Fluidized bed gasifier, coal gasification system and method

Abstract

The invention relates to the technical field of coal gasification, in particular to a fluidized bed gasifier, a coal gasification system and a method, can satisfy the heat requirement of overall reaction in the furnace, have no need for introducing oxygen burning coal to provide heat, lower the risk of easy slagging in the gasifier due to introduction of oxygen, at the same time can promote forward overall reaction in the furnace, have no need for returning substantial synthesis gas to the furnace to increase the methane yield, and lower the risk of inhibition on overall reaction in the furnace caused by return of synthesis gas to the furnace. According to the fluidized bed gasifier, the bottom is a gas distribution plate area, a fluidized bed reaction area is disposed above the gas distribution plate area, a variable diameter section with a gradually enlarging inner diameter from the bottom up is disposed between the fluidized bed reaction area and the gas distribution plate area, thebottom of the fluidized bed gasifier is equipped with deslagging port, the side wall of the fluidized bed gasifier corresponding to the fluidized bed reaction area is equipped with coal inlets, and the lower part of the variable diameter section is equipped with a carbon carrier inlet.

Description

technical field [0001] The invention relates to the technical field of coal gasification, in particular to a fluidized bed gasification furnace, a coal gasification system and a method. Background technique [0002] With the rapid economic development and increasingly stringent environmental regulations, the demand for natural gas, a clean energy, is growing explosively. Catalytic gasification technology is an important way to use coal cleanly and efficiently, and it is one of the most effective ways to produce natural gas from coal. Using catalytic gasification technology, coal is gasified with a gasification agent (such as water vapor) at a relatively low temperature under the catalytic action of a catalyst to generate high-concentration methane. Concrete reaction process is as follows: [0003] 2C+2H 2 O→2H 2 +2CO (1) endothermic reaction [0004] CO+H 2 O→CO 2 +H 2 (2) Exothermic reaction [0005] 3H 2 +CO→CH 4 +H 2 O (3) exothermic reaction [0006] Theref...

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Problems solved by technology

[0008] In the existing technology, the catalytic gasification process needs to return a certain amount of synthesis gas, namely carbon monoxide and hydrogen, into the furnace, and the heat generated by the methanation reaction occurs in the furnace to meet the heat required for the carbon-water reaction. Even so, because the total reaction in the furnace is Micro-endothermic reaction still needs to provide a certain amount of heat to ensure the gasification reaction in the furnace, which is usually achieved by introducing oxygen or increasing the temperature of the gasification agent entering the furnace. Therefore, the overall process still requires air separation equipment and increased investment, and After the synthesis gas is returned to the furnace, the progress of formula (1) will be inhibited, and the further increase of methane yield will be limited

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