Vinyl Chloride Production from Acetylene

The process under analysis comprises three major sections: (1) Reaction; (2) VCM Purification; and (3) Acetylene Recovery.

Reaction. Compressed acetylene is passed through dryers for removal of any residual moisture and then fed to guard beds to remove any contaminants that may damage catalyst activity. Purified acetylene is mixed with anhydrous hydrogen chloride. The gaseous raw materials are fed to a multi-tubular heat exchanger, in which tubes are packed with catalyst and a cooling fluid is fed to the shell to remove the heat generated by the reaction.

VCM Purification. The reaction effluent is twice scrubbed with water and caustic solution to remove any hydrogen chloride. A diluted hydrochloric acid is sent to hydrogen chloride recovery and wastewater is disposed. Gaseous effluent is recompressed, cooled and fed to a three-phase separator. The uncondensed light ends are transferred to the Acetylene Recovery.The organic liquid phase is transferred to a column for further purification. Vinyl Chloride crude product is recovered as the bottom stream. VCM crude product is fed to the final purification column, where purified VCM is recovered in the column overhead and stored.

Acetylene Recovery. Uncondensed light ends from the Dehydration Column are fed to an absorption column, in which acetylene is absorbed in liquid chlorinated hydrocarbons. Acetylene absorbed is recovered in a stripping column. The acetylene removed as overhead stream is recycled to reactor feed.