摘要:
Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst comprising zeolite beta. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.
摘要:
Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst under endothermic conditions in a second reaction zone. Heat is added to the endothermic reaction zone to initiate and maintain octane restoring reactions. The preferred acidic catalyst is an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. The addition of heat at the second zone prolongs hydrodesulfurization catalyst life by allowing a lower hydrodesulfurization reactor temperature. The addition of heat also maximizes octane increase in the second zone.
摘要:
Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst defined by its x-ray diffraction pattern and preferably comprising the synthetic zeolite MCM-22. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.
摘要:
Low sulfur gasoline is produced from a catalytically cracked, sulfur-containing naphtha by fractionating the naphtha feed into a low boiling fraction in which the majority of the sulfur is present in the form of mercaptans and a high-boiling fraction in which the sulfur is predominantly in non-mercaptan form such as thiophenes. The low boiling fraction is desulfurized by a non-hydrogenatile mercaptan extraction process which retains the olefins present in this fraction. The second fraction is desulfurized by hydrodesulfurization, which results in some saturation of olefins and loss of octane. The octane loss is restored by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5, to form a low sulfur gasoline product with an octane number comparable to that of the feed naphtha but which contains some recombined sulfur in the form or mercaptans which are removed in a final hydrotreatment.
摘要:
Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization and treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 in an octane restoration step, followed by separation of a C.sub.9 -containing fraction, and recycling the C.sub.9 -containing fraction to the octane restoration step. A hydrocarbon fraction comprising C.sub.1 to C.sub.3 hydrocarbons may also be separated from the octane restored product and recycled for purposes of alkylating aromatic hydrocarbons and for this purpose, it may be advantageous to introduce a benzene-rich feed, such as a reformate, to the process. The treatment over the acidic catalyst in the octane restoration step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha.
摘要:
Low sulfur gasoline is produced from a catalytically cracked, sulfur-containing naphtha by fractionating the naphtha feed into a number of fractions of differing boiling range and hydrodesulfurizing them by by feeding them into a hydrodesulfurization reactor at spaced locations along the length of the reactor in order of descending boiling range, with the highest boiling fraction first. Staged introduction of the feed into the hydrodesulfurization reactor in this way promotes desulfurization of the sulfur-rich, olefin poor back end of the feed while reducing the saturation of the high octane olefins in the olefin-rich, sulfur-poor front end, so preserving octane while achieving the desired desulfurization. The hydrodesulfurization is followed by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha.
摘要:
Methods are provided for processing a gas oil boiling range feedstock, such as a vacuum gas oil, in a single reaction stage and/or without performing intermediate separations. The methods are suitable for forming lubricants and distillate fuels while reducing or minimizing the production of lower boiling products such as naphtha and light ends. The methods can provide desirable yields of distillate fuels and lubricant base oils without requiring separate catalyst beds or stages for dewaxing and hydrocracking. The methods are based in part on use of a dewaxing catalyst that is tolerant of sour processing environments while still providing desirable levels of activity for both feed conversion and feed isomerization.
摘要:
A divided wall column allows for fractionation of multiple streams while maintaining separate product qualities. Effluents from multiple stages of a reaction system can be processed in a single divided wall column. The divided wall column can produce multiple cuts from each separated area, as well as at least one output from a common area.
摘要:
This invention relates to a process involving hydrocracking of a feedstream in which a converted fraction can exhibit relatively high distillate product yields and maintained or improved distillate fuel properties, while an unconverted fraction can exhibit improved properties particularly useful in the lubricant area. In this hydrocracking process, it can be advantageous for the yield of converted/unconverted product for gasoline fuel application to be reduced or minimized, relative to converted distillate fuel and unconverted lubricant. Catalysts and conditions can be chosen to assist in attaining, or to optimize, desirable product yields and/or properties.
摘要:
Methods are provided for processing a gas oil boiling range feedstock, such as a vacuum gas oil, in a single reaction stage and/or without performing intermediate separations. The methods are suitable for forming lubricants and distillate fuels while reducing or minimizing the production of lower boiling products such as naphtha and light ends. The methods can provide desirable yields of distillate fuels and lubricant base oils without requiring separate catalyst beds or stages for dewaxing and hydrocracking. The methods are based in part on use of a dewaxing catalyst that is tolerant of sour processing environments while still providing desirable levels of activity for both feed conversion and feed isomerization.