摘要:
A process is disclosed for enhancing the production of light olefins using a catalyst with small pores. The catalyst comprises a molecular sieve having 10 membered rings with channels of limited length. The molecular sieve has a high silica to alumina ratio and has pores sized to limit production of aromatics in the cracking process.
摘要:
A process for forming a zeolite beta dielectric layer onto a substrate such as a silicon wafer has been developed. The zeolite beta is characterized in that it has a Si/Al of at least 25 and has crystallites from about 5 to about 40 nanometers. The process involves first dealuminating a starting zeolite beta, then preparing a slurry of the dealuminated zeolite beta followed by coating a substrate, e.g. silicon wafer with the slurry, heating to form a zeolite beta film and treating the zeolite beta with a silylating agent.
摘要:
A process for the production of C8 alkenes with high selectivities to 2,4,4-trimethylpentene by the oligomerization of isobutene and/or n-butene at lower temperatures is disclosed. Higher proportions of heavy paraffins mixed with the butene feed in the oligomerization zone improve the selectivity to 2,4,4-trimethylpentene along with better selectivity to octene and lower selectivity to dodecene. Additionally, we have found that n-butene codimerizes with isobutene selectively to 2,4,4-trimethylpentene.
摘要:
A hybrid reactor arrangement provides a reactive design that achieves higher acrylonitrile yield and lower catalyst circulating rate. The hybrid reactor design first passes a mixture of reactants and catalyst through a circulating bubbling bed reaction section. Heat exchange coils or other cooling medium in the bubbling bed reactor section maintain temperature in a range that will maximize the selectivity of reactants to the acrylonitrile product. The bubbling bed reactor section provides the initial conversion of the reactant. A circulating fluidized bed reaction zone finishes the conversion of reactants to a high yield under conditions that reduce the occurrence of secondary reactions that could otherwise produce unwanted by-products. The circulating fluidized bed reactor section maintains nearly plug flow conditions that allow continued conversion of unreacted feed components through primary reactions while limiting the time for secondary reactions to continue and diminish the final yield of products. Selectivity and conversion may also be improved by sequential addition of oxygen into the CFB reaction section. The sequential addition of oxygen may occur by the direct injection of an oxygen-containing gas or by the delivery of re-oxidized catalyst particles that are fully recharged with the lattice oxygen necessary for the reaction. Through this method the hybrid reactor provides the typical 5% improvement of higher acrylonitrile product yield from CFB-type reaction zones while reducing the required catalyst circulation by a factor of 10 or more.
摘要:
A hybrid reactor arrangement provides a reactive design that achieves higher acrylonitrile yield and lower catalyst circulating rate. The hybrid reactor design first passes a mixture of reactants and catalyst through a circulating bubbling bed reaction section. Heat exchange coils or other cooling medium in the bubbling bed reactor section maintain temperature in a range that will maximize the selectivity of reactants to the acrylonitrile product. The bubbling bed reactor section provides the initial conversion of the reactant. A circulating fluidized bed reaction zone finishes the conversion of reactants to a high yield under conditions that reduce the occurrence of secondary reactions that could otherwise produce unwanted by-products. The circulating fluidized bed reactor section maintains nearly plug flow conditions that allow continued conversion of unreacted feed components through primary reactions while limiting the time for secondary reactions to continue and diminish the final yield of products. Selectivity and conversion may also be improved by sequential addition of oxygen into the CFB reaction section. The sequential addition of oxygen may occur by the direct injection of an oxygen-containing gas or by the delivery of re-oxidized catalyst particles that are fully recharged with the lattice oxygen necessary for the reaction. Through this method the hybrid reactor provides the typical 5% improvement of higher acrylonitrile product yield from CFB-type reaction zones while reducing the required catalyst circulation by a factor of 10 or more.
摘要:
A process is presented for the selective catalytic cracking of naphtha to light olefins. The process includes contacting a naphtha feedstream with a mixture of catalysts to reduce the amount of recycle, and especially the recycle of light paraffins. The mixture of catalysts includes a first molecular sieve made up from a small pore zeolite having a pore index between 13 and 26, and a second molecular sieve made up from an intermediate pore zeolite having a pore index between 26 and 30.
摘要:
The present invention comprises a hydrocarbon-conversion process using an improved MgMxAPSO-31 molecular sieve which demonstrates a favorable combination of conversion and selectivity in aromatics conversion. The sieve comprises at least two divalent elements with narrow specific concentration limits in the framework structure having defined crystal characteristics. The element Mx may comprise one or more of manganese, cobalt, nickel, iron and zinc.
摘要:
The present invention comprises a hydrocarbon-conversion process using an improved MgAPSO-31 molecular sieve which demonstrates a favorable combination of conversion and selectivity in aromatics conversion. The sieve has a specific combination of crystal configuration, being limited in diameter and length, specified crystallinity as measured by an X-Ray Diffraction Index (XRDI), and a narrow range of magnesium content.
摘要:
The present invention comprises an improved MgMxAPSO-31 molecular sieve and a catalyst composite which demonstrates a favorable combination of conversion and selectivity in aromatics conversion. The sieve comprises a at least two divalent elements with narrow specific concentration limits in the framework structure having defined crystal characteristics. The element Mx may comprise one or more of manganese, cobalt, nickel, iron and zinc.
摘要:
A process is presented for the selective catalytic cracking of naphtha to light olefins. The process includes contacting a naphtha feedstream with a mixture of catalysts to reduce the amount of recycle, and especially the recycle of light paraffins. The mixture of catalysts includes a first molecular sieve made up from a small pore zeolite having a pore index between 13 and 26, and a second molecular sieve made up from an intermediate pore zeolite having a pore index between 26 and 30.