Abstract: A process for producing diesel fuel from a diesel hydrocarbon feed. Hydrogen is fed cocurrently with the feed to a first hydrogenation zone in the presence of a hydrogenation catalyst. Liquid effluent from the first hydrogenation zone is then passed to a second hydrogenation zone, wherein the liquid effluent is contacted countercurrently with hydrogen in the presence of a hydrogenation catalyst. Preferred hydrogenation catalysts are those comprising non-noble metals in the first hydrogenation zone, and may comprise noble or non-noble metals in the second hydrogenation zone.

Abstract: In the two stage liquefaction of a carbonaceous solid such as coal wherein coal is liquefied in a first stage in the presence of a liquefaction solvent and the first stage effluent is hydrogenated in the presence of a supported hydrogenation catalyst in a second stage, catalyst which has been previously employed in the second stage and comminuted to a particle size distribution equivalent to 100% passing through U.S. 100 Mesh, is passed to the first stage to improve the overall operation.

Abstract: In a process for producing distillates from coal by a first stage thermal liquefaction followed by a catalytic hydrogenation, liquefaction solvent is added at points spaced over the length of the thermal liquefaction heater.Coal may be co-processed with petroleum oil by adding pre-hydrogenated oil to the first stage or unhydrogenated oil to the second stage.

Abstract: A process for reactivating alkylation catalyst which comprises contacting alkylation catalyst with hydrogen and benzene in the essential absence of olefin. The reactivation process may be conducted under conditions (eg., temperature, pressure) similar to that employed in an alkylation reaction. This process enables one to reactivate the catalyst in situ in a relatively short time, thus minimizing disruption of the alkylation operation.

Abstract: A pressurized feed material (30) in aqueous suspension is oxidized in a supercritical temperature reaction zone (20) in an upper region of a vertically elongated, cyclindrical walled, closed pressure vessel (10) to form an oxidized super fluid phase (46) which is removed from the upper region of the vessel and a brine (44) containing precipitates and other solids which are collected in and removed from a subcritical temperature zone (16) in the lower region of the vessel. The wall (12) of the cylindrical pressure vessel (10) is scraped by rotatable scraper means (60) which upon rotation will dislodge precipitated solids from the wall (12).

Abstract: An improved process for the alkylation of benzene in the presence of an alkylation catalyst. The catalyst bed may be caused to move in a direction countercurrent to the movement of the benzene and olefin, or a portion of the catalyst bed is periodically removed and replaced. A regeneration step, whereby the catalyst is heated in a controlled oxygen atmosphere in order to reactivate the catalyst, is also described.

Abstract: A process for the catalytic distillation production of alkylated aromatic compounds is provided wherein the vapor pressure of the olefin may be increased while maintaining the same olefin feed rate and aromatic to olefin ratio. In one embodiment a side stream from the vapor from the second column below the catalyst and olefin feed is condensed and rerouted to the aromatic make up stream from the reflux drum. The vapor pressure of the olefin in the lower end of the first column in the catalyst bed is thus increased which increases the equilibrium concentration of the olefin in the liquid phase. In another embodiment of the invention the effective driving force for the reaction is increased by injecting the olefin at different heights within the catalyst bed. If additional olefin is injected more catalyst bed height would be required, but the additional catalyst is more that offset by the increased throughput at the same overall olefin conversion.

Abstract: A process for recovering hydrogen from a cracking effluent wherein a cracking effluent is compressed, and then at least a portion of the hydrogen is separated from the cracking effluent prior to cooling of the cracking effluent to remove lower-boiling components. The separation of hydrogen is preferably accomplished by passing the cracking effluent through at least one semi-permeable membrane.

Abstract: A system for adding and withdrawing solids to a high pressure reactor wherein there is provided improved control of flow and concentrations of a slurry of solids in a transport oil for introducing and withdrawing solids from the reactor. In addition, there is provided for improved heating and cooling of the solids.

Abstract: A process for the manufacture of alkylbenzenes wherein a feed of fresh and recycle benzene and fresh olefin are reacted in the presence of an alkylation catalyst in an alkylator having at least two reaction stages wherein each stage is adiabatic. Essentially all of the olefin is completely reacted in each stage of the alkylator. Fresh olefin is fed into each stage of the alkylator. Preferred alkylbenzenes which are produced by this process are ethylbenzene and cumene.

Abstract: A process for producing coke from a combined feed. The combined feed is initially provided as a first portion which comprises easily cokable components and a second portion which is essentially free of easily cokable components. The first portion is heated to a temperature lower than that normally employed by a coking heater in a delayed coking process. The second portion is heated to a temperature at which a combination of the first and second portion provides combined feed at coking temperatures. The combined feed is then subjected to coking conditions.The first portion, in one embodiment, may be comprised of a fresh feed and the second portion may be comprised of a coker recycle. In another alternative, a fresh feed and a coker recycle are combined and fractionated to produce the first portion and the second portion. The first portion may include components which boil above a temperature of about 900.degree. F., and the second portion may be essentially free of easily cokable components.

Abstract: An improved process for the alkylation of benzene in the presence of an alkylation catalyst. The catalyst bed may be caused to move in a direction countercurrent to the movement of the benzene and olefin, or a portion of the catalyst bed is periodically removed and replaced. A regeneration step, whereby the catalyst is heated in a controlled oxygen atmosphere in order to reactivate the catalyst, is also described.

Abstract: Dienes and/or acetylene impurities in an olefin feed; in particular a propylene feed, may be selectively hydrogenated in a single stage by use of a catalyst of palladium supported on alumina which is substantially crystalline alpha alumina, wherein the average pore radius is 200-2000 .ANG., with at least 80% of the pores having a pore radius within the range of 100 to 3000 .ANG.. The surface acidity of the catalyst is generally from 0.002 to 0.05 millimole of pyridine absorbed per gram of catalyst. The active palladium surface area is from 20 to 200 m.sup.2 /g. The palladium is in the form of crystallines having an average size of at least 25 .ANG..

Abstract: A thermowell assembly consists of an elongated tube member including a channel and having a plurality of arm members disposed at diverse lengths and extending into the channel of the tube member. Thermocouple guide tubes including passageways for receiving a thermocouple are disposed in the channel of the elongated tube member with a terminal end portion of each thermocouple guide tube being mounted to respective arm members.

Abstract: A system for adding and withdrawing solids to a high pressure reactor wherein there is provided improved control of flow and concentrations of a slurry of solids in a transport oil for introducing and withdrawing solids from the reactor. In addition, there is provided for improved heating and cooling of the solids.

Abstract: The severity of a visbreaking operation is increased by treating product to remove a heavier phase in an amount of less than 15 weight percent and recycling treated product.

Abstract: In the solvent refining of a residual oil, a mixture of refined oil and refining solvent, and a mixture of pitch impurities and refining solvent are introduced into separate zones of a combination tower operated at a pressure of no greater than 100 psig to recover refining solvent from each of the mixtures. The combination tower is preferably A modified crude distillation tower from a preexisting crude unit, whereby idle crude units may be converted to solvent refining.

Abstract: The severity of a visbreaking operation is increased by treating product to remove a heavier phase in an amount of less than 15 weight percent and provide a remaining product having a Shell Hot Filtration number of less than 0.25.

Abstract: Prior to upgrading a viscous feed by visbreaking, at least a portion of the feed is treated to remove a heavy phase in specified amounts, whereby the severity of the visbreaking may be increased. The Shell Hot Filtration number of the visbreaking product is reduced by at least 75%, compared to visbreaking of untreated feed at some severity.

Abstract: Two immiscible liquids are vaporized in heat exchanger tubes in a manner such that each tube receives both liquids and neither liquid is completely vaporized in the tubes.