Ultra-Deep Diesel Hydrodesulfurization Catalysis and Process: A Tale of Two Sites

Octo­ber 2018 — F.G. Cia­pet­ta Award Lec­ture

Dr. Teh C. Ho
Hydro­car­bon Con­ver­sion Tech­nolo­gies
E-mail: , Web:
Abstract: Hydrodesul­fu­r­iza­tion cat­a­lysts have two types of active sites for hydro­gena­tion and hydrogenol­y­sis reac­tions. While hydro­gena­tion sites are more active for desul­fu­r­iz­ing refrac­to­ry sul­fur species, they are more vul­ner­a­ble to organon­i­tro­gen inhi­bi­tion than hydrogenol­y­sis sites. In con­trast, hydrogenol­y­sis sites are less active for desul­fu­r­iz­ing refrac­to­ry sul­fur species but are more resis­tant to organon­i­tro­gen inhi­bi­tion. This dichoto­my is exploit­ed to devel­op an ultra-deep hydrodesul­fu­r­iza­tion stacked-bed reac­tor com­pris­ing two cat­a­lysts of dif­fer­ent char­ac­ter­is­tics. The per­for­mance of this cat­a­lyst sys­tem can be supe­ri­or or infe­ri­or to that of either cat­a­lyst alone. A the­o­ry is devel­oped to pre­dict the opti­mum stack­ing con­fig­u­ra­tion for max­i­mum syn­er­gies between the two cat­a­lysts. The best con­fig­u­ra­tion pro­vides the pre­cise envi­ron­ment for the cat­a­lysts to reach their full poten­tials, result­ing in the small­est reac­tor vol­ume and max­i­mum ener­gy sav­ing. Mod­el pre­dic­tions are con­sis­tent with exper­i­men­tal results. A selec­tiv­i­ty-activ­i­ty dia­gram is devel­oped for guid­ing the devel­op­ment of stacked-bed cat­a­lyst sys­tems.