Abstract:
The invention relates to a gas-phase continuous method for preparing 2,3,3,3-tetrafluoro-1-propene, said method comprising the following steps: (i) hydrogenation of hexafluoropropylene to form 1,1,1,2,3,3-hexafluoropropane; (ii) dehydrofluorination of the 1,1,1,2,3,3-hexafluoropropane obtained in the previous step to 1,2,3,3,3-pentafluoropropene-1; (iii) hydrogenation of the 1,2,3,3,3-pentafluoropropene-1 obtained in the previous step to form 1,1,1,2,3-pentafluoropropane; and (iv) dehydrofluorination of the 1,1,1,2,3-pentafluoropropane obtained in the previous step to form 2,3,3,3-tetrafluoro-1-propene.
Abstract:
The subject of the invention is a process for the purification of 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf). More particularly, it relates to a purification process in which 2,3,3,3-tetrafluoro-1-propene, comprising impurities based on halogen compounds, is brought into contact with an adsorbent, preferably molecular sieves and advantageously molecular sieves having a pore opening with an average diameter between 5 and 11 Å, preferably between 5 and 9 Å.
Abstract:
The subject of the invention is a process for the purification of 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf). More particularly, it relates to a purification process in which 2,3,3,3-tetrafluoro-1-propene, comprising impurities based on halogen compounds, is brought into contact with an adsorbent, preferably molecular sieves and advantageously molecular sieves having a pore opening with an average diameter between 5 and 11 Å, preferably between 5 and 9 Å.
Abstract:
The invention relates to a method for producing hydrofluorocarbons. The method comprises a step of reacting at least one hydro(fluoro)chlorocarbon or chlorocarbon with hydrofluoric acid in a gaseous phase in the presence of a catalyst, and a step of separating fluorination reaction products from the mixture. The method is characterized in that the gaseous flow from the reaction is compressed by means of a compressor before being subjected to the separation step. The invention also relates to a device for implementing the method.
Abstract:
This invention concerns a device comprising a cylindrical vertical stirred reactor (v), provided with centrifugal turbines (a) arranged along a single vertical agitated shaft, and its uses for implementing any process whereby several gas constituents are made to react in the presence of a solid suspended in a liquid phase. The device is particularly suited for directly making hydrogen peroxide.
Abstract:
The present invention relates to a process for the synthesis of 2-carboxyanthraquinone from 2-ethylanthraquinone by oxidation of the said ethyl group by means of a nitric acid solution. Anthra-quinones are used in the manufacture of oxygen-absorbing films which make possible the preparation of packagings suited to the preservation of oxygen-sensitive products, such as foodstuffs.
Abstract:
A process of dignifying lignocellulosic pulp with oxygen followed by treatment of the delignified pulp with a chelating agent, followed by washing, followed by treatment with hydrogen peroxide at an alkaline pH in the presence of an alkali metal silicate at a temperature greater than 100.degree. C. and a pressure greater than 1.5 times the saturated vapor pressure.
Abstract:
A variety of plant materials adopted for processing into, e.g., low-calorie vegetable fibers and dietary flours, are bleached by (1) prebleaching such plant material in a first aqueous solution containing an alkaline agent and hydrogen peroxide, the alkaline agent being present in solution in such amount that the final pH of the resulting suspension is no greater than 9, (2) filtering and washing the suspension produced in step (1) with water, to an effectiveness of at least 50%, (3) bleaching the material obtained after step (2) in a second aqueous solution containing an alkaline agent and hydrogen peroxide, the alkaline agent being present in solution in such amount that the final pH of the resulting suspension is no greater than 8.5, and, characteristically, (4) filtering and washing the suspension produced in step (3) with water.
Abstract:
A process for the decomposition of complexes of ortho-benzoyl benzoic acids, hydrogen fluoride, and boron trifluoride, whether or not the ortho-benzoyl benzoic acid is substituted, is disclosed wherein the ortho-benzoyl benzoic acid is obtained separately from the hydrogen fluoride and boron trifluoride. This process is characterized in that the complex is treated with an inert solvent at a temperature of at least 20.degree. C., in a distillation column having at least about 8 theoretical plates whereby the solvent reflux is operated at a rate equal to about 5 to about 40 times the weight of the feed delivery rate of the column.The process of the present invention also makes it possible to recover hydrogen fluoride and boron trifluoride for reuse as catalysts in the synthesis of ortho-benzoyl benzoic acid without causing decomposition of the acid.
Abstract:
A process for the preparation of anthraquinone compounds by condensation of phthalic anhydride with a benzene derivative wherein a mixture of hydrofluoric acid and boron trifluoride is utilized as catalyst.