Process for producing 3,5-xylenol under reduced pressure by using organic heat carrier heating technology

A technology of xylenol and industrial xylenol, which is applied in the field of coking, can solve the problems of difficult control of gas heating temperature, insensitive temperature adjustment, and poor fraction separation effect, etc., to achieve convenient operation and maintenance, sensitive and accurate temperature adjustment, and reduce production cost effect

Inactive Publication Date: 2019-01-22
鞍钢化学科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The content of xylenol in coal tar only accounts for about 0.1%. To obtain raw materials for the production of 3,5-xylenol requires multiple processes such as separation and washing of coal tar, and the process is relatively complicated.
[0004] The basic raw material for purifying 95% of 3,5-xylenol in the conventional process is generally industrial xylenol, which is extracted by gas heating and atmospheric distillation. The main defects are: 1. The gas heating temperature is not easy Control, temperature adjustment is not sensitive; 2. Atmospheric distillation has many disadvantages such as poor separation effect of each fraction, large energy consumption, etc.

Method used

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  • Process for producing 3,5-xylenol under reduced pressure by using organic heat carrier heating technology
  • Process for producing 3,5-xylenol under reduced pressure by using organic heat carrier heating technology
  • Process for producing 3,5-xylenol under reduced pressure by using organic heat carrier heating technology

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Effect test

Embodiment 1

[0041] See figure 1 , a process for producing 3,5-xylenol under reduced pressure with organic heat carrier heating technology. Heat carrier heating technology adopts the production process of negative pressure batch rectification to industrially produce 3,5-xylenol in a single tank, the details are as follows:

[0042] 1) The heat-conducting oil heated by the burner 7 is used as a heat carrier to circulate heat for the distillation kettle 4 .

[0043] Start the burner 7, and the heat transfer oil continues to heat up in the circulation pipeline (the outlet of the thermal oil pump 6 → the burner 7 → the instant heat unit of the still 4 → the oil return main pipe → the inlet of the thermal oil pump 6). The temperature at the top of the tower controls the heating rate.

[0044] 2) Start the vacuum pump 8, adjust the opening of the outlet valve of the vacuum pump 8 to keep the vacuum degree in the rectification tower between 60-90KPa, and the pressure difference between the bott...

Embodiment 2

[0052] See figure 1 , a process for producing 3,5-xylenol under reduced pressure using organic heat carrier heating technology. The industrial production of 3,5-xylenol in kettles is as follows:

[0053] 1) The heat-conducting oil heated by the burner 7 is used as a heat carrier to circulate heat for the distillation kettle 4 .

[0054] 2) Start the vacuum pump 8, adjust the opening of the outlet valve of the vacuum pump 8 to keep the vacuum degree in the rectification tower between 60-90KPa, and the pressure difference between the bottom and the top of the tower is 6-10KPa.

[0055] 3) Negative pressure rectification of two kettles to process industrial xylenol at the same time. After the raw materials in the still 4 are heated, the mixed vaporized fraction enters the rectification tower from the still 4 through the riser, and a part of the top gas phase fraction is liquefied and combined with the tower The bottom gas phase fraction conducts heat and mass transfer on the pa...

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Abstract

The invention provides a process for producing 3,5-xylenol under reduced pressure by using an organic heat carrier heating technology. According to the process, commercial xylenol is used as a base material to cut an intermediate fraction with a 3,5-xylenol content of no less than 50%; and the organic heat carrier heating technology and the production process of negative-pressure batch rectification are employed for industrially producing 3,5-xylenol in a single kettle. The invention has the following beneficial effects: negative-pressure rectification effectively saves energy and lowers production cost; the organic heat carrier heating technology has the advantages of low pressure and high temperature, and the heat supply temperature of the organic heat carrier heating technology is up to340 DEG C in a liquid phase and 400 DEG C in a gas phase; and heat-conducting oil is used as a medium and a hot-oil circulation oil pump is used for forcing the medium to perform liquid phase circulation, so sensitive and precise temperature adjustment is realized; a system is high in heat utilization rate, and due to overall installation of modules, the system is convenient to operate and maintain, safe, highly efficient and energy-saving, and is especially applicable to the production of small-tonnage tar products and the like; and important process parameters for single-kettle and dual-kettle rectification with different raw material contents are accumulated, so a solid data foundation is laid for the development of new varieties.

Description

technical field [0001] The invention relates to the technical field of coking, in particular to a process for producing 3,5-xylenol under reduced pressure by heating an organic heat carrier. Background technique [0002] 3,5-Xylenol is widely used in the preparation of pharmaceutical intermediates, preservatives, dyes, etc. The content of xylenol in coal tar only accounts for about 0.1%. To obtain raw materials for the production of 3,5-xylenol requires multiple processes such as separation and washing of coal tar, and the process is relatively complicated. [0003] 95% content of 3,5-xylenol is a high value-added small-tonnage product with a large profit margin and obvious competitive advantages. 95% content 3,5-xylenol can also be used as an ideal raw material for purifying 99% content 3,5-xylenol. [0004] The basic raw material for purifying 95% of 3,5-xylenol in the conventional process is generally industrial xylenol, which is extracted by gas heating and atmospheric...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/74C07C39/08
CPCC07C37/74C07C39/08Y02P20/10
Inventor 范壮穆春丰张德敬臧旭王晓楠贾楠楠
Owner 鞍钢化学科技有限公司
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