The application discloses a
system and method for recovering
dichloroethane by VOCs
membrane method, which comprises a
water washing tower, a
temporary storage tank, a condenser, a gas-liquid separator, an air draught fan, a membrane
assembly and a
storage tank; the gas inlet of the
water washing tower is connected with the VOCs
tail gas, and the gas outlet at the top of the
water washing tower is connected with the gas inlet of the
temporary storage tank; the gas outlet at the top of the
temporary storage tank is connected with the gas inlet of the condenser, the gas outlet of the condenser is connected with the gas-liquid separator, and the liquid outlet at the bottom of the temporary
storage tank and the gas-liquid separator is used for discharging the condensate; the gas outlet at the top of the gas-liquid separator is connected with the air draught fan, and the air draught fan is connected with the membrane
assembly; the first outlet at the bottom of the membrane
assembly is communicated with the
storage tank, the storage tank is kept in vacuum negative pressure, the second outlet at the upper end of the membrane assembly is used for discharging the treated
tail gas, and the
system and method adopt the process of water washing pretreatment, deep cold pre-
recovery and vacuum negative pressure membrane separation, a stable
transmembrane pressure difference is built on both sides of the membrane through vacuum negative pressure, the
mass transfer driving force of
dichloroethane is greatly increased, the
recovery efficiency is remarkably improved, and the product purity is high.