Limestone calcination, coal gasification and dry distillation cogeneration method

Abstract

The invention discloses a limestone calcination, coal gasification and dry distillation cogeneration method. Calcination kiln tail gas generated after limestone is calcinated in a calcination kiln isintroduced into a coal dry distillation furnace, heating, dry distillation and coal gasification reaction are conducted on coal materials in the coal dry distillation furnace through the introduced calcination kiln tail gas to generate CO, the generated CO and the coal dry distillation gas in the coal dry distillation furnace are mixed to form mixed gas, and dry distillation is conducted on the coal materials through the mixed gas; the calcination of the limestone or the heating of other materials is conducted through the mixed gas generated in the coal dry distillation furnace. The heat and CO2 in high-temperature high-CO2-content waste gas generated in the limestone calcination process can be sufficiently used, the gas emission of a greenhouse is reduced, energy consumption for coal gasification and dry distillation is reduced, coal pyrolysis is sufficient, semi-coked high-CO-concentration mixed coal gas is obtained, and the heat value of the mixed coal gas is increased.

Description

technical field [0001] The invention belongs to the technical field of coal gasification, dry distillation and limestone calcination, and in particular relates to a method for coproducing limestone calcination, coal gasification and dry distillation. Background technique [0002] Coal dry distillation is one of the important processes in coal chemical industry. It refers to the process in which coal is heated and decomposed under the condition of isolating the air or controlling the amount of air to produce products such as coke / semi-coke (semi-coke), coal tar, crude benzene and gas. According to the difference in the final heating temperature, it can be divided into three types: 900°C~1100°C is high-temperature dry distillation, that is, coking; 700°C-900°C is medium-temperature dry distillation; 500°C-700°C is low-temperature dry distillation. [0003] The coal dry distillation process mainly undergoes the following changes: when the temperature of the coal material is hig...

AI Technical Summary

Problems solved by technology

[0004] At present, coal carbonization methods are divided into external heat method and internal heat method. The external heat method uses the furnace wall outside the carbonization chamber to transfer heat to the coal material. Although the quality of the gas produced is stable, the heat transfer is uneven and the pyrolysis time is long. The efficiency is relatively low; the internal heat method uses the heat carrier to directly transfer heat to the coal material, which has the advantage of uniform heat transfer, but the generated gas will be diluted, increasing the amount of gas, reducing the effective component content of the gas, and further comprehensive utilization of the gas Unfavorable, and the pyrolysis rate of coal is low and the pyrolysis time is long

[0005] Lime is an important raw material for wet desulfurization in power plants, calcium carbide production and metallurgical processes. Limestone is calcined at about 1050°C to generate CaO. The equipment for calcining limestone mainly includes rotary kilns and shaft kilns. The heating methods of these two calcining equipment are: Fuel (coal, heavy oil, gas, etc.) and air are fed into the furnace (kiln), and the exothermic reaction between the air and fuel is used to heat the limestone. The temperature rises to 1050-1200°C, so that the limestone is thermally decomposed, and the furnace (kiln) is calcined. Limestone will produce a lot of high CO 2 The high-temperature waste gas, usually the temperature of the waste gas is 1000 ℃, at present, the waste gas discharged from the limestone calciner (kiln) is only used as waste heat, and the CO in it is not used 2 for recycling, CO 2 It is a greenhouse gas and will cause great damage to the environment. Therefore, it is necessary to reduce the high temperature and high CO generated during the calcination of limestone. 2 content of the tail gas to be utilized as much as possible

Images