Abstract: A shaft furnace is provided for gasifying granular fuels in a fluidized bed. Such a furnace comprises a gasification zone containing the fluidized fuel bed and an overlying gas cooling zone having surfaces cooled by the tube surfaces of a radiation tube boiler. By providing such a gas cooling zone with a cross-sectional area substantially greater than that of the gasification zone, the gas effluent is cooled in such a manner that residues entrained in the effluent do not sinter onto the surfaces of the equipment in the subsequent path of the effluent.

Abstract: A process is described for producing methyl tert.-butyl ether from butane-containing light hydrocarbon mixtures. The n-butane is isomerized to isobutane which is dehydrogenated to an isobutene/isobutane molar ratio of 0.4 to 2:1, the isobutene in the mixture is etherified with methanol to form methyl tert.-butyl ether and the residual isobutane is recycled for dehydrogenation. After the isomerization step, the n-butane and isobutane can be separated and the n-butane recycled. The product containing methyl tert.-butyl ether can be used as a gasoline additive.

Abstract: A process for removing hydrogen sulphide and sulphur dioxide from a Claus reaction tail gas comprises separating the tail gas into two partial streams, conducting the first partial stream through a first catalyst bed charged with sulphur while at a temperature above the sulphur dew point, separating out the discharged sulphur from the first partial stream by condensation, combining the first partial stream freed from sulphur with the second partial stream, and passing the combined gas stream through a second catalyst bed already freed from sulphur while at a temperature below the sulphur dew point. When the second catalyst bed becomes charged with sulphur and the first catalyst bed becomes free of sulphur, the flow of gas through the beds is reversed.

Abstract: A process and a plant are disclosed whereby nitric acid is produced by the catalytic combustion of ammonia with air to form nitrous gases which are contacted with water in an absorption zone to form nitric acid. Gas flow into and through the plant is maintained by a compressor system powered by turbines that are propelled by the heat energy released during ammonia combustion. In accordance with the present invention, a portion of the ammonia combustion heat energy is stored using heat accumulating means positioned at various possible locations throughout the system. Such stored heat provides a thermal energy reserve available to power the compressor turbines for a short period of time in the event that ammonia combustion is discontinued.

Abstract: A process is provided for the production of hydrogen and sulphur from a gas containing hydrogen sulphide. Such a process comprises passing the gas through a cracking zone at a temperature of from about 850.degree. C. to 1600.degree. C., cooling the cracked gas to a temperature of from about 110.degree. C. to 150.degree. C., and separating the condensed elemental sulphur. The uncracked hydrogen sulphide is separated and returned to the cracking zone; the remaining gas is withdrawn as hydrogen-rich gas.

Abstract: In a process for the catalytic oxidation of gaseous sulfur compounds to sulfur trioxide comprising passing said gaseous sulfur compounds through a plurality of serially connected catalytic stages at 400.degree.-580.degree. C., the improvement which comprises circulating a liquid heat exchange medium in indirect heat exchange relationship to the reaction gases in the catalytic stages and with a heat consumer and optionally a heat source at a rate and amount such that the liquid heat exchange medium absorbs substantially all the exothermic reaction heat and fluctuates no more than 5 centrigrade degrees, thereby controlling the temperature of said catalytic stages.

Abstract: Phthalic anhydride is continuously separated from the reaction gas mixture formed by the catalytic oxidation of o-xylene and/or naphthalene, by treating said rection gas mixture in at least two absorption stages with organic absorbents. The absorbent employed in the first absorption stage is a mixture of phthalic anhydride and benzoic acid. The absorbent employed in the subsequent absorption stage(s) contains maleic anhydride and may also contain phthalic anhydride.

Abstract: Phthalic anhydride is continuously separated from the reaction gas mixture formed by the catalytic oxidation of o-xylene and/or naphthalene, by treating said reaction gas mixture with a maleic anhydride absorbent.

Abstract: An improved process is provided for the recovery and storage of maleic anhydride from maleic anhydride-containing gases. Such gases are scrubbed with a water or maleic acid scrubbing solution in a scrubbing zone to form a maleic acid-containing solution. This maleic acid-containing solution is then concentrated and dehydrated in an evaporation zone and a dehydration zone, respectively, to form maleic anhydride. The maleic anhydride so formed is then purified by distillation in a distillation zone. The evaporation, dehydration, and distillation steps are all carried out under a vacuum maintained by withdrawing gases containing organic and water vapor from said evaporation, dehydration and distillation zones using jet pumps propelled by pressurized air. The vapor-containing gases so removed are admixed with the pressurized air pump propellant streams, and this mixture is then introduced into the scrubbing zone for the maleic anhydride-containing gases.

Abstract: An apparatus is provided for the condensation of sulphur vapor and for the separation of sulphur droplets from a gas flow, preferably from the reaction gas flow from a Claus catalyst. Such apparatus comprises a vessel, a nest of tubes arranged in the vessel between tube plates, pipe connections at the vessel for the supply and discharge of a coolant flowing around the nest of tubes and an inlet pipe connection and an outlet pipe connection for the gas flow at the vessel, upstream and downstream of the said nest of tubes, respectively. Positioned in the vessel is a sulphur separation unit through which the sulphur-containing gas flows and on the surfaces of which sulphur vapor condenses and/or liquid sulphur collects and agglomerates. Sulphur discharge openings are provided in the bottom of the vessel on both the upstream and downstream sides of the separation unit.

Abstract: Water-containing glycol is heated first at atmospheric or superatmospheric pressure to partially remove water and concentrate the glycol and is then heated at subatmospheric pressure to further concentrate the glycol.