Dehydration and alcohol depolymerization process for low-disintegration coal in mild condition

Abstract

A dehydration and alcohol depolymerization process for low-rank coal under mild condition comprises the following steps: mixing acetone and butanone at equal volume ratio to obtain an organic dehydration solvent, adding brown coal powder in a reaction kettle to obtain dehydrated brown coal powder and organic dehydration mixture solution, and separating the organic dehydration solvent for recycling; adding the dehydrated brown coal powder and methanol into a reaction kettle to obtain residual coal and alcoholysis products, and press-filtering the alcoholysis products to an extractor through a filter plate under stirring and the pressure in the kettle; adding the alcoholysis products into the extractor, spraying eluant into the extractor to obtain a soluble material, adding the soluble material into a distilling still to obtain fine organic components rich in low-carbon hydrocarbon, low-carbon alkoxyl organic materials, phenols, esters, heavy organic components, etc.; and recrystallizing the methanol solvent by heating and cooling to obtain pure organic chemicals with high value added such as alkyl naphthalene, alkyl anthracene and chemical containing polyatomic rings with N and S heteroatoms.

Description

technical field [0001] The invention relates to a method for dehydration and alcohol depolymerization of lignite or low metamorphic bituminous coal, in particular to a low metamorphic coal dehydration and alcohol depolymerization process under mild conditions. Background technique [0002] Lignite is a typical low-rank coal, which retains the oxygen-rich macromolecular structure of coal-forming plants to a greater extent. The organic oxygen in lignite exists in the form of aromatic ring substituents, and part of it acts as a bridge to connect two or more aromatic rings to form a macromolecular system. The strong hydrogen bond between organic oxygen and water molecules in lignite micropores makes it difficult to dehydrate lignite, which is also an important factor leading to low calorific value and high moisture content of lignite. [0003] my country is rich in lignite resources, accounting for about 77% of the national lignite reserves. Due to the problems of high ash con...

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Problems solved by technology

[0004] At present, the water in lignite and the organic oxygen in coal are combined through hydrogen bonds. A physical evaporation drying method is used to dehydrate lignite. This method consumes a lot of energy when dehydrating lignite, and the dehydrated lignite is difficult to preserve; A hydrothermal treatment method: This method is to increase the temperature of hydrothermal treatment to increase the dehydration rate, but it also makes more organic matter in lignite become wastewater leached matter, so the high temperature hydrothermal treatment method pays a higher energy consumption price and does not Realize the high value-added utilization of lignite; a lignite solvent extraction dehydration treatment method uses 2,2-dimethoxypropane as a solvent to dehydrate lignite. Preliminary basic research shows that the use of lignite with higher boiling point and price Solvents are difficult to recycle; "HyperCoal" is one of the clean coal technologies developed internationally in recent years, but there are often problems such as blockage of filter plates during thermal filtration

[0005] To sum up, the traditional method of lignite dehydration has high energy consumption and low dehydration rate; conventional coal conversion and utilization are generally carried out under high temperature, high pressure or the presence of catalysts, requiring high quality coal, and the hydrogenation involved The energy consumption and hydrogen consumption of cracking and pyrolysis are relatively large, the requirements for the material of the reactor are strict, and the added value is low

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