A process is presented for the treatment of spent catalyst to manage sulfur-containing compounds on the catalyst. The catalyst may be a dehydrogenation catalyst, where sulfur accumulates during a dehydrogenation process. Sulfur compounds are stripped from the spent catalyst and the catalyst may be cooled before a regeneration step. The process includes controlling removal of sulfur compounds from the spent catalyst before regeneration.

Systems and methods are provided for using a high heat capacity gas as at least a portion of the diluent during the regeneration step of a reverse flow reactor process. Instead of using nitrogen or air as the primary diluent gas, CO.sub.2 and/or H.sub.2O can be added as diluent gas for the regeneration step in the reaction cycle. Increasing the heat capacity of the diluent gas provides a reduction in the peak temperature within the reactor relative to the amount of fuel combusted during regeneration. This can allow for a reduction in the volume of diluent used during regeneration and/or an increase in the amount of fuel used. Reducing the volume of diluent can reduce the pressure drop during regeneration, which can provide a corresponding reduction in the amount of compression required for recycle of the diluent. Increasing the amount of fuel can allow for a corresponding increase in the amount of endothermic reaction performed during the reaction step.

A catalyst obtainable by exsolving particles of Ni, Co and/or a mixture of Ni and Co from a perovskite metal oxide of formula (I) (M.sup.1.sub.aM.sup.2.sub.b)(CO.sub.xNi.sub.yM.sup.3.sub.z)O.sub.3, wherein M.sup.1 and M.sup.2 are each independently an alkali earth metal or a rare earth metal, M.sup.3 is Ti or Cr, 0a1, 0b1, 0<a+b1, 0x<1, 0y<1, 0z<1, x+y+z=1 and where at least one of x and y>0. The invention includes methods of converting this catalyst into one or more catalytically active forms. The catalysts and the activated forms of same are useful in the catalysing CO oxidation and/or NO oxidation.

The invention relates to a catalyst material comprising a support, a first metal and a second metal on said support. The first and second metals are in the form of a chemical compound. The first metal is Fe, Co or Ni, and the second metal is selected from the group consisting of Sn, Zn and In. The invention also relates to a process for the preparation of hydrogen cyanide (HCN) from methane (CH.sub.4) and ammonia (NH.sub.3), wherein the methane and ammonia are contacted with a catalyst according to the invention.

The invention relates to a catalyst material comprising a support, a first metal and a second metal on said support. The first and second metals are in the form of a chemical compound. The first metal is Fe, Co or Ni, and the second metal is selected from the group consisting of Sn, Zn and In. The invention also relates to a process for the preparation of hydrogen cyanide (HCN) from methane (CH.sub.4) and ammonia (NH.sub.3), wherein the methane and ammonia are contacted with a catalyst according to the invention.

The invention relates to a method for separating formic acid from a reaction mixture by means of extraction, wherein, in addition to the formic acid, the reaction mixture comprises a polyoxometalate ion of general formula [PMo.sub.xV.sub.yO.sub.40].sup.n as a catalyst and a solvent that dissolves the catalyst, wherein 6x11, 16, x+y=12 and 3<n<10, wherein n, x, and y are each a whole number, wherein the separation occurs via extraction by means of a polar organic extraction agent which extracts the formic acid and the catalyst and which is N-(n-hexadecyl)formamide, N-di-n-acetamide or an N,N-dialkylcarboxamide, wherein the N,N-dialkylcarboxamide forms a phase boundary between the solvent and the extraction agent during mixing with the solvent.

The invention relates to a method for separating formic acid from a reaction mixture by means of extraction, wherein, in addition to the formic acid, the reaction mixture comprises a polyoxometalate ion of general formula [PMo.sub.xV.sub.yO.sub.40].sup.n as a catalyst and a solvent that dissolves the catalyst, wherein 6x11, 16, x+y=12 and 3<n<10, wherein n, x, and y are each a whole number, wherein the separation occurs via extraction by means of a polar organic extraction agent which extracts the formic acid and the catalyst and which is N-(n-hexadecyl)formamide, N-di-n-acetamide or an N,N-dialkylcarboxamide, wherein the N,N-dialkylcarboxamide forms a phase boundary between the solvent and the extraction agent during mixing with the solvent.

Oxidative dehydrogenation of alkanes employs a catalyst, usually a mixed metal oxide, to convert, in the presence of oxygen, a lower alkane into its corresponding alkene. Continuous operation of an oxidative dehydrogenation process may result in a gradual decrease of catalyst activity and or selection, requiring downtime for regeneration. Provided herein is a process for regeneration of an oxidative dehydrogenation catalyst including initiating regeneration by passing a regeneration gas over the catalyst, monitoring regeneration by comparing the oxygen concentration of the regeneration gas before and after being passed over the catalyst, and ceasing regeneration when the oxygen concentration of the regeneration gas after passed over the catalyst is at least 90% of the concentration of the regeneration gas before being passed over the catalyst.

The present disclosure provides an air-soak containing regeneration process reducing its time. The process includes (i) removing surface carbon species from a gallium-based alkane dehydrogenation catalyst in a combustion process in the presence of a fuel gas; (ii) conditioning the gallium-based alkane dehydrogenation catalyst after (i) in air-soak treatment at a temperature of 660 C. to 850 C. with (iii) a flow of oxygen-containing gas having (iv) 0.1 to 100 parts per million by volume (ppmv) of a chlorine source selected from chlorine, a chlorine compound or a combination thereof; and achieving a predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) 10% to 50% sooner in air-soak treatment than that required to achieve the same predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).

The present disclosure provides an air-soak containing regeneration process reducing its time. The process includes (i) removing surface carbon species from a gallium-based alkane dehydrogenation catalyst in a combustion process in the presence of a fuel gas; (ii) conditioning the gallium-based alkane dehydrogenation catalyst after (i) in air-soak treatment at a temperature of 660 C. to 850 C. with (iii) a flow of oxygen-containing gas having (iv) 0.1 to 100 parts per million by volume (ppmv) of a chlorine source selected from chlorine, a chlorine compound or a combination thereof; and achieving a predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) 10% to 50% sooner in air-soak treatment than that required to achieve the same predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).