A kind of device and method for preparing benzene and xylene from toluene and heavy aromatics

A technology for heavy aromatics and xylene, applied in chemical instruments and methods, organic chemistry, hydrocarbons, etc., can solve the problems of hydrogen waste, PSA pressure swing adsorbent deactivation, etc., to reduce the amount of replenishment, reduce the impact, The effect of improving economic efficiency

Active Publication Date: 2018-10-02
NINGBO ZHONGJIN PETROCHEM CO LTD
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing technology of alkyl migration of toluene and heavy aromatics maintains the concentration and partial pressure of hydrogen by continuously adding new hydrogen and discharging low-purity waste hydrogen. The hydrogen content in waste hydrogen is 70%, which has caused severe hydrogen waste; some enterprises recover this part of the waste hydrogen through the supporting PSA pressure swing adsorption system, but because the waste hydrogen contains a small amount of C5 components, especially when the alkyl migration process fluctuates, the C5 content is higher, and this part of the C5 will be Causes deactivation of PSA pressure swing adsorbent

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
  • A kind of device and method for preparing benzene and xylene from toluene and heavy aromatics

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 2

[0025] A method for preparing benzene and xylenes from toluene and heavy aromatics, comprising the following steps:

[0026] a. After mixing toluene, heavy aromatics and hydrogen, heat it through the feed heat exchanger 1 to 350°C with a pressure of 3.2MPa, then enter the feed heating furnace 2 for heating, and raise the temperature to 390°C with a pressure of 3.1MPa;

[0027] b. Enter reactor 3 for reaction, the reaction pressure is 1MPa, the reaction temperature is 350°C; the molar ratio of hydrogen to oil molecules is 3.0; the reaction space velocity is 3.0h -1 ;

[0028] c. After the reaction product comes out of the reactor 3, it is cooled to 110°C through the feed heat exchanger 1, and the pressure reaches 2.6MPa, and then cooled to 40°C through the air cooler 4, and the pressure reaches 2.0MPa, and then enters the gas-liquid separation tank 5 ;

[0029] d. The gas-liquid separation tank 5 divides the reaction product into two streams of gas phase and liquid phase. The...

Embodiment 3

[0035] A method for preparing benzene and xylenes from toluene and heavy aromatics, comprising the following steps:

[0036] a. After mixing toluene, heavy aromatics and hydrogen, heat it through the feed heat exchanger 1 to 400°C, the pressure is 3.2MPa, and then enter the feed heating furnace 2 to heat, and the temperature is raised to 400°C, the pressure is 3.1MPa;

[0037] b. Enter reactor 3 for reaction, the reaction pressure is 3MPa, the reaction temperature is 450°C; the molar ratio of hydrogen to oil molecules is 4.5; the reaction space velocity is 3.5h -1 ;

[0038] c. After the reaction product comes out of the reactor 3, it is cooled to 130°C through the feed heat exchanger 1, and the pressure reaches 2.8MPa, and then cooled to 60°C through the air cooler 4, and the pressure reaches 2.6MPa, and then enters the gas-liquid separation tank 5 ;

[0039] d. The gas-liquid separation tank 5 divides the reaction product into two streams of gas phase and liquid phase. The...

Embodiment 4

[0045] A method for preparing benzene and xylenes from toluene and heavy aromatics, comprising the following steps:

[0046] a. After mixing toluene, heavy aromatics and hydrogen, heat it through the feed heat exchanger 1 to 380°C with a pressure of 3.2MPa, and then enter the feed heating furnace 2 to heat up to 410°C with a pressure of 3.1MPa;

[0047] b. Enter reactor 3 for reaction, the reaction pressure is 2MPa, the reaction temperature is 380°C; the molar ratio of hydrogen to oil molecules is 3.5; the reaction space velocity is 3.2h -1 ;

[0048] c. After the reaction product comes out of the reactor 3, it is cooled to 120°C through the feed heat exchanger 1, and the pressure reaches 2.7MPa, and then cooled to 50°C through the air cooler 4, and the pressure reaches 2.5MPa, and then enters the gas-liquid separation tank 5 ;

[0049] d. The gas-liquid separation tank 5 divides the reaction product into two streams of gas phase and liquid phase. The gas phase stream is mai...

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 discloses a device and method for preparing benzene and xylene from methylbenzene and heavy aromatics. Methylbenzene, heavy aromatics and hydrogen are preheated and then sent to a reactor, a reaction product is cooled and then divided into a gas-phase material flow and a liquid-phase material flow in a gas-liquid separating tank, the gas-phase material flow is refrigerated through a low-temperature reformate heat exchanger and a refrigerator and then enters a frozen contact tank, foreign matter in hydrogen after reaction is removed, and hydrogen is boosted through a compressor and then is recycled; the liquid-phase material flow in the gas-liquid separating tank is subjected to heat exchange and then enters a stripping tower, bottom liquid fractions in the stripping tower enter a benzol stripper to be rectified so that benzene can be obtained, and then enter a methylbenzene tower to be rectified so that methylbenzene can be recovered, and re-feeding is conducted; bottom liquid of the methylbenzene tower enters a xylene tower to be rectified so that xylene can be obtained, and bottom heavy aromatics in the xylene tower are sent to a raw material inlet for re-feeding. By the adoption of the device and method, on the premise that the concentration of reaction hydrogen and partial pressure are maintained, new hydrogen supplement and influences on follow-up processes are reduced, and total recovery of methylbenzene and heavy aromatics is achieved on the premise that benzene and xylene with high purity are obtained.

Description

technical field [0001] The invention belongs to the field of petrochemical production, and more specifically relates to a device and a method for preparing benzene and xylene from toluene and heavy aromatics. Background technique [0002] With the development of economy, the consumption of p-benzene and xylene chemical products in my country is increasing year by year. Domestic enterprises mostly use reformed gasoline as raw material to produce products such as benzene, p-xylene and o-xylene, but by-product toluene and C9 / C10 and above heavy aromatics. Alkyl migration technology uses cheap toluene and heavy aromatics as raw materials to generate benzene and xylene through shape-selective catalysis, and then obtain high value-added benzene and xylene through simple separation. Therefore, the economic benefit is remarkable. The existing technology of alkyl migration of toluene and heavy aromatics maintains the concentration and partial pressure of hydrogen by continuously ad...

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 Patents(China)
IPC IPC(8): C07C6/12C07C15/04C07C15/06
CPCC07C6/126C07C15/04C07C15/06
Inventor 张风雷杨春孙晓明
Owner NINGBO ZHONGJIN PETROCHEM CO LTD
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