A trichloro
ethylene preparation method relates to chlorinated
alkene. The method comprises the following steps: 1), mixing vaporized
tetrachloroethane with
acetylene to form a
raw material mixture gas, and controlling the
molar ratio of
tetrachloroethane to
acetylene at 1:(0.5-2); 2), pumping the
raw material mixture gas into a reactor filled with a catalyst for reaction at controlled temperature, pressure and gas flow rate, so as to allow the conversion rate of
acetylene or
tetrachloroethane to reach more than 70 percent; and 3), cooling the
reaction product obtained in the step 2 to a
room temperature by water, and separating out liquid-phase product and gas-phase product, wherein the liquid-phase product passes through a rectification column to produce a trichloro
ethylene product, the gas-phase product, which is subjected to compression and freezing, is adopted for further liquification separation of
vinyl chloride, and the uncooled gas after the completion of compression and freezing is used for circulating and recycling. According to the method provided by the invention, tetrachloroethane is adopted to eliminate
coupling between the reaction and an acetylene
addition reaction so as to form intermolecular energy direct conversion; and accordingly, the
energy transfer process is simplified, the
reaction energy consumption is reduced, the technological process is also simplified, and the equipment investment is lower. In addition, as for by-products,
vinyl chloride is higher than
hydrochloric acid in additional value.