Device and method for manufacturing liquefied natural gas and hydrogen-rich products out of coke oven gas

Abstract

The invention relates to a device and method for manufacturing liquefied natural gas and hydrogen-rich products out of coke oven gas. The device comprises a mixed refrigerant compressor refrigerating system, a precooling system and a liquefying cold box system. The method comprises a mixed refrigerant cycle process and a purified coke oven gas liquification and separation process. A single mixed refrigeration and single tower rectification process is adopted, and a refrigerant compressor and a rectifying tower can be adopted only; compared with a coke oven gas separation liquification device comprising two refrigerant compressors and two rectifying towers, device investment and system energy consumption are reduced, and starting and shutdown operation is convenient; in overall economic benefit, the device is suitable for a liquefying device which enables the coke oven gas pressure to be high after purification and no lower than 2.3MPa and is not large in coke oven gas treatment scale and enables the scale to be no larger than 1 million standard cubes of purified coke oven gas per day, the device investment is less, unit energy consumption is lower, and the device is simpler to operate.

Description

technical field [0001] The invention relates to a device and method for producing liquefied natural gas and hydrogen-rich products from coke oven gas. Background technique [0002] The most common way to produce methane-rich gas is to increase the calorific value of coke oven gas through methanation reaction, so that most of carbon monoxide and carbon dioxide are converted into methane. The volume fraction of methane obtained is more than 40-50%, and it is also rich in hydrogen and nitrogen. The methane-rich gas is then liquefied at low temperature and rectified at low temperature to produce LNG and hydrogen-rich products. Methane-enriched coke oven gas is purified, liquefied and separated to produce liquefied natural gas, which can not only alleviate the problem of domestic natural gas shortage, but also promote technological progress and industrial development in the coking and energy industries. The development of coke oven gas to LNG projects can generate significant be...

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Problems solved by technology

[0003] The composition of methane-rich gas is quite different from that of conventional natural gas, and the content of nitrogen and hydrogen is relatively high, so the liquefaction and separation process is more complicated and the energy consumption per unit product is higher

[0004] The existing process for producing liquefied natural gas and hydrogen-rich products from coke oven gas includes two refrigerant compressors and two rectification towers, requiring large equipment investment and high energy consumption

[0005] The application number is 200810135211.0, and the name is the Chinese patent of the separation process and equipment for producing liquefied natural gas from coke oven gas. There are still deficiencies in refrigeration effect, coke oven gas liquefaction and separation effect, the unit energy consumption is high, and the production of hydrogen-rich gas is insufficient, which is easy to cause waste

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