Process for the selective dehydrohalogenation of an admixture of alkylhalides

In a process for the selective dehydrohalogenation of a liquid feed comprising an admixture of primary, secondary and tertiary alkylhalides to convert the secondary and tertiary alkylhalides to olefins, with minimum dehydrohalogenation of the primary alkylhalides,

• the improvement comprising
• introducing said liquid alkylhalide feed stream into a staged distillation-reactor column at temperature and residence time sufficient to dehydrohalogenate and convert the secondary and tertiary alkylhalides components of said liquid feed stream to vaporous olefins and gaseous hydrogen halide, the vaporous olefins, and gaseous hydrogen halide ascending through the distillation-reactor column,
• condensing and recovering vaporous olefins at the top of the column, withdrawing the hydrogen halide and one portion of the condensed olefins as coproducts, and recycling as reflux a second portion of the condensed olefins into the top of the column, the recycled liquid olefins passing downwardly through the column as a boiling stream which countercurrently intimately contacts said ascending vaporized and gaseous components throughout the length of the column, the rising vapor at or near its condensing temperature becoming enriched in olefins and gaseous hydrogen halide, with the descending liquid at or near its boiling temperature becoming enriched in primary alkylhalides, and
• withdrawing primary alkylhalides from the bottom of the column.