Synthesis of Chemical Precursors via the Catalytic Hydrogenation of 2-Chloropropene

Allyl chloride, which is a cross-linking agent for synthetic resins and a synthetic intermediate that is used as an alkylating agent for pharmaceuticals, is often utilized and synthesized at production sites related organochlorides. In the synthesis process of allyl chloride, however, 2-chloropropene (2-PEN) is produced as the by-product and that is a problem because it essentially has no practical use. In this study, it was investigated about the hydrogenation of 2-PEN to 2-chloropropane (2-PAN) and propylene, which are precursors for various chemical products. The commercially available palladium catalysts such as OleMax 201, OleMax 301, OleMax 600, and HyFlex 500 were used for 2-PEN hydrogenation. The maximum yield of 2-PAN (10.6 %) was detected at 348 K, P(H2) = 13.5 kPa and P(2-PEN) = 8.8 kPa, on OleMax 600 (0.5 g), while the maximum yield of propylene (26.0 %) was realized under the same reaction conditions, with the exception of using at P(H2) = 7.9 kPa on HyFlex 500 (0.5 g). The selective formation of propylene such as 8.9, 100, and 8.9 % for the conversion of 2-PEN, the selectivity of propylene, and the yield of propylene, respectively, was realized on OleMax 201. The selective formation of 2-PAN, however, was not observed on all catalysts. Palladium loading strongly influenced the catalytic activity, but had none on either the specific surface area, or basic and acidic properties.