The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 2 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing a regeneration loop for the inert gas and at least one regeneration loop for the gas streams comprising oxygen.

A system and method for coproduction in the production of ethylene, including contacting ethane with an oxidative dehydrogenation (ODH) catalyst in presence of oxygen in a first reactor to dehydrogenate ethane to ethylene, and contacting a first-reactor effluent with an ODH catalyst in a second reactor to form ethanol and acetaldehyde.

Provided in this disclosure are catalyst compositions. The catalyst compositions include an oxidative dehydrogenation catalyst that includes a mixed metal oxide having the empirical formula:
Mo.sub.1.0V.sub.0.12-0.49Te.sub.0.05-0.17Nb.sub.0.10-0.20Al.sub.cO.sub.d
wherein c is from 0 to 2.0 and d is a number to satisfy the valence of the oxide. The compositions are at least 40 wt. % amorphous as measured by XRD. The disclosure also provides methods of making the compositions.

Disclosed is a method for preparing aromatic hydrocarbons by hydrocracking a polymer containing aromatic rings, which includes reacting the polymer fragment with hydrogen under the action of a catalyst at a temperature of no more than 350° C.; separating a reaction product to obtain the aromatic hydrocarbons. The catalyst comprises a carrier and an active ingredient supported on the carrier, the active ingredient is at least one selected from Ru, Rh, Pt, Pd, Fe, Ni, Cu and Co, the carrier is at least one selected from metal oxide, phosphate, molecular sieve, SiO.sub.2 and sulfonated carbon, the metal oxide is at least one selected from Al.sub.2O.sub.3, Nb.sub.2O.sub.5, Nb.sub.2O.sub.5—Al.sub.2O.sub.3, Nb.sub.2O.sub.5—SiO.sub.2, TiO.sub.2, ZrO.sub.2, CeO.sub.2 and MoO.sub.3; the phosphate is at least one selected from NbOPO.sub.4 and ZrOPO.sub.4; and the molecule sieve is at least one selected from Nb-SBA-15, Nafion, H-ZSM-5, H-Beta and H-Y.

A method for making a supported tantalum oxide catalyst precursor or catalyst with controlled Ta distribution and the resulting supported Ta catalyst. In an embodiment, the method comprises selecting a Ta-precursor with appropriate reactivity with the surface hydroxyls of the solid oxide support material to give a desired Ta distribution in the catalyst precursor or catalyst. In an embodiment the method comprises controlling the number of surface hydroxyls available on the support material to react with the Ta-precursor by thermal methods, such as calcination, to achieve the desired Ta distribution.

Provided in this disclosure is a process for the oxidative dehydrogenation of a lower alkane into a corresponding alkene. The process includes providing a gas stream comprising the lower alkane to a reactor; contacting, in the oxidative dehydrogenation reactor, the lower alkane with a catalyst that includes a mixed metal oxide; and providing to the last 50% of the oxidative dehydrogenation reactor a stream comprising from 0.01 vol. % to 10 vol. % of a C.sub.1-C.sub.3 alcohol.

The invention concerns a catalyst comprising at least the element tantalum, and at least one mesoporous oxide matrix that has undergone an acid wash comprising at least 90% by weight of silica before washing, the mass of the element tantalum being in the range 0.1% to 30% of the mass of said mesoporous oxide matrix.

Provided in this disclosure is a process for the oxidative dehydrogenation of a lower alkane into a corresponding alkene. The process includes providing a gas stream comprising the lower alkane to a reactor; contacting, in the oxidative dehydrogenation reactor, the lower alkane with a catalyst that includes a mixed metal oxide; and providing to the last 50% of the oxidative dehydrogenation reactor a stream comprising from 0.01 vol. % to 10 vol. % of a C.sub.1-C.sub.3 alcohol.

The invention relates to a process for treatment of a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium, comprising contacting a gas stream comprising methane, an inert gas or oxygen or any combination of two or more of these with the catalyst, wherein said gas stream comprises 0 to 25 vol. % of an alkane containing 2 to 6 carbon atoms and/or alkene containing 2 to 6 carbon atoms.

Oxidative dehydrogenation catalysts comprising MoVNbTeO having improved consistency of composition and a 25% conversion of ethylene at less than 420° C. and a selectivity to ethylene above 95% are prepared by treating the catalyst precursor with H.sub.2O.sub.2 in an amount equivalent to 0.30-2.8 mL H.sub.2O.sub.2 of a 30% solution per gram of catalyst precursor prior to calcining.