摘要:
Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.
摘要:
A process using a niobium catalyst includes the step of reacting an ester or carboxylic acid with oxygen and an alcohol in the presence a niobium catalyst to respectively produce an .alpha.,.beta.-unsaturated ester or carboxylic acid. Methanol may be used as the alcohol, and the ester or carboxylic acid may be passed over the niobium catalyst in a vapor stream containing oxygen and methanol. Alternatively, the process using a niobium catalyst may involve the step of reacting an ester and oxygen in the presence the niobium catalyst to produce an .alpha.,.beta.-unsaturated carboxylic acid. In this case the ester may be a methyl ester. In either case, niobium oxide may be used as the niobium catalyst with the niobium oxide being present on a support. The support may be an oxide selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide and mixtures thereof. The catalyst may be formed by reacting niobium fluoride with the oxide serving as the support. The niobium catalyst may contain elemental niobium within the range of 1 wt % to 70 wt %, and more preferably within the range of 10 wt % to 30 wt %. The process may be operated at a temperature from 150 to 450.degree. C. and preferably from 250 to 350.degree. C. The process may be operated at a pressure from 0.1 to 15 atm. absolute and preferably from 0.5-5 atm. absolute. The flow rate of reactants may be from 10 to 10,000 L/kg.sub.(cat) /h, and preferably from 100 to 1,000 L/kg.sub.(cat) /h.
摘要:
A method for producing esters and carboxylic acids from lower alkyl alcohols, ethers, esters and ester-alcohol reactant mixtures and includes the step of contacting a vaporous mixture of the reactants, carbon monoxide and a halide with a supported catalyst under vapor-phase carbonylation conditions. The catalyst includes iridium and a second metal selected from group 4 (titanium, zirconium, hafnium) metals of the periodic table of elements. Desirably, the iridium and secondary metal are deposited on activated carbon as a support material. In a preferred aspect of the invention, the vapor phase carbonylation process is useful for preparing acetic acid, methyl acetate or a mixture thereof.
摘要:
A carbonylation catalyst useful for producing esters and carboxylic acids in a vapor phase carbonylation process, wherein the catalyst includes a solid component having a catalytically effective amount of platinum and tin associated with a solid catalyst support material and a vaporous halide promoter component.
摘要:
A vapor phase process for the carbonylation of lower alkyl alcohols to esters and optionally, carboxylic acids using a catalyst containing iridium and at least one second metal selected from the Lanthanide Series. Desirably, the iridium and secondary metal are deposited on activated carbon as a support material. In a preferred aspect of the invention, the vapor phase process is useful for preparing acetic acid, methyl acetate or a mixture thereof by contacting the catalyst with a vapor comprising methanol, a halide and carbon monoxide under carbonylation process conditions.
摘要:
Disclosed is a process wherein a mixture of methanol or a methanol source, a halide and carbon monoxide are contacted in the vapor phase with a supported catalyst comprising iridium and at least one second metal selected from ruthenium, molybdenum, tungsten, palladium, platinum and rhenium deposited on a catalyst support material.
摘要:
Disclosed herein is a vapor phase carbonylation process useful for producing carboxylic acids, esters and mixtures thereof from lower aliphatic alcohols, ethers, ester, and ester-alcohol mixtures. The vapor phase carbonylation process is characterized in that it utilizes a solid supported catalyst having an effective amount of gold associated with a solid support material.
摘要:
A solid supported catalyst suitable for the vapor phase carbonylation of lower aliphatic alcohols, ethers, ester, and ester-alcohol mixtures, and desirably, methanol, to produce acetic acid, methyl acetate and mixtures thereof. The solid supported catalyst includes an effective amount of iridium and at least one second metal selected from group metals of the periodic table of elements, their respective salts and mixtures thereof associated with a solid support material. Desirably, the support material is selected from carbon, activated carbon, pumice, alumina, silica, silica-alumina, magnesia, diatomaceous earth, bauxite, titania, zirconia, clay, magnesium silicate, silicon carbide, zeolites, ceramics and combinations thereof.
摘要:
This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.
摘要:
A vapor-phase carbonylation method for producing esters and carboxylic acids from reactants comprising lower alkyl alcohols, lower alkyl alcohol generating compositions and mixtures thereof. The method includes contacting the reactants and carbon monoxide in a carbonylation zone of a carbonylation reactor under vapor-phase conditions with a catalyst having a catalytically effective amount of platinum and tin associated with a solid carrier material.