A hydrogen-carbon ratio control system and control method

Abstract

The invention provides a system and method for controlling a hydrogen-carbon ratio in a process of synthesizing natural gas. The system comprises a large-scale or mixed gas methanation reactor, a supplemental methanation reactor, a CO-rich gas inlet pipeline, a H2-rich gas inlet pipeline, a first regulating valve, a second regulating valve and a main pipeline, wherein the large-scale or mixed gas methanation reactor is connected with the supplemental methanation reactor by virtue of the main pipeline, and the CO-rich gas inlet pipeline and the H2-rich gas inlet pipeline are arranged in parallel and crossed with the main pipeline; the first regulating valve is positioned on the CO-rich gas inlet pipeline; the second regulating valve is positioned on the H2-rich gas inlet pipeline. The system for controlling the hydrogen-carbon ratio has the beneficial effects of simple structure and precise control. The method comprises the following steps: mixing the reaction gas from the large-scale or mixed gas methanation reactor with the rich Co and the rich H2 which are regulated by virtue of the first regulating valve or the second regulating valve, and then, introducing the gas mixture to the supplemental methanation reactor. The method disclosed by the invention has the effects of being simple, convenient and quick to operate.

Description

technical field [0001] The invention relates to the field of synthetic natural gas, in particular to a hydrogen-carbon ratio control system and control method in a synthetic natural gas process. Background technique [0002] Natural gas is a multi-component mixed gaseous fossil fuel, the main component is alkanes, of which methane accounts for the vast majority, and a small amount of ethane, propane and butane. It mainly exists in oil fields, gas fields, coal seams and shale formations. There is no waste residue or waste water after natural gas is burned. Compared with coal, oil and other energy sources, it has the advantages of safe use, high calorific value, and cleanliness. Natural gas can be further divided into associated gas and non-associated gas. [0003] Natural gas refers to all gases that exist naturally in nature, including gases formed by various natural processes in the atmosphere, hydrosphere, and lithosphere (including oil field gas, gas field gas, mud volc...

AI Technical Summary

Problems solved by technology

However, no matter whether it is large-scale methanation or gas distribution methanation, due to the large amount of gas, it is difficult to achieve an accurate ratio of hydrogen and carbon in the reaction raw material gas. The hydrogen-carbon molar ratio is only analyzed and adjusted before the raw material gas enters the large-scale methanation stage. Due to the high requirement of CO content in natural gas, CO is poisonous, and its high content will be dangerous. At present, the method of hydrogen content slightly higher than the stoichiometric ratio is usually used in industrial production. Synthetic natural gas requires CO 2 <4%(v)

However, in fact, CO, CO in the raw material gas of the existing process 2 and H 2 It is difficult to enter the reactor in the optimal ratio, resulting in the synthetic natural gas product H 2 The content is easy to exceed the standard, resulting in a decrease in the calorific value of synthetic natural gas

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