Systems and methods are provided for performing hydrocarbon reforming within a reverse flow reactor environment (or another reactor environment with flows in opposing directions) while improving management of CO.sub.2 generated during operation of the reactor. The improved management of CO.sub.2 is achieved by making one or more changes to the operation of the reverse flow reactor. The changes can include using an air separation unit to provide an oxygen source with a reduced or minimized content of nitrogen and/or operating the reactor at elevated pressure during the regeneration stage. By operating the regeneration at elevated pressure, a regeneration flue gas can be generated that is enriched in CO.sub.2 at elevated pressure. The CO.sub.2-enriched stream can include primarily water as a contaminant, which can be removed by cooling while substantially maintaining the pressure of the stream. This can facilitate subsequent recovery and use of the CO.sub.2.

Increase propane dehydrogenation activity of a partially deactivated dehydrogenation catalyst by heating the partially deactivated catalyst to a temperature of at least 660° C., conditioning the heated catalyst in an oxygen-containing atmosphere and, optionally, stripping molecular oxygen from the conditioned catalyst.

Increase propane dehydrogenation activity of a partially deactivated dehydrogenation catalyst by heating the partially deactivated catalyst to a temperature of at least 660° C., conditioning the heated catalyst in an oxygen-containing atmosphere and, optionally, stripping molecular oxygen from the conditioned catalyst.

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 4 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing three regeneration loops.

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 catalyst regeneration process for a tar reforming catalyst within a catalyst bed in a tar reformer. The process comprises the steps of:—Admitting a main gas stream with controlled temperature and oxygen content to an inlet into the tar reformer;—Passing the main gas stream through the catalyst bed to form an oxygen depleted gas stream;—Exiting the oxygen depleted gas stream from the tar reformer; and—Recycling at least a part of the oxygen depleted gas stream exiting from the tar reformer back into said main gas stream upstream said tar reformer. The temperature of said main gas stream at the inlet is controlled to be within the range from about 500° C. to about 1000° C.

The invention relates to a catalyst regeneration process for a tar reforming catalyst within a catalyst bed in a tar reformer. The process comprises the steps of:—Admitting a main gas stream with controlled temperature and oxygen content to an inlet into the tar reformer;—Passing the main gas stream through the catalyst bed to form an oxygen depleted gas stream;—Exiting the oxygen depleted gas stream from the tar reformer; and—Recycling at least a part of the oxygen depleted gas stream exiting from the tar reformer back into said main gas stream upstream said tar reformer. The temperature of said main gas stream at the inlet is controlled to be within the range from about 500° C. to about 1000° C.

A lower olefin by using a zeolite catalyst, a composite catalyst capable of further extending the lifetime of catalytic activity, a method for producing the composite catalyst, a method for producing a lower olefin by using the composite catalyst, and a method for regenerating a composite catalyst in the method for producing a lower olefin are provided. The composite catalyst is a catalyst for producing a lower olefin from a hydrocarbon feedstock. This composite catalyst is constituted of a zeolite being a crystalline aluminosilicate containing gallium and iron or iron and further having a framework with 8- to 12-membered ring, and of silicon dioxide. By using the composite catalyst, a lower olefin can be continuously produced over a long period of time.

The present invention relates to a method for producing long-chain alkylbenzene by reacting an aromatic hydrocarbon and a long-chain olefin, wherein the reaction is carried out in the presence of a solid acid catalyst, the aromatic hydrocarbon is selected from the group consisting of benzene, toluene and xylene, the long-chain olefin is selected from the group consisting of C.sub.8-C.sub.26 alkenes, the catalyst is a HMCM-22 type molecular sieve solid acid catalyst modified with heteroatom(s), the heteroatom(s) is/are selected from the group consisting of boron, gallium, indium, chromium, molybdenum, tungsten, manganese and phosphorus, and the molar ratio of silicon atoms to heteroatoms in the solid acid catalyst is in the range of 1:0.01-0.03. The invention also relates to a method for regenerating the solid acid catalyst used in the reaction.