A medium and low rank coal pyrolysis gasification system and its application

Abstract

The invention provides a medium / low-grade coal pyrolysis gasification system which comprises a pyrolysis reactor, a first cyclone separator, a first cross grain moving bed, a gasification reactor, a second cyclone separator and a second cross grain moving bed, wherein the pyrolysis reactor is provided with a synthetic gas inlet; a gas outlet pipeline on the upper part of the pyrolysis reactor is connected with a gas inlet pipe of the first cyclone separator; the bottom of the pyrolysis reactor is connected with a first burning semicoke screw and a hot-state semicoke discharge screw; the first burning semicoke screw is connected with the gasification reactor; and the hot-state semicoke discharge screw is divided into two paths which are respectively connected to material inlets of the first and second cross grain moving beds. The system performs primary cyclone dedusting and secondary cross grain moving bed dedusting on the coal pyrolysis gas, so that the obtained pyrolysis oil contains less dust, thereby effectively avoiding blockage of the pipelines and equipment due to tar condensing. Partial hydrogen-rich synthetic gas enters the pyrolysis reactor to provide a pyrolysis atmosphere, and the raw material coal is subjected to hydrogen-rich pyrolysis, so the tar quality is high.

Description

technical field [0001] The invention belongs to the field of coal chemical industry, and in particular relates to a system for pyrolysis and gasification of middle and low rank coal and its application. Background technique [0002] Modern coal chemical industry has developed a variety of comprehensive coal chemical technologies, such as pyrolysis-combustion coupling, pyrolysis-gasification coupling, pyrolysis-chemical product coupling, etc. There are not many, and various technical difficulties have been encountered in the process of scaling up from pilot test to industrialization. Pyrolysis is the forerunner of various technologies. The oil and gas resources produced during the pyrolysis process enter the subsequent treatment process after the first stage of dust removal by the cyclone separator. However, the dust removal capacity of the cyclone separator is limited, and the interception and removal efficiency of fine particles below Φ10μm is low, resulting in a large amo...

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Problems solved by technology

[0004] For the current pyrolysis-gasification, pyrolysis-combustion and other low-rank coal polygeneration process systems, because the dust removal efficiency of the first-stage cyclone dust collector is not high, the amount of dust in the coal pyrolysis gas is large, and the quality of tar is not high, resulting in subsequent The tar treatment process is complicated, and in the subsequent condensation process, the pipeline and equipment are blocked due to tar dust. The purpose of this invention is to propose a medium and low rank coal pyrolysis gasification system

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