Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.

Systems and methods for processing a C.sub.3 and C.sub.4 hydrocarbon mixture have been disclosed. The C.sub.3 and C.sub.4 hydrocarbon mixture is separated to remove propane from C.sub.4 hydrocarbons. The resulting C.sub.4 hydrocarbons are then processed in an isomerization unit to produce additional isobutane. The isobutane of the isomerization unit effluent is dehydrogenated in a dehydrogenation unit to produce isobutene. The resulting isobutene is reacted with an alkanol to produce an alkyl tert-butyl ether.

Tungstated zirconium catalysts for paraffin isomerization may comprise: a mixed metal oxide that is at least partially crystalline and comprises tungsten, zirconium, and a variable oxidation state metal selected from Fe, Mn, Co, Cu, Ce, Ni, and any combination thereof. The mixed metal oxide comprises about 5 wt. % to about 25 wt. % tungsten, about 40 wt. % to about 70 wt. % zirconium, and about 0.01 wt. % to about 5 wt. % variable oxidation state metal, each based on a total mass of the mixed metal oxide. The mixed metal oxide has a total surface area of about 50 m.sup.2/g or greater as measured according to ISO 9277, and at least one of the following: an ammonia uptake of about 0.05 to about 0.3 mmol/g as measured by temperature programmed adsorption/desorption, or a collidine uptake of about 100 μmol/g or greater as measured gravimetrically.

According to one or more embodiments described herein, a method for dehydrogenating hydrocarbons may include passing a hydrocarbon feed comprising one or more alkanes or alkyl aromatics into a fluidized bed reactor, contacting the hydrocarbon feed with a dehydrogenation catalyst in the fluidized bed reactor to produce a dehydrogenated product and hydrogen, and contacting the hydrogen with an oxygen-rich oxygen carrier material in the fluidized bed reactor to combust the hydrogen and form an oxygen-diminished oxygen carrier material. In additional embodiments, a dual-purpose material may be utilized which has dehydrogenation catalyst and oxygen carrying functionality.

The present disclosure provides a modified catalyst, and preparation method and a method for producing aromatic hydrocarbons by aromatization of olefins using the modified catalyst. The modified catalyst comprises an acidic molecular sieve and an olefin aromatization active metal component, the total acid amount of the catalyst as measured by NH.sub.3-TPD method is not higher than 0.35 mmol/g, and ratio of the strong acid to weak acid is within a range of 0.8-1.2.

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

A process for producing propylene involves dehydration of isopropanol. The dehydration process includes a step of subjecting a starting material containing isopropanol to a dehydration reaction in the presence of a dehydration catalyst comprising alumina to produce a product containing propylene. The starting material has a water content of 0.1 to 10.0 wt % (relative to 100 wt % of the total mass of the starting material), and the product has a total content of C2 unsaturated impurities and C3-C4 unsaturated impurities of 80 ppm or less (relative to 100 wt % of the total mass of the product).

Provided is a method capable of producing an olefin with high selectivity and high yield using a vicinal diol as a raw material. A method for producing an olefin includes a step of reacting a compound including two adjacent carbon atoms each containing a hydroxy group with hydrogen and forming an olefin, and in this step, the reaction of the compound including two adjacent carbon atoms each containing a hydroxy group with the hydrogen proceeds in the presence of a catalyst under a condition substantially free of a solvent. The catalyst includes a carrier, at least one oxide supported on the carrier and selected from the group consisting of oxides of group-6 elements and oxides of group-7 elements, and at least one metal supported on the carrier and selected from the group consisting of silver, iridium, and gold.

Provided in this disclosure are oxidative dehydrogenation catalysts that include a mixed metal oxide having the empirical formula:

Mo.sub.1.0V.sub.0.12-0.49Te.sub.0.05-0.17Nb.sub.0.10-0.20O.sub.d

wherein d is a number to satisfy the valence of the oxide. The oxidative dehydrogenation catalyst is characterized by having XRD diffraction peaks (2θ degrees) at 22±0.2, 27±0.2, 28.0±0.2, and 28.3±0.1. The disclosure also provides methods of making the catalysts that include wet ball milling.

Processes for cracking an alkane reactant to form a lower aliphatic hydrocarbon product and for converting an alkane reactant into a higher aliphatic hydrocarbon product are disclosed, and these processes include a step of contacting the alkane reactant with a supported chromium (II) catalyst. In addition to the formation of various aliphatic hydrocarbons, such as linear alkanes, branched alkanes, 1-alkenes, and internal alkenes, aromatic hydrocarbons and hydrogen also can be produced.