Technology for preparing liquefied natural gas and liquid ammonia by using coke oven gas

Abstract

The invention discloses a technology for preparing liquefied natural gas and liquid ammonia by using coke oven gas. The coke oven gas is subjected to the steps of compression, purification, methanation, cryogenic separation and liquefaction of synthetic natural gas, variable pressure adsorptive separation and liquid ammonia preparation with hydrogen rich gas, so that the liquefied natural gas (LNG) of which methane purity is more than 99 percent and the liquid ammonia reaching national first level standard are obtained. By the technology, the hydrogen byproduct of the coke oven gas for preparing the LNG is fully utilized; effective ingredients of the coke oven gas such as H2, N2, CH4, CO and CO2 are furthest utilized; the CO and the CO2 are methanated, so that the yield of the CH4 is improved by about 1 / 3; the liquefied CH4 is used as the LNG and sold; and the rest nitrogen-containing hydrogen-rich gas is used as a raw material for synthesizing ammonia, so that the additional value of the coke oven gas is improved, and reliable raw material guarantee is provided for developing downstream products with high additional values and prolonging the product chain.

Description

technical field [0001] The invention belongs to the technical field of application of coke oven gas, and in particular relates to a process for producing liquefied natural gas and co-producing liquid ammonia by using coke oven gas. Background technique [0002] my country is the world's largest coke producer. The current total coke production capacity is about 400 million tons. In 2010, the coke output was 388 million tons, accounting for about 62% of the world's total production, and a huge amount of coke oven gas is produced by-product. About 400m by-product per ton of coke 3 Calculation of coke oven gas, in addition to returning to the furnace for heating for personal use, civil use (as city gas), and production of synthetic ammonia or methanol, the annual release of coke oven gas is about 20 billion Nm 3 . [0003] In recent years, there have been many related elaborations on domestic coke oven gas through methanation to produce synthetic natural gas and liquefied natu...

AI Technical Summary

Problems solved by technology

[0006]CN1919985A discloses a hydrogen-rich coke oven gas that returns to the coke oven for combustion. The calorific value and added value are low, and the H in the coke oven gas cannot be effectively and fully utilized. 2 resources

[0007]CN101280235 A: Concentrating hydrogen-rich gas through pressure swing adsorption to produce pure hydrogen, with relatively low added value

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