Catalytic coal gasifaction furnace of differential speed bed, and method of catalytic gasification

Abstract

This invention discloses method and differential-speed bed furnace for catalytically gasifying high-ash, high-sulfur and high-ash-melting-point coal abundant in China. The hearth is set in a pressure shell. The hearth comprises a lower hearth and an upper hearth. The lower hearth is a chamber with a wide bed diameter, working at a low speed and high temperature. There are inlets for air, coal powder, limestone, steam and catalyst on both the bottom and lateral side of the lower hearth. The upper part of the lower hearth tapers to form the upper hearth working at a high speed and high temperature. The upper hearth has a shorter inner diameter than the lower hearth. The outlet of the upper hearth is connected with a cyclone separator with the lower part connected with a falling pipe. The lower part of the falling pipe is connected with a horizontal L-shaped valve. The other end of the L-shaped valve is connected with the lateral underside of the lower hearth.

Description

technical field [0001] The invention relates to a coal catalytic gasification method and device, in particular to a coal catalytic gasification method and device using a differential velocity bed, belonging to the technical field of coal gasification. Background technique [0002] The clean and efficient utilization of coal is a major technical issue in the field of energy and environment in our country today, and it is one of the key factors related to the sustainable development of our national economy. Coal gasification technology is the core of many modern clean energy technologies, such as coal-based polygeneration, integrated gasification combined cycle power generation (IGCC), coal liquefaction, etc. Among the numerous gasifiers currently available, there are mainly two types of entrained-bed gasifiers and fluidized-bed gasifiers. [0003] Texaco gasifier and Shell gasifier are two main types of entrained bed gasifiers, both of which use oxygen and water vapor with a...

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Problems solved by technology

But the disadvantages are also obvious: for example, the Texaco gasifier has strict requirements on coal quality (ash content, ash melting point, and slurryability, etc.), only a few coal types such as Shenhua, Datong, Huating, and Yima can be used, and the gasifier The availability rate of the gasifier is only 80%-85%; the main disadvantage of the Shell gasifier is: the drying of the dry powder, the preparation system is complicated, and it is necessary to use N with a purity of 99.9%. 2 For gas transportation, the working pressure of the gasifier should generally not exceed 4-4.5MPa; the structure of the furnace body and the control system are complicated, and the investment cost is high

However, the fluidized bed gasifier does not have a high gasification temperature like the entrained bed gasifier, which can ensure the rapid gasification reaction. Therefore, it is required to use coal with higher activity and higher ash melting point in terms of coal types. At the same time, because the semi-coke gasification reaction is not thorough enough, it brings about the problem of high carbon content and large loss in the discharged ash and fly ash brought out with the gas. In addition, the amplification capacity of the fluidized bed gasifier is poor At present, the daily coal processing capacity of the largest fluidized bed gasifier in commercial operation in the world is about 1000t, which is far lower than the 2000t / d level of entrained bed gasifier

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