Hydrodewaxing
AssigneeMobil Oil Corporation
InventorFritz A. Smith
Life of this patent
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Abstract
An improved method for hydrodewaxing a petroleum or shale oil fraction, e.g. petroleum distillate, in a reactor is provided which involves contacting said fraction with hydrogen in the presence of a catalyst comprising a crystalline zeolite having a silica to alumina mole ratio of at least 12 under hydrodewaxing conditions wherein the average reactor temperature at start-up of from about 200.degree. C. to 310.degree. C. is increased uniformly to at least 360.degree. C. within about seven days from start-up.
Claims18
In the method for catalytically hydrodewaxing a petroleum or shale oil fraction in a reactor by contacting said fraction with hydrogen in the presence of a catalyst comprising a crystalline zeolite having a silica to alumina mole ratio of at least 12 at an average reactor temperature of from about 200.degree. C. to about 712.degree. C., a liquid hourly space velocity of from about 0.2 to about 10, a reactor pressure of from about 100 psig to about 3000 psig and a hydrogen to hydrocarbon mole ratio of from about greater than 0 to about 20, and wherein said reactor is started up at an average reactor temperature of from about 200.degree. C. to about 310.degree. C., the improvement which comprises increasing the average reactor temperature in a uniform manner to at least about 360.degree. C. within about the first seven days after start-up of the reactor.
A catalytic hydrodewaxing process for a heavy oil fraction comprising the steps of
- contacting the heavy oil during startup with hydrogen in the presence of an acidic zeolite having a constraint index of about 1 to 12, at an average reactor temperature of about 200.degree. C. to 310.degree. C.;
- and
- uniformly increasing average reactor temperature at a daily increase of at least 10.degree. C. to an average reactor temperature of at least about 360.degree. C. with hydrogen circulation, wherein the average reactor temperature is increased to 360.degree. C. within about the first seven days after startup of the reactor.
Dependencies are inferred from the claim text.