Underground Coal Gasification Method

An underground gasification and coal technology, applied in coal gasification, underground mining, construction, etc., can solve the problems of minimizing heat loss and achieve high-quality results

CN103556979BActive Publication Date: 2017-04-05ENN SCI & TECH DEV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-04-05

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Abstract

The invention relates to a coal underground gasification method. The coal underground gasification method comprises the following sequential steps of (1) establishing a gas inlet passage, a gas outlet passage and a gasification passage which enables the gas inlet passage to be communicated with the gas outlet passage; (2) injecting a gasification agent through the gas inlet passage, wherein the gasification agent comprises water vapor and oxygen-enriched gas, and an initial volume ratio between the water vapor and the oxygen-enriched gas ranges from 0.5 : 1 to 4 : 1; (3) igniting a coal seam; (4) forming a new volume ratio by adjusting the ratio between the water vapor and the oxygen-enriched gas according to the characteristics of generated coal gas. According to the coal underground gasification method disclosed by the invention, a little water vapor is enabled to be carried in raw coal gas, the cost for recovering waste water in raw coal gas is reduced, the situation that the water vapor and the coal seam are in full reaction so as to generate hydrogen can be ensured, and thus the quality of coal gas can be increased; in addition, the temperature uniformity on a gasification working surface can be ensured due to reactions, i.e. exothermic reaction of oxygen and the coal seam and endothermic reaction of water and the coal seam, which are carried out in the same time, and the phenomenon that the continuous gasification of the coal seam is obstructed as gasification coal ash is melted and attached to a gasification coal wall due to over-high local temperature can be prevented from happening.
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Description

technical field

[0001] The invention relates to an underground coal gasification method. Background technique

[0002] Underground coal gasification technology is a technology that converts underground coal into combustible gas in situ through thermochemical reactions. In the specific implementation process, a plurality of channels are usually established, and they are respectively used as the inlet channel and the gas outlet channel, and then the gasification channel is connected to the inlet channel and the gas outlet channel, and the coal seam is ignited and the gasification agent is sent to the inlet channel, and the generated Combustible gas (coarse gas) is discharged to the ground through the gas outlet channel. The combustion reactions carried out in the gasification channel here are mainly:

[0003] C+H 2 O(g)=CO+H 2 -131.5MJ / kmol (1)

[0004] C+1 / 2O 2 =CO+110.9kJ / mol (2)

[0005] During the underground coal gasification process, the temperature of the crude g...

Examples

Embodiment Construction

[0025] Specific embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0026] refer to figure 1 , the underground coal gasification method of the present invention comprises the following steps in sequence:

[0027] (1) Establish an inlet channel, an outlet channel, and a gasification channel connecting the inlet channel and the outlet channel; (2) inject a gasification agent through the inlet channel, wherein the gasification agent includes water vapor and oxygen-enriched gas, water The initial volume ratio of steam and oxygen-enriched gas is in the range of 0.5:1 to 4:1; (3) ignite the coal seam; (4) adjust the ratio of water vapor and oxygen-enriched gas according to the characteristics of the produced gas to form a new volume ratio. Among them, the initial volume ratio is the volume ratio of water vapor and oxygen-enriched gas in the gasification agent injected before the coal seam is ignited, in other words, the init...