Abstract: Normal paraffins are separated from a hydrocarbon vapor feedstream having 10 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil - containing feedstocks. A portion of the countercurrent, desorption purge effluent is employed as a hexane - containing cocurrent purge stream, thereby significantly reducing the required amount of n-hexane purge recycle material, and the size of the equipment and the energy consumed in the processing of said recycle stream. A portion of said countercurrent purge effluent can also be used to provide a source of n-hexane diluent for the gas oil - containing feedstocks, as can the cocurrent purge effluent, resulting in further reduction in required equipment and energy costs, and increasing adsorption efficiency and adsorbent utilization.

Abstract: Carbon monoxide-containing gas streams are passed over a catalyst to deposit a surface layer of active surface carbon thereon essentially without the formation of inactive coke. The active carbon is thereafter reacted with steam or hydrogen to form methane. Enhanced catalyst stability for long term, cyclic operation is obtained by the incorporation of an alkali or alkaline earth dopant in a silica binding agent added to the catalyst-support additive composition.

Abstract: A gas mixture, having a more readily adsorbable gas component to be recovered and a less readily adsorbable gas component, is introduced to an adsorption zone at low pressure, with the pressure being increased prior to purging the less readily adsorbable gas component from the adsorption zone at high pressure. Upon depressurization, the readily adsorbable gas component is recovered at enhanced purity levels. In multiple adsorption zone operations, each zone is passed through the low pressure adsorption, pressurization, high pressure purging and depressurization cycle, in sequence, with pressure equalization steps advantageously being employed between the zones to be pressurized following adsorption and those being depressurized following purging. The invention can be used to recover nitrogen of enhanced purity from air, and to recover high purity methane from mixtures thereof with nitrogen.

Abstract: An oriented graphite layer is formed on a metallic substrate by providing a coating of particulate carbon thereon, heating the coated substrate in a non-reactive atmosphere to a temperature of between 800.degree. and 1350.degree. C. for saturational diffusion of carbon into the substrate and cooling to a temperature below about 200.degree. C., thereby providing a precipitated oriented graphite film at the surface of the substrate.The substrate may be formed by covering a copper or copper alloy member with a continuous layer of nickel, cobalt, nickel alloy or cobalt alloy. In another embodiment, the substrate with an attached graphite coating is spirally bonded onto a copper tube for use in the field of condensation heat transfer.

Abstract: Normal paraffins are separated from a gas oil-containing hydrocarbon vapor feed stream having 16 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil-containing feedstock. Cocurrent purge effluent is used to provide a source of such n-hexane diluent, thereby reducing the equipment size and energy consumption for processing of the n-hexane purge recycle stream and increasing adsorbent utilization or the efficiency of the adsorption process.

Abstract: Gas separation is facilitated by imposing cyclic gas flow and pressure variations on a gas mixture in an adsorption column from the opposite ends thereof. By employing specified relative volume displacements and phase angles for such cyclic variations, the productivity of desired product is enhanced.

Abstract: Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

Abstract: Normal paraffins are separated from a gas oil-containing hydrocarbon vapor feed stream having 16 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil-containing feedstocks. Countercurrent purge effluent is used to provide a source of such n-hexane diluent, thereby effecting a savings in the amount of energy necessary to process the purge recycle stream and the size of the equipment used therefor.

Abstract: Void space gas is released from an adsorbent bed at a higher adsorption pressure by cocurrent depressurization of the bed. The released gas is passed to another bed of a pressure swing adsorption system to equalize the pressure therebetween, the other bed being initially at a lower pressure. A portion of the product effluent withdrawn from yet another bed of the system is not passed to the bed undergoing repressurization, as in conventional practice, but is passed to an external repressurization storage tank during said pressure equalization step. Upon completion of this step, the product effluent is withdrawn from the repressurization tank and passed to said bed undergoing repressurization.

Abstract: An improvement in a wash system for gas separation wherein a wash liquid is contacted countercurrently with a feed gas mixture containing a high volatility component and a low volatility component in a plate and fin type exchanger where the heat of absorption is removed by a refrigerant passed in indirect heat exchange relationship with the countercurrently flowing feed gas mixture and wash liquid and then passing the resulting product stream to a wash column to further purify the product stream.

Abstract: The hot effluent from the catalytic steam reforming of a major portion of a fluid hydrocarbon feed stream in the reformer tubes of a primary reformer, or said effluent after secondary reforming thereof, is mixed with the hot effluent from the catalytic steam reforming of the remaining portion of the feed discharged from the reformer tubes of a primary reformer-exchanger. The combined gas steam is passed on the shell side of the reformer-exchanger countercurrently to the passage of feed in the reformer tubes thereof, thus supplying the heat for the reforming of the portion of the feed passed through the reformer tubes of the reformer-exchanger. At least about 2/3 of the hydrocarbon feed stream is passed to the reformer tubes of said primary reformer, heated by radiant heat transfer and/or by contact with combustion gases, at a steam/hydrocarbon mole ratio of about 2-4/1.

Abstract: A selected paraffinic or olefinic liquid is used to scrub acetylene from a minor gas fraction of uncondensed gas from a hydrocarbon feed mixture containing ethylene, hydrogen, acetylene and methane. Hydrogen product gas is separated and recovered from said minor gas fraction. The major gas fraction is processed without said acetylene removal operation, but under elevated pressure conditions effectively avoiding acetylene solidification during the separation and recovery of an ethylene-enriched liquid.

Abstract: One portion comprising about 30-80% of a hydrogen-containing feed gas having a relatively high carbon dioxide content is preheated to remove a substantial portion of said carbon dioxide therefrom. The thus - preheated stream is passed to a pressure swing adsorption bed from which a purified hydrogen stream is withdrawn. Upon completion of this step, the unpretreated portion of the feed gas is passed to the feed end of the bed, with purified hydrogen continuing to be withdrawn from the bed. In cyclic pressure swing adsorption operations employing such a two-feed process, the recovery of purified hydrogen is enhanced as compared with operations in which none of the feed gas is pretreated for carbon dioxide removal or in which all of the feed gas is so treated for removal of carbon dioxide therefrom.

Abstract: Method of decoking furnace tubes using a turbulent stream of impact resistant, particle-enriched gas. Non-angular, non-abrasive particles are entrained at a concentration of about 0.1 to about 10 pounds per pound of gas, and the gas is introduced into the inlet end of the furnace tubes at a gas flow rate corresponding to an outlet gas velocity of from about 5,000 feet per minute up to sonic velocity of said gas, preferably at an outlet gas velocity of about 14,000 to 40,000 feet per minute.

Abstract: A system for enhancing the performance of the external condensing surfaces of the vertical tubes of a film condensation heat exchanger comprising a network of enhancement elements adjacent the tube surface to collect the condensate into rivulets and connecting elements wrapped around and bonded to the enhancement elements to maintain the latter in their proper positions. In a preferred embodiment, both the enhancement and connecting elements are made of a wettable plastic polymeric material in the form of a sleeve to slip over the condenser tube as a prefabricated unit.

Abstract: Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst essentially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO.sub.2, from which a relatively pure methane product may be obtained. For practical commercial operations utilizing the two-step process of the invention of a cyclic basis, nickel, cobalt, ruthenium, thenium and alloys thereof are especially prepared for use in a metal state, with CO disproportionation being carried out at temperatures up to about 350.degree. C. and with the conversion of active surface carbon to methane being carried out by reaction with steam. The catalyst is employed in such cyclic operations without the necessity for employing a regeneration step as part of each processing cycle.

Abstract: Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst essentially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO.sub.2, from which a relatively pure methane product may be obtained. Dilute carbon monoxide-containing streams, as from underground coal gasification with air or the effluent from blast furnace operations, can be used without pretreatment to convert the carbon monoxide and/or to separate inert gases therefrom. Conversion of the active surface carbon with high pressure steam enables a high pressure product methane stream to be generated without expensive compression equipment and high energy consumption. Nickel, cobalt, iron, ruthenium, rhenium and alloys thereof are preferred catalysts, with the surface area thereof being preferably at least about 10 m.sup.2 /gr.

Abstract: Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst essentially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO.sub.2, from which a relatively pure methane product may be obtained. While carbon monoxide-containing gas streams having hydrogen or water present therein can be used only the carbon monoxide available after reaction with said hydrogen or water is decomposed to form said active surface carbon. Although hydrogen or water will be converted, partially or completely, to methane that can be utilized in a combustion zone to generate heat for steam production or other energy recovery purposes, said hydrogen is selectively removed from a CO--H.sub.2 -containing feed stream by partial oxidation thereof prior to disproportionation of the CO content of said stream.

Abstract: An inner surface substrate of metal tubes is provided with a single layer of randomly distributed metal bodies bonded to the substrate, spaced from each other, and substantially surrounded by the substrate to form body void space.

Abstract: A fluidized stream of coal particles is introduced into the bottom of a vertical reaction zone in a fluidized bed process at a velocity of greater than about 200 ft/sec in a vertically upwards direction, wherein agglomeration of the fluidized bed is prevented. A separate liquid hydrocarbon stream is simultaneously introduced as a separate injection stream in a vertically upwards direction, said coal particles and said liquid hydrocarbons being rapidly and uniformly dispersed within the fluidized bed and reacted therein with a suitable reagent.