Supercritical water circulating fluidized bed gasification system and method

Abstract

A supercritical water circulating fluidized bed gasification system and method are disclosed. The system includes a first water tank, a first high pressure plunger pump, a second high pressure plungerpump, a third high pressure plunger pump, a slag discharge pump, a return pump, a storage tank, a first feeder, a second feeder, a slag discharger, a slag discharge cooler, a riser, a cyclone separator, a vertical pipe, a return valve, a pulse damper, a regenerator, a cooler, a preheater, a back pressure valve, a gas-liquid separator, a wet gas flowmeter, a second water tank, a cooling tower, a cooling water pump and a plurality of valves, a temperature and pressure measurement and control system. As that supercritical water circulating fluidized bed is adopted as a reactor, the fluidized bedhas higher operating gas velocity compared with that of the bubbling fluidized bed, high gas velocity, high coal flux and high coal concentration gasification can be realized, and the efficiency andcapability of the gasification furnace are greatly improved; at the same time, the bed is nearly bubble-free, which reduces the influence of the gasifier geometry and makes the device easy to be enlarged.

Description

technical field [0001] The invention belongs to the field of clean conversion and utilization of coal and renewable resources, and in particular relates to a supercritical water circulating fluidized bed gasification system and method. Background technique [0002] For a long time, the traditional use of coal has caused irreversible pollution to the natural environment such as the atmosphere, seriously threatening and affecting the health of residents. Therefore, it is of great strategic significance to develop clean coal technology, improve coal utilization efficiency and reduce pollution emissions for the coordinated development of economy, energy and environment. [0003] Supercritical water gasification technology can directly process coal with high moisture content and convert it into hydrogen-rich gas. It has the advantages of high gasification rate, fast gasification speed, high hydrogen content and strong adaptability of raw materials, and has attracted extensive att...

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Problems solved by technology

In 2007, the research group invented a coal and biomass supercritical water fluidized bed gasification / partial oxidation hydrogen production device and method (ZL200710017691.6), which solved the problem of slagging and clogging in tubular reactors and realized High-efficiency gasification of high-concentration biomass is achieved, but its operation can only be carried out at medium and low gas velocities. From the perspective of two-phase flow state, it belongs to a bubbling fluidized bed. Although it can solve the problem of slagging and clogging in tubular reactors, Realize high-efficiency gasification of high-concentration biomass and coal, but similar to traditional bubbling fluidized beds, some important parameters in the reactor, such as bed expansion, gas-solid mixing, bubble characteristics, heat transfer characteristics, and mass transfer of reaction gases characteristics, etc., strongly depend on the size of the reactor

The bubble behavior of the bubbling fluidized bed also brings about the reduction of reactor efficiency and the difficult problem of reactor scale-up

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