Embodiments of catalyst systems and methods of synthesizing catalyst systems are provided. The catalyst system may include a core comprising a zeolite; and a shell comprising a microporous fibrous silica. The shell may be in direct contact with at least a majority of an outer surface of the core. The catalyst system may have a Si/Al molar ratio greater than 5. At least a portion of the shell may have a thickness of from 50 nanometers (nm) to 360 nm.

The present invention is a process for dehydrating an alcohol to prepare a corresponding olefin, comprising: (a) providing a composition (A) comprising at least an alcohol having at least 2 carbon atoms, optionally water, optionally an inert component, in a dehydration unit, (b) placing the composition (A) into contact with an acidic catalyst in a reaction zone of said dehydration unit at conditions effective to dehydrate at least a portion of the alcohol to make a corresponding olefin, (c) recovering from said dehydration unit an effluent (B) comprising : at least an olefin, water, undesired by-products including aldehydes and light products, optionally unconverted alcohol(s), optionally the inert component,
wherein, said composition (A)-providing step (a) comprises adding an effective amount of one or more sulfur containing compound capable to reduce the undesired by-products by comparison with a non introduction of such sulfur containing compound.

The component introduced at step (a) can be chosen from the group consisting of thiols, sulfides, disulfides.

The present disclosure relates to the technical field of industrial waste gas purification, in particular to a core-shell structured catalyst, a preparation method and use thereof. The present disclosure provides a core-shell structured catalyst including a metal oxide-molecular sieve as a core and porous silica (SiO.sub.2) as a shell, where the metal oxide-molecular sieve includes a molecular sieve and a metal oxide loaded on the molecular sieve, the metal oxide includes an oxide of a first metal and an oxide of a second metal, the first metal is Fe, Cu, Ti, Ni or Mn, and the second metal is Ce or La. The core-shell structured catalyst of the present disclosure can enable effective removal of HCN and AsH.sub.3 at the same time with a stable effect, and no secondary pollution.

A catalyst system for dewaxing of a hydrocarbon feedstock comprising at least two catalytic sections, the first section comprising a first dewaxing catalyst and a subsequent section comprising a second dewaxing catalyst, wherein the first dewaxing catalyst is a ZSM-12 zeolite based catalyst and the second dewaxing catalyst is a EU-2 and/or ZSM-48 zeolite based catalyst. The catalyst system displays enhanced performance when compared to systems containing either ony ZSM-12 based catalyst or EU-2/ZSM-48 based catalyst only.

An integrated process for conversion of a hydrocarbon stream comprising light naphtha to enhanced value products. The process includes passing the hydrocarbon stream through a first reactor, the first reactor being a catalytic bed reactor with a dual-function catalyst to simultaneously reform light naphtha to BTEX and crack light naphtha to ethane, propane, and butanes. Further, the process includes passing an effluent of the first reactor to a gas-liquid separating unit to generate a liquid stream and a gas stream, and passing the gas stream to a gas separator unit to remove hydrogen gas and methane and generate an enhanced gas stream. The process further includes passing the enhanced gas stream through a second reactor, the second reactor being a pyrolysis unit operated at steam cracking conditions to convert ethane, propane, and butanes in the enhanced gas stream to light. An associated system for performing the process is also provided wherein the integrated process does not include passage of a process stream to a separate and independent hydrocracking unit to crack light alkanes in the hydrocarbon stream to smaller alkanes.

A skeletal isomerization process for isomerizing olefins is described. The process includes the steps of feeding an olefin-containing feed to a reactor at a space velocity of 1-100 hr.sup.−1 for a first period of time at a first temperature, followed by discontinuing, or stopping, the olefin-containing feed for a second period of time while maintaining the reactor at a second temperature, before resuming the flow of the olefin-containing feed for a third period of time. The methods of this disclosure increase the yield of the skeletal isomers product while reducing the production of C5+ heavy olefins. Additionally, the methods of this disclosure can be applied to feeds containing iso-olefins (for the production of linear olefins) or linear olefins (for the production of iso-olefins).

An integrated process for conversion of a hydrocarbon stream comprising light naphtha to enhanced value products. The process includes passing the hydrocarbon stream through a first reactor, the first reactor being a catalytic bed reactor with a dual-function catalyst to simultaneously reform light naphtha to BTEX and crack light naphtha to ethane, propane, and butanes. Further, the process includes passing an effluent of the first reactor to a gas-liquid separating unit to generate a liquid stream and a gas stream, and passing the gas stream to a gas separator unit to remove hydrogen gas and methane and generate an enhanced gas stream. The process further includes passing the enhanced gas stream through a second reactor, the second reactor being a pyrolysis unit operated at steam cracking conditions to convert ethane, propane, and butanes in the enhanced gas stream to light. An associated system for performing the process is also provided wherein the integrated process does not include passage of a process stream to a separate and independent hydrocracking unit to crack light alkanes in the hydrocarbon stream to smaller alkanes.

Embodiments of the present disclosure are directed to a method of producing an encapsulated hydroprocessing catalyst comprising: preparing a hydroprocessing catalyst comprising a porous support and at least one metal supported on the porous support, the porous support comprising alumina, silica, titania, or combinations thereof, and the at least one metal selected from IUPAC Groups 6, 9 and 10 metals; applying a catalyst activation precursor comprising a sulfur containing compound, a catalyst deactivation precursor comprising a nitrogen containing compound, or both onto pores of the hydroprocessing catalyst to form a loaded hydroprocessing catalyst; and coating the loaded hydroprocessing catalyst with a coating material to produce the encapsulated hydroprocessing catalyst, wherein the coating material comprises a polymer or a paraffinic oil.

Embodiments of the present disclosure are directed to a coated hydroprocessing catalyst comprising: a hydroprocessing catalyst comprising a porous support and at least one metal supported on the porous support; wherein the porous support comprising silica, alumina, titania, or combinations thereof; and the at least one metal selected from IUPAC Groups 6, 9 and 10 metals; a catalyst activation agent, a catalyst deactivation agent, or both loaded onto pores of the porous support, the catalyst activation agent comprising at least one sulfur compound and the catalyst deactivation agent comprising at least one nitrogen compound; and a coating layer on a surface of the hydroprocessing catalyst, the coating layer encapsulating the catalyst activation agent, the catalyst deactivation agent, or both within the hydroprocessing catalyst, wherein the coating layer comprises a polymer, or a paraffinic oil.

Embodiments of the present disclosure are directed towards methods of etherification including modifying a zeolite catalyst with silica to provide a silica modified zeolite catalyst; and contacting the silica modified zeolite catalyst with an olefin and an alcohol to produce a monoalkyl ether.