Abstract: A process and apparatus for dehydrogenating alkanes such as iso-butane comprises contacting the alkane in admixture with steam under dehydrogenation conditions with a dehydrogenation catalyst. The catalyst is substantially free of Group VIII metals of Atomic Number 27 and higher. The catalyst is provided in a heated tubular reactor which preferably contains groups of tubes mounted in a furnace each group of tubes having a common header, to enable continuous dehydrogenation, while permitting catalyst reactivation.

Abstract: Hydrocarbon feed to a steam cracking furnace is heated to near cracking temperature by indirect heat exchange with steam to permit use of a range of feedstocks.

Abstract: A hydrogen donor diluent cracking process in which the pitch fraction from the cracking step is heat soaked in the presence of hydrogen donor solvent and then returned to the cracking coil.

Abstract: A process and apparatus capable of cracking hydrocarbon to produce a reaction product containing a high proportion of ethylene. A hydrocarbon such as naphtha is vaporized and admixed with superheated steam at high temperature in a mixing device. The resulting hydrocarbon-steam mixture is passed through a reaction zone consisting of a reactor conduit which extends through a passageway defined in a radiation block structure. Heating gases at extremely high temperatures are directed through the passageway, co-currently with the hydrocarbon-steam mixture, to produce a desirable heat flux for the cracking reaction. A short residence time in the reactor conduit is maintained to prevent undesirable side reactions.

Abstract: Combustion gas passes upwardly through the radiant section of a fired process heater having vertical tubes in such manner that the gas is in predominantly back-mixed flow condition in the lower portion of the radiant section and predominantly plug-flow condition in the upper portion of the radiant section.

Abstract: Protection of cast austenitic stainless steel tubes is provided against initiation of carburization by (a) cold-working the inner surfaces of said tubes to deform the surface to such a degree that upon the subsequent heat treatment of step (b) below, dissolution of the M.sub.23 C.sub.6 carbides in the deformed region is accompanied by recrystallization resulting in a refined micrograin structure in the deformed regions to a substantially uniform minimum depth of about 20 microns; and (b) heating the cold-worked inner surfaces of said tubes, for an effective amount of time, at a temperature between its recrystallization temperature and its melting temperature, in an atmosphere of which the oxygen partial pressure is at least oxidizing with respect to chromium.

Abstract: A method of decoking (decarbonizing) surfaces of a cracking plant in which the cracking furnace is connected to a heat exchanger for cooling the cracked gas mixture, in which steam and air are admitted as a gas mixture to the cracking furnace and then the gas mixture is conducted through the cooler. The cooling medium is thus passed through the cracking gas cooler during the decoking operation while in a first stage the mixture is fed through the device at such a mass flow rate that the temperature of the deposits on the heat exchange surface is approximately at the temperature corresponding to cracking operations while, in a second stage, the gas flow rate is increased to raise the temperature of the deposits on the heat exchange surfaces of the cooler.

Abstract: A process for upgrading a heavy hydrocarbonaceous oil is provided in which the oil is hydrorefined, heat-treated and hydrocracked to increase the selectivity of the hydrocracked product to components boiling in the range of 350.degree. to 675.degree. F.

Abstract: A cracking furnace has a radiant heating zone provided with fuel-fired burners and through which a preheated feedstock is passed, combustion gases from the radiant heating zone passing into a convection zone before being discharged from said furnace. The convection zone is provided with heat-exchanger means for preheating said feedstock. The heat-exchanger means in the convection zone is subdivided into a plurality of functionally separated heat-exchanger bundles and the feedstock is passed selectively through the bundles in accordance with the composition of the feedstock.

Abstract: A portion of a steam pyrolysis tubular coil, preferably the outlet portion, is provided with an insert to provide a radiation absorption surface within the tube. The insert is dimensioned to increase heat flux without adversely increasing pressure drop. A preferred insert has a central body and outwardly extending vanes in contact with the interior of the coil.

Abstract: Combustion gas passes upwardly through the radiant section of a fired process heater having vertical tubes in such manner that the gas is in predominantly back-mixed flow condition in the lower portion of the radiant section and predominantly plug-flow condition in the upper portion of the radiant section.

Abstract: The mass production system disclosed herein provides a method for producing highly aromatic petroleum pitch, comprising, preheating a liquefied petroleum residuum to a temperature of 450.degree.-520.degree. C. by passing the same through a tubular heater for 0.5-15 minutes, feeding the preheated residuum into a reaction vessel, thermally cracking the same by introducing an inert gas heated to a temperature of 400.degree.-2,000.degree. C. through a heating furnace into the reaction vessel for direct contact with the residuum for 0.5-10 hours, and adjusting to be coincident the ratio of the number of feeding flow lines for the preheated residuum from the tubular heater into the reaction vessels to the total number of reaction vessels with the ratio of the charging time .theta.C required for charging one reaction vessel with one feeding flow of preheated residuum to the total time .theta.T required for carrying out one batch of the thermal cracking in one reaction vessel.

Abstract: Improved method and apparatus for distributing a fluid, e.g., a liquid-vapor mixture, through a conduit, e.g., a tube in a direct fired heater, involving at least one reduction means located inside the conduit to abruptly reduce the inside cross-sectional area of the conduit available for flow of the fluid, provided that the inside cross-sectional area of the conduit is substantially the same both before and after the reduction means.

Abstract: A process for the non-catalytic riser cracking of shale oil to produce ethylene in the presence of entrained hot, inert solids.

Abstract: A fluid-wall reactor for high temperature chemical reactions comprising (A) a porous reactor tube, at least a portion of the interior of which defines a reaction zone, the tube being made of an electrically resistive, porous refractory material; (B) a pressure vessel enclosing the reactor tube to define an inert fluid plenum, the pressure vessel having at least one inlet for admitting the inert fluid which is directed under pressure through the porous tube wall to provide a protective blanket for the inside surface of the reactor tube; (C) means for introducing at least one reactant into the reaction zone, the reactants being directed in a predetermined path axially of the reactor tube and being confined by the protective blanket substantially centrally within the reaction zone; (D) means for passing an electric current through the reactor tube for heating the reactor tube to the temperature level at which it emits sufficient radiant energy to initiate and sustain the desired chemical reaction, the radiant en

Abstract: In the thermal cracking of a hydrocarbon feed oil to produce a product including ethylene, the feed oil is passed together with entrained hot solids through a high temperature cracking zone. Coke-laden hot solids are recovered and passed to a burner zone together with crushed oil shale as supplementary fuel. An acidic material, such as HF catalyst from an alkylation unit, can also be employed as supplementary fuel. The acidic material will react with alkaline components in the oil shale to form stable neutral salts which circulate as heat carrier solids.

Abstract: High temperature chemical reaction processes utilizing fluid-wall reactors can be conducted in fluid-wall reactors by a process which includes the steps of (a) generating a shell of a refractory material which reflects radiation, the volume enclosed by the shell constituting a black body cavity; (b) generating within the black body cavity an annular envelope of an inert fluid which is substantially transparent to radiation, the envelope having substantial axial length and the interior of the envelope defining a reaction chamber; (c) passing at least one reactant into the black body cavity and through the reaction chamber along a predetermined path substantially coincident with the longitudinal axis of the envelope, the reactants being confined within the reaction chamber; and (d) directing high intensity radiant energy into the reaction chamber to coincide with at least a portion of the predetermined path of the reactants, sufficient radiant energy being absorbed within the reaction chamber to raise the tempe

Abstract: High temperature chemical reaction processes utilizing fluid-wall reactors can be conducted in fluid-wall reactors by a process which includes the steps of (1) generating a shell of a refractory material which reflects radiation, the volume enclosed by the shell constituting a black body cavity; (2) generating within the black body cavity an annular envelope of an inert fluid which is substantially transparent to radiation, the envelope having substantial axial length and the interior of the envelope defining a reaction chamber; (3) passing at least one reactant into the black body cavity and through the reaction chamber along a predetermined path substantially coincident with the longitudinal axis of the envelope, the reactants being confined within the reaction chamber; and (4) directing high intensity radiant energy into the reaction chamber to coincide with at least a portion of the predetermined path of the reactants, sufficient radiant energy being absorbed within the reaction chamber to raise the tempe

Abstract: In the thermal cracking of a heavy petroleum oil (having an API specific gravity of not more than 25) in a tubular type heating furnace, possible occurrence of coking trouble inside the furnace can be prevented by applying a magnetic field of fixed magnitude transversely to the flow of the heavy petroleum oil being introduced into the furnace or by applying a fixed magnitude of magnetic field transversely and, at the same time, applying a fixed magnitude of direct-current voltage parallel to the flow of the heavy petroleum oil being introduced into the furnace. More effective prevention of occurrence of coking can be obtained by having a specific inorganic substance incorporated in the heavy petroleum oil before the oil is subjected to the magnetic field or to simultaneous application of the magnetic field and voltage.

Abstract: A tube furnace, especially for the cracking of hydrocarbons, comprises a heat and combustion chamber in which the hydrocarbons are passed through a plurality of tube coils lying in planes parallel to the walls of the chamber and having predominantly vertical stretches. Preferably, a plurality of tube coils is provided and lies along respective walls of the vessel with each pair of tube coils communicating with a common tube coil of larger cross section extending into the interior of the chamber.

Abstract: An improved hydrogen donor diluent cracking process for upgrading hydrogen deficient hydrocarbonaceous materials such as petroleum residua to more valuable liquid distillates. The hydrogen donor diluent, which is a material that has been partially hydrogenated and which readily gives up hydrogen under thermal cracking conditions, is injected into the cracking unit at a plurality of points so that the ratio of the rate of hydrogen transfer to the rate of cracking is more uniform throughout the cracking unit than if all the hydrogen donor diluent is injected with the feed charge to the cracking unit.