A novel process

thermally coupled catalytic distillation for selective hydrogenation of C3 alkyne into alkene

was proposed. Methylacetylene and propadiene were separated from propylene in propylene column

and converted into propylene at the same time by catalytic hydrogenation. Deethanizer and propylene distillation were thermally coupled by liquid and vapor streams. The proposed process had two advantages: reactive distillation can raise the selectivity of hydrogenation effectively; thermally coupled distillation columns could avoid propylene backmixing in deethanizer and then save energy. Simulation of the process was performed by using Aspen Plus software. Propylene yield increased by 0.74%—2.19%. At the same time

the annual cost for refrigeration was saved by 2.44%—3.61%. The simulation also showed that the novel process was especially suitable for heavy cracking feedstock.