Abstract: A process produces dimethyl ether (DME) from methanol (MeOH). The process includes charging a feed mixture consisting of raw MeOH and a process-internally obtained return flow substantially consisting of unconverted MeOH and reaction water to an MeOH column. The feed mixture is evaporated in the MeOH column to form a first distillate substantially consisting of vaporous MeOH. The first distillate is supplied to a reactor and the MeOH is converted to DME by splitting off water in the reactor so as to form a reaction mixture. The reaction mixture is withdrawn from the reactor, charged to a mixture column and separated into a bottom product substantially consisting of water and a second distillate substantially consisting of DME and MeOH. The second distillate is separated in a DME column into a third distillate substantially consisting of DME, a bottom product consisting essentially of water-poor MeOH, and uncondensable gases discharged overhead.

Abstract: In a process for the preparation of C2- to C4-olefins, a feed stream comprising oxygenates and steam is passed through at least one fixed-bed zone comprising zeolite catalyst, where the oxygenates are converted catalytically into olefins with high selectivity for lower olefins, and the reaction mixture leaving the fixed-bed zone is separated into a first product stream comprising C2- to C3-olefins and inert gas components, at least one second product stream comprising C4+-olefins, and a third product stream consisting of aqueous phase. In order to improve the yield of lower olefins, the aim is to regulate the temperature of the catalytic reaction in accordance with a target temperature value in the range from 440 to 520° C. specified for the reaction mixture exiting the fixed-bed zone by means of a supplementary stream consisting of olefins and inert gas components fed into the feed stream.

Abstract: A process produces dimethyl ether (DME) from methanol (MeOH). The process includes charging a feed mixture consisting of raw MeOH and a process-internally obtained return flow substantially consisting of unconverted MeOH and reaction water to an MeOH column. The feed mixture is evaporated in the MeOH column to form a first distillate substantially consisting of vaporous MeOH. The first distillate is supplied to a reactor and the MeOH is converted to DME by splitting off water in the reactor so as to form a reaction mixture. The reaction mixture is withdrawn from the reactor, charged to a mixture column and separated into a bottom product substantially consisting of water and a second distillate substantially consisting of DME and MeOH. The second distillate is separated in a DME column into a third distillate substantially consisting of DME, a bottom product consisting essentially of water-poor MeOH, and uncondensable gases discharged overhead.

Abstract: In a process for the preparation of C2- to C4-olefins, a feed stream comprising oxygenates and steam is passed through at least one fixed-bed zone comprising zeolite catalyst, where the oxygenates are converted catalytically into olefins with high selectivity for lower olefins, and the reaction mixture leaving the fixed-bed zone is separated into a first product stream comprising C2- to C3-olefins and inert gas components, at least one second product stream comprising C4+-olefins, and a third product stream consisting of aqueous phase. In order to improve the yield of lower olefins, the aim is to regulate the temperature of the catalytic reaction in accordance with a target temperature value in the range from 440 to 520° C. specified for the reaction mixture exiting the fixed-bed zone by means of a supplementary stream consisting of olefins and inert gas components fed into the feed stream.

Abstract: In an apparatus for continuously recovering sulfur from a gas stream containing 0.1 to 3.0 vol-% H2S, further gaseous sulfur compounds and sulfur, the gas stream first is passed over a reduction stage consisting of hydrogenation catalyst and then over a selective oxidation stage consisting of oxidation catalyst. To reduce the amount of apparatus involved, it is provided to arrange the reduction stage and the selective oxidation stage in a reaction tank and to leave a space for introducing a gaseous cooling medium into the gas stream between the two stages.

Abstract: In an apparatus for continuously recovering sulfur from a gas stream containing 0.1 to 3.0 vol-% H2S, further gaseous sulfur compounds and sulfur, the gas stream first is passed over a reduction stage consisting of hydrogenation catalyst and then over a selective oxidation stage consisting of oxidation catalyst. To reduce the amount of apparatus involved, it is provided to arrange the reduction stage and the selective oxidation stage in a reaction tank and to leave a space for introducing a gaseous cooling medium into the gas stream between the two stages.

Abstract: The invention relates to a heat-recovery boiler (3) consisting of a tube bundle heat exchanger (7) which is incorporated into a pressure vessel (2) downstream of a gasification device. Displacement bodies (9) are inserted into pipes which are flowed around by hot process gas. According to said invention, in order to avoid corrosion problems like metal dusting, said displacement bodies (9) are made of graphite.

Abstract: In the presence of a catalyst, at least one isoparaffin having 4 to 6 C atoms per molecule is reacted with at least one olefin having 2 to 6 C atoms per molecule in a liquid phase to obtain a product containing alkylate, a suspension containing isoparaffin and a granular zeolite catalyst being supplied to the upper region of a reaction column. Below the point where the catalyst-containing suspension is supplied, an isoparaffin-olefin mixture is introduced into the reaction column, the temperatures in the reaction column being maintained in the range from 50 to 120° C. From the bottom region of the reaction column a product mixture containing alkylate is withdrawn, and in a separation by distillation alkylate product is recovered therefrom. Preferably, isoparaffin and catalyst are recovered from the separation by distillation and at least partly recirculated to the upper region of the reaction column.

Abstract: The invention relates to a heat-recovery boiler (3) consisting of a tube bundle heat exchanger (7) which is incorporated into a pressure vessel (2) downstream of a gasification device. Displacement bodies (9) are inserted into pipes which are flowed around by hot process gas. According to said invention, in order to avoid corrosion problems like metal dusting, said displacement bodies (9) are made of graphite.

Abstract: The granular, form-selective zeolite catalyst used as bed in a process of producing lower olefins from a feed mixture of higher olefins must be decoked from time to time. This is effected such that the reactor is rinsed with a nitrogen stream heated to 460 to 500° C. for expelling the hydrocarbons, the reactor is then cooled with a nitrogen stream heated to 420 to <460° C., a nitrogen/air mixture heated to 460 to 500° C. then flows through the reactor until complete decoking, and subsequently the reactor is rinsed with a nitrogen stream heated to 460 to 500° C.

Abstract: In the presence of a catalyst, at least one isoparaffin having 4 to 6 C atoms per molecule is reacted with at least one olefin having 2 to 6 C atoms per molecule in a liquid phase to obtain a product containing alkylate, a suspension containing isoparaffin and a granular zeolite catalyst being supplied to the upper region of a reaction column. Below the point where the catalyst-containing suspension is supplied, an isoparaffin-olefin mixture is introduced into the reaction column, the temperatures in the reaction column being maintained in the range from 50 to 120° C. From the bottom region of the reaction column a product mixture containing alkylate is withdrawn, and in a separation by distillation alkylate product is recovered therefrom. Preferably, isoparaffin and catalyst are recovered from the separation by distillation and at least partly recirculated to the upper region of the reaction column.

Abstract: The metal surface protected against metal-dusting corrosion has an insulating layer of a gas-permeable, thermally insulating material. The side of the thermal insulating layer that is colder during operation is in direct vicinity of the metal surface, and the side of the insulating layer that is hotter during operation is heated by a gas stream containing carbon monoxide, which in addition contains hydrogen and/or steam and has a temperature in the range from 300 to 1700.degree. C. In the region between the metal surface to be protected and the hot side of the insulating layer a catalyst is provided for reacting carbon monoxide with hydrogen and/or steam.

Abstract: The methanol vapor is mixed with a gas mixture which consists mainly of carbon dioxide and hydrogen and a high-methanol mixed feedstock is thus obtained. The mixed feedstock is fed to a first catalytic breakdown zone at an entrance temperature from 300.degree. to 400.degree. C., which contains a zinc-containing catalyst, which is indirectly heated. An intermediate having a methanol content not in excess of 1% by volume is withdrawn at a temperature in the range from 350.degree. to 600.degree. C. from the first breakdown zone and is cooled. Condensed water is removed at least in part from the intermediate, which is subsequently heated to a temperature in the range from 320.degree. to 420.degree. C. At least one-half of the heated intermediate product is supplied to a second catalytic breakdown zone, which also contains a zinc-containing catalyst, which is indirectly heated. A precursor product is withdrawn from the second breakdown zone at temperature from 350.degree. to 600.degree. C.

Abstract: A process for the catalytic production of gasoline hydrocarbons from synthesis gas comprising carbon oxides and hydrogen is disclosed wherein the synthesis gas is fed initially to a methanol synthesis and thereafter effluent from the methanol synthesis is converted to gasoline hydrocarbons in a gasoline synthesis stage. The invention resides in that the entire effluent from the methanol synthesis stage is fed to the gasoline synthesis stage and at least a portion of the residual gases from the gasoline synthesis stage comprising carbon oxides, hydrogen, methane and minor amounts of C.sub.2 -C.sub.4 hydrocarbons is fed to the methanol synthesis stage together with fresh synthesis gas.