A process and system for producing natural gas by catalytic gasification with coal-fired self-heating

Abstract

The present invention provides a process and system for producing natural gas from coal-fired self-heating catalytic gasification. Coal, catalyst and gasification agent are supplied to a gasification device, wherein the gasification agent is distributed and supplied from different positions of the gasification device to the gasification device. gasification unit, and oxygen is introduced into the gasification unit. According to the process for producing natural gas from coal-fired self-heating coal catalytic gasification disclosed in the present invention, the coal-fired self-heating method can provide the required heat for the catalytic gasification reaction, no additional heating equipment is required, the process is simple, and the technical economy is good , the single furnace realizes heat coupling, and the system efficiency is high; in addition, by providing gasification agent dispersedly to the gasification device, while providing the heat required for the reaction, it can control the oxygen distribution in the whole bed and adjust the oxygen distribution in the distribution plate and the bed. The ratio of steam and oxygen is used to control the oxygen concentration within a certain range, which can avoid local high temperature areas in the bed, thereby effectively avoiding slagging.

Description

technical field [0001] The invention relates to the technical field of coal catalytic gasification, and more specifically, to a process and a system for producing natural gas through coal catalytic gasification for self-heating by burning coal. Background technique [0002] With the rapid development of the economy and increasingly stringent environmental protection regulations, my country's demand for natural gas, a clean energy source, will grow explosively in the next ten years. Although the production of natural gas has increased, it is far below the growth trend of demand. The contradiction is becoming more and more prominent, and the supply gap is increasing year by year. In view of the characteristics of my country's energy resource status of "rich in coal, low in oil, and lack of gas", the long-term maintenance of coal-based energy consumption structure will not change in the short term. According to the development trend of clean coal technology and the development t...

AI Technical Summary

Problems solved by technology

The technical equipment investment is high, the process is complex, the energy consumption is large, the overall economic efficiency of the process is poor, and the overall efficiency is low

[0007] Existing catalytic gasification processes all use external heat supply, that is, a large amount of superheated steam and circulating part of the product gas carbon monoxide and hydrogen are required to enter the gasifier to generate heat from the methanation reaction to provide the heat required by the system. Cryogenic separation, product Partial oxidation of gas or adding an oxygen-fired oxidation furnace to provide superheated steam and CO, H 2 , the energy consumption of the process is large, the equipment investment is high, the process flow is complicated, the load of the steam superheating system and the heat exchange system is high, and the overall economic efficiency of the process is not good, and the overall efficiency is low.

[0008] The addition of the catalyst can catalyze the combustion reaction and increase the heat release of pulverized coal combustion. At the same time, the added alkali metal catalyst may form a low-temperature eutectic product with the coal minerals under certain process conditions and reaction atmosphere, which will reduce the ash melting point of coal; and The catalytic gasification process requires a high gas-solid contact time, the bed is relatively high, and it is relatively difficult to transfer heat uniformly and quickly in the entire bed area. If the local temperature in the bed is too high, the coal ash particles will stick to each other and slag, resulting in a fluidized state. Not good, in severe cases, it is difficult to discharge slagging, or even lose fluidization, which makes it difficult for the reactor to operate continuously and stably

Images