Process method and device for transformation and quality improvement of low-rank coal

Abstract

The invention provides process method and device for the transformation and quality improvement of low-rank coal. The process method comprises the following steps of: drying the low-rank coals in a drying device by utilizing hypoxic gas supplied by a first combustion chamber; pyrolyzing the dried low-rank coals input in a pyrolysis device by utilizing the hypoxic gas supplied by a second combustion chamber; separating the pyrolysis gas generated by the pyrolysis device; and respectively transporting combustible gas obtained by separating the pyrolysis gas to the first combustion chamber and the second combustion chamber to be used as combustion gas for recycle. In the device, a combustion device respectively supplies the hypoxic gas to the drying device and the pyrolysis device through the first combustion chamber and the second combustion chamber which are mutually independent; the combustible gas obtained by separating the pyrolysis gas is respectively transported to the first combustion chamber and the second combustion chamber to be cycled as the combustion gas. The invention lowers the energy consumption, effectively controls local combustion and temperature in the drying device and the pyrolysis device and reduces the environmental pollution.

Description

technical field [0001] The invention relates to a low-rank coal conversion and upgrading process method and device, in particular to a process method and device that can recycle fuel gas by-produced in the low-rank coal conversion and upgrading process. Background technique [0002] The reserves of low-rank coal account for about 15% of the total reserves of coal resources in my country, and it is one of the main coal resources in China. The distribution of low-rank coal is relatively concentrated, mainly in Inner Mongolia and Xinjiang, but the economic development of these places is basically relatively backward, so coal resources need to be transported to places with relatively better economic development. Due to the characteristics of this type of coal, its high water content and easy spontaneous combustion, it is necessary to dry and lightly gasify the low-rank coal locally to improve the utilization rate of the railway. [0003] So far, there are two main treatment met...

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Problems solved by technology

There are also many graduate students and units in our country carrying out research in this area, but there are still relatively few mature technologies that can be industrialized

The patent CN101260307A applied by Tsinghua University on April 28, 2008 proposed a lignite drying and upgrading process method, which uses part of the water vapor to dry the lignite instead of using anoxic gas to control the drying process of low-rank coal. and local spontaneous combustion during the pyrolysis process, although this can reduce the risk of spontaneous combustion of lignite during the drying process, but this increases the complexity of the process, that is, increases the steam generation device, and there will be during the steam generation process Part of the high-temperature combustion process will generate a large amount of nitrogen oxides, which will pollute the environment if left untreated

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