Sewage treatment process capable of recovering low-carbon hydrocarbons and low-carbon oxygen-containing organic matters

Abstract

The invention discloses a sewage treatment process capable of recovering low-carbon hydrocarbons and low-carbon oxygen-containing organic matters. The process comprises the following steps: delivering a sewage raw material subjected to heat exchange into a flash evaporation separation tank; delivering a separated gas mixture containing ethene, propylene and low-carbon oxygen-containing organic matters into an oxide removing tower to obtain a low-carbon organic matter flow and a low-carbon hydrocarbon (such as ethene and propylene) flow; and delivering a separated liquid mixture into a stripping tower to obtain pure water. The total methanol and dimethyl ether content in pure water obtained by the method is not more than 100ppm. The pure water meets the inflow water quality requirement of sewage water treatment plant, and at the same time, the low-carbon hydrocarbon matters and low-carbon oxygen-containing organic matters in sewage are recovered.

Description

technical field [0001] The invention belongs to the field of sewage treatment. It particularly relates to a sewage treatment process for recovering low-carbon hydrocarbons and low-carbon oxygen-containing organic matter. Background technique [0002] Petroleum refining, petrochemical and other industrial processes often produce sewage. If it is not treated in time, it will seriously pollute the environment and cause the loss of effectively used resources. The technology of producing olefins from coal or natural gas through methanol (MTO) is at the forefront of technology development in the world, and has obvious competitive potential. Under the situation of high oil prices in recent years, the international production of low-carbon olefins from coal or natural gas through methanol is about to enter the stage of industrial application. [0003] Because the sewage produced by the methanol to low-carbon olefins unit (hereinafter referred to as the MTO unit) and the olefin sep...

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Problems solved by technology

[0006] The present invention aims at the shortcomings of the prior art that low-carbon hydrocarbons (mainly ethylene and propylene) and low-carbon oxygenated organics (mainly methanol and / or dimethyl ether) in sewage cannot be recovered, and provides a The treatment process for low-carbon hydrocarbons containing ethylene, propylene and other components and low-carbon oxygen-containing organic substances containing methanol, dimethyl ether, acetone and acetaldehyde to ensure that the obtained purified water The total weight content of methanol and dimethyl ether is not more than 100ppm, which meets the water quality requirements of sewage treatment plants, and at the same time recovers these low-carbon hydrocarbons and low-carbon oxygen-containing organic substances in sewage

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