The invention provides a deep cooling and film coupled
ethylene cyclic
refrigeration system non-condensed
effluent gas separating and recycling technology, and belongs to the technical field of
petrochemical engineering. According to the technology, starting from the characteristics of an
ethylene cyclic
refrigeration system, deep cooling conditions formed through
ethylene throttling expansion areutilized for conducting liquidation and rectification on non-condensed
effluent gas, most of ethylene is recycled in the form of the
liquid state, then, a gas film is used for separating and enriching ethylene left in deep cooling
tail gas, and low-pressure ethylene-rich gas obtained on the
permeation side returns to a compressor of the ethylene cyclic
refrigeration system. Deep cooling and filmseparation
coupling is adopted for treating the non-condensed
effluent gas, and ethylene losses are obviously reduced while
oxygen and
nitrogen accumulation is avoided. Taking a
butyl rubber device of60,000 tons / year as an example, by adoption of the provided efficient non-condensed effluent gas separating and recycling technology, the ethylene content of the
tail gas exhausted towards a
torch islower than 5.0 vol%, the ethylene recycling rate reaches 99%, about 210 tons of ethylene can be recycled every year, and the annual
economic benefits exceed 2 million yuan.