Fixed bed coal seam gas non-catalytic deoxidization method and device

Abstract

The invention discloses a fixed bed coal seam gas non-catalytic deoxidization method and a fixed bed coal seam gas non-catalytic deoxidization device. The device comprises a fixed bed coal seam gas deoxidization device body including a furnace body (1), wherein the side wall of the furnace body (1) is provided with a water jacket (2) enclosing the side wall of the furnace body; the upper part of the water jacket (2) is connected with an air inlet of a steam pocket (23) through a pipeline; and a water inlet pipe on the lower part of the water jacket is connected with a water outlet of the steam pocket (23). The device deoxidizes the coal seam gas, can effectively control the deoxidization temperature and reduce the oxygen content in the coal seam gas to less than 0.5 percent, and maximallyreduces methane decomposition to make the methane loss less than 5 percent.

Description

technical field [0001] The invention belongs to the field of deoxidation of coal bed gas, in particular to a non-catalytic deoxidation method and device for fixed bed coal bed gas. Background technique [0002] Coalbed methane, commonly known as coal mine gas, is mainly composed of methane (CH 4 ), and also contains a certain amount of carbon dioxide, nitrogen and oxygen, which is an unconventional natural gas. It is a gas resource associated and symbiotic with coal. [0003] Because coalbed methane contains oxygen, in addition to being directly used as fuel or power generation, oxygen must be removed for pressurized transportation or concentration, so as to ensure the safe operation of subsequent processes. Currently available coalbed methane deoxidation methods mainly include catalytic deoxidation method (CN02113627.0) and coke combustion method. Compared with the two, the catalytic deoxygenation method requires the use of a catalyst, and the cost of deoxidation is rela...

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Problems solved by technology

The former is because the coke deoxidation reactor is an adiabatic reactor, and the reaction between coke and oxygen, methane and oxygen in the deoxidation process is a strong exothermic reaction. Therefore, as the reaction time goes on, the temperature in the reactor continues to rise. The degree of methane cracking increases, and it is difficult to control the reaction temperature in the required temperature range

The latter adopts the method of circulating partially deoxidized and cooled CBM into the CBM before deoxidation. Although the reaction temperature can be controlled by adjusting the oxygen content of the CBM in the deoxidation reactor, only the oxygen content of the reaction gas entering the deoxidation reactor can be adjusted. Only when the gas is deoxidized to 5-9%, the effect is better. The oxygen concentration is low, the circulating gas volume is large, and the water jacket structure is not used, so the excessive heat in the deoxidation reactor cannot be removed well.

[0004] Most of the existing fixed bed gasification devices are designed for the purpose of coal gasification. If they are used for non-catalytic deoxidation of coal bed methane, or the height and diameter are relatively large, the gas stays in the furnace for a long time, resulting in serious methane loss; The ash device mostly adopts the ash lock structure to discharge ash. During the ash discharge, a small amount of coal bed gas will be discharged together with the ash, which is not conducive to safe production; or the device is insulated and has no water jacket structure outside, which cannot be well Protecting the furnace wall and removing excessive heat from the device will easily lead to excessive temperature in the reactor, which will cause a large amount of methane cracking in coalbed methane and increase the loss of methane, which cannot meet the purpose of non-catalytic deoxidation of coalbed methane

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