摘要:
Synthesis gas (a mixture of hydrogen gas and carbon monoxide) is converted to hydrocarbons by flowing the gas first over iron-containing Fischer-Tropsch catalyst and then over a zeolite. The Fischer-Tropsch catalyst contains relatively little nitrogen as a result of its preparation by continuous precipitation at a pH ranging from about 6.6 to 6.9 and a temperature ranging from about 80.degree. to about 100.degree. C.
摘要:
Synthesis gas (a mixture of hydrogen gas and carbon monoxide) is converted to hydrocarbons by flowing the gas first over iron-containing Fischer-Tropsch catalyst and then over a zeolite. The Fischer-Tropsch catalyst contains relatively little nitrogen as a result of its preparation by continuous precipitation at a pH ranging from about 6.6 to 6.9 and a temperature ranging from about 80.degree. to about 100.degree. C.
摘要:
A process for catalytically converting cyclohexanone oxime to epsilon caprolactam. The conversion catalyst is a crystalline aluminosilicate zeolite having a Constraint Index greater than 1 and a reduced surface acidity. The surface acidity is reduced by selective surface dealumination of the crystalline aluminosilicate zeolite by contacting the zeolite with dicarboxylic acid, such as oxalic acid.
摘要:
A catalytic process is provided for the manufacture of ethers by reacting a linear monoolefin with a primary or secondary alcohol having up to 4 carbon atoms. The process selectively forms methyl isopropyl ether from a propylene feed and methanol by contact with a zeolite such as Zeolite Beta or ZSM-5, or by contact with a macroreticular sulfonated ion-exchange resin.
摘要:
A process is disclosed for the production of alkyl tertiary alkyl ether from alkanol and iso-olefin employing zeolite catalyst, particularly zeolite Beta, that results is a high ether selectivity and a significant reduction in the formation of olefin oligomer by-product. The improvement is realized by incorporating a catalyst pretreatment step in the overall etherification process. The zeolite catalyst pretreatment comprises either steaming or a hydrothermal treatment using liquid water at elevated temperature. The process is particularly effective in reducing the formation of dimer by-product in the zeolite Beta catalyzed process for the formation of MTBE with high selectivity.
摘要:
A process for synthesizing di-isopropyl ether (DIPE) by etherification of isopropanol. A multi-stage process can employ propene in mixture with other feedstock materials, such as propane from refinery gas, in a primary hydration stage to produce isopropanol. The isopropanol is enriched between stages to remove water. In the second reaction stage the isopropanol is converted catalytically with large pore acidic zeolite to yield DIPE, which can be separated to recover pure propene.
摘要:
A process is disclosed for converting a light hydrocarbon feedstock that contains a mixture of linear and branched olefins to ether-rich high octane gasoline streams that include tertiary alkyl and isoalkyl ethers such as MTBE, TAME, methyl isopropyl ether (MIPE), and methyl sec-butylether (MSBE). The conversion is achieved by utilizing the differing reactivity of tertiary olefins under selected conditions compared to linear olefins in the catalyzed etherification processes. The discovery has been made that unreacted olefins from the etherification reactions can be converted to gasoline boiling range hydrocarbons by contacting them with zeolite catalyst at elevated temperature. Further, it has been discovered that unreacted paraffins in the integrated process can be dehydrogenated to produce C.sub.3 -C.sub.4 olefins which can be recycled to the etherification process.
摘要:
A novel Fischer Tropsch iron catalyst that has unusually high selectivity for liquid hydrocarbons (low selectivity for methane) is provided. The catalyst is prepared by treatment of the usual inactive catalyst precursor with water vapor at elevated temperature either after conventional activation by syngas or concurrently therewith. Surprisingly, the "selectivation" with water vapor does not affect catalytic activity. The novel "selectivated" catalyst may be used to advantage either to increase temperature and throughput, or to increase liquid hydrocarbon selectivity, compared with conventional catalyst that has not been "selectivated".
摘要:
A process is provided for catalytically converting cyclohexanone oxime to epsilon caprolactam. The conversion is characterized by exceptionally high selectivity and reduced rate of catalyst aging, even at single pass conversion above 90 percent. The conversion catalyst is a medium pore size crystalline zeolite exemplified by ZSM-5 which has low acid activity. Recycling unconverted oxime provides excellent ultimate yield of caprolactam.
摘要:
The medium pressure Fischer-Tropsch synthesis of liquid hydrocarbons conducted with an iron catalyst is made more efficient by temporarily suspending conventional synthesis and treating the catalyst with a high partial pressure of water vapor, after which conventional synthesis is resumed. The treatment inparts a large increase in selectivity for liquids with reduction of methane formation. The treatment is very effective with alkali (e.g. potassium) promoted precipitated iron catalyst.