초록 ▼

An improved process for catalytic desulfurization of petroleum residua feedstocks to provide at least about 75% desulfurization of the liquid product while achieving low catalyst deactivation and increased catalyst age. In the process which uses an ebullated catalyst bed reactor, the reaction condit

An improved process for catalytic desulfurization of petroleum residua feedstocks to provide at least about 75% desulfurization of the liquid product while achieving low catalyst deactivation and increased catalyst age. In the process which uses an ebullated catalyst bed reactor, the reaction conditions are usually maintained at 790°-860°F. temperature, 1000-1800 psig hydrogen partial pressure, and 0.2-2.0 Vf/hr/Vr space velocity. To control carbon and metals deposition on the catalyst, used catalyst is withdrawn from the reactor, a minor portion of the catalyst is discarded to control metals deposition and maintain catalyst activity, and the remaining catalyst is regenerated to remove carbon by carbon burnoff and returned to the reactor for further use. If desired, the regenerated catalyst can be presulfided before returning it to the reactor. Following phase separation and distillation steps, the desulfurized hydrocarbon liquid products are withdrawn from the process. For feedstocks requiring higher desulfurization, two stages of catalytic reaction are provided in which the used catalyst is withdrawn from each stage reactor and regenerated to remove carbon and then returned to the same stage reactor. Alternatively, fresh catalyst is added to the second stage only, some used catalyst from the second stage reactor is transferred to the first stage reactor, and used catalyst is discarded from the first stage reactor.

대표청구항 ▼

A process for the catalytic desulfurization of heavy petroleum residua feedstocks containing at least about 2 W% sulfur and less than about 400 ppm total metals to produce lower sulfur liquid products wherein the effective catalyst deactivation is minimized while catalyst age is increased, said proc

A process for the catalytic desulfurization of heavy petroleum residua feedstocks containing at least about 2 W% sulfur and less than about 400 ppm total metals to produce lower sulfur liquid products wherein the effective catalyst deactivation is minimized while catalyst age is increased, said process comprising: (a) feeding the petroleum residua feedstock together with hydrogen into a reaction zone containing an ebullated catalyst bed of high activity desulfurization catalyst, said reaction zone being maintained at a 790°-860°F. temperature and 1000-1800 psig hydrogen partial pressure with a liquid space velocity of 0.2-2.0 Vf/hr/Vr and a catalyst space velocity of 0.02-0.4 barrel/day/pound catalyst to provide at least about 75% desulfurization of the feed and to produce a hydroconverted hydrocarbon material; (b) withdrawing used catalyst containing carbon deposits from said reaction zone at a rate of at least about 0.4 lb/bbl feed, discarding between 10 and 50 W% of said used catalyst, regenerating the remainder of said used catalyst to remove substantially all carbon deposits, and returning the regenerated catalyst to the reaction zone for further use along with fresh catalyst to minimize the catalyst effective deactivation rate and increase catalyst age; and (c) withdrawing said hydroconverted hydrocarbon material from said reaction zone, and phase separating and distilling the material to produce gas and lower boiling desulfurized hydrocarbon liquid products.