Method and system for performing drying and dry distillation on fluidized bed pulverized coal based on overheating steam medium

Abstract

The invention provides a method and a system for performing drying and dry distillation on fluidized bed pulverized coal based on an overheating steam medium. The method comprises the following steps of: heating and drying pulverized coal by taking overheating steam as a drying medium, performing the dry distillation in a horizontal multichamber fluidized bed dry distillation furnace on the dried pulverized coal by utilizing the overheating steam as a fluidizing medium, dedusting high-temperature dry distillation gas by a cyclone separator, conveying the dedusted high-temperature dry distillation gas to an oil gas cooling separation system for cooling, and performing oil-water separation on the cooled mixture; conveying discharged semicoke to a coke quenching system, and cooling for storing; and allowing gas generated by the dry distillation to be used as heating fuel for a low-temperature overheating steam boiler and a high-temperature overheating steam boiler, and conveying the generated overheating steam to vibrated fluidized bed drying equipment and the horizontal multichamber fluidized bed dry distillation furnace. By the method and the system, the overheating steam is low in consumption and low in energy consumption, and the dried pulverized coal is low and uniform in moisture content; and the quality and yield of tar generated by the pyrolysis of the pulverized coal can be improved, a process is simple, and the system is operated safely in an anaerobic environment.

Description

technical field [0001] The invention relates to the technical field of coal chemical industry, in particular to a fluidized bed pulverized coal drying and dry distillation method and system based on a superheated steam medium. Background technique [0002] With the improvement of coal mining technology, the low metamorphic pulverized coal in my country's coal production areas has increased a lot, but due to the limitation of existing coal conversion technology, many pulverized coal resources cannot be utilized. Low-deterioration pulverized coal usually has the characteristics of large moisture, small particle size, good chemical reactivity, flammability and fragility, high ash content, and low calorific value. It is not suitable for long-distance transportation and long-term storage; Pulverized coal not only has low combustion efficiency, but also causes serious environmental pollution. Therefore, the development of drying and carbonization upgrading technologies for low-me...

AI Technical Summary

Problems solved by technology

Most of the existing coal dry distillation technologies are suitable for high-quality lump coal, but not suitable for low metamorphic pulverized coal; the existing dry distillation furnaces are small in scale, small in coal processing capacity, and low in yield of liquid and gaseous products

For example: the dust content in the tar obtained by the dry distillation of pulverized coal fluidized bed carbonization furnace is high, and the calorific value of dry distillation gas is low; the airflow internal heating type carbonization furnace requires the raw coal lump size to be between 20 and 80mm, the thermal conductivity of lump coal is poor, and the gas permeability of the material layer Not good, the heating is uneven, the yield of tar obtained by dry distillation is low, and the quality of semi-coke is uneven; while the heat required for dry distillation of vertical dry distillation furnace is introduced from the heating furnace wall, and the thermal efficiency is low

Therefore, so far there is no mature coal carbonization technology that can be promoted on a large scale, especially for low-modified pulverized coal.

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