A two-stage entrained bed gasification method

Abstract

The invention discloses a two-stage airflow bed gasification method. In order to popularize entrained bed gasification technology widely, it is necessary to develop a gasification reaction method with long service life, high carbon conversion rate and uniform gasification reaction intensity. In the first stage of the present invention, the gasification fuel is partially gasified in the pre-gasification chamber to generate high-temperature crude gas, and in the second stage, the gasification agent is continuously supplemented in the main gasification chamber so that the high-temperature crude gas injected into the pre-gasification chamber and the residual Gasified fuel is completely gasified. The invention improves the service life of the furnace lining, the carbon conversion rate can reach more than 99.5%, the fly ash component in the gas can be reduced by 40-70%, and the fuel waste caused by coal powder falling into the slag pool through the slag discharge port is reduced, which is very It is suitable for occasions where coal powder is used to prepare industrial gas.

Description

technical field [0001] The invention relates to the field of coal gasification, in particular to a two-stage entrained-bed gasification method. Background technique [0002] China's industrial development is inseparable from coal, and the current main work is to solve the problem of clean and efficient utilization of coal, so as to reduce pollutant emissions and improve fuel utilization. In industry, pulverized coal gasification is the most effective way to utilize clean coal, and it is one of the important development directions of my country's energy strategy. [0003] At present, almost all dry coal pulverized entrained bed gasifiers use pulverized coal and gasification agents (oxygen, water vapor) directly into the gasifier, and mainly rely on the kinetic energy of the gasification agent jet to achieve gasification in the gasifier. Mixed mass transfer effect between agent and coal powder, this gasification method is likely to cause the following problems: [0004] 1. N...

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Problems solved by technology

[0004] 1. Near the jet outlet of the process burner, on the one hand, because the oxygen concentration is quite high, and because the pulverized coal injected into the furnace quickly escapes the volatile matter, under the entrainment action of the jet, the vicinity of the burner is often accompanied by high-intensity Oxidation reaction, the temperature is very high, and the lining near the burner is easily eroded and burned, which directly leads to the shutdown of the gasifier

[0005] 2. There is no uniform mass transfer intensity in the gasifier. The mass transfer intensity in the area near the burner is high, and the mass transfer intensity in the area far away from the burner is the smallest, which ultimately affects the gasification efficiency; because the mixed mass transfer intensity in the gasifier is mainly It is caused by the gasification agent jet. Naturally, the mass transfer intensity in the area near the jet outlet is very high, the temperature level is high, and the pulverized coal particles have just started the gasification reaction, and the activity is relatively high, so the gasification reaction rate in this area is also high. Soon; then in the area far away from the jet outlet, the intensity of the mixed mass transfer in the furnace is gradually weakened, and the reaction temperature is also reduced. The reactivity of the semi-coke particles in this area is the lowest, so that these semi-coke particles cannot be completely gas. , affecting the efficiency of coal gasification

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