Simulation of Purification of Lower Olefins in Pyrogas from Acetylene Hydrocarbons on Nickel Polymetallic Catalysts

The kinetics of the reactions of selective hydrogenation of acetylenic hydrocarbons in ethane–ethylene and propane–propylene fractions (EEF and PPF) of pyrogas on a polymetallic nickel catalyst promoted with group I, III, IV, and VI metals is studied. The dimensions of the cylindrical granules used in the catalytic studies are 2 mm diameter and 10 mm length. The nickel content in the catalyst is less than 32 wt %. The kinetic experiments are carried out in a laboratory flow reactor 2 cm in diameter with a reaction-zone length of 20 cm and a bench reactor with an inner tube diameter of 3.2 cm and a reaction-zone length of 600 cm. Experimental conditions were varied as: feed flow rate of 2000–42000 h–1, reaction-zone temperature 330–410 K, pressure 1–30 atm, and hydrogen : acetylenic hydrocarbon molar ratio 2–10. A staged two-route mechanism for the reaction of hydrogenation of acetylenic hydrocarbons is proposed and a kinetic model corresponding to it is derived. A total of 80 experiments are carried out on laboratory and bench installations. The kinetic model constants and the macrokinetic constants of the bench reactor model are estimated by the nonlinear least-squares method. The correspondence of the proposed models to the experimental results is shown. The possibility of joint purification of EEF and PPF pyrogas in a single reactor with an increase in olefins in the product stream compared to the feed stream is demonstrated.