# US 7,608,734 B2 · Method of producing unsaturated acid in fixed-bed catalytic partial oxidation reactor with high efficiency > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,734 B2 - Document ID: US7608734B2 - Status: Granted - Kind: B2 - Application number: 11/483,752 - Filed: 2006-07-10 - Published: 2007-03-29 - Granted: 2009-10-27 - Earliest claimed: 2005-07-08 - Assignees: LG Chem, Ltd. - Inventors: Kyoung Su Ha; Boo Gon Woo; Jun Seok Ko; Seong Pil Kang; Seok Hwan Choi; Young Bae Kim - Web page: https://patentgrep.com/patent/US7608734B2 ## CPC - C07C 45/34: in unsaturated compounds - B01J 8/0453: {the beds being superimposed one above the other} - B01J 8/0457: {the beds being placed in separate reactors} - B01J 8/067: {Heating or cooling the reactor (B01J8/062 takes precedence)} - C07C 45/35: in propene or isobutene - C07C 45/36: in compounds containing six-membered aromatic rings - C07C 45/37: of >C—O—functional groups to >C=O groups - C07C 51/215: of saturated hydrocarbyl groups - C07C 51/252: {of propene, butenes, acrolein or methacrolein} - B01J 2208/00212: Plates; Jackets; Cylinders - B01J 2208/0053: Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling - B01J 2208/025: Two or more types of catalyst - B01J 2219/0004: Processes in series - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract Disclosed is a process for producing unsaturated aldehydes and/or unsaturated acids from olefins or alkanes in a fixed bed shell-and-tube heat exchanger-type reactor by catalytic vapor phase oxidation. A heat exchanger-type reactor for use in such a process is also disclosed. The process utilizes at least one first-step reaction zone and a second-step reaction zone that is divided into two or more shell spaces by at least one partition. The process may be applied to a single-step process for producing unsaturated acids from alkanes or alkenes. ## Claims ### Claim 1 A process for producing unsaturated aldehydes from olefins by fixed-bed catalytic partial oxidation in a shell-and-tube heat exchanger-type reactor, wherein the reactor comprises a reaction zone for producing the unsaturated aldehydes; the reaction zone is divided into two or more shell spaces by at least one partition; each of the divided shell spaces is independently heat-controlled; a heat transfer medium in the first shell space has a temperature ranging from the lowest active temperature of a catalyst layer packed in a reaction tube corresponding to the first shell space to the lowest active temperature of the catalyst layer plus 20° C., wherein the two or more shell spaces are sequentially referred to as the first shell space, the second shell space, . . ., the nth shell space; and the first shell space is controlled in such a manner that it provides an olefin conversion contribution per length as defined in a following equation of 1.2 to 2.5: olefin conversion contribution per length =(mole number of olefins that have reacted in the relevant catalyst layer zone / mole number of the total olefins supplied to the the reaction zone) / volumetric ratio of the revelant catalyst layer zone to the total catalyst layer of the reaction zone. ### Claim 2 A process for producing unsaturated acids from unsaturated aldehydes or alkanes by fixed-bed catalytic partial oxidation in a shell-and-tube heat exchanger-type reactor, wherein the reactor comprises a reaction zone for producing the unsaturated acids; the reaction zone is divided into two or more shell spaces by at least one partition; each of the divided shell spaces is independently heat-controlled; a heat transfer medium in the first shell space has a temperature ranging from the lowest active temperature of a catalyst layer packed in a reaction tube corresponding to the first shell space to the lowest active temperature of the catalyst layer plus 20° C., wherein the two or more shell spaces are sequentially referred to as the first shell space, the second shell space, . . ., the nth shell space; and the first shell space is controlled in such a manner that it provides an unsaturated aldehyde or alkane conversion contribution per length as defined in a following equation of 1.2 to 2.5: unsaturated aldehyde or alkane conversion contribution per length =(mole number of unsaturated aldehydes or alkanes that have reacted in the relevant catalyst layer zone/mole number of the total unsaturated aldehydes or alkanes supplied to the reaction zone)/volumetric ratio of the relevant catalyst layer zone to the total catalyst layer of the reaction zone. ### Claim 3 (depends on 1) The process according to claim 1, which is for producing (meth)acrolein from at least one compound selected from the group consisting of propylene, isobutylene, t-butyl alcohol, methyl-t-butyl ether and o-xylene. ### Claim 4 (depends on 2) The process according to claim 2, which is for producing (meth)acrylic acid from (meth)acrolein, propane or isobutane. ### Claim 5 (depends on 1) The process according to claim 1, wherein the partition dividing the first shell space from the second shell space is disposed in such a manner that the first shell space covers a temperature peak generated in a front portion of each reaction zone. ### Claim 6 (depends on 5) The process according to claim 5, wherein the partition dividing the first shell space from the second shell space is disposed in a position corresponding to 25% to 50% of the axial length of each reaction zone. ### Claim 7 (depends on 2) The process according to claim 2, wherein the partition dividing the first shell space from the second shell space is disposed in such a manner that the first shell space covers a temperature peak generated in a front portion of each reaction zone. ### Claim 8 (depends on 7) The process according to claim 7, wherein the partition dividing the first shell space from the second shell space is disposed in a position corresponding to 25% to 50% of the axial length of each reaction zone. ### Claim 9 (depends on 1) The process according to claim 1, the first shell space, the second shell space, . . . the nth shell space, divided by the partitions are controlled in such a manner that temperature of the heat transfer medium circulating in each shell space increases along the axial direction. ### Claim 10 (depends on 2) The process according to claim 2, which is for producing unsaturated acids from unsaturated aldehydes, wherein the second shell space through the nth shell space divided by the partitions are controlled in such a manner that temperature of the heat transfer medium circulating in each shell space increases along the axial direction. ### Claim 11 (depends on 2) The process according to claim 2, which is for producing unsaturated acids from alkanes, wherein the first shell space, the second shell space, . . ., the nth shell space divided by the partitions are controlled in such a manner that temperature of the heat transfer medium circulating in each shell space increases along the axial direction. ### Claim 12 (depends on 1) The process according to claim 1, wherein Th1-Tsalt1 ° C. 150 ° C., and ThN-TsaltN ° C. 120° C. wherein N is an integer of 2 or more; Th1 is the highest peak temperature of a reaction mixture in a catalyst layer corresponding to the first shell space; ThN is the highest peak temperature of a reaction mixture in a catalyst layer corresponding to the nth shell space; Tsalt1 is the temperature of a heat transfer medium filled in the first shell space; and TsaltN is the temperature of a heat transfer medium filled in the nth shell space. ### Claim 13 (depends on 2) The process according to claim 2, which is for producing unsaturated acids from unsaturated aldehydes, wherein Thh1-Tsalt1 ° C. 130 ° C., and Thhn-TsaltN ° C. 110 ° C. wherein N is an integer of 2 or more; ThhN is the highest peak temperature of a reaction mixture in a catalyst layer corresponding to the first shell space; ThN is the highest peak temperature of a reaction mixture in a catalyst layer corresponding to the nth shell space; Tsalt1 is temperature of a heat transfer medium filled in the first shell space; and TsaltN is the temperature of a heat transfer medium filled in the nth shell space. ### Claim 14 (depends on 2) The process according to claim 2, which is for producing unsaturated acids from alkanes, wherein Th1-Tsalt1° C. 150 ° C., and ThhN-TsaltN ° C. 120 ° C. wherein N is an integer of 2 or more; Th1 is the highest peak temperature of a reaction mixture in a catalyst layer corresponding to the first shell space; ThhN is the highest peak temperature of a reaction mixture in a catalyst layer corresponding to the nth shell space; Tsalt1 is the temperature of a heat transfer medium filled in the first shell space; and TsaltN is the temperature of a heat transfer medium filled in the nth shell space. ### Claim 15 (depends on 1) The process according to claim 1, wherein a reaction inhibition layer formed of an inactive material alone or a mixture of inactive materials and a catalyst is placed within the catalytic tube in a position corresponding to the position of the partition. ### Claim 16 (depends on 2) The process according to claim 2, wherein a reaction inhibition layer formed of an inactive material alone or a mixture of inactive materials and a catalyst is placed within the catalytic tube in a position corresponding to the position of the partition.