LIQUID-PHASE HYDROGENATION OF 3C FRACTION

PURPOSE:The feed of hydrogen is divided into 3 or more stages to effect the liquid-phase hydrogenation of the 3C fraction in the presence of a catalyst by staircase reactions to increase the efficiency of the reaction. CONSTITUTION:The liquid-phase hydrogenation of the 3C fraction containing, as major components, propylene and propane and, as trace components, propadiene and methylacetylene is carried out by dividing the hydrogen feed into 3 or more stages at 0-100 deg.C under a pressure of 5-20 atmospheric pressure to give propylene free from propadiene and methylacetylene. The hydrogen feed at the first stage is adjusted in molar ratio calculated as pure hydrogen, to less than 1.0 to the total amounts of propadiene and methylacetylene in the 3C fraction. EFFECT:The process can inhibit propylene from being converted into propane by side-reactions, when a trace amount of propadiene and methylacetylene is converted into propylene with hydrogen.