Patents by Inventor Jih-Dar Hwang
Jih-Dar Hwang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9902700Abstract: The present disclosure provides a method for preparing a caprolactam and the method includes steps of subjecting cyclohexanone oxime and sulfuric acid to a Beckmann rearrangement reaction to obtain a rearrangement mixture; neutralizing the rearrangement mixture and extracting the neutralized rearrangement mixture using an organic solvent sequentially; and subjecting the extracted organic solution to a hydrogenation reaction so as to simplify the process to produce a high quality caprolactam.Type: GrantFiled: November 14, 2016Date of Patent: February 27, 2018Assignee: China Petrochemical Development CorporationInventors: Yung-Shun Kung, Jih-Dar Hwang, Yao-Ching Tsai
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Publication number: 20170121289Abstract: The present disclosure provides a method for preparing a caprolactam and the method includes steps of subjecting cyclohexanone oxime and sulfuric acid to a Beckmann rearrangement reaction to obtain a rearrangement mixture; neutralizing the rearrangement mixture and extracting the neutralized rearrangement mixture using an organic solvent sequentially; and subjecting the extracted organic solution to a hydrogenation reaction so as to simplify the process to produce a high quality caprolactam.Type: ApplicationFiled: November 14, 2016Publication date: May 4, 2017Inventors: Yung-Shun Kung, Jih-Dar Hwang, Yao-Ching Tsai
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Patent number: 9518024Abstract: The present disclosure provides a method for preparing a caprolactam and the method includes steps of subjecting cyclohexanone oxime and sulfuric acid to a Beckmann rearrangement reaction to obtain a rearrangement mixture; neutralizing the rearrangement mixture and extracting the neutralized rearrangement mixture using an organic solvent sequentially; and subjecting the extracted organic solution to a hydrogenation reaction so as to simplify the process to produce a high quality caprolactam.Type: GrantFiled: January 15, 2016Date of Patent: December 13, 2016Assignee: China Petrochemical Development CorporationInventors: Yung-Shun Kung, Jih-Dar Hwang, Yao-Ching Tsai
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Publication number: 20160237038Abstract: The present disclosure provides a method for preparing a caprolactam and the method includes steps of subjecting cyclohexanone oxime and sulfuric acid to a Beckmann rearrangement reaction to obtain a rearrangement mixture; neutralizing the rearrangement mixture and extracting the neutralized rearrangement mixture using an organic solvent sequentially; and subjecting the extracted organic solution to a hydrogenation reaction so as to simplify the process to produce a high quality caprolactam.Type: ApplicationFiled: January 15, 2016Publication date: August 18, 2016Inventors: Yung-Shun Kung, Jih-Dar Hwang, Yao-Ching Tsai
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Patent number: 9012679Abstract: A method for continuously preparing a carboxylic acid ester is disclosed. In the method of the present invention, a vertical reactor is filled with a solid catalyst, a carboxylic acid and an alcohol are introduced into a lower part of the vertical reactor, esterification is performed to form an esterized mixture, the esterized mixture is output from an upper part of the vertical reactor, and distillation is performed to isolate the carboxylic acid ester. The method of the present invention is simple, easily controlled and environmental friendly, and has significantly high conversion rate and selectivity.Type: GrantFiled: October 15, 2012Date of Patent: April 21, 2015Assignee: China Petrochemical Development CorporationInventors: Jih-Dar Hwang, Yung-Shun Kung, Yao-Ching Tsai
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Publication number: 20130303796Abstract: A method for continuously preparing a carboxylic acid ester is disclosed. In the method of the present invention, a vertical reactor is filled with a solid catalyst, a carboxylic acid and an alcohol are introduced into a lower part of the vertical reactor, esterification is performed to form an esterized mixture, the esterized mixture is output from an upper part of the vertical reactor, and distillation is performed to isolate the carboxylic acid ester. The method of the present invention is simple, easily controlled and environmental friendly, and has significantly high conversion rate and selectivity.Type: ApplicationFiled: October 15, 2012Publication date: November 14, 2013Applicant: China Petrochemical Development Corporation, Taipei (Taiwan)Inventors: Jih-Dar Hwang, Yung-Shun Kung, Yao-Ching Tsai
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Patent number: 7785549Abstract: A recycling system for hydroxylamine formation and oximation is proposed. The recycling system includes a hydroxylamine formation zone, an oximation zone, a purification zone, and an adjusting zone having a nitrate absorption tower. An inorganic process solution, used by the recycling system, partially enters the nitrate absorption tower supplementing nitrate, followed by mixing with the residual inorganic process solution, thereby reducing the loss rate of hydroxylamine in the inorganic process solution due to degradation. In addition, the organic impurities with high boiling point in the inorganic process solution can be effectively removed in the purification zone. As a result, the reduced activity or selectivity of the catalyst for hydroxylamine formation, caused by the toxic effects of these organic impurities on the catalyst, can be avoided, and hence, a high concentration of hydroxylamine can be obtained.Type: GrantFiled: September 11, 2007Date of Patent: August 31, 2010Assignee: China Petrochemical Development CorporationInventors: Jih-Dar Hwang, Hsiu-Li Cheng, Shou-Li Luo
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Patent number: 7671236Abstract: Provided is a process of producing cyclohexanone oxime comprising the steps of: pre-mixing an inorganic process solution containing a high concentration of hydroxylamine phosphate with a first stream of cyclohexanone such that the concentration of hydroxylamine phosphate is reduced to 80% or less of its initial concentration; and subjecting hydroxylamine phosphate in the premixed inorganic process solution to an oximation reaction with a second stream of cyclohexanone. According to the process, oximation is performed after the inorganic process solution containing a high concentration of hydroxylamine phosphate has been pre-mixed with the first stream of cyclohexanone to reduce the concentration of hydroxylamine phosphate. As a result, not only that the efficiency of oximation and the yield of cyclohexanone oxime are increased, but also the organic content of the inorganic process solution discharged from the oximation tower is reduced.Type: GrantFiled: November 20, 2007Date of Patent: March 2, 2010Assignee: China Petrochemical Development CorporationInventors: Jih-Dar Hwang, Kai-Hung Haung, Hsiu-Li Cheng, Shou-Li Luo
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Publication number: 20080167496Abstract: Provided is a process of producing cyclohexanone oxime comprising the steps of: pre-mixing an inorganic process solution containing a high concentration of hydroxylamine phosphate with a first stream of cyclohexanone such that the concentration of hydroxylamine phosphate is reduced to 80% or less of its initial concentration; and subjecting hydroxylamine phosphate in the premixed inorganic process solution to an oximation reaction with a second stream of cyclohexanone. According to the process, oximation is performed after the inorganic process solution containing a high concentration of hydroxylamine phosphate has been pre-mixed with the first stream of cyclohexanone to reduce the concentration of hydroxylamine phosphate. As a result, not only that the efficiency of oximation and the yield of cyclohexanone oxime are increased, but also the organic content of the inorganic process solution discharged from the oximation tower is reduced.Type: ApplicationFiled: November 20, 2007Publication date: July 10, 2008Applicant: China Petrochemical Development CorporationInventors: Jih-Dar Hwang, Kai-Hung Haung, Hsiu-Li Cheng, Shou-Li Luo
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Publication number: 20080167495Abstract: A recycling system for hydroxylamine formation and oximation is proposed. The recycling system includes a hydroxylamine formation zone, an oximation zone, a purification zone, and an adjusting zone having a nitrate absorption tower. An inorganic process solution, used by the recycling system, partially enters the nitrate absorption tower supplementing nitrate, followed by mixing with the residual inorganic process solution, thereby reducing the loss rate of hydroxylamine in the inorganic process solution due to degradation. In addition, the organic impurities with high boiling point in the inorganic process solution can be effectively removed in the purification zone. As a result, the reduced activity or selectivity of the catalyst for hydroxylamine formation, caused by the toxic effects of these organic impurities on the catalyst, can be avoided, and hence, a high concentration of hydroxylamine can be obtained.Type: ApplicationFiled: September 11, 2007Publication date: July 10, 2008Applicant: China Petrochemical Development CorporationInventors: Jih-Dar Hwang, Hsiu-Li Cheng, Shou-Li Luo
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Patent number: 6063958Abstract: A method of recovering adipic acid and 6-hydroxycaproic acid from the waste solution of alkali metal salts of organic acids coming from the process of cyclohexane oxidation, which comprises:(i) basifying the reaction mixture coming from cyclohexane oxidation with an aqueous solution of an alkali-metal base so that the organic acids essentially comprising adipic acid and 6-hydroxycaproic acid therein, are saponified, extracting the formed alkali metal salts of organic acids from the mixture with water, then acidifying the aqueous extract comprising the alkali metal salts of organic acids to a pH value of 3 or lower with an aqueous solution of a protic inorganic acid, as a result, said aqueous extract is separated into an oily layer and an aqueous layer;(ii) extracting the organic acid from said oily layer obtained from the step (i) with an aqueous solution of a protic inorganic acid, to obtain an aqueous extract;(iii) extracting the organic acid from the aqueous layer obtained from the step (i) with an organicType: GrantFiled: December 22, 1998Date of Patent: May 16, 2000Assignee: China Petrochemical Development CorporationInventors: Kuang-Ruei Chen, Jih-Dar Hwang, Shu-Hui Chen