Method using quality-based utilization of low-rank coal to prepare natural gas

Abstract

The invention provides a method using the quality-based utilization of low-rank coal to prepare natural gas. The method includes: drying, performing gasification reduction, performing desulfurization,preparing synthetic gas and preparing the natural gas. The method has the advantages that the raw material of the method mainly comes from the quality-based utilization process of the low-rank coal,high product additional value is achieved, and transportation is benefited; the synthetic gas is prepared by using coal-water slurry, and the reutilization of the low-rank coal solves the problem of environmental pollution; multi-approach gas preparation and high synthetic gas yield are achieved, the economic competiveness of gas preparation using the low-rank coal is enhanced greatly, and efficient, graded and comprehensive utilization of coal resources is achieved; the synthetic gas methane is prepared through the method, the method conforms to the industry policy of clean coal utilization and the current direction of 'turning coal into gas', pipeline transportation is facilitated, the problems that the low-rank coal is prone to dust raising and spontaneous combustion during transportation are solved, and by the quality-based and graded utilization of the low-rank coal, the coal is turned into the gas, west-east natural gas transmission is achieved, and energy self-supply is achieved.

Description

technical field [0001] The invention relates to the technical field of clean utilization of coal substances, in particular to a method for preparing natural gas by utilizing low-rank coal by quality. Background technique [0002] my country is a country rich in coal, poor in oil, and low in gas. Coal consumption accounts for more than 60% of primary energy consumption, which determines that it will be difficult to change the coal-based energy structure for a long period of time. Judging from the proven quality of coal mines, the proportion of middle and low-rank coal in my country's coal is very large, so it is particularly important to use middle and low-rank coal reasonably and efficiently to produce high-quality chemical products. In recent years, with the continuous development of technologies such as coal gasification, coal pyrolysis, coal gas purification and gas separation, more and more attention has been paid to the clean and efficient utilization of middle and low ...

AI Technical Summary

Problems solved by technology

Because CO2 cannot be combusted, it is an ineffective gas, and because of aerobic combustion, the nitrogen content in the crude gas is too high, which reduces the H2 and CO in the crude gas Energy density reduces the calorific value of the crude gas. In addition to returning to the furnace for combustion, the crude gas produced by pyrolysis is difficult to have other economic value

The biggest problem in the coal gasification process is that the chemical components contained in the coal cannot be fully utilized, and the molecules cannot be completely interrupted to produce CO, H 2 , and then chemically synthesize natural gas, while the combination of low-rank coal gasification reduction, reforming technology and synthetic methane technology can maximize the retention of chemical components in coal in the form of natural gas

In addition, during pyrolysis, a part of the coal will be consumed by the reaction of oxygen, resulting in less amount of upgraded coal, and finally the amount of natural gas produced by upgrading coal is less or even no upgraded coal, which is a great waste Effective Coal Resources in Low Rank Coals

In addition, crude gas contains a large amount of water vapor. However, considering that the water content in low-rank coal is high, and water resources are often very precious in areas rich in low-rank coal; if the precious low-rank coal can be recovered effectively at the same time Water resources, etc., use waste to prepare coal-water slurry, then burn the coal-water slurry to produce reformed gas, and use the reformed gas to produce natural gas, which is of great significance to solve the insufficient water recovery and environmental pollution in the existing low-rank coal.

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