Abstract: An optical device includes a first optically dimmable switch for providing a first transmittance while the first optically dimmable switch is in a first state and providing a second transmittance distinct from the first transmittance while the first optically dimmable switch is in a second state distinct from the first state. The optical device also includes a dynamic heat source thermally coupled with the first optically dimmable switch. The dynamic heat source is at a first temperature at a first time and is at a second temperature distinct from the first temperature at a second time mutually exclusive from the first time. The optical device may operate as an optical dimming device, which may be used in head-mounted display devices or as dimmable windows or shutters.

Abstract: An oxidation process employing a mechanically stable catalyst of an active metal or combination of active metals supported on aluminum oxide, which is predominantly alpha-aluminum oxide, is provided. The active metal or metals is optionally one or a mixture of ruthenium, copper, gold, an alkaline earth metal, an alkali metal, palladium, platinum, osmium, iridium, silver, and rhenium. The process is applicable to the oxidation of hydrogen chloride to chlorine in a Deacon process.

Abstract: A catalytic process for preparing chlorine from hydrogen chloride, which includes recycle of process streams with reduced accumulation of inert gases in the system is provided. The process includes a step wherein a compressed liquid stream comprising chlorine, carbon dioxide and oxygen is recycled into a column countercurrent to the ascending gas phase and feeding part of the chlorine-rich liquid phase leaving the bottom of the column back into the top of the column. Carbon dioxide present in the ascending gas stream is dissolved out of the gas stream and can later be separated from chlorine without problems by distillation.

Abstract: The invention relates to a method of controlling a hydrogenation of a starting material in a hydrogenation reactor, in which the amount of hydrogen reacted in the hydrogenation is firstly determined, the ratio of the amount of hydrogen reacted to the amount of starting material fed in is then derived, this ratio is compared with a prescribed value and, finally, at least one process parameter is altered if the ratio of the amount of hydrogen reacted to the amount of starting material fed in deviates by a prescribed amount from the prescribed value.

Abstract: A catalyst for gas-phase reactions which has high mechanical stability and comprises one or more active metals on a support comprising aluminum oxide as support material, wherein the aluminum oxide in the support consists essentially of alpha-aluminum oxide. Ruthenium, copper and/or gold are preferred as active metal. Particularly preferred catalysts according to invention comprise a) from 0.001 to 10% by weight of ruthenium, copper and/or gold, b) from 0 to 5% by weight of one or more alkaline earth metals, c) from 0 to 5% by weight of one or more alkali metals, d) from 0 to 10% by weight of one or more rare earth metals, e) from 0 to 10% by weight of one or more further metals selected from the group consisting of palladium, platinum, osmium, iridium, silver and rhenium, in each case based on the total weight of the catalyst, on the support comprising alpha-Al2O3. The catalysts are preferably used in the oxidation of hydrogen chloride (Deacon reaction).

Abstract: A catalyst for gas-phase reactions which has high mechanical stability and comprises one or more active metals on a support comprising aluminum oxide as support material, wherein the aluminum oxide in the support consists essentially of alpha-aluminum oxide. Ruthenium, copper and/or gold are preferred as active metal. Particularly preferred catalysts according to invention comprise a) from 0.001 to 10% by weight of ruthenium, copper and/or gold, b) from 0 to 5% by weight of one or more alkaline earth metals, c) from 0 to 5% by weight of one or more alkali metals, d) from 0 to 10% by weight of one or more rare earth metals, e) from 0 to 10% by weight of one or more further metals selected from the group consisting of palladium, platinum, osmium, iridium, silver and rhenium, in each case based on the total weight of the catalyst, on the support comprising alpha-Al2O3. The catalysts are preferably used in the oxidation of hydrogen chloride (Deacon reaction).

Abstract: (Chloro)hydrocarbon-free hydrogen chloride and phosgene-free (chloro)hydrocarbons are recovered from a hydrogen chloride stream having (chloro)hydrocarbons and phosgene.

Abstract: The invention relates to a catalyst provided in the form of an extrudate, which contains 5 to 85% by weight of copper oxide and comprises, in the active material and as binders, the same oxidic carrier material. The invention also relates to the use of the catalyst for hydrogenating carbonyl compounds.

Abstract: The invention relates to a reactor and a process for preparing chlorine from hydrogen chloride by gas-phase oxidation by means of oxygen in the presence of a heterogeneous catalyst in a fluidized bed, with gas-permeable plates being located in the fluidized bed. The gas-permeable plates are connected in a thermally conductive manner to a heat exchanger located in the fluidized bed.

Abstract: The invention relates to a process for recovering ruthenium from a used ruthenium-comprising catalyst which comprises ruthenium as ruthenium oxide on a support material which is sparingly soluble in mineral acid, which comprises the steps: a) the catalyst comprising ruthenium oxide is treated in a stream of hydrogen, with ruthenium oxide present on the support being reduced to metallic ruthenium; b) the reduced catalyst from step a) comprising metallic ruthenium on the support material is treated with hydrochloric acid in the presence of an oxygen-comprising gas, with the metallic ruthenium present on the support being dissolved as ruthenium(III) chloride and being obtained as ruthenium(III) chloride solution; c) if appropriate, the ruthenium(III) chloride solution from step b) is worked up further.

Abstract: A process for preparing chlorine in a fluidized-bed reactor, in which a gaseous reaction mixture comprising hydrogen chloride and oxygen flows from the bottom upward through a heterogeneous particulate catalyst forming a fluidized bed, wherein the fluidized bed is provided with internals which divide the fluidized bed into a plurality of cells arranged horizontally in the fluidized-bed reactor and a plurality of cells arranged vertically in the fluidized-bed reactor, with the cells having cell walls which are permeable to gas and have openings which ensure an exchange number of the heterogeneous, particulate catalyst in the vertical direction in the range from 1 to 100 liters/hour per liter of reactor volume, is proposed.

Abstract: Process for recovering (chloro)hydrocarbon-free hydrogen chloride and phosgene-free (chloro)hydrocarbons from a hydrogen chloride stream comprising (chloro)hydrocarbons and phosgene, which comprises i) in a first step, connecting a first adsorber and a second adsorber in series and passing the fresh hydrogen chloride stream comprising phosgene and (chloro)hydrocarbons firstly through the first adsorber and subsequently through the second adsorber until essentially no more (chloro)hydrocarbon is adsorbed by the first adsorber, ii) in a second step, passing the fresh hydrogen chloride stream through the second adsorber while the first adsorber is regenerated, with essentially phosgene-free (chloro)hydrocarbon being obtained in the regeneration, iii) in a third step, passing the fresh hydrogen chloride steam firstly through the second adsorber and subsequently through the regenerated first adsorber until essentially no more (chloro)hydrocarbon is adsorbed by the second adsorber, iv) in a fourth step, passing

Abstract: Catalyst in the form of an extrudate which comprises from 5 to 85% by weight of copper oxide and in which the same oxidic support material is present in the active composition and as binder, and the use of the catalyst for the hydrogenation of carbonyl compounds.

Abstract: The invention relates to a process for recovering ruthenium from a used ruthenium-comprising catalyst which comprises ruthenium as ruthenium oxide on a support material which is sparingly soluble in mineral acid, which comprises the steps: a) the catalyst comprising ruthenium oxide is treated in a stream of hydrogen, with ruthenium oxide present on the support being reduced to metallic ruthenium; b) the reduced catalyst from step a) comprising metallic ruthenium on the support material is treated with hydrochloric acid in the presence of an oxygen-comprising gas, with the metallic ruthenium present on the support being dissolved as ruthenium(III) chloride and being obtained as ruthenium(III) chloride solution; c) if appropriate, the ruthenium(III) chloride solution from step b) is worked up further.

Abstract: A process for variably preparing mixtures of optionally alkyl-substituted BDO, GBL and THF by two-stage hydrogenation in the gas phase of C4 dicarboxylic acids and/or derivatives thereof, which comprises a) hydrogenating in a gas phase a gas stream of C4 dicarboxylic acids and/or derivatives thereof over a particular catalyst at a particular pressure and temperature to give a stream mainly containing of optionally alkyl-substituted GBL and THF, b) removing any succinct anhydride, c) converting the products remaining predominantly in the gas phase in the partial condensation, THF, water and GBL to give a stream comprising a mixture of BDO, GBL and THF, d) removing the hydrogen from the products and recycling it into the hydrogenation, e) distillatively separating the products, THF, BDO, GBL and water, if appropriate recycling a GBL-rich stream or if appropriate discharging it, and working up BDO, THF and GBL distillatively, and setting the ratio of the products, THF, GBL and BDO, relative to one another wi

Abstract: A catalyst for gas-phase reactions which has high mechanical stability and comprises one or more active metals on a support comprising aluminum oxide as support material, wherein the aluminum oxide in the support consists essentially of alpha-aluminum oxide. Ruthenium, copper and/or gold are preferred as active metal. Particularly preferred catalysts according to invention comprise a) from 0.001 to 10% by weight of ruthenium, copper and/or gold, b) from 0 to 5% by weight of one or more alkaline earth metals, c) from 0 to 5% by weight of one or more alkali metals, d) from 0 to 10% by weight of one or more rare earth metals, e) from 0 to 10% by weight of one or more further metals selected from the group consisting of palladium, platinum, osmium, iridium, silver and rhenium, in each case based on the total weight of the catalyst, on the support comprising alpha-Al2O3. The catalysts are preferably used in the oxidation of hydrogen chloride (Deacon reaction).

Abstract: A process for preparing chlorine by gas-phase oxidation of hydrogen chloride by means of a gas stream comprising molecular oxygen in the presence of a fixed-bed catalyst, wherein the process is carried out in a reactor (1) having heat-exchange plates (2) which are arranged in the longitudinal direction of the reactor (1) and have a spacing between them and through which a heat transfer medium flows, inlet and outlet facilities (3, 4) for the heat transfer medium to the heat-exchange plates (2) and also gaps (5) between the heat-exchange plates (2) in which the fixed-bed catalyst is present and into which the hydrogen chloride and the gas stream comprising molecular oxygen are passed, is described.

Abstract: A process for preparing an organometallic framework material comprising reacting at least one metal salt with at least one at least bidentate compound capable of coordination to the metal ion of said metal salt, in the presence of an aqueous solvent system and at least one base wherein at least one bidentate compound comprises at least carboxy group and at least one further group which is not a carboxy group and which is capable of forming a hydrogen bridge linkage.

Abstract: The invention relates to a method of controlling a hydrogenation of a starting material in a hydrogenation reactor, in which the amount of hydrogen reacted in the hydrogenation is firstly determined, the ratio of the amount of hydrogen reacted to the amount of starting material fed in is then derived, this ratio is compared with a prescribed value and, finally, at least one process parameter is altered if the ratio of the amount of hydrogen reacted to the amount of starting material fed in deviates by a prescribed amount from the prescribed value.

Abstract: Process for preparing chlorine from hydrogen chloride, which comprises the steps: a) feeding of a stream a1 comprising hydrogen chloride and of a stream a2 comprising oxygen into an oxidation zone and catalytic oxidation of hydrogen chloride to chlorine, giving a product gas stream a3 comprising chlorine, water, oxygen, carbon dioxide and inert gases; b) cooling of the product gas stream a3 and removal of water and hydrogen chloride as aqueous hydrochloric acid, leaving a gas stream b comprising chlorine, water, oxygen, carbon dioxide and inert gases; c) optional drying of the gas stream b) to leave a gas stream c which is substantially free of water and comprises chlorine, oxygen, carbon dioxide and inert gases; d) at least partial liquefaction of the gas stream c and of a chlorine-rich recycle stream f1 comprising chlorine, oxygen and carbon dioxide by compression and cooling, giving an at least partially liquefied stream d; e) gas/liquid separation of the stream d into a gas stream e1 comprising chlorine,