Method for production of hydroxylammonium phosphate in the synthesis of caprolactam

A technology of caprolactam and oxygen, which is applied to the preparation of lactam, oxime preparation, chemical instruments and methods, etc., can solve the problems of increased production capacity, large capital investment, etc., and achieve the effect of reducing residence time

Inactive Publication Date: 2004-06-30
PRAXAIR TECH INC
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the increase in production capacity of such e

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for production of hydroxylammonium phosphate in the synthesis of caprolactam
  • Method for production of hydroxylammonium phosphate in the synthesis of caprolactam
  • Method for production of hydroxylammonium phosphate in the synthesis of caprolactam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0060] The process of the present invention is used to retrofit an existing caprolactam production plant using the DSM-HPO process, where the upper part of the absorption tower has been damaged. This in turn reduces the reoxidation of NO to NO by the absorber 2 and the ability to absorb nitrate ions. As a result, production is limited and nitrogen oxide emissions increase.

[0061] test

[0062] Therefore, in these tests, about 50-100% of the secondary air stream was diverted from the deaerator to the converter. Oxygen is added at a rate of 3.2-3.8 moles per mole of ammonia added. Oxygen addition removes dissolved NO from nitrate-rich stream 2 , thereby helping to increase NO to NO 2 oxidation and an increase in hydroxylammonium phosphate production of up to 9.8%. Furthermore, said increase in the production of hydroxylammonium phosphate is obtained without an increase in the nitrogen oxide content of the exhaust gas.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A method for production of caprolactam involves: reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; oxidizing at least a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; reactively absorbing the NOx-rich gas stream with phosphoric acid containing solution in an absorption zone to form nitrate ions; contacting the nitrate ions with air in a degassing zone to produce a nitrate-rich aqueous process stream; reducing the nitrate-rich aqueous stream with hydrogen in the presence of phosphoric acid to produce hydroxylammonium phosphate; oximating the hydroxylammonium phosphate with cyclohexanone to produce cyclohexanone oxime; and converting the cyclohexanone oxime to caprolactam. Supplemental oxygen is added downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream.

Description

technical field [0001] The present invention provides improvements to the Dutch State Mines-hydroxyammonium phosphate-oxime process for the preparation of caprolactam. Background technique [0002] Caprolactam can be produced from three hydrocarbon feedstocks: cyclohexane, phenol and toluene. About 68% of the world's caprolactam is produced from cyclohexane, while 31% comes from phenol and 1% from toluene. All production based on cyclohexane and phenol takes place through the formation of cyclohexanone oxime. In 94% of caprolactam production based on cyclohexane and phenol, the formation of this oxime requires an ammoxidation step. [0003] In processes involving an ammoxidation step, the preparation of caprolactam with cyclohexane or phenol can be divided into the following steps: [0004] Oxidation of cyclohexane or hydrogenation of phenol to synthesize cyclohexanone; [0005] Oxidation of ammonia to nitric oxide, followed by various reaction steps to form hydroxylamin...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C07D201/06C07D201/10
CPCC07D201/06C07D201/10C01B21/1418C07C249/08C07C2601/14C07C251/44C07D227/087
Inventor D·F·埃切加赖A·A·M·维洛索M·L·瓦格纳
Owner PRAXAIR TECH INC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap