Method and system for regulating hydrogen-carbon ratio of Fischer-Tropsch synthesis gas and co-producing hydrogen

Abstract

The invention provides a method and a system for regulating a hydrogen-carbon ratio of Fischer-Tropsch synthesis gas and co-producing hydrogen. The method comprises the following steps of sending purified synthesis gas into a Fischer-Tropsch synthesis unit and a purified synthesis gas separation unit respectively; carrying out a Fischer-Tropsch synthesis reaction on the purified synthesis gas, sent into the Fischer-Tropsch synthesis unit, under the action of a Fischer-Tropsch catalyst, and sending produced high-temperature oil gas into an oil-gas separation unit; in the oil-gas separation unit, separating out the unreacted synthesis gas and a lightweight hydrocarbon compound, which are contained in the high-temperature oil gas, as tail gas, sending at least part of the tail gas into a decarbonization unit, removing, in the decarbonization unit, CO2 in the tail gas, and partially or completely circulating to the Fischer-Tropsch synthesis unit as purified tail gas; separating the purified synthesis gas sent into the purified synthesis gas separation unit into CO-rich gas and H2-rich gas, and using at least part of the CO-rich gas for regulating a hydrogen-carbon ratio of raw gas input by the Fischer-Tropsch synthesis unit. By adopting the method and the system which are provided by the invention, not only can the hydrogen-carbon ratio of the synthesis gas be adjusted, but also the by-product hydrogen can be obtained.

Description

Technical field [0001] The invention relates to the technical field of adjusting the hydrogen-carbon ratio of Fischer-Tropsch synthesis gas, in particular to a method and system for adjusting the hydrogen-carbon ratio of Fischer-Tropsch synthesis gas co-producing hydrogen. Background technique [0002] With the ever-decreasing petroleum resources and the increasingly stringent requirements of mankind to protect the ecological environment, the world's demand for clean liquid fuels has increased dramatically. In order to meet this demand, scientific researchers from various countries are committed to the research and development of clean fuel oil production technology. Among them, Fischer-Tropsch synthesis technology has attracted the most attention. The Fischer-Tropsch synthesis technology is mainly composed of three parts: ① synthesis gas production technology; ② synthetic liquid hydrocarbon production technology; ③ synthetic product processing technology. The typical Fischer-T...

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Problems solved by technology

Due to the very large amount of recycle gas and the supplementary fresh synthesis gas is less than 30%, it is difficult to realize the precise ratio of hydrogen and carbon in the recycle gas (feed gas) entering the Fischer-Tropsch reactor

The results of industrial operation show that the current process is difficult to achieve the optimum ratio of hydrogen and carbon in the cycle gas to enter the reactor, resulting in the Fischer-Tropsch reaction often being in a non-optimal state, which restricts the maximization of the economic benefits of the Fischer-Tropsch unit

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