Method for preparing high-carbon hydrocarbons from methane through vacuum ultraviolet radiation

Abstract

The invention provides a method for preparing high-carbon hydrocarbons from methane through vacuum ultraviolet radiation. Major equipment comprises a methane storage tank, a refining system, an argon gas storage tank, a blender and a plurality of series vacuum ultraviolet radiation reactors, wherein the high-carbon hydrocarbons are separated from a product flowing out of a last-stage reactor by a primary condenser, and uncondensed gas mixture is pumped back; hydrogen gas produced by a reaction is subjected to recovery by a hydrogen-pervious palladium membrane separator and a hydrogen gas vacuum pump and then is pumped into fuel cells for power generation, the high-carbon hydrocarbons are recovered from impervious methane, ethane, propane, butane and pentane by a condenser and a gas-liquid separator, and then, uncondensed gas returns to a system. According to the method, multistage vacuum ultraviolet radiation reactions are adopted, the byproduct hydrogen gas is recovered, and the high-carbon hydrocarbons are subjected to primary separation, so that the dehydrogenation of the methane and the production of alkanes are promoted; the alkanes are circularly applied mechanically as a reaction assistant of the methane and an initiator of optical free radical chains, so that the efficiency of photo-induced reaction is increased, the conversion ratio of the methane and the product yield are increased, and the production cost of the high-carbon hydrocarbons is reduced.

Description

technical field [0001] The invention relates to a multi-stage series or parallel connection, honeycomb type ultraviolet radiation, methane catalytic activation reaction to prepare high carbon hydrocarbon C 4 + The method belongs to the field of chemical technology. Background technique [0002] Converting natural gas (more than 90% methane) or biomethane (50-80% methane, 20-45% carbon dioxide and nitrogen) into high-carbon hydrocarbons can provide raw materials for chemical processes and obtain more economical transportation; Stable. At present, the patent reports of methane to high-carbon hydrocarbons include: CN200780010896.x, CN201010005422.x and CN200980128134.9 disclose a continuous method for converting natural gas into liquid hydrocarbons, which are obtained through alkane halogenation, carbon-carbon coupling, and halogen regeneration cycles. High-carbon hydrocarbons; while large-scale technologies such as Fischer-Tropsch technology or partial oxidation process cons...

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Problems solved by technology

[0005] The present invention is based on a method for preparing high-carbon hydrocarbons through photocatalytic activation of biomethane disclosed earlier, patent number CN201610100005.0, and the process includes CO 2 Separation, air pump, preheater, multi-stage parallel photocatalytic activation reactor, methane tail gas circulation, palladium gas permeable membrane to recover hydrogen, condensation and cooling to separate high-carbon hydrocarbons; use ultraviolet lamps or high-pressure mercury lamps for multi-stage parallel photocatalytic activation reactors , its wavelength range is 200-400nm, the main peak is 365nm, which is equivalent to an energy of 327.3kJ / mol, and the energy of methane carbon-hydrogen bond is higher, which is 435kJ / mol, and the light radiation in this band can obtain partial cleavage of methane C-H bond. However, it is difficult to break completely, and most of the ultraviolet rays of this wavelength cannot pass through quartz glass, and the loss of light energy is relatively large; it is well known that the shorter the wavelength of light radiation, the stronger the energy of photons with a wavelength of 110-200nm. Ar; the window material is LiF, MgF 2 ;The driving mode is DC and RF, and the photoionization intensity is 9.6, 10.0, 10.6 and 11.8eV; the ultraviolet light of this intensity can convert methane into high-carbon hydrocarbons with a high yield

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