1588results about "Molecular sieve catalyst" patented technology

There is described a process and a catalyst for the hydroalkylation of an aromatic hydrocarbon, particularly benzene, wherein the catalyst comprises a first metal having hydrogenation activity and a crystalline inorganic oxide material having a X-ray diffraction pattern including the following d-spacing maxima 12.4+/-0.25, 6.9+/-0.15, 3.57+/-0.07 and 3.42+/-0.07.

The present invention provides a process for producing a monoalkylated aromatic compound, particularly cumene, comprising the step of contacting a polyalkylated aromatic compound with an alkylatable aromatic compound under at least partial liquid phase conditions and in the presence of a transalkylation catalyst to produce the monoalkylated aromatic compound, wherein the transalkylation catalyst comprises a mixture of at least two different crystalline molecular sieves, wherein each of said molecular sieves is selected from zeolite beta, zeolite Y, mordenite and a material having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom.

Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogenous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.

The average propylene cycle yield of an oxygenate to propylene (OTP) process using a dual-function oxygenate conversion catalyst is substantially enhanced by the use of a combination of: 1) moving bed reactor technology in the catalytic OTP reaction step in lieu of the fixed bed technology of the prior art; 2) a separate heavy olefin interconversion step using moving bed technology and operating at an inlet temperature at least 15° C. higher than the maximum temperature utilized in the OTP reaction step; 3) C₂ olefin recycle to the OTP reaction step; and 4) a catalyst on-stream cycle time of 700 hours or less. These provisions hold the build-up of coke deposits on the catalyst to a level which does not substantially degrade dual-function catalyst activity, oxygenate conversion and propylene selectivity, thereby enabling maintenance of average propylene cycle yield for each cycle near or at essentially start-of-cycle levels.

There is provided a process for converting methanol and/or dimethyl ether to a product containing C2 to C4 olefins which comprises the step of contacting a feed which contains methanol and/or dimethyl ether with a catalyst comprising a porous crystalline material, said contacting step being conducted in the presence of an aromatic compound under conversion conditions including a temperature of 350 DEG C. to 480 DEG C. and a methanol partial pressure in excess of 10 psia (70 kPa), said porous crystalline material having a pore size greater than the critical diameter of the aromatic compound and the aromatic compound being capable of alkylation by the methanol and/or dimethyl ether under said conversion conditions.

There is provided a catalyst and a process for converting methanol or dimethyl ether to a product containing C2 to C4 olefins. The catalyst comprises a porous crystalline material having a Diffusion Parameter for 2,2-dimethylbutane of about 0.1-20 sec-1 when measured at a temperature of 120 DEG C. and a 2,2-dimethylbutane pressure of 60 torr (8 kPa). In addition, the catalyst is characterized by a hydrothermal stability such that, after steaming the catalyst at 1025 DEG C. for 45 minutes in 1 atmosphere steam, the catalyst exhibits a methanol conversion activity of at least 50% when contacted with methanol at a methanol partial pressure of 1 atmosphere, a temperature of 430 DEG C. and 0.5 WHSV. The porous crystalline material is preferably a medium-pore zeolite, particularly ZSM-5, which contains phosphorus and has been severely steamed at a temperature of at least 950 DEG C.

The present invention provides a process for producing a monoalkylated aromatic compound, particularly ethylbenzene or cumene, in which a polyalkylated aromatic compound is contacted with an alkylatable aromatic compound in the liquid phase and in the presence of a transalkylation catalyst comprising TEA-mordenite having an average crystal size of less than 0.5 micron.

This invention provides processes for forming light olefins from methanol and/or from syngas through a dimethyl ether intermediate. Specifically, the invention is to converting methanol and/or syngas to dimethyl ether and water in the presence of a first catalyst, preferably comprising γ-alumina, and converting the dimethyl ether to light olefins and water in the presence of a second catalyst, preferably a molecular sieve catalyst composition.

An improved continuous process for converting methane, natural gas, or other hydrocarbon feedstocks into one or more higher hydrocarbons or olefins by continuously cycling through the steps of alkane halogenation, product formation (carbon-carbon coupling), product separation, and regeneration of halogen is provided. Preferably, the halogen is continually recovered by reacting hydrobromic acid with air or oxygen. The invention provides an efficient route to aromatic compounds, aliphatic compounds, mixtures of aliphatic and aromatic compounds, olefins, gasoline grade materials, and other useful products.

The present invention is directed to a method for preparing renewable and relatively high purity p-xylene from biomass. For example, biomass treated to provide a fermentation feedstock is fermented with a microorganism capable of producing a C₄ alcohol such as isobutanol, then sequentially dehydrating the isobutanol in the presence of a dehydration catalyst to provide a C₄ alkene such as isobutylene, dimerizing the C₄ alkene to a form one or more C₈ alkenes such as 2,4,4-trimethylpentenes or 2,5-dimethylhexene, then dehydrocyclizing the C₈ alkenes in the presence of a dehydrocyclization catalyst to selectively form renewable p-xylene in high overall yield. The p-xylene can then be oxidized to form terephthalic acid or terephthalate esters.

A liquid or partially liquid phase process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene uses a zeolitic catalyst system preferably based on zeolite beta and on pentasil-type zeolite. The invention obtains an improved yield of para-xylene from the mixture relative to prior art processes in a more economical manner. A preferred beta zeolite is a surface-modified zeolite beta resulting from acid washing of a templated native zeolite at conditions insufficient to effect bulk dealumination. A preferred pentasil zeolite is a MTW-type with a silica-to-alumnina ratio between 20 and 45.

The average propylene cycle selectivity of an oxygenate to propylene (OTP) process using a dual-function oxygenate conversion catalyst is substantially enhanced by the use of a combination of: 1) moving bed reactor technology in the hydrocarbon synthesis portion of the OTP flow scheme in lieu of the fixed bed technology of the prior art; 2) a hydrothermally stabilized and dual-functional catalyst system comprising a molecular sieve having dual-function capability dispersed in a phosphorus-modified alumina matrix containing labile phosphorus and/or aluminum anions; and 3) a catalyst on-stream cycle time of 400 hours or less. These provisions stabilize the catalyst against hydrothermal deactivation and hold the build-up of coke deposits on the catalyst to a level which does not substantially degrade dual-function catalyst activity, oxygenate conversion and propylene selectivity, thereby enabling maintenance of average propylene cycle yield near or at essentially start-of-cycle levels.

This invention is drawn to a process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene using an oil-dropped catalyst comprising a zeolite, a platinum-group metal and an aluminophosphate binder, resulting in a greater yield of para-xylene at favorable conditions compared to processes of the known art.

Aromatization of alkanes having one to four carbon atoms per molecule to aromatics, such as benzene, toluene and xylenes (BTX), uses a catalyst of a crystalline zeolite on which platinum has been deposited, specifically a platinum-containing ZSM-5. A byproduct of the process is a light gas fraction of methane and ethane. The use of a platinum-containing ZSM-5 catalyst in an alkane aromatization process, such as the Cyclar process, suppresses the formation of methane and increases selectivity to BTX. The high content of ethane relative to methane in the light gas fraction allows this process effluent to be a feedstream for a cracker.

A process for producing aromatic hydrocarbons which comprises (a) contacting ethane with a dehyroaromatization aromatic catalyst which is comprised of about 0.005 to about 0.1 wt % platinum, an amount of gallium which is equal to or greater than the amount of the platinum, from about 10 to about 99.9 wt % of an aluminosilicate, and a binder, and (b) separating methane, hydrogen, and C_2-5 hydrocarbons from the reaction products of step (a) to produce aromatic reaction products including benzene.

A method of synthesizing hydrocarbons from smaller hydrocarbons includes the steps of hydrocarbon halogenation, simultaneous oligomerization and hydrogen halide neutralization, and product recovery, with a metal-oxygen cataloreactant used to facilitate carbon-carbon coupling. Treatment with air or oxygen liberates halogen and regenerates the cataloreactant.

The present invention provides processes for producing light olefins from a feedstock comprising methanol and ethanol. The ethanol is converted to ethylene and water over a dehydration catalyst, while the methanol is converted to light olefins and water over a molecular sieve catalyst. These conversion steps may occur in two separate reactors operating in series or in parallel, or in a single reactor containing a mixture of dehydration catalyst and molecular sieve catalyst.

This invention is to a process of making olefin, particularly ethylene and propylene, from an oxygenate feed. The invention uses two or more zeolite catalysts. Examples of zeolite catalysts include a first catalyst containing of ZSM-5, and a second catalyst containing a 10-ring molecular sieve, including but not limited to, ZSM-22, ZSM-23, ZSM35, ZSM-48, and mixtures thereof. The ZSM-5 can be unmodified, phosphorous modified, steam modified having a micropore volume reduced to not less than 50% of that of the unsteamed ZSM-5, or various mixtures thereof.

A method of producing liquid fuels by providing an olefin feed containing at least one C2-C20 olefin, oligomerizing a part of the feed in the presence of a first catalyst to form a first product comprising oligomers of the at least one olefin, and oligomerizing a portion of the first product in the presence of a second catalyst to produce a second product. A system of producing liquid hydrocarbons, the system including a first reactor configured to provide a first product by oligomerizing, in the presence of a first catalyst, at least a portion of an olefin feed comprising at least one olefin, a separator configured to provide an unreacted olefin-reduced first product by separating unreacted olefin from the first product, and a second reactor configured to provide a second product by oligomerizing, in the presence of a second catalyst, at least a portion of the unreacted olefin-reduced first product.

A process for producing cumene is provided which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch⁻¹.

A process for the production of propylene from an olefinic feedstock containing at least one olefin of C₄ or greater, the process comprising contacting the olefinic feedstock with a catalyst of the MFI-type having a silicon/aluminum atomic ratio of at least about 180 to produce an effluent containing propylene, the propylene yield on an olefin basis being from 30 to 50k based on the olefinic content of the feedstock.

Provided is a process for producing an aromatic hydrocarbon using a molybdenum-containing solid catalyst, more specifically a process for producing an aromatic hydrocarbon efficiently from a lower hydrocarbon gas essentially containing methane by activating the molybdenum-containing solid catalyst with maintaining a high yield for a long period of time.

The process comprises a pre-contacting step of allowing a molybdenum-containing solid catalyst to contact with a pre-contacting gas comprising at least one selected from a lower hydrocarbon and a hydrogen gas; and a reaction step of allowing the pre-contacted catalyst to contact with a raw material gas essentially containing methane, to generate an aromatic hydrocarbon, wherein the starting temperature in the pre-contacting step is lower than the reaction temperature, and the temperature during the pre-contacting step from the beginning to the end is not over the reaction temperature.

There is provided a process for converting methanol or dimethyl ether to a product containing C2 to C4 olefins, which comprises the step of contacting a feed containing methanol or dimethyl ether with a catalyst which comprises a zeolite having 10-ring intersecting channels, such as ZSM-5, and which has a Diffusion Parameter for 2,2-dimethylbutane of less than 100 sec-1 when measured at a temperature of 120° C. and a 2,2-dimethylbutane pressure of 60 torr (8 kPa). The contacting step is conducted at a temperature of 370 to 480° C., a methanol partial pressure of 30 to 150 psia and a methanol conversion per pass of less than 95%.

Heterogeneous catalysts with optional dopants are provided. The catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to C₂₊ hydrocarbons. Related methods for use and manufacture of the same are also disclosed.

This invention relates to a process for the aromatization of C₆ to C₁₂ alkanes, such as hexane, heptane and octane, to aromatics, such as benzene, ethyl benzene, toluene and xylenes, with a germanium-containing zeolite catalyst. The catalyst is a non-acidic aluminum-silicon-germanium zeolite on which a noble metal, such as platinum, has been deposited. The zeolite structure may be of MFI, BEA, MOR, LTL or MTT. The zeolite is made non-acidic by being base-exchanged with an alkali metal or alkaline earth metal, such as cesium, potassium, sodium, rubidium, barium, calcium, magnesium and mixtures thereof, to reduce acidity. The catalyst is sulfur tolerant and may be pretreated with a sulfur compound, i.e., sulfided. The hydrocarbon feed may contain sulfur up to 1000 ppm. The present invention could be applicable to a feedstream which is predominantly paraffinic and/or low in naphthenes. Lowering the hydrogen to hydrocarbon ratio increases conversion and aromatics selectivity.

Provided is a method of preparing a ZSM-5 catalyst for preparing light olefins including ethylene and propylene through a catalytic cracking of a hydrocarbon mixture of C4 to C7 produced after a naphtha cracking. The method includes (a) forming a gel by aging a mixture solution including a silica precursor and an aluminum precursor; (b) adding a template possibly forming mesopores through a heat treatment, into the gel, stirring and then aging; (c) forming a solid product by crystallizing the aged mixture in step (b); and (d) heat treating the solid product to remove the template. The ZSM-5 catalyst may include micropores and mesopores and may have good physical and chemical properties along with a good pore property. The production yield of the light olefins may be increased.

The present invention provides a process for producing lower olefins by catalytic cracking a feedstock comprising an olefins-enriched mixture containing C4 or higher olefins and optionally an organic oxygenate compound. The technical problem mainly addressed in the present invention is to overcome the defects presented in the prior art including low yield and selectivity of lower olefins as the target products, and short regeneration period of catalyst. The present process, which is carried out under the conditions of catalytic cracking olefins and adopts as a feedstock an olefins-enriched mixture containing one or more C4 or higher olefins and optionally an organic oxygenate compound, comprises the steps of: a) letting the feedstock firstly enter a first reaction zone to contact with a first crystalline aluminosilicate catalyst having a SiO₂/Al₂O₃ molar ratio of at least 10, to thereby produce a first reaction effluent containing lower olefins; b) letting the first reaction effluent enter in turn at least one second reaction zone to contact with a second crystalline aluminosilicate catalyst having a SiO₂/Al₂O₃ molar ratio of at least 10, to thereby produce a second reaction effluent containing lower olefins; and c) separating lower olefins from the second reaction effluent; wherein the reaction temperatures in the first and second reaction zones are controlled. The present process, which desirably solves the above technical problem, can be used in industrial production of lower olefins.

Hydrocarbon or oxygenate conversion process in which a feedstock is contacted with a non zeolitic molecular sieve which has been treated to remove most, if not all, of the halogen contained in the catalyst. The halogen may be removed by one of several methods. One method includes heating the catalyst in a low moisture environment, followed by contacting the heated catalyst with air and/or steam. Another method includes steam-treating the catalyst at a temperature from 400° C. to 1000° C. The hydrocarbon or oxygenate conversion processes include the conversion of oxygenates to olefins, the conversion of oxygenates and ammonia to alkylamines, the conversion of oxygenates and aromatic compounds to alkylated aromatic compounds, cracking and dewaxing.

The average cycle propylene selectivity of an oxygenate to propylene (OTP) process using one or more fixed or moving beds of a dual-function oxygenate conversion catalyst with recycle of one or more C₄⁺ olefin-rich fractions is substantially enhanced by the use of selective hydrotreating technology on these C₄⁺ olefin-rich recycle streams to substantially eliminate detrimental coke precursors such as dienes and acetylenic hydrocarbons. This hydrotreating step helps hold the build-up of detrimental coke deposits on the catalyst to a level which does not substantially degrade dual-function catalyst activity, oxygenate conversion and propylene selectivity, thereby enabling a substantial improvement in propylene average cycle yield. The propylene average cycle yield improvement enabled by the present invention over that achieved by the prior art using the same or a similar catalyst system but without the use of the hydrotreating step on the C₄⁺ olefin-rich recycle stream is of the order of about 1.5 to 5.5 wt-% or more.

A system and process for producing olefins from oxygenate, e.g., methanol or dimethylether, includes a fluidized bed reaction zone that provide contact between the oxygenate and a molecular sieve catalyst such as ZSM-34 or SAPO-34. Improved ethylene selectivity is realized when the oxygenate is stagewise injected into the fluidized bed at one or more locations along the axial direction of the fluidized bed reaction zone.