the loss of shaped particles that result in insufficient realization of the value of the expensive lithium. As shown in fig. 2, this approach is to ion exchange the binder-containing agglomerated material after calcination. These agglomerated materials can then be used in column or batch ion exchange processes to minimize losses and maximize lithium utilization. However, when conventional ion exchange processes are applied to sorbent compositions in which the binder content is low (e.g., +≤10 wt.% binder, more particularly+≤7 wt.% binder, and/or core-shell materials containing similar or even slightly higher levels (up to 25 wt.%, more typically 15 wt.%) binder) after calcination, the result is poor manufacturing yields. A batch of zeolite X formulation with only 5wt% clay binder was processed according to the process scheme shown in fig. 2, which was prepared without cores and without any binder conversion step (e.g., caustic digestion process). The production yield reached an acceptable 90% by agglomeration and calcination. Advancing the material to rehydration and lithium ion exchange, the manufacturing yield of this part of the process is reduced to 75%. Among the products recovered from the ion exchange system are "fragments" and pieces of agglomer