Alkylation systems and methods of minimizing alkylation catalyst regeneration are described herein. The alkylation systems generally include a preliminary alkylation system adapted to receive an input stream including an alkyl aromatic hydrocarbon and contact the input stream with a preliminary alkylation catalyst disposed therein to form a first output stream. The preliminary alkylation catalyst generally includes a zeolite catalyst having a SiO.sub.2/Al.sub.2O.sub.3 ratio of less than about 25. The alkylation systems further include a first alkylation system adapted to receive the first output stream and contact the first output stream with a first alkylation catalyst disposed therein and an alkylating agent to form a second output stream.

In a process for producing methyl-substituted biphenyl compounds, a feed comprising at least one aromatic hydrocarbon selected from the group consisting of toluene, xylene and mixtures thereof is contacted with hydrogen in the presence of a hydroalkylation catalyst under conditions effective to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluenes and/or (dimethylcyclohexyl)xylenes together with dialkylated C.sub.21+ compounds. At least part of the dialkylated C.sub.21+ compounds is then removed from the hydroalkylation reaction product to produce a dehydrogenation feed; and at least part of the dehydrogenation feed is dehydrogenated in the presence of a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575 C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.

The present invention provides a method for directly producing lactide by subjecting lactic acid to a dehydration reaction in the presence of a catalyst comprising a tin compound, preferably, a tin (IV) compound, wherein lactide can be produced directly or by one step from lactic acid, without going through the step of producing or separating lactic acid oligomer. The method of the present invention has advantages of causing no loss of lactic acid, having a high conversion ratio to lactic acid and a high selectivity to optically pure lactide, and maintaining a long life time of the catalyst. Further, since lactic acid oligomer is not or hardly generated and the selectivity of meso-lactide is low, the method also has an advantage that the cost for removing or purifying this can be saved.

An oxidation catalyst composite, methods, and systems for the treatment of exhaust gas emissions from a diesel engine are described. More particularly, described is an oxidation catalyst composite including a first oxidation component comprising a first refractory metal oxide support, palladium (Pd) and platinum (Pt); a NO.sub.x storage component comprising one or more of alumina, silica, titania, ceria, or manganese; and a second oxidation component comprising a second refractory metal oxide, a zeolite, and Pt. The oxidation catalyst composite is sulfur tolerant, adsorbs NO.sub.x and thermally releases the stored NO.sub.x at temperature less than 350 C.

Described herein are zeolite catalysts, methods of producing same, and methods of using same. The zeolite catalysts are particularly useful for producing liquefied petroleum gas (LPG).

Provided herein are methods for hydroisomerization of a hydrocarbon feedstock comprising contacting the hydrocarbon feedstock with hydrogen and a catalyst to yield a hydrocarbon product having an increase in branched hydrocarbons relative to the hydrocarbon feedstock. The present catalysts comprise a heteroatom-doped Beta zeolite having a trivalent cation as a framework metal oxide, an extra-framework species comprised of cerium and/or cobalt, and from 0.01 to 1.5 wt. % of a group VIII or VIB metal, or a combination thereof.

The present disclosure is directed to methods of and catalyst systems for converting natural gasoline liquid (NGL) feed to light olefins. The catalyst systems are capable of catalyzing both catalytic cracking and dehydrogenation processes. The catalyst systems include a metal-substituted zeolite comprising a MFI-type and/or a BEA-type framework comprising 0.5 wt. % to 30 wt. % cerium and/or vanadium atoms based on a total weight of the metal-substituted zeolite. The methods include contacting the NGL feed with the catalyst system in a reactor system, thereby converting a portion of the NGL feed to the light olefins and yielding a product stream comprising the light olefins.

Embodiments are directed towards a process for producing a (poly)alkylene glycol monoalkyl ether. The process includes providing an admixture of a crystalline metallosilicate molecular sieve catalyst and an oxide of a metal and reacting in a liquid phase process an olefin and a (poly)alkylene glycol in the presence of the admixture to yield the (poly)alkylene glycol monoalkyl ether. Reacting the olefin and the (poly)alkylene glycol in the presence of the admixture is at a temperature of 80 C. to 200 C.

Disclosed herein is a fluid catalyst cracking (FCC) catalyst composition that includes a first component and a second component. The first component includes zeolite Y and a first matrix that includes a metal passivating constituent. The second component includes beta zeolite and a second matrix. Also disclosed herein are methods of preparing the FCC catalyst composition and method of using the FCC catalyst composition.