Research On Reactive Adsorption Desulfurization Coupling Hydrocarbon Oriented Tranformation Catalyst

Reaction adsorption desulfurization technology is one of the effective desulfurization technologies.Which can realize the deep desulfurization of oils and reduction of octane loss at the same time.Although the Ni/ZnO catalyst used in this technology is effective in desulfurization,the problem of olefin saturation that leads to the decrease of octane number is still exist.This paper is based on the adsorption desulfurization technology,introduced the hydrocarbon isomerization process and prepared Ni/ZnO/SAPO-11 catalyst.By studying the catalytic reaction on different hydrocarbons,we have built a reaction network and distinguished the active centers.Therefore,the direction of catalyst modification is guided.The catalyst was modified by second metal Cu and Pb,and the modified metal load was adjusted to prepare the catalyst with the ability of deep desulfurization and the reduction of octane loss.Through mechanical mixing and equal volume impregnation,the reactive adsorption desulfurization catalyst（composition for 4 wt%Ni/40 wt%ZnO/30 wt%diatomite）and the coupling catalyst（composition for 4 wt%Ni/40 wt%ZnO/30 wt%SAPO-11）were prepared.The desulfurization rate of the two catalyst is up to 99%,the sulfur content of the product is below 1 ug·g^-1,and the octane loss of the reactive adsorption desulfurization catalyst is 5.45units,while the coupling catalyst is only 3.75 units.The reaction of different hydrocarbons by coupling catalyst shows that the reaction of naphthenic dehydrogenation,alkene hydrogenation saturation,olefin isomerism and alkanes isomerism exist in the coupling reaction system.Among them,the selectivity of naphthenic hydrocarbon dehydrogenation to aromatics is about 97%.The reaction rate of alkane isomerization is low,and the yield of isomeric alkanes is only 2%.The conversion rate of olefin is about 100%,the highest yield of isoparaffin is 18%,however,when the catalyst is composed of 40 wt%ZnO/30 wt%SAPO-11,the conversion of olefin is more than 95%,and the selectivity of isomers is about 80%.Therefore,inhibiting olefin saturation and promoting olefin isomerization are the main ways to reduce octane loss.Modified coupling catalyst can effectively reduce the loss of octane number,but the desulfurization capability decreases.Among them,the octane number of the C-Pb10 catalyst product is above 93 units,which is only 0.6 units lower than that of the raw material octane number.Increasing the mass ratio of nickel and lead,the desulfurization capacity of the catalyst increased,but the ability to reduce octane loss decreased,and the octane number of the product was about 90 units.In order to balance the desulphurization capacity of the catalyst and reduce the loss of octane number,when the mass ratio is Ni:Pb=13:1,the sulfur content of the product is 5.11 ug·g^-1,the octane number is 92.42,it has only 1.39 units lower than the octane number of raw materials,and the catalytic performance is the best..