Study On FCC Diesel Hydro-upgrading Catalyst

Cetane number is the important quality index denoting burning performance and blast resistance. There are two methods to solve the problem about lower cetane number of FCC diesel in recent years: one is two-stage process to deep desulfurization and dearomatization, this method has the drawback of high investment and operating cost; the other is MHUG (Moderate Pressure Hydro-Upgrading) or MPHC(Moderate Pressure Hydrocracking) technology, many commercial application results showed that this technology converted aromatic hydrocarbon from diesel distillate into gasoline distillate, consequently it can greatly improve diesel cetane number, but it has the drawback of lower diesel yield and higher hydrogenation consumption. So it is urgent to develop a new hydro-upgrading technology to effectively and economically improve FCC diesel qualities.The goal of this paper is to develop a hydro-upgrading catalyst, to prepare a diesel hydro-upgrading catalyst which has higher activity and higher diesel selectivity, this paper introduced aromatic hydrocarbon hydro-upgrading reaction network firstly, then put forward a design scheme for hydro-upgrading catalyst; Modified methods affecting crystallization, SiO2/Al2O3, specific surface area and pore structure of Y molecular sieve were investigated,Y molecular sieves were characterized with the following characterization techniques: XRD, BET and SEM; HDA-1 catalyst was prepared by pore volume co-impregnation method,it consists of metallic Ni-W as hydrogenation components and Y molecular sieve as ring opening components, alumina as carrier; To carry through catalyst performance evaluation, operating conditions affecting catalyst performance were investigated firstly. Then performance evaluation of HDA-1catalyst was carried out on a 20ml and a 100ml fixed-bed hydrogenation test unit,100ml fixed-bed hydrogenation test unit evaluation results exhibited that HDA-1 catalyst had excellent HDA, HDS, HDN performance: single-stage, single catalyst, once-through process was adopted in the HDA-1 catalyst performance evaluation, Daqing FCC diesel fraction was used as feed oil, under the following operating conditions: pressure of 8.5MPa, hydrogen oil volume ratio of 800:1, volume space velocity of 1.0 h-1, the average operating bed temperature of 360℃, desulfurization rate of 99.6%, denitrogenation rate of 99.4%, cetane number gain of 6.6, diesel yield of 97.7wt%.