Staged gasification method and device

Abstract

A staged gasification method and device, the staged gasification method includes passing a fuel B and a first gasification agent A into a primary gasification unit for a gasification reaction to generate a gas-solid mixture C and bottom slag K; the gas-solid mixture C undergoes gas-solid separation to form initial coal gas E and hot semi-coke D; send hot semi-coke D and second gasification agent F into the first reactor to react to form mixture G; mixture G and initial coal gas E enter the heat exchange reactor The heat exchange reaction is completed, solid bottom slag L and final gas H are generated, and staged gasification is completed. The invention makes full use of the sensible heat of the product of the high-temperature reactor to promote the pyrolysis of primary coal gas tar and the transformation of carbon, and improves the gasification performance of the system.

Description

technical field [0001] The invention relates to the technical field of gasification, in particular to a gasification device and method for carbonaceous raw materials, in particular to a hierarchical gasification method and device. Background technique [0002] Coal gasification technology is an important part of clean coal technology and one of the main ways to use coal efficiently and cleanly. It has become the core technology of many modern energy and chemical systems. Fluidized bed gasification can achieve good back-mixing and contact between gasification agent and fuel, and can use wide-screened crushed coal particles as fuel, and the coal type has strong adaptability; however, fluidized bed gasification is limited by the fluidization of particles. Due to limited conditions, it can only be operated below 1000°C, and the gasification reaction rate is low, resulting in a low carbon conversion rate. The entrained bed coal gasification process has high reaction temperature,...

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Problems solved by technology

[0004] (1) For example, the products generated by the reaction of the primary gasification unit are first separated to form the first gas flow and the second gas flow, and then the first gas flow and the second gas flow are respectively sent to the secondary gasification unit for staged reaction , is conducive to improving the gasification efficiency, but the semi-coke content ratio between the first gas flow and the second gas flow is too small, and a large amount of fly ash exists in the second gas flow, which cannot react with the gasification agent, which will directly affect the system. gasification performance, especially when the secondary gasification unit is operating under solid slagging conditions

[0005] (2) The gas holdup and solid holdup in the first gas flow and the second gas flow are crucial to the rapid formation of the high-temperature reaction zone in the secondary gasification unit and the carbon conversion rate of the system, which is not proposed in the prior art Control measures for the above-mentioned gas holdup and solid holdup

[0006] (3) In the existing entrained entrained bed technology, there are measures to quench the high-temperature slag with cold gas, water quench or waste heat boiler to cool the slag, but it cannot solve the problem of tar and residual carbon contained in the initial coal gas in the staged gasification The problem is that high-temperature sensible heat cannot be effectively used, and there are also problems such as complex systems and waste water

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