It is a natural gas mainly composed of methane in the coal seam and surrounding rock in the state of adsorption and free state. On the one hand, it is a serious threat to the safety of coal mines when it is poured into the mine. At the same time, it is discharged into the atmosphere and becomes a strong greenhouse gas, which can destroy the ozone layer. However, coalbed methane is a high-quality, high-efficiency, clean energy source that emits no sulphur dioxide gas and soot when burned. According to the calorific value, 1 000 m3 of methane can be equivalent to 1 t of standard coal. Due to the high thermal efficiency of the former, the actual 250 m3 methane can replace 1 t of standard coal. China's coalbed methane resources are abundant, and the amount of gas emitted by coal mining is only 6 billion m3 per year. Coal gangue The output of coal gangue accounts for about 20% of the original coal, which not only occupies the land, but also seriously pollutes the environment. However, coal gangue can be used for the benefit of pollution, in which the calorific value is higher than 6MJ/kg for boiling furnace fuel; the low calorific value can be used to build roads or produce building materials; the higher Al2O3 can produce polymerized aluminum and chlorine. Aluminum; high sulfur-containing recoverable sulfide; low carbon content can be used for backfilling or covering soil in underground mining areas. 3. Associated minerals Including kaolin , refractory clay , bentonite , diatomaceous earth , graphite , pyrite, etc., can be comprehensively developed and utilized. Humic acid The extraction of humic acid from low rank coal can be widely used in agriculture, animal husbandry and many industrial sectors. In addition, montan wax can be extracted from lignite, and coal can be used as a raw material to produce non-fuel-utilized industrial products. 10 Subwoofer,8 Ohm Woofer,Best Subwoofer,Subwoofer Bass Ningbo Sonice Electroacoustic Science and Technology Co., Ltd. , https://www.secspk.com
Comprehensive utilization technology of coal
1. CBM