Abstract: Improved process and apparatus for purifying paraxylene from mixed C8-aromatic feedstocks are disclosed in which the use of at least two crystallization stages operated at different temperatures in combination with a final product separator improves purity and recovery while reducing capital and energy costs.

Abstract: A method and apparatus are disclosed for regenerating and/or stabilizing the activity of a dehydrogenation catalyst used in dehydrogenating an alkylaromatic hydrocarbon to obtain an alkenylaromatic hydrocarbon, the method comprising the steps of continuously or intermittently adding to a reactant stream an effective amount of an alkali metal or alkali metal compound without interrupting the dehydrogenation reaction.

Abstract: A method and associated apparatus for regenerating and/or stabilizing catalyst used in dehydrogenation of alkylaromatic hydrocarbons is disclosed. The alkylaromatic hydrocarbon (1) and steam (2) are combined to form feedstream (3) and pass into reactor (50). The ensuing product stream (4) is reheated in heater (52) to restore the heat lost and passed as partially converted reactant stream (5) into second reactor (54) and leaves as stream (6) comprising the dehydrogen product. Restoration and/or stabilization of catalyst is accomplished by an alkali metal compound which is fed into feedstream (2) and/or product stream (5) via supply means (46 and 66), respectively. The amount of alkali metal compound entering the reactor(s) is monitored by means (42 and 62) which may in turn be coupled to activating means (44 and 64) to signal and activate the supply means. This method and apparatus permit the restoration and/or stabilization of the catalyst to be performed without interrupting the dehydrogenation reaction.

Abstract: A method and apparatus are disclosed for regenerating and/or stabilizing the activity of a dehydrogenation catalyst used in dehydrogenating an alkylaromatic hydrocarbon to obtain an alkenylaromatic hydrocarbon, the method comprising the steps of continuously or intermittently adding to a reactant stream an effective amount of an alkali metal compound without interrupting the dehydrogenation reaction.

Abstract: A novel method and apparatus are described for modifying the field within the toroidal chamber of a stellarator or a tokamak. At least one additional electrical conductor is arranged around the straight axis of the toroidal chamber and has a sawtooth or zigzag shape with the number of teeth being the same as the number of toroidal field coils or a factor thereof. The conductor is shaped so that one edge of each tooth is substantially parallel to a portion of one of the toroidal field coils while the other edge of the tooth extends from the upper portion of one coil to a lower portion of the toroidal field coil associated with another tooth. The conductor is adapted to carry a current that is approximately the same as that in the toroidal field coil but in the opposite direction.

Abstract: A process is disclosed for pretreating a dilute ethylene feedstock with benzene, ethylbenzene, or mixtures thereof to reduce the higher olefin content of the ethylene feedstock and to render it suitable as the feed to an alkylation reactor for producing ethylbenzene. Benzene and ethylbenzene recovery are integrated with other downstream operations in the ethylbenzene production.

Abstract: Repowering industrial and utility boilers with a circulating fluidized bed combustor to reduce SOx and NOx emissions emanating from the boilers by the following steps.First combusting high sulfur-containing carbonaceous solid fuel in a circulating fluidized bed combustor in admixture with limestone and air.Secondly combusting a carbonaceous fuel in an industrial or utility boiler.Thirdly mixing the flue gases generated in the circulating fluidized bed combustor with the exhaust gases produced in the industrial or utility boiler.Finally controlling the total heat generation by maintaining the circulating fluidized bed heat input to the boiler furnace from about 70 to 90% and the heat input of the boiler furnace from about 30 to 10%.

Abstract: A method and apparatus are disclosed for regenerating and/or stabilizing the activity of a dehydrogenation catalyst used in dehydrogenating an alkylaromatic hydrocarbon to obtain an alkenylaromatic hydrocarbon, the method comprising the steps of continuously or intermittently adding to a reactant stream an effective amount of an alkali metal compound without interrupting the dehydrogenation reaction.