Method and system for preparing coal water slurry from waste water and preparing synthetic gas from coal water slurry

Abstract

The invention provides a method for preparing coal water slurry from waste water and preparing synthetic gas from coal water slurry, comprising the following steps: (1) treating low-rank coal througha drying process to obtain dried low-rank coal and exhaust gas, and treating the exhaust gas through a first dedusting process to obtain first coal dust; (2) treating the dried low-rank coal through agasification-reduction process to obtain a gas-oil mixture, wherein the gasification-reduction process is a chemical reaction process of heating the dried low-rank coal under the anaerobic or micro-aerobic condition; (3) treating the gas-oil mixture successively through a second dedusting process and a gas-oil cooling process to obtain first waste water; and (4) treating the coal water slurry andO2 through a coal water slurry gasification process to obtain synthetic gas containing CO and H2, wherein the coal water slurry contains the first waste water, the first coal dust and a coal water slurry additive. By the method and the system, moisture in the low-rank coal and the coal dust generated in the drying process are effectively recovered to manufacture the coal water slurry, and the coal water slurry is gasified to prepare the synthetic gas.

Description

technical field [0001] The invention relates to the technical field of clean utilization of coal materials, in particular to a method and a system for producing coal-water slurry from waste water and synthesizing gas through the coal-water slurry. Background technique [0002] More than half of my country's proven coal reserves are low-rank coals, and the volatile matter contained in them is equivalent to 100 billion tons of oil and gas resources. Low-rank coal mainly has the material characteristics of high moisture and high volatility. When burning, the flame is long and smokey, and the degree of coalification is low. Typical coal types are lignite and long-flame coal. my country is rich in coal and lacks oil and gas. How to efficiently utilize low-rank coal has become a major issue in today's clean coal technology. However, whether it is combustion power generation or modern coal chemical utilization, the efficiency of comprehensive utilization is extremely low because o...

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Problems solved by technology

[0004] In view of this, the purpose of the present invention is to address the deficiencies of the prior art, to provide a method and system for producing coal-water slurry from waste water and syngas through the coal-water slurry, effectively reclaiming the moisture in low-rank coal and drying The coal powder produced in the process is used to make coal-water slurry, which is then used to gasify the coal-water slurry to produce synthesis gas, waste utilization, resource saving, and solve the problems of insufficient water recovery and environmental pollution in the existing low-rank coal

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