Medium-low rank coal pyrolysis and gasification system and medium-low rank coal pyrolysis and gasification method

Abstract

The present invention provides a medium-low rank coal pyrolysis and gasification system, which comprises a pyrolysis reactor, a first cyclone separator, a second cyclone separator, a first semi-coke bin, a second semi-coke bin, a gasification reactor and a first downer, wherein the pyrolysis reactor is provided with a synthetic gas inlet and is connected with the first cyclone separator, the cyclone separator is connected with the first semi-coke bin and the first downer, the bottom portion of the pyrolysis reactor is connected with a gasification semi-coke screw and a hot-state semi-coke discharge screw, the gasification semi-coke screw is connected with the gasification reactor, and the hot-state semi-coke discharge screw is connected with the first downer and a second downer. According to the present invention, the hot-state pyrolysis semi-coke is adopted as the dust removal and desulfurization adsorbent of the coarse synthetic gas, such that the dust content and the sulfur content in the coarse synthetic gas meet the downstream treatment requirements after the first-stage cyclone dust removal and the downer second-stage dust removal are performed; the partial synthetic gas refluxes to the pyrolysis reactor and the hydrogen content in the synthetic gas is high so as to provide the important effect on the lightweight of the pyrolysis tar; and the with the combined way, the low rank coal pyrolysis and gasification is achieved while the high quality tar and the high quality synthetic gas can be obtained.

Description

technical field [0001] The invention belongs to the field of coal chemical industry, and in particular relates to a method and a system for the pyrolysis and gasification of middle and low rank coal. Background technique [0002] my country's energy structure is characterized by rich coal, poor oil, and little gas. Coal resources have been the dominant energy source in my country for a long period of time. my country's proven coal reserves are 114.5 billion tons, of which medium and low rank coal (lignite, low metamorphic bituminous coal) accounts for about 55.15% of the country's reserves. Because low-rank coal has the characteristics of high moisture content, easy weathering, difficult sorting, and unsuitable for long-distance transportation and storage, its comprehensive utilization is greatly limited. Among them, direct combustion power generation is one of the most common utilization methods. According to incomplete statistics, more than 90% of lignite in my country is...

AI Technical Summary

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 comp

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