Low-rank coal microbial stepwise degradation method

Abstract

The invention discloses a low-rank coal microbial stepwise degradation method. The method comprises the following steps: I, making low-rank coal into coal powder; II, performing photooxidation on thecoal powder to obtain photooxidized coal powder; III, adding the photooxidized coal powder into a liquid culture medium inoculated with streptomyces viridosporous, and performing primary degradation;IV, adding primary degradation coal residues subjected to sterilization into a liquid culture medium inoculated with pseudomonas putida, and performing secondary degradation; and V, adding the secondary degradation coal residues subjected to sterilization into a liquid culture medium inoculated with phanerochaete chrysosporium, and performing tertiary degradation. According to the invention, the streptomyces viridosporous, the pseudomonas putida and the phanerochaete chrysosporium are adopted to stepwise degrade the low-rank coal sequentially; various active substances, such as alkali, enzymes, chelating agents and surfactants, generated by the metabolism of the three kinds of bacteria are respectively utilized; the synergistic effects are realized on different degradation activity pointsin a low-rank coal structure; the degradation rate of the low-rank coal is improved; and basic conditions are created for further clean and efficient utilization of the low-rank coal.

Description

technical field [0001] The invention belongs to the technical field of microbial conversion of coal, and in particular relates to a method for microbial graded degradation of low-rank coal. Background technique [0002] As we all know, coal is one of the most important energy sources. China's coal reserves rank third in the world, and its coal production and consumption have always ranked first in the world. In the process of coal mining and utilization, with the preemptive mining, processing and utilization of high-quality high-rank coal, the proportion of low-rank coal in coal reserves is increasing. At present, more than 50% of low-rank coal in my country is used for power generation, followed by coking, gasification, liquefaction, and direct combustion for heating. The following problems exist in the utilization process of the above-mentioned low-rank coal: [0003] (1) Low power generation efficiency; low-rank coal has the characteristics of low calorific value and hi...

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Problems solved by technology

[0003] (1) Low power generation efficiency; low-rank coal has the characteristics of low calorific value and high moisture, which leads to low thermal efficiency;

[0004] (2) The processing conditions are harsh; low-rank coal gasification, liquefaction, pyrolysis, coking and other processing methods generally require high temperature and high pressure, and have high requirements for equipment;

[0005] (3) High combustion pollution; low-rank coal contains high N, S, heavy metal elements, and ash content. In addition to carbon dioxide and hydrocarbons, low-rank coal will also generate a large amount of smoke, nitrogen oxides, and sulfur during combustion. Pollutants such as oxides and heavy metal compounds

Often a single strain cannot produce many coal-degrading active substances (enzymes, alkalis, chelating agents, surfactants, etc.) that degrade coal

At present, most researchers use a single strain of bacteria to degrade coal by microorganisms, so the degradation rate is often low. Corresponding to the large number of degradation active sites in the coal), but the bacteria does not necessarily have a high degradation rate for other coals with different structural functional groups, that is, the strain lacks universality

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