Technology for producing hydrogen from coke oven gas through deep deoxygenation and dehydration

Abstract

The invention relates to a technology for producing hydrogen from coke oven gas. The feed gas contains 45-55% of hydrogen. The technology comprises the following steps: removing most of carbon dioxide, C<2+> and methane through first-stage pressure swing adsorption so that the concentration of hydrogen-rich gas is 93-96% and the hydrogen yield is greater than 97%; compressing the hydrogen-rich gas to 0.8-2.8MPa, wherein the compressed exit gas is not cooled (interstage cooling is needed); at 80-110 DEG C, catalyzing oxygen in a deoxygenation tower and generating carbon dioxide with carbon monoxide or catalyzing oxygen and generating water with hydrogen; removing oxygen to below 1ppm and cooling the deoxygenated gas to below 40 DEG C; removing non-hydrogen gas through second-stage pressure swing adsorption; and purifying the hydrogen to 99-99.99999% as required.

Description

technical field [0001] The invention relates to the fields of chemical industry and environmental protection, and is a method for effectively reducing production energy consumption and raw material consumption. Background technique [0002] 1. The hydrogen content of coke oven gas is 45%~55%. To purify hydrogen, the usual practice is to pre-purify heavy hydrocarbons and hydrogen sulfide in coke oven gas, and then compress it to the required hydrogen pressure. Combined adsorbent is used for pressure swing adsorption once. It can effectively increase the concentration of hydrogen to the required concentration of 99%~99.99999%. [0003] 2. Under 1.8MPa, it is difficult to obtain 99.99% hydrogen concentration and 80% hydrogen yield, and it is difficult to obtain 99.9% hydrogen concentration and 90% hydrogen yield. [0004] 3. Especially when the oxygen content in pure hydrogen is required to be as low as <1ppm, the recovery rate of purely using one-stage pressure swing adsor...

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Problems solved by technology

[0004] 3. Especially when the oxygen content in pure hydrogen is required to be as low as <1ppm, the recovery rate of purely using one-stage pressure swing adsorption to extract hydrogen is even lower

Dehydration heat regeneration requires high energy consumption, the regeneration gas needs to be recompressed and then dehydrated repeatedly, the equipment is complicated, and the maintenance cost is high

Moreover, the non-hydrogen components in the coke oven gas are 55-45%, and all these components are compressed to the pressure of hydrogen, which is a serious waste of energy.