A process for dehydrating methanol to dimethyl ether using a Brønsted acid catalyst which is a 1-dimensional or a 3-dimensional aluminosilicate zeolite or a heteropolyacid, and a promoter of Formula I C.sub.nH.sub.(2n+1)CO.sub.2CH.sub.3 wherein n=1 to 11 or Formula II C.sub.mH.sub.2m(CO.sub.2CH.sub.3).sub.2 wherein m=2 to 7 and the molar ratio of promoter to methanol is maintained at less than 1.

A process for dehydrating methanol to dimethyl ether product in the presence of a solid Brønsted acid catalyst which is an aluminosilicate zeolite or a heteropolyacid and a promoter which is (i) a ketone of formula R.sup.1COR.sup.2 (Formula I) in which R.sup.1 and R.sup.2 are identical or different and are each a C.sub.1-C.sub.11 alkyl group and furthermore R.sup.1 and R.sup.2 together with the carbonyl carbon atom to which they are bonded may form a cyclic ketone; or (ii) a ketal derivative of a ketone of Formula I; and the molar ratio of promoter to methanol is maintained at 0.5 or less.

A process for dehydrating methanol to dimethyl ether product in the presence of a solid Brønsted acid catalyst which is an aluminosilicate zeolite or a heteropolyacid and a promoter which is (i) a ketone of formula R.sup.1COR.sup.2 (Formula I) in which R.sup.1 and R.sup.2 are identical or different and are each a C.sub.1-C.sub.11 alkyl group and furthermore R.sup.1 and R.sup.2 together with the carbonyl carbon atom to which they are bonded may form a cyclic ketone; or (ii) a ketal derivative of a ketone of Formula I; and the molar ratio of promoter to methanol is maintained at 0.5 or less.

A catalyst for synthesizing aromatic hydrocarbons, a preparation method thereof and a method for synthesizing aromatic hydrocarbons by using the catalyst. The catalyst comprises acidic molecular sieve particles and zinc-aluminum composite oxide particles. The catalyst has relatively high selectivity to aromatic hydrocarbons, particularly BTX, stable performance, and a long single-pass life.

A catalyst for synthesizing aromatic hydrocarbons, a preparation method thereof and a method for synthesizing aromatic hydrocarbons by using the catalyst. The catalyst comprises acidic molecular sieve particles and zinc-aluminum composite oxide particles. The catalyst has relatively high selectivity to aromatic hydrocarbons, particularly BTX, stable performance, and a long single-pass life.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present invention provides a method for preparing acrylic acid and methyl acrylate. The method comprises passing the feed gas containing dimethoxymethane and carbon monoxide through a solid acid catalyst to generate acrylic acid and methyl acrylate with a high conversion rate and selectivity at a reaction temperature in a range from 180 to 400 and a reaction pressure in a range from 0.1 MPa to 15.0 MPa, the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.05 h.sup.−1 to 10.0 h.sup.−1, and the volume percentage of dimethoxymethane in the feed gas is in a range from 0.1% to 95%.

The present invention provides a method for preparing acrylic acid and methyl acrylate. The method comprises passing the feed gas containing dimethoxymethane and carbon monoxide through a solid acid catalyst to generate acrylic acid and methyl acrylate with a high conversion rate and selectivity at a reaction temperature in a range from 180 to 400 and a reaction pressure in a range from 0.1 MPa to 15.0 MPa, the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.05 h.sup.−1 to 10.0 h.sup.−1, and the volume percentage of dimethoxymethane in the feed gas is in a range from 0.1% to 95%.

The present disclosure generally provides selective catalytic reduction (SCR) catalyst compositions, catalyst articles and catalyst systems including such catalyst articles for treating engine exhaust gas. In particular, the SCR catalyst composition includes a first zeolite and a second zeolite and has not been subjected to temperatures above 650° C. The first zeolite includes a promoter metal and has a first framework structure and at least a portion of the second zeolite is in a form selected from H.sup.+ form, NH.sub.4.sup.+ form, alkali metal form, alkaline earth metal form, and combinations thereof and has a second framework structure. The first framework structure and the second framework structure are different.

A modified UZM-14 zeolite is described. The modified UZM-14 zeolite has a Modification Factor of 6 or more. The modified UZM-14 zeolite may have one or more of: a Si/Al.sub.2 ratio of 14 to 30; a total pore volume in a range of 0.5 to 1.0 cc/g; at least 5% of a total pore volume being mesopores having a diameter of 10 nm of less; a cumulative pore volume of micropores and mesopores having a diameter of 100 or less of 0.25 cc/g or more; or a Collidine IR Bronsted acid site distribution greater than or equal to an area of 3/mg for a peak in a range of 1575 to 1700 cm.sup.1 after desorption at 150 C. Processes of making the modified UZM-14 zeolite and transalkylation processes using the modified UZM-14 zeolite are also described.