Device and method for purifying trifluoromethane

A trifluoromethane and purification device technology, which is applied in chemical instruments and methods, disproportionation separation/purification of halogenated hydrocarbons, organic chemistry, etc., can solve the problem of failure to meet the requirements for semiconductor use, easy formation of azeotropes, and low purity of trifluoromethane And other issues

Active Publication Date: 2014-07-30
FOSHAN HUATE GASES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Generally, the purity of high-purity trifluoromethane used in the semiconductor industry is 99.999%, and its purification involves the deep removal technology of various impurities. Trifluoromethane has high polarity, and the raw materials generally contain a large amount of CHCl 3 , CCl 2 f 2 , CHClF 2 , O 2 , N 2 , CO 2 Other impurities, CHF 3 and CO 2 The boiling point is very close to the boiling point and properties of difluorochloromethane, and the two are easy to form an azeotrope, which is difficult to separate
[0004] The purity of the existing industrial trifluoromethane in my country is relatively low, generally 99.8%-99.9%, and there are few reports on the purification of trifluoromethane. Patent 201110423419.4 adopts a low-temperature batch distillation process to prepare high-purity trifluoromethane with a purity of 99.99%. but only considering CHCl 3 , CCl 2 f 2 、CHCl 3 , O 2 , N 2 Impurities are removed, which does not meet the requirements of the semiconductor industry

Method used

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  • Device and method for purifying trifluoromethane
  • Device and method for purifying trifluoromethane

Examples

Experimental program
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Effect test

Embodiment 1

[0049] An embodiment of trifluoromethane purification device of the present invention, such as figure 1 As shown, the device includes a rectification device and an adsorption device connected with the rectification device, and the rectification device includes a primary rectification device 1, a secondary rectification device 2 and a tertiary rectification device connected in sequence 3. The adsorption device includes a low-temperature adsorption device 4 and a filling device 5 connected in sequence, and the low-temperature adsorption device 4 of the adsorption device is connected to the rectification device.

[0050] The primary rectification device 1 comprises a primary rectification tower 13, the top of the primary rectification tower 13 is connected with a primary condenser 15 and a primary discharge pipeline 16 connected with the top of the primary condenser 15 , the middle part of the primary rectification tower 13 is connected with a primary precooler 12 and a primary r...

Embodiment 2

[0061] A method for purifying trifluoromethane using the trifluoromethane purification device described in the present invention, the method is that the trifluoromethane raw material passes through a primary rectification device, a secondary rectification device, a tertiary rectification device, low-temperature adsorption After installing and filling the device, high-purity trifluoromethane is obtained.

[0062] Described trifluoromethane purification method specifically comprises the following steps:

[0063] (1) Purge the entire purification device with high-purity nitrogen, and then vacuumize the entire purification device until the pressure is below 5pa;

[0064] (2) Feed liquid nitrogen into the shell side of the primary condenser and the shell side of the primary precooler of the primary rectification unit, and pass the trifluoromethane raw material at a flow rate of 50Nm3 / h from the primary raw material inlet pipe through the primary pre-cooler The tube side of the coo...

Embodiment 3

[0070] A method for purifying trifluoromethane using the trifluoromethane purification device described in the present invention, the method is that the trifluoromethane raw material passes through a primary rectification device, a secondary rectification device, a low-temperature adsorption device and a filling device in sequence , to obtain high-purity trifluoromethane.

[0071] Described trifluoromethane purification method specifically comprises the following steps:

[0072] (1) Purge the entire purification device with high-purity nitrogen, and then vacuumize the entire purification device until the pressure is below 5pa;

[0073] (2) Feed liquid nitrogen into the shell side of the primary condenser and the shell side of the primary precooler of the primary rectification unit, and pass the trifluoromethane raw material at a flow rate of 50Nm3 / h from the primary raw material inlet pipe through the primary pre-cooler The tube side of the cooler enters the first-stage rectifi...

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Abstract

The invention discloses a device and a method for purifying trifluoromethane. The device comprises a rectification device and an adsorption device connected with the rectification device, wherein the rectification device comprises a first-stage rectification device, a second-stage rectification device and a third-stage rectification device which are connected in sequence; the adsorption device comprises a low-temperature adsorption device and a filling device which are connected in sequence; the low-temperature adsorption device of the adsorption device is connected with the rectification device. Compared with the prior art, the purity of trifluoromethane purified by adopting the device is relatively high, the device is easy to operate, and a purification process is complete, reliable and good in repeatability. The removal of conventional impurities is considered, difficultly removed carbon dioxide, monochlorodifluoromethane, pentafluoroethane, water and particles are removed to be in a qualified range, and the product purity is 99.999% and meets the use requirements of the semiconductor industry.

Description

technical field [0001] The invention belongs to the technical field of gas purification, and in particular relates to a trifluoromethane purification device and a purification method. Background technique [0002] Trifluoromethane is a versatile and chemically stable fluoroalkane. In semiconductor processing, CHF 3 Commonly used in plasma etching or reactive ion etching silicon dioxide process, CHF 3 The characteristic of silicon dioxide is that the etching speed of silicon dioxide is fast, and the etching speed of silicon is slow, that is, not only the selectivity is good, but also the rate difference is large, which meets the requirements of semiconductor technology. The demand for high-purity trifluoromethane used as an etchant in the manufacturing process of 8-12 inch chips continues to increase with the rapid development of the semiconductor industry. [0003] Generally, the purity of high-purity trifluoromethane used in the semiconductor industry is 99.999%, and its...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C19/08C07C17/38C07C17/383C07C17/389
Inventor 马建修陈艳珊
Owner FOSHAN HUATE GASES
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