摘要:
Continuous methylation of tetralin with methanol over several solid acid catalysts affords a mixture of 5-methyltetralin and 6-methyltetralin with selectivity of better than 65% at high conversions. Zeolite .beta. is a particularly effective catalyst insofar as it catalyzes the reaction at a temperature approximately 100.degree. C. lower than that required for silica-aluminas. However, the reaction temperature is quite sensitive to the concentration of methanol in the feedstock.
摘要:
There is described a method of selectively and continuously converting a cyanohydrin to its corresponding aldehyde using as a catalyst zerovalent palladium dispersed on an organic polymeric resin with a surface area above 30 m.sup.2 /g under highly acidic conditions where the formed imine is resistant to further reduction to the amine. Where the aqueous cyanohydrin feedstock contains more than 1.4 equivalent proportions of a strong acid, less than 5% of the theoretical yield of amine is formed. Hydrogenation may be performed at a pressure as great as 2000 psig without significant deleterious effects on selectivity. Hydrolysis of the hydrogenation product affords the corresponding aldehydes in good yields.
摘要:
There is described a method of selectively and continuously converting a cyanohydrin to its corresponding aldehyde using as a catalyst zerovalent palladium dispersed on an organic polymeric resin with a surface area above 30 m.sup.2 /g. The aqueous cyanohydrin feedstock contains from about 0.5 to about 1.1 equivalents of an acid over and above that necessary to provide a pH of 2. Selective conversions may be obtained using hydrogen pressures up to about 450 pounds per square inch.
摘要:
A process and apparatus is presented for the desalination of water by freezing seawater. The process is integrated into a liquefied natural gas regasification system. The process comprises alternating the flow of liquefied natural gas to freeze seawater in a heat exchanger and then flowing a hot flue gas through the heat exchanger to melt the frozen seawater, and then repeating the process.
摘要:
A catalyst and a process for using the catalyst have been developed. The catalyst is a metal chelate dispersed on a basic support which is a combination of a solid base and a secondary component. The solid base can be a solid solution of metal oxides and/or a layered double hydroxide (LDH) and the secondary component can be calcium oxide, magnesium oxide, calcium hydroxide and magnesium hydroxide. The process involves contacting a sour hydrocarbon fraction which contains mercaptans with the catalyst in the presence of an oxidizing agent and a polar compound. Examples of these polar compounds are water and alcohols, with methanol being especially preferred. The process is unique in that the solid solution or LDH are solid bases which eliminates the need for a liquid base. Optionally, an onium compound may be used as a catalyst promoter.
摘要:
A process for treating a hydrocarbon fraction which contains mercaptans has been developed. The process uses a novel catalyst which is composed of a metal chelate dispersed on a basic support which is either a solid solution of metal oxides or a layered double hydroxide (LDH). In the process the hydrocarbon fraction is contacted with the catalyst in the presence of an oxidizing agent and a polar compound. Examples of these polar compounds are water and alcohols, with methanol being especially preferred. The process is unique in that the solid solution or LDH are solid bases which eliminates the need for a liquid base. Optionally, an onium compound may be used as a catalyst promoter.
摘要:
A process is presented for the continuous oxidation of alditols to aldoses accompanied by under 20 weight percent of aldonic and/or alduronic acids relative to the aldoses that are formed. The use of zerovalent platinum on a support such as theta-alumina and at superatmospheric oxygen partial pressures up to about 1,000 pounds per square inch is partially successful in affording good conversion of alditols with relatively low aldonic and/or alduronic acid formation.
摘要:
D-Talose and D-allose are reduced calorie sugars which taste sweet, provide bulk, and undergo the browning reaction. They can be effectively used per se or in combination with intense sweeteners to provide a method of sweetening a broad variety of foods and foodstuffs while providing bulk and body to the product. These materials are especially valuable in baked goods because they closely mimic sucrose in undergoing browning.
摘要:
Although feedstocks of L-mannose prepared from hydrocyanation of L-arabinose contain inhibitors to the soluble molybdate-catalyzed epimerization of L-mannose to L-glucose, experimental conditions have been found which minimize such inhibition. A method is presented for improving the yield of L-glucose in a preparative route using hydrocyanation of L-arabinose as the entry to the L-hexoses by incorporating a soluble molybdate-catalyzed empimerrization stage conducted at a pH below 3.0.
摘要:
A broad variety of modified inorganic oxides may be prepared by surface-metallating the oxide with a metal tetrahalide followed by displacement of a halogen bonded to the metal by a nucleophilic organic functional group. The results are organic moieties coating the surface of the oxide by being covalently bonded to a metal which, in turn, is covalently bonded to an oxygen originally associated with a surface hydroxyl of the inorganic oxide.