Method and system for low-temperature dry distillation and separation recycling of solid thermal carrier low-rank coal and oil shale

Abstract

The invention discloses a method and a system for low-temperature dry distillation and separation recycling of solid thermal carrier low-rank coal and oil shale. The method comprises the following steps: by taking the low-rank coal and / or the oil shale as raw materials, drying the raw materials by middle-temperature smoke; carrying out gas-solid separation to obtained dried grains; mixing the dried grains, high-temperature circulating ash dreg and recycled heavy oil and conveying into a dry distillation chamber; raising the temperature to carry out the dry distillation; leading out dry distillation gas and separating to obtain coal gas and tar; discharging a semi-coke and ash dreg mixture generated by the dry distillation out of the dry distillation chamber; enabling separated semi-coke to fall off, and further cooling and discharging; conveying the semi-coke and ash dreg mixture into a circulating fluidized bed to be fluidized and combusted; carrying out gas-solid separation on high-temperature dust-containing smoke obtained by fluidizing and combusting to obtain high-temperature circulating ash dreg; providing heat to the dry distillation by taking the high-temperature circulating ash dreg as the solid thermal carrier; and separating the obtained high-temperature smoke and carrying out secondary gas-solid separation and residual heat recycling, and furthermore, carrying out subsequent smoke treatment. The invention further provides a low-temperature dry distillation and separation recycling system used for the method.

Description

technical field [0001] The invention relates to a method and system for utilizing low-rank coal and oil shale low-rank dry distillation fractionation of solid heat carrier, and belongs to the technical field of low-rank coal and oil shale dry distillation fractionation. Background technique [0002] Coal is the most widely distributed fossil energy resource with huge reserves in the world. The proven coal reserves are more than 63 times that of oil reserves. my country's coal resources are very rich, with a total of 5.57 trillion tons of coal resources and a proven reserve of 1,020.2 billion tons. Coal resources are mainly divided into ten categories: lean coal, coking coal, fat coal, gas coal, weakly bonded, non-bonded, long-flame coal, anthracite, lean coal and lignite. Anthracite can be used to make gas or directly used as fuel, bituminous coal (lean coal, coking coal, fat coal, gas coal, weakly bonded, non-bonded, long-flame coal) is used in coking, coal blending, power...

AI Technical Summary

Problems solved by technology

Cause waste of transport capacity during lignite transportation, reduce power generation efficiency and increase power generation cost

Secondly, during lignite drying or dry distillation, a large amount of water evaporates to generate water vapor, which causes lignite particles to shrink and pulverize, making it difficult to improve lignite quality.

At the same time, it will also make the flammability of lignite worse and affect the molding effect of pulverized coal

[0007] 2. Poor stability:

[0011] 4. Environmental pollution:

Most of the existing lignite carbonization and upgrading technologies are in the laboratory or industrial pilot scale, and there is no lignite low-temperature carbonization and upgrading technology that can be large-scale, safe, long-term, and stable.

Images