Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for preparing aniline through liquid phase hydrogenation of nitrobenzene with low phenol generation amount

A technology of nitrobenzene liquid and nitrobenzene is applied in the preparation of amino compounds, chemical instruments and methods, preparation of organic compounds, etc., can solve the problem of high separation energy consumption, achieve simple process adjustment, reduce purification difficulty, impurity phenol low content effect

Pending Publication Date: 2022-01-18
WANHUA CHEMICAL (NINGBO) CO LTD +2
View PDF5 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In the current mainstream nitrobenzene hydrogenation liquid phase process, the mass concentration of phenol in crude aniline can reach 60-100ppm, and the separation energy consumption is high

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 preparing aniline through liquid phase hydrogenation of nitrobenzene with low phenol generation amount
  • Method for preparing aniline through liquid phase hydrogenation of nitrobenzene with low phenol generation amount
  • Method for preparing aniline through liquid phase hydrogenation of nitrobenzene with low phenol generation amount

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] like figure 1 As shown, the aniline reactor adopts 30 trays. Mix the nitrobenzene with a flow rate of 16850kg / h at 135°C and the aniline solution with a flow rate of 18600kg / h at 90°C containing 2wt% catalyst and send it to the reactor of the reaction tower, and feed hydrogen at a flow rate of 1912kg / h at 72°C , with a flow rate of 10800kg / h, water at 40°C is used to control the temperature of the tower kettle to 69°C. The nitrobenzene with a flow rate of 10110kg / h and 135°C is passed into the 24th tray, and the feed flow rate is 14400kg / h, and the water at 40°C is used to control the temperature of the feed plate to be 183°C. The nitrobenzene with a flow rate of 6740kg / h and 135°C is passed into the 16th tray, the flow rate is 10800kg / h, and the temperature of the feed plate is controlled at 195°C by water at 40°C. During the reaction process, the pressure at the top of the tower was controlled at 17 bar, the temperature at the top of the tower was 218°C, the flow ra...

Embodiment 2

[0031] The aniline reactor uses 32 trays. Mix the nitrobenzene with a flow rate of 18600kg / h at 135°C and the aniline solution with a flow rate of 18600kg / h heated to 90°C containing 2wt% catalyst and send it to the reactor of the reaction tower, and feed hydrogen at a flow rate of 1912kg / h at 72°C , with a flow rate of 16200kg / h, 40 ℃ of water control tower kettle temperature is 66 ℃. The nitrobenzene with a flow rate of 7414kg / h and 135°C is passed into the 25th tray, and the feed flow rate is 7200kg / h, and the temperature of the feed plate is controlled at 188°C by water at 40°C. The nitrobenzene with a flow rate of 7751kg / h and 135°C is passed into the 15th tray, the feed flow rate is 12600kg / h, and the temperature of the feed plate is controlled at 193°C by water at 40°C. During the reaction process, the pressure at the top of the tower was 17 bar, the temperature at the top of the tower was 217°C, the flow rate of aniline in the side line was 14448 kg / h, and 75764 kg / h ...

Embodiment 3

[0033] The aniline reactor uses 28 trays. Mix the nitrobenzene with a flow rate of 13480kg / h at 135°C and the aniline solution containing 2wt% catalyst with a flow rate of 18600kg / h heated to 90°C and send it into the reactor of the reaction tower. Hydrogen, with a flow rate of 13680kg / h, 40 ℃ of water control tower kettle temperature is 65 ℃. The nitrobenzene with a flow rate of 11121kg / h and 135°C is passed into the 23rd tray, and the flow rate is 11880kg / h, and the water at 40°C is used to control the temperature of the feed plate to be 176°C. The nitrobenzene with a flow rate of 9099kg / h and 135°C is passed into the 15th tray, and the feed flow rate is 10440kg / h, and the water at 40°C is used to control the temperature of the feed plate to be 191°C. During the reaction process, the pressure at the top of the tower was controlled at 17 bar, the temperature at the top of the tower was 218°C, the flow rate of aniline in the side line was 13503 kg / h, and 76709 kg / h of crude a...

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

The invention relates to a method for preparing aniline through liquid-phase hydrogenation of nitrobenzene with low phenol generation amount. The method comprises the following steps: feeding raw material nitrobenzene into different height positions of a tower reactor in different streams, controlling the concentration of nitrobenzene in the reaction raw material liquid at the bottom of the reactor to be below 50%, controlling the mass ratio of nitrobenzene to hydrogen at the bottom of the reactor to be 6: 1-10: 1, and reducing the generation amount of a byproduct phenol raw material benzene in the tower, so that the generation amount of phenol is reduced to 20-40ppm. According to the invention, the aniline with low phenol mass concentration prepared by the method is beneficial to reduction of rectification energy consumption of a product rectification tower and improvement of aniline quality.

Description

technical field [0001] The invention relates to a method for preparing aniline, in particular to a method for preparing aniline by liquid-phase hydrogenation of nitrobenzene with low phenol generation. Background technique [0002] Aniline is one of the important organic chemical raw materials. Widely used in industries such as dyes, medicines, explosives, spices, rubber vulcanization accelerators, etc., especially as an important raw material for MDI (4,4-diphenylmethane diisocyanate). In the liquid-phase hydrogenation stage of nitrobenzene, impurities such as cyclohexanol, cyclohexylamine, methylaniline, phenol, and cyclohexanone will be generated. There are no requirements for the mass concentration of cyclohexanol, cyclohexylamine, methylaniline, and phenol in ordinary grade aniline products, but clear regulations are made in MDI grade products. Among these impurities, phenol is difficult to separate due to its small separation coefficient with aniline and requires hig...

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
Patent Type & Authority Applications(China)
IPC IPC(8): C07C209/36C07C211/46
CPCC07C209/36C07C211/46
Inventor 陆洋李艳杰李江孙路滨张宏科何轩
Owner WANHUA CHEMICAL (NINGBO) CO LTD
Features
  • Generate Ideas
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

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

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com