JP-7857374-B2 - Apparatus and process for activating ammonia decomposition catalysts

JP7857374B2JP 7857374 B2JP7857374 B2JP 7857374B2JP-7857374-B2

Inventors

アンドリューショー
ジェイコブシェリー
コイシエ
サイモンクレイグサロウェイ
ダバルドンドゥパティル

Assignees

エアプロダクツアンドケミカルズインコーポレイテッド

Dates

Publication Date: 20260512
Application Date: 20241030
Priority Date: 20240318

Claims (20)

A process for activating a catalyst for ammonia decomposition, wherein the process is A first reactant containing hydrogen is fed to at least one pre-reactor located upstream of a furnace, wherein the furnace has at least one tube within its radiation section, thereby allowing the first reactant to pass through the catalyst material of the at least one pre-reactor and then through the catalyst material of the at least one tube within the radiation section of the furnace. A process comprising, in response to detecting a first level of catalyst activation, stopping the feeding of the first reactant and starting to feed a second reactant, comprising ammonia, to the at least one prereactor and the at least one tube in the radiating section of the furnace, thereby starting the second reactant to pass through the catalyst material of the at least one prereactor and then through the at least one tube in the radiating section of the furnace to fully activate the catalyst material of the at least one tube.
The process according to claim 1, wherein the feeding of the first reactant and the feeding of the second reactant are carried out such that the catalyst material in the upstream portion of the at least one tube is fully activated, then the catalyst material in the at least one pre-reactor is fully activated, then, after the catalyst material in the at least one pre-reactor is fully activated, and after the catalyst material in the upstream portion of the at least one tube is fully activated, the catalyst material in the downstream portion of the at least one tube is fully activated.
The process according to claim 1, wherein the feeding of the second reactant containing ammonia is carried out such that the catalyst material in the downstream portion of at least one tube is finally fully activated.
The process according to claim 1, comprising: mixing nitrogen with the ammonia of the second reactant such that the second reactant has ammonia at a pre-selected ammonia concentration and/or the second reactant has a pre-selected flow rate; and/or mixing nitrogen with the hydrogen of the first reactant such that the first reactant has hydrogen at a pre-selected hydrogen concentration and/or the first reactant has a pre-selected flow rate.
The process according to claim 1, wherein the at least one pre-reactor includes a first pre-reactor having a catalytic material in the vessel of the first pre-reactor, and a second pre-reactor having a catalytic material in the vessel of the second pre-reactor, wherein the second pre-reactor is located downstream of the first pre-reactor, such that the second pre-reactor is located between the at least one tube of the furnace and the first pre-reactor.
The feeding of the first reactant is (a) The catalyst material in the upstream portion of at least one tube is fully activated, (b) The catalyst material in the second pre-reactor is fully activated, and (c) The catalyst material in the first pre-reactor is fully activated. The feeding of the second reactant is (d) The process according to claim 5, wherein the catalyst material in the downstream portion of at least one tube is fully activated.
The process according to claim 6, wherein the catalyst material in the downstream portion of the at least one tube has a higher activation temperature than the catalyst material in the upstream portion of the at least one tube.
The process according to claim 7, wherein the catalyst material in the downstream portion of at least one tube has a higher activation temperature than the catalyst material in the first pre-reactor.
The process according to claim 8, wherein the catalyst material in the downstream portion of the at least one tube has a higher activation temperature than at least a portion of the catalyst material in the second pre-reactor.
The process according to claim 1, wherein the feeding of the first reactant further includes recirculating the first reactant through the at least one tube and the at least one pre-reactor over a first period of time.
The process according to claim 1, comprising, in response to detecting a first level of catalyst activation, exhausting the first reactant and simultaneously beginning to feed the second reactant toward the at least one pre-reactor and the at least one tube.
An apparatus for ammonia decomposition configured to facilitate catalyst activation, wherein the apparatus is , At least one of a temperature sensor and a hydrogen concentration sensor, A furnace having at least one tube, wherein the furnace includes a catalytic material in the at least one tube for the decomposition of ammonia, and the catalytic material in the at least one tube has an upstream portion of the catalytic material and a downstream portion of the catalytic material, A pre-reactor located upstream of the at least one tube, wherein the at least one tube is in fluid communication with the at least one pre-reactor, comprising the at least one pre-reactor The aforementioned device A first reactant containing hydrogen is feedable to the at least one pre-reactor and the at least one tube such that the first reactant passes through the catalyst material of the at least one pre-reactor and then through the catalyst material of the at least one tube, and Apparatus sized and configured such that a second reactant containing ammonia can be fed to the at least one prereactor and the at least one tube, thereby allowing the first reactant to be exhausted in response to the detection of a first level of catalyst activation, and allowing the second reactant to be fed to the at least one prereactor and the at least one tube so as to be able to pass through the catalyst material of the at least one prereactor to completely activate at least a portion of the catalyst material of the at least one tube , and then pass through the at least one tube.
The apparatus is configured such that the feeding of the first reactant is carried out so that the upstream portion of the catalyst material in the at least one tube is first fully activated, and then the catalyst material in the at least one pre-reactor is fully activated. The apparatus according to claim 12, wherein the second reactant can be supplied to the at least one tube and the at least one pre-reactor so that the downstream portion of the catalyst material in the at least one tube is fully activated after the catalyst material in the at least one pre-reactor has been fully activated and the upstream portion of the catalyst material in the at least one tube has been fully activated.
The apparatus according to claim 12, wherein the apparatus is configured such that the feeding of the second reactant is carried out so that the downstream portion of the catalyst material in at least one tube is finally fully activated.
The apparatus according to claim 12, wherein the at least one pre-reactor includes a first pre-reactor having a catalyst material in the vessel of the first pre-reactor, and a second pre-reactor having a catalyst material in the vessel of the second pre-reactor, wherein the second pre-reactor is located downstream of the first pre-reactor so that the second pre-reactor is located between the at least one tube of the furnace and the first pre-reactor.
The apparatus, the feeding of the first reactant, (a) The upstream portion of the catalyst material in at least one tube is fully activated, (b) The catalyst material in the second pre-reactor is fully activated, and (c) The catalyst material in the first pre-reactor is fully activated. The feeding of the second reactant is (d) The apparatus according to claim 15, wherein the catalyst material in the downstream portion of the catalyst material of at least one tube is configured to be fully activated.
The apparatus according to claim 16, wherein the downstream portion of the catalyst material of the at least one tube has a higher activation temperature than the upstream portion of the catalyst material of the at least one tube.
The downstream portion of the catalyst material in at least one tube has a higher activation temperature than the catalyst material in the first pre-reactor. The apparatus according to claim 17, wherein the catalyst material in the downstream portion of the at least one tube has a higher activation temperature than at least a portion of the catalyst material in the second prereactor.
The apparatus according to claim 12, comprising a reactant recirculation conduit arrangement positioned such that the first reactant can be recirculated from the outlet of at least one tube to the at least one pre-reactor.
An apparatus for ammonia decomposition configured to facilitate catalyst activation, wherein the apparatus is , At least one of a temperature sensor and a hydrogen concentration sensor, A furnace having at least one tube, wherein the furnace contains a catalytic material in the at least one tube for the decomposition of ammonia, and the catalytic material in the at least one tube has a more active portion of the catalytic material that is more active than the less active portion of the catalytic material, A pre-reactor located upstream of the at least one tube, wherein the at least one tube is in fluid communication with the at least one pre-reactor, comprising the at least one pre-reactor The aforementioned device A first reactant containing hydrogen is feedable to the at least one pre-reactor and the at least one tube such that the first reactant passes through the catalyst material of the at least one pre-reactor and then through the catalyst material of the at least one tube, and Apparatus sized and configured such that a second reactant containing ammonia can be fed to the at least one prereactor and the at least one tube, thereby allowing the first reactant to be exhausted in response to the detection of a first level of catalyst activation, and allowing the second reactant to pass through the catalyst material of the at least one prereactor to completely activate the less active portion of the catalyst material in the at least one tube, and then pass through the at least one tube, so that the second reactant can be fed to the at least one prereactor and the at least one tube.

Description

Cross-reference of related applications This application claims priority to U.S. Provisional Patent Application No. 63/596,320, filed on 6 November 2023. This invention relates to a process and apparatus for activating catalytic materials used in ammonia decomposition plants and processes. Ammonia can be decomposed to produce hydrogen. Examples of processes that may be used to decompose ammonia can be understood from U.S. Patent Application Publication No. 2023/0242395 and International Publication Nos. 2022/265647, 2022/265648, 2022/265649, 2022/265650, 2022/265651, and pending U.S. Patent Applications Nos. 17/990,832, 17/990,823, 17/990,817, and 17/990,815. The ammonia decomposition process may involve the use of catalytic materials that facilitate the decomposition of ammonia into hydrogen and nitrogen gases. Catalyst activation can depend on the catalyst formulation. Activation typically begins at a relatively low temperature and increases towards a higher final temperature. The final temperature generally depends on the active metal species on the catalyst. For example, ruthenium (Ru) catalysts typically use lower final activation temperatures (e.g., below 350°C), while nickel (Ni) catalysts often require higher final activation temperatures (e.g., above 350°C). Ru catalysts may also have more stringent requirements regarding temperature rise and retention time for catalyst activation compared to Ni catalysts. Andrew, S. P. (1981), Theory and practice of the formulation of heterogeneous catalytics. Chemical Engineering Science, 36(9), 1431-1445 discloses that activation of catalytic materials may involve exposing the catalytic material to a combination of a higher temperature environment (e.g., application of heat) and exposure to a reducing agent. Twigg, M. V. (1996). Catalyst Handbook (2nd ed.). London: Manson Publishing Ltd. ("Twigg") discloses that hydrogen is a commonly used reducing agent. Twigg also discloses that the catalyst activation process is carried out to reduce the precursor metal oxide of the supported metal catalyst to microcrystals of the metal catalyst, so that the catalyst is activated and can provide a change in the reaction mechanism that can help reduce the activation energy or accelerate the chemical reaction. It has been identified that catalysts used for ammonia decomposition can be shipped in an oxidized, semi-oxidized, or at least partially passivated state that may require activation before use in ammonia decomposition. As described above, activation of the catalyst material may involve the use of a process in which the catalyst material is exposed to a reducing environment, such as hydrogen-containing gas and heat, for activation (e.g., removing oxides, removing an oxide layer surrounding or covering the internal catalyst metal material, removing a passivation layer surrounding or covering the internal catalyst metal material, etc.). Conventionally, activation would be carried out using hydrogen mixed with an inert gas such as nitrogen (see, for example, Twigg, M.V. (1996). Catalyst Handbook (2nd ed.). London: Manson Publishing Ltd.). However, we have found that the activation of catalytic materials that can be positioned in furnaces used for ammonia decomposition (e.g., hydrogen ( H₂ ) and nitrogen ( N₂) ) is important. We have identified that the heat exchangers located within the furnace tubes through which ammonia can pass to be heated and decomposed in the furnace to form a catalyst may require very high temperatures (e.g., temperatures above 500°C or above 600°C (e.g., 450°C–700°C, 550°C–675°C, 500°C–700°C, etc.)). We have identified that such high temperatures in the furnace during the long-duration catalyst activation process may cause some types of front-end heat exchangers disclosed in U.S. Patent Applications No. 17/990,823, 17/990,817, and 17/990,815 to exceed their design temperatures unless they are made of special materials that can withstand very high temperatures due to how the reducing agent and heat can be recirculated through the reactor and furnace for the activation of the catalyst material. However, utilizing such special equipment may be detrimental to the procurement of such equipment and result in increased costs, delays in production or installation, and increased special maintenance work and/or maintenance costs. For example, the use of more specialized equipment may increase safety risks due to the increased rating of different metals or equipment, which can introduce an increase in items requiring maintenance supervision and monitoring. Avoiding or minimizing the use of such equipment may help avoid this increased safety risk and the additional maintenance activities of these types that would be utilized to account for that increased risk. We identified that such a high-temperature profile for catalyst activation within an ammonia decomposition unit configured to implement an ammonia decomposition process can be avoided, allowing the use of f