Abstract: A fuel supply circuit for an aeronautical cryogenic turbomachine including: at least one cryogenic reservoir containing a liquid fuel topped with a boil-off gas and including a high-pressure liquid pump to supply at least one main propulsion device of the turbomachine with liquid fuel, an auxiliary turbomachine including an electric generator, a gas compressor to supply the auxiliary turbomachine with gaseous fuel, and a buffer gas reservoir connecting the gas compressor to the cryogenic reservoir to reinject gas into the cryogenic reservoir in order to maintain the pressure in the cryogenic reservoir above a predefined value, the electric generator supplying the high-pressure liquid pump and the gas compressor.

Abstract: A fuel supply circuit for an aeronautical cryogenic turbomachine including: at least one cryogenic reservoir containing a liquid fuel topped with a boil-off gas and including a high-pressure liquid pump to supply at least one main propulsion device of the turbomachine with liquid fuel, an auxiliary turbomachine including an electric generator, a gas compressor to supply the auxiliary turbomachine with gaseous fuel, and a buffer gas reservoir connecting the gas compressor to the cryogenic reservoir to reinject gas into the cryogenic reservoir in order to maintain the pressure in the cryogenic reservoir above a predefined value, the electric generator supplying the high-pressure liquid pump and the gas compressor.

Abstract: A pressure regulating device includes an on-board storage tank, a mixing chamber, first and second lines, a recirculation line, a pressure sensor and a controller. The storage tank stores and supplies cryogenic fuel to a combustion chamber and includes a booster pump. The first line supplies cryogenic fuel in the liquid state and includes a pressurizing pump and a first regulation valve. The second line supplies cryogenic fuel in the gaseous state and includes a compressor and a first control valve. The recirculation line includes a second regulation valve and with a first heat exchanger. The pressure sensor detects the pressure inside the storage tank. The controller receives the pressure and controls the first and second regulation valves, the first control valve, the pressurizing pump, the booster pump and the compressor, as a function of a value of a setpoint pressure inside the storage tank.

Abstract: A cristobalite includes: a d50 particle size selected within a range of from 1 ?m to 15 ?m; an L color coordinate of greater than 96; a color coordinate of less than 1; and a b color coordinate of 1 or less, in which the cristobalite is a powder. Also provided are compositions containing the cristobalite, coatings formed with compositions, and methods of preparing cristobalite.

Abstract: The present invention concerns a process for the reduction of content of carboxylic acids and derivatives thereof in oleum, disulfuric acid or concentrated sulfuric acid. The invention further concerns a process for the manufacture of carboxylic acid anhydrides comprising the process for the reduction of content of carboxylic acids and derivatives thereof from oleum, disulfuric acid or concentrated sulfuric acid.

Abstract: The present invention concerns a process for the reduction of content of carboxylic acids and derivatives thereof in oleum, disulfuric acid or concentrated sulfuric acid. The invention further concerns a process for the manufacture of carboxylic acid anhydrides comprising the process for the reduction of content of carboxylic acids and derivatives thereof from oleum, disulfuric acid or concentrated sulfuric acid.

Abstract: Process for synthesizing a chemical, in particular an agriculturally or pharmaceutically active compound, including: a first step comprising reacting a carboxylic acid halide with a vinyl ether to prepare a halogenated precursor of an alkenone; a second step comprising eliminating hydrogen halide from such precursor to form an alkenone, preferably by thermolysis under specific conditions; and a third step which uses the formed alkenone as a building block to synthesize the chemical. First step may be done in a liquid reaction medium comprising an alkenone or a halogenated alkenone precursor, or in a liquid reaction medium in turbulent state, specifically by creation of gas bubbles of the carboxylic acid halide herein. Second step may include a flash thermolysis, vacuum thermolysis, thermolysis under stripping with inert gas, and/or a thermolysis at a temperature from >90° C. to 120° C. Third step preferably comprises reacting the alkenone with a nitrogen-containing compound.

Abstract: Process for synthesizing a chemical, in particular an agriculturally or pharmaceutically active compound, including: a first step comprising reacting a carboxylic acid halide with a vinyl ether to prepare a halogenated precursor of an alkenone; a second step comprising eliminating hydrogen halide from such precursor to form an alkenone, preferably by thermolysis under specific conditions; and a third step which uses the formed alkenone as a building block to synthesize the chemical. First step may be done in a liquid reaction medium comprising an alkenone or a halogenated alkenone precursor, or in a liquid reaction medium in turbulent state, specifically by creation of gas bubbles of the carboxylic acid halide herein. Second step may include a flash thermolysis, vacuum thermolysis, thermolysis under stripping with inert gas, and/or a thermolysis at a temperature from >90° C. to 120° C. Third step preferably comprises reacting the alkenone with a nitrogen-containing compound.

Abstract: Process for preparing an alkenone, which comprises (a) reacting a carboxylic acid halide with a vinyl ether by introducing vinyl ether into a liquid reaction medium containing carboxylic acid halide to form a halogenated precursor of the alkenone and (b) eliminating hydrogen halide from said precursor to form the alkenone.

Abstract: Process for preparing an alkenone, which comprises the following steps: (a) providing a halogenated precursor of the alkenone; and (b) eliminating the hydrogen halide from said precursor to form the alkenone by a thermolysis treatment selected from the group consisting of flash thermolysis, vacuum thermolysis, and thermolysis under stripping with inert gas.

Abstract: A process for the manufacture of fluoroethylene carbonate or difluoroethylene carbonate by reaction of ethylene carbonate and F2 or for the manufacture of fluoromethyl methyl carbonate or difluorinated dimethyl carbonate by reaction of dimethyl carbonate and F2 is described wherein such fluorination process is performed continuously.

Abstract: Crude fluoroethylene carbonate obtained by the fluorination of ethylene carbonate and elemental fluorine containing not more than 5% by weight of HF is purified by at least two subsequent distillation steps. The bulk of HF can be removed, if desired, in a preliminary HF removal step, e.g., by stripping, before performing the distillation. Further, if desired, a second HF removal step can be performed by contacting the crude mixture or the distillate obtained after the first distillation step with an adsorbent for HF, e.g., silica gel. The distillation can be performed batch wise. It is preferred to perform the distillation continuously. It yields purified fluoroethylene carbonate with an HF content of equal to or less than 30 ppm. The purified fluoroethylene carbonate can be applied as solvent additive for lithium ion batteries.

Abstract: Process for preparing an alkenone, which comprises the following steps: (a) providing a halogenated precursor of the alkenone; and (b) eliminating the hydrogen halide from said precursor to form the alkenone by a thermolysis treatment selected from the group consisting of flash thermolysis, vacuum thermolysis, and thermolysis under stripping with inert gas.

Abstract: Process for preparing an alkenone, which comprises (a) reacting a carboxylic acid halide with a vinyl ether by introducing vinyl ether into a liquid reaction medium containing carboxylic acid halide to form a halogenated precursor of the alkenone and (b) eliminating hydrogen halide from said precursor to form the alkenone.

Abstract: Mixtures comprising organic carbonates, such as carbonates not substituted by fluorine, but especially fluorosubstituted organic carbonates, which are depleted in HF can be obtained from respective mixtures with a higher HF content by a step of stripping such mixture with an inert gas. For example, a reaction mixture comprising fluoroethylene carbonate and HF can be treated in this way. The mixture comprising organic carbonate which is depleted in HF can be distilled to obtain highly purified organic carbonate.

Abstract: Process for obtaining a hydrofluoroalkane which is purified of organic impurities, according to which the hydrofluoroalkane containing organic impurities is subjected to at least one purification treatment chosen from (a) a treatment with chlorine in the presence of a initiator (b) a reaction with hydrogen fluoride (c) a distillation in which the purified hydrofluoroalkane is removed from the top of the distillation column or from the side (d) an extractive distillation (e) an adsorption onto a solid adsorbent (f) a reaction with a compound containing oxygen, and (g) a reaction with a compound containing oxygen and a gas-phase reaction with a reagent capable of reacting with at least some of the organic impurities, with the exception of a reaction with elemental chlorine.

Abstract: Process for the separation of a mixture comprising at least one hydrofluoroalkane and hydrogen fluoride, according to which a hydrofluoroalkane/hydrogen fluoride mixture is reacted with at least one chlorinated or chlorofluorinated precursor of the hydrofluoroalkane. Process for the preparation of a hydrofluoroalkane comprising such a separation, in combination with a catalytic reaction stage. Azeotropic compositions.

Abstract: Process for obtaining a hydrofluoroalkane which is purified of organic impurities, according to which the hydrofluoroalkane containing organic impurities is subjected to at least one purification treatment chosen from (a) a treatment with chlorine in the presence of a initiator (b) a reaction with hydrogen fluoride (c) a distillation in which the purified hydrofluoroalkane is removed from the top of the distillation column or from the side (d) an extractive distillation (e) an adsorption onto a solid adsorbent (f) a reaction with a compound containing oxygen, and (g) a reaction with a compound containing oxygen and a gas-phase reaction with a reagent capable of reacting with at least some of the organic impurities, with the exception of a reaction with elemental chlorine.

Abstract: Process for obtaining a hydrofluoroalkane which is purified of organic impurities, according to which the hydrofluoroalkane containing organic impurities is subjected to at least one purification treatment chosen from (a) a treatment with chlorine in the presence of a initiator (b) a reaction with hydrogen fluoride (c) a distillation in which the purified hydrofluoroalkane is removed from the top of the distillation column or from the side (d) an extractive distillation (e) an adsorption onto a solid adsorbent (f) a reaction with a compound containing oxygen, and (g) a reaction with a compound containing oxygen and a gas-phase reaction with a reagent capable of reacting with at least some of the organic impurities, with the exception of a reaction with elemental chlorine.

Abstract: Process for the separation of a mixture comprising at least one hydrofluoroalkane and hydrogen fluoride, according to which a hydrofluoroalkane/hydrogen fluoride mixture is reacted with at least one chlorinated or chlorofluorinated precursor of the hydrofluoroalkane. Process for the preparation of a hydrofluoroalkane comprising such a separation, in combination with a catalytic reaction stage. Azeotropic compositions.