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 invention provides a magnesium-modified ultra-stable rare earth type Y molecular sieve and the preparation method thereof, which method is carried out by subjecting a NaY molecular sieve as the raw material to a rare earth exchange and a dispersing pre-exchange, then to an ultra-stabilization calcination treatment, and finally to a magnesium modification. The molecular sieve comprises 0.2 to 5% by weight of magnesium oxide, 1 to 20% by weight of rare earth oxide, and not more than 1.2% by weight of sodium oxide, and has a crystallinity of 46 to 63%, and a lattice parameter of 2.454 nm to 2.471 nm. In contrast to the prior art, in the molecular sieve prepared by this method, rare earth ions are located in sodalite cages, which is demonstrated by the fact that no rare earth ion is lost during the reverse exchange process. Moreover, the molecular sieve prepared by such a method has a molecular particle size D(v,0.5) of not more than 3.0 μm and a D(v,0.9) of not more than 20 μm. Such a molecular sieve has both high stability and high selectivity for the target product, while cracking catalysts using the molecular sieve as an active component is characterized by a high heavy-oil-conversion capacity and a high yield of valuable target products.

The present invention relates to a catalyst for preparing a light olefin, a preparation method therefor, and a method for preparing a light olefin by using same, and can provide a catalyst for preparing a light olefin, a preparation method therefor, and a method for preparing a light olefin by using same, the catalyst comprising a porous zeolite, a clay, an inorganic oxide binder, and Ag.sub.2O and P.sub.2O.sub.5 which are supported in the pores and/or on the surface of the porous zeolite.

The present invention relates to a catalyst for preparing a light olefin, a preparation method therefor, and a method for preparing a light olefin by using same, and can provide a catalyst for preparing a light olefin, a preparation method therefor, and a method for preparing a light olefin by using same, the catalyst comprising a porous zeolite, a clay, an inorganic oxide binder, and Ag.sub.2O and P.sub.2O.sub.5 which are supported in the pores and/or on the surface of the porous zeolite.

A family of new crystalline molecular sieves designated SSZ-91 is disclosed, as are methods for making SSZ-91 and uses for SSZ-91. Molecular sieve SSZ-91 is structurally similar to sieves falling within the ZSM-48 family of molecular sieves, and is characterized as: (1) having a low degree of faulting, (2) a low aspect ratio that inhibits hydrocracking as compared to conventional ZSM-48 materials having an aspect ratio of greater than 8, and (3) is substantially phase pure.

A method for producing a catalyst or catalyst precursor is described including: applying a slurry of a particulate catalyst compound in a carrier fluid to an additive layer manufactured support structure to form a slurry-impregnated support, and drying and optionally calcining the slurry-impregnated support to form a catalyst or catalyst precursor. The mean particle size (D50) of the particulate catalyst compound in the slurry is in the range 1-50 μm and the support structure has a porosity ≧0.02 ml/g.

A method for producing a catalyst or catalyst precursor is described including: applying a slurry of a particulate catalyst compound in a carrier fluid to an additive layer manufactured support structure to form a slurry-impregnated support, and drying and optionally calcining the slurry-impregnated support to form a catalyst or catalyst precursor. The mean particle size (D50) of the particulate catalyst compound in the slurry is in the range 1-50 μm and the support structure has a porosity ≧0.02 ml/g.

The present invention provides a photocatalyst particle comprising titanium dioxide particles, a zeolite particle, and a carbon layer. The titanium dioxide particles are adsorbed on a part of an external surface of the zeolite particle. The carbon layer coats a part of an external surface of the zeolite particle other than the part of the external surface of the zeolite particle on which the titanium dioxide particles are adsorbed. The carbon layer is in contact with a part of surfaces of the titanium dioxide particles. At least a part of the other part of the surfaces of the titanium dioxide particles is not coated with the carbon layer and are exposed on a surface of the photocatalyst particle. The present invention provides a photocatalyst particle used even in an alkaline aqueous solution.

A method for preparing a molecular sieve SCR (selective catalytic reduction) catalyst and a prepared catalyst therethrough. In the method, several molecular sieves are mixed and modified by transition metal or rare-earth metal via ion exchange, then loaded Fe by equivalent-volume impregnation, and loaded Cu by one or more liquid ion exchange. This present invention, combined with several techniques, such as modification of stable molecular sieve by transition and rare-earth metal, Fe loading by equivalent-volume impregnation and Cu loading by one or more liquid ion exchange, and after through stable and effective modification and loading control, the obtained catalyst material is coated on a carrier substrate via size mixing and coating process to be prepared into an integral catalyst.

A method for preparing a molecular sieve SCR (selective catalytic reduction) catalyst and a prepared catalyst therethrough. In the method, several molecular sieves are mixed and modified by transition metal or rare-earth metal via ion exchange, then loaded Fe by equivalent-volume impregnation, and loaded Cu by one or more liquid ion exchange. This present invention, combined with several techniques, such as modification of stable molecular sieve by transition and rare-earth metal, Fe loading by equivalent-volume impregnation and Cu loading by one or more liquid ion exchange, and after through stable and effective modification and loading control, the obtained catalyst material is coated on a carrier substrate via size mixing and coating process to be prepared into an integral catalyst.