Industrial arts for dehydrogenation and denitrogen and de-carbon monoxide from high methane gas and liquefied natural gas production

Abstract

Disclosed is industrial arts for dehydrogenation, denitrogen and de-carbon monoxide from high methane gas and liquefied natural gas production. The industrial arts comprise two parts which are low temperature liquefaction and rectification separation. The low temperature liquefaction part is finished in a cold box through cooling provided by a mixed cryogen. A single tower procedure or a double tower procedure is adopted by the rectification separation part to remove hydrogen, nitrogen and carbon monoxide. Methane component in high methane mixed gas with the hydrogen and the nitrogen is liquefied sequentially through the cold box, rectifying tower bottom reboiler and the cold box, and the high methane mixed gas with the hydrogen and the nitrogen enters into a rectification separation system, and then the hydrogen, the nitrogen and the carbon monoxide are removed. Hydrogen content in obtained liquefied natural gas (LNG) products is less than or equal to 2000 ppm, nitrogen content is less than or equal to 4%, and carbon monoxide content is less than or equal to 6%. The invention further provides a natural gas liquefaction art of the high methane gas with the hydrogen, the nitrogen and the carbon monoxide. The hydrogen, the nitrogen and the carbon monoxide are removed, and meanwhile the LNG with a better separating effect compared with a traditional industrial art is obtained, and process route is advanced. Compared with the traditional industrial art, power consumption of the system can be reduced by 20%.

Description

technical field [0001] The invention provides a process for dehydrogenation, nitrogen and carbon monoxide from methane-rich gas to produce liquefied natural gas. Coal-based synthesis gas, coke oven gas, and methanized coke oven gas contain not only methane, but also nitrogen, hydrogen, and carbon monoxide. In order to obtain liquefied natural gas, they must be removed to a certain extent before they can be used as liquefied natural gas ( LNG) product output. Background technique [0002] Under the pressure of environmental protection and energy cost, the proportion of natural gas as primary energy in various fields of society is gradually increasing, and its application fields have gradually expanded to power generation, automobile gas, industrial gas, urban residential gas, chemical gas, etc. , the market demand is increasing rapidly. The traditional natural gas pipeline supply method is still the mainstream, but due to the limitations of raw material conditions and user ...

AI Technical Summary

Problems solved by technology

Generally speaking, the separation purity of pressure swing adsorption and membrane separation is low, and there is often a contradiction between product yield and purity. However, there are few reports on the application of low temperature liquefaction separation to the purification of methane-rich gas and the production of liquefied natural gas.

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