摘要:
Described are SCR catalyst systems comprising a first SCR catalyst composition and a second SCR catalyst composition arranged in the system, the first SCR catalyst composition promoting higher N2 formation and lower N2O formation than the second SCR catalyst composition, and the second SCR catalyst composition having a different composition than the first SCR catalyst composition, the second SCR catalyst composition promoting lower N2 formation and higher N2O formation than the first SCR catalyst composition. The SCR catalyst systems are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.
摘要:
An alkylation catalyst having a zeolite catalyst component and a binder component providing mechanical support for the zeolite catalyst component is disclosed. The binder component is an ion-modified binder that can include metal ions selected from the group consisting of Co, Mn, Ti, Zr, V, Nb, K, Cs, Ga, B, P, Rb, Ag, Na, Cu, Mg, Fe, Mo, Ce, and combinations thereof. The metal ions reduce the number of acid sites on the zeolite catalyst component. The metal ions can range from 0.1 to 50 wt % based on the total weight of the ion-modified binder. Optionally, the ion-modified binder is present in amounts ranging from 1 to 80 wt % based on the total weight of the catalyst.
摘要:
The present invention relates to a catalytic wall-flow monolith for use in an emission treatment system, the monolith comprising a porous substrate and having a first face and a second face defining a longitudinal direction therebetween and first and second pluralities of channels extending in the longitudinal direction, the first plurality of channels provides a first plurality of inner surfaces and is open at the first face and closed at the second face, and the second plurality of channels is open at the second face and closed at the first face, a first catalytic material is distributed within the porous substrate, a microporous membrane is provided in the first plurality of channels on a first portion, extending in the longitudinal direction, of the first plurality of inner surfaces, and the first portion extends from the first face for 75 to 95% of a length of the first plurality of channels.
摘要:
An alkylation catalyst having a zeolite catalyst component and a binder component providing mechanical support for the zeolite catalyst component is disclosed. The binder component is an ion-modified binder that can include metal ions selected from the group consisting of Co, Mn, Ti, Zr, V, Nb, K, Cs, Ga, B, P, Rb, Ag, Na, Cu, Mg, Fe, Mo, Ce, and combinations thereof. The metal ions reduce the number of acid sites on the zeolite catalyst component. The metal ions can range from 0.1 to 50 wt % based on the total weight of the ion-modified binder. Optionally, the ion-modified binder is present in amounts ranging from 1 to 80 wt % based on the total weight of the catalyst.
摘要:
There is provided a zeolite bound zeolite catalyst which can be tailored to optimize its performance and a process for converting hydrocarbons utilizing the zeolite bound zeolite catalyst. The zeolite bound zeolite catalyst comprises a first zeolite and a binder comprising a second zeolite. The structure type of the second zeolite is different from the structure type of the first zeolite. The zeolite bound zeolite finds particular application in hydrocarbon conversion process, e.g., catalytic cracking, alkylation, disproportional of toluene, isomerization, and transalkylation reactions.
摘要:
A method for producing a polyoxyalkylene glycol by ring opening polymerization of a cyclic ether, wherein a zeolite (other than ZSM-5, ZSM-11 and Nu-5) is used as a catalyst.
摘要:
Silica-bound extruded zeolites may be converted into binder-free zeolite aggregates by aging the zeolite in an aqueous ionic solution which contains hydroxy ions such that the initial molar ratio of OH-:SiO.sub.2 is up to 1.2 and which causes the silica binder to be converted substantially to zeolite of the type initially bound. Such extrudates have excellent mechanical strength and show advantageous properties such as adsorption comparable with non-extruded zeolite powder.
摘要:
Zeolite L in very small crystalline form is prepared by a process in which an alkaline reaction mixture comprising water, a source of silicon (SiO.sub.2), a source of alkali metal (M) (KOH) and a source of aluminium (Al.sub.2 O.sub.3.3H.sub.2 O) or gallium is heated to a temperature of at least 80.degree. C. for a period of time long enough to form zeolite L, the composition of the reaction mixture having the following molar ratios (expressed as oxides):______________________________________ M.sub.2 O/SiO.sub.2 0.4 to 0.5 H.sub.2 O/M.sub.2 O 15 to 30 and SiO.sub.2 /Al.sub.2 O.sub.3 or Ga.sub.2 O.sub.3 5 to 11 ______________________________________ where M is potassium or a mixture of potassium and one or more other alkali metals.
摘要:
The cracking catalyst of the invention contains:(a) 20-95% by weight of at least one matrix, selected from the group consisting of alumina, silica, magnesia, clay, titanium oxide, zirconia, combinations of at least two of these compounds and alumina-boron oxide combinations,(b) 1-60% by weight of at least one zeolite of open structure whose main dodecagonal channels have openings of at least 7 Angstroms, said zeolite of open structure being selected from the group formed of X, Y, L, omega and beta zeolites,(c) 0.5-60% by weight of at least one offretite whose main dodecagonal channels have openings smaller than 7 Angstroms and which have a SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio from about 15 to about 500, the crystalline paramaters a and c of elementary mesh ranging respectively from 1.285 to 1.315 nm for a and from 0.748 to 0.757 nm for c and have a potassium content lower than 1.5% by weight.