718 results about "Methyl iodide" patented technology

A methanol carbonylation system 10 includes an absorber tower 75 adapted for receiving a vent gas stream and removing methyl iodide therefrom with a scrubber solvent, the absorber tower being coupled to first and second scrubber solvent sources 16, 56 which are capable of supplying different first and second scrubber solvents. A switching system including valves 90, 92, 94, 96, 98 alternatively provides first or second scrubber solvents to the absorber tower and returns the used solvent and sorbed material to the carbonylation system to accommodate different operating modes.

The invention pertains to heat transfer compositions, particularly to automobile refrigerants comprising a hydrofluoroalkene, an iodocarbon, a polyol ester and at least one compound comprising trifluoromethane, methyl iodide, heptafluorobutane or propene.

Acetic acid is produced while inhibiting an increased concentration or production of hydrogen iodide in a carbonylation reactor or corrosion of the carbonylation reactor.

A production process of acetic acid comprises a reaction step for continuously allowing methanol to react with carbon monoxide in the presence of a catalyst system comprising a metal catalyst (e.g., a rhodium catalyst), an ionic iodide (e.g., lithium iodide), and methyl iodide in a carbonylation reactor; and in the process, (i) the concentration of the metal catalyst is maintained at not less than 860 ppm on the basis of weight, the concentration of water is maintained at 0.8 to 15% by weight, the concentration of methyl iodide is maintained at not more than 13.9% by weight, and the concentration of methyl acetate is maintained at not less than 0.1% by weight, in a whole liquid phase in the reactor, and/or (ii) the concentration of the metal catalyst is maintained at not less than 660 ppm on the basis of weight, the concentration of water is maintained at 0.8 to 3.9% by weight, the concentration of the ionic iodide is maintained at not more than 13% by weight, the concentration of methyl iodide is maintained at not more than 13.9% by weight, and the concentration of methyl acetate is maintained at not less than 0.1% by weight, in a whole liquid phase in the reactor.

Acetic acid is produced while inhibiting increased concentrations of hydrogen iodide and acetic acid in an acetaldehyde distillation column.

A production process of acetic acid comprises a step for allowing methanol to react with carbon monoxide; a step for feeding a flasher with the reaction mixture to separate a volatile component (2A) and a low-volatile component (2B); a step for feeding a distillation column with the volatile component (2A), and separating an overhead (3A) containing methyl iodide, acetic acid, methyl acetate, water, acetaldehyde, and hydrogen iodide, and a stream (3B) containing acetic acid to collect acetic acid; and a separation step for feeding an acetaldehyde distillation column with at least part of the overhead (3A) and separating a liquid object to be treated containing the overhead (3A) into a lower boiling point component (4A) containing acetaldehyde and a higher boiling point component (4B); wherein, in the separation step, the liquid object contains methanol and/or dimethyl ether in a concentration of 0.1 to 50% by weight is subjected to distillation.

Disclosed is a carbonylation process for the production of carboxylic acids, carboxylic acid esters and/or carboxylic acid anhydrides wherein a carbonylation feedstock compound selected from one or more organic oxygenates such as alcohols, ethers, and esters is contacted with carbon monoxide in the presence of a carbonylation catalyst and one or more onium compounds. The carbonylation process differs from known carbonylation processes in that a halide compound such as a hydrogen halide, typically hydrogen iodide, and/or alkyl halide, typically methyl iodide, extraneous or exogenous to the carbonylation process is not fed or supplied separately to the process.

Disclosed is a method of controlling a separation process for removing moving permanganate reducing compounds from a process stream in the methanol carbonylation process for making acetic acid, where the method includes the steps of measuring the density of a stream containing acetaldehyde and methyl iodide, optionally calculating the relative concentrations of acetaldehyde and methyl iodide in the stream, and adjusting distillation or extraction process parameters based on the measured density or one or more relative concentrations calculated therefrom.

A carbonylation process for producing acetic acid including: (a) carbonylating methanol or its reactive derivatives in the presence of a Group VIII metal catalyst and methyl iodide promoter to produce a liquid reaction mixture including acetic acid, water, methyl acetate and methyl iodide; (b) feeding the liquid reaction mixture at a feed temperature to a flash vessel which is maintained at a reduced pressure; (c) heating the flash vessel while concurrently flashing the reaction mixture to produce a crude product vapor stream, wherein the reaction mixture is selected and the flow rate of the reaction mixture fed to the flash vessel as well as the amount of heat supplied to the flash vessel is controlled such that the temperature of the crude product vapor stream is maintained at a temperature less than 90° F. cooler than the feed temperature of the liquid reaction mixture to the flasher and the concentration of acetic acid in the crude product vapor stream is greater than 70% by weight of the crude product vapor stream.

The invention provides quaternized polybenzimidazole and a preparation method thereof. Polyanions are formed by polybenzimidazole and derivatives thereof (PBIs) under the function of a dehydrogenized reagent and a solvent, small molecules such as tertiary amine halide, methyl iodide and the like are inoculated to the side chain of the polybenzimidazole molecule and ion exchange is carried out in an alkaline solution, therefore, the quaternized polybenzimidazole with good thermal stability, solubility and membrane forming performance can be prepared. The quaternized polybenzimidazole can be used as an OH<->ion-exchange membrane in alkali fuel cells and has broad application prospect.

An improved process is disclosed for producing acetic acid, including the following steps: reacting a carbonylatable reactant such as methanol, methyl acetate, methyl formate or dimethyl ether with carbon monoxide in a reaction medium containing water, methyl iodide, and a catalyst to produce a reaction product that contains acetic acid; separating the reaction product to provide a volatile phase containing acetic acid, water, and methyl iodide and a less volatile phase; distilling the volatile phase to produce a purified acetic acid product and a first overhead containing water, methyl acetate, and methyl iodide; phase separating the first overhead to provide a first liquid phase containing water and a second liquid phase containing methyl iodide; and adding dimethyl ether to the process in an amount effective to enhance separation of the first overhead to form the first and second liquid phases.

This working medium for a heat cycle contains trifluoroethylene and a first component comprising at least one substance selected from carbon dioxide, fluoromethane, trifluoroiodomethane, methane, ethane, propane, helium, neon, argon, krypton, xenon, nitrogen, and ammonia.

The invention provides a cationic fluorosurfactant (I) and a preparation method thereof. The method comprises adopting perfluorobutenyloxy benzoic acid and thionyl chloride as raw materials to perform a chloroacylation reaction at -30 DEC C to 70 DEC C in polar solvent, adding N,N-dimethyl propylene diamine and base catalyst, performing an amidation reaction at -20 DEC C to 120 DEC C, separating the reactant liquor to obtain N-[3-(p-perfluorobutenyloxybenzamido)propyl]-N, N-dimethyl amine, dissolving into non-proton polar solvent, adding iodomethane, performing a quaternization reaction at 0 DEC C to 100 DEC C, and filtering the reactant liquor to obtain N-[3-(p-butenyloxybenzamido)propyl]-N,N,N-trimethyl ammonium iodide. The method has simple synthetic method and high reaction yield. Aqueous solution prepared from the N-[3-(p-butenyloxybenzamido)propyl]-N,N,N-trimethyl ammonium iodide has low surface tension.

A process for stably producing high-purity acetic acid while efficiently removing acetaldehyde is provided.

The process for producing acetic acid comprises a reaction step for allowing methanol to react with carbon monoxide in the presence of a metal catalyst, a halide salt, and methyl iodide; a step for continuously feeding a flasher with the reaction mixture and separating a lower boiling point component (2A) containing acetic acid and methyl iodide and a higher boiling point component (2B) containing the metal catalyst and the halide salt; a step for feeding a distillation column with the lower boiling point component (2A), and separating a lower boiling point component (3A) containing methyl iodide and acetaldehyde and a stream (3B) containing acetic acid to collect acetic acid; a condensation step for condensing and temporarily holding the lower boiling point component (3A) in a decanter and discharging the lower boiling point component (3A) from the decanter; and a step for separating the lower boiling point component (3A) discharged from the decanter into acetaldehyde and a liquid residue and recycling the liquid residue to the reaction system. In the condensation step, the amount of the lower boiling point component (3A) to be held is controlled based on a fluctuating flow rate of the lower boiling point component (3A) to be fed to the decanter.

The invention provides a method for preparing trifluoroiodomethane through utilizing industrial waste trifluoroacetic acid and industrially recovered iodine. The method has the characteristics of low cost, simple operation, mild reaction, fast reaction speed, high yield, high selectivity, environmental protection and the like. The synthesized trifluoroiodomethane is an important fluorine-containing fine chemical engineering raw material, and can be used for producing fluorine-containing finishing agents, fluorine-containing surfactants and other fluorine-containing fine chemicals.

The invention provides a preparation method of 3, 5-dimethyl phenol. The method comprises the following steps that halogenated hydrocarbon catalysts such as methyl iodide or n-bromobutane are premixed with 3, 5, 5-trimethyl 2-cyclohexene-1-ketone and then are fed into a tubular reactor so as to carry out reaction under the conditions of 400 to 600 DEG C and 1 to 5atm; then, a target product can be obtained after separation. The method can reduce the consumption of catalysts, and can substantially increase conversion rate and selectivity; moreover, reaction conditions are more moderate and more suitable for industrial production.