Acetylene Hydrogenation Kinetics And Reactor Simulation

Olefins produced by steam-cracking processes invariably are contaminated with alkynes and diolefins .The presence of these compounds is undesirable in different degrees depending on the end use of the olefins . Nowadays , the selective hydrogenation of dienes and alkynes to the corresponding mono-olefins in the procedure must usual for the removal of such objectionable contaminants .Depending on the selectivity of the catalyst and the process and on the relative concentration of the various alkynes, a net increase may be obtained in the content of the useful olefins. Today, palladium research has proved that, among the metals of the group VIII,palladium is the most active and selective metal for the hydrogenation of alkynes to the corresponding olefins. BRICI is one of the earliest institutes major in the selective hydrogenation ,and it has achieved the commercial catalysts BC-1-037,BC-H-20 series. BRICI catalyst BC-H-20A has been developed for the selective hydrogenation of acetylene in C2 streams .It has been widespread used in domestic petrochemical factories.In this paper ,the kinetics and reaction performance of tail end selective hydrogenation of a steam cracking C2 cut over BC-H-20A catalyst have been studied .Experimental runs have been carried out in a isothermal reactor .The jacketed fixed bed reactor operates isothermally using diethylene glycol as the cooling and heating medium .It indicates that the reaction rate of acetylene is first-order via hydrogen ,and -0.5 order via acetylene from the kinetic equation of the hydrogenation of acetylene derived from experimental data .The activation energy is 47.7KJ/mol.Simulation of fixed-bed gas-solid catalytic reactor based on the two-dimensional pseudohomogeneous model has been presented in this paper .The distribution of temperature and concentration in the reactor can be calculated from the mathematical models .The models are simplified for little calculation. BC-H-20A is a bimetallic catalyst with a palladium active phase supported on alumina and 0.03 mass percent .The bimetallic catalyst performs selective hydrogenation more efficiently and economically .The selectivity of the hydrogenation is over 90% in the micro-isothermal reactor, and 80% in the beginning on the industrial reactor .This can be easily scaled up with little error.Running data for BC-H-20A in a petrochemical factory have been collected . The BC-H-20A catalyst has performed an outstanding selectivity ,high activity and cycle length .Simulating result can be fit very well with the actual data in the beginning .The error will be evidential when the side reaction occurred .