Method for deoxidizing and concentrating mine gas

Abstract

The invention discloses a method for deoxidizing and concentrating a mine gas, which comprises: a step of deoxidization, in which a raw material gas is delivered into a deoxidization reactor so as to reduce oxygen in the raw material gas from about 10 volume percent to less than 1 volume percent by dense and dilute phase two-stage catalysis process in the deoxidization reactor; a step of system fluctuation control, in which software and hardware are used to monitor and process coal bed gas disturbance and gas composition change; a step of denitrification, in which a pressure swing adsorption denitrifying device is used to remove most nitrogen to purify the methane in a coal bed gas till the content of the methane is above 90 percent; a step of decarbonization, in which gas treated by the denitrification step is subjected to CO2 absorption by an amine method as well as H2S removal; and a step of compression, in which the decarbonized gas is compressed in a compression process, dehydrated and liquefied to be turned into a compressed natural gas or a liquefied natural gas.

Description

technical field [0001] The invention relates to the field of mine gas deoxygenation and concentration production, in particular to a mine gas deoxygenation and concentration process for converting gas with low methane content into natural gas. Background technique [0002] Gas gushing out of coal cracks during coal mining is commonly known as "gas", and its main component is CH 4 (methane). For the safe production of coal mines, the national "Coal Mine Safety Regulations" requires that coal mines must install a complete ventilation system, through which fresh air will be introduced into the tunneling roadway and coal mining face, and the gas-containing airflow will be extracted to the ground for centralized discharge. The gas mixed with gas and air is what we call extraction coalbed methane (commonly known as mine gas). Mine gas is generally a mixture of air and methane, of which CH 4 The (methane) concentration is low, the calorific value is low, and the fluctuation of r...

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Problems solved by technology

[0042] Compared with hydrogenation and CO catalysts, the preparation cost of this type of catalyst is lower, but due to the poor temperature resistance of the catalyst (250-300 ° C), a single catalytic deoxygenation does not exceed 1.5% (volume percentage), for high oxygen content Low concentration gas (O 2 >10%) still requires multiple catalytic reactors to be linked, and the catalyst needs to be activated at high temperature, the cost of deoxidation operation is still high, and it is not suitable for low-cost low-concentration gas deoxidation

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