Some embodiments of the present disclosure relate to a method of regenerating at least one filter medium comprising: providing at least one filter medium, wherein the at least one filter medium comprises: at least one catalyst material; and ammonium bisulfate (ABS) deposits, ammonium sulfate (AS) deposits, or any combination thereof; flowing a flue gas stream transverse to a cross-section of a filter medium, such that the flue gas stream passes through the cross section of the at least one filter medium, wherein the flue gas stream comprises: NOx compounds comprising: Nitric Oxide (NO), and Nitrogen Dioxide (NO.sub.2); and increasing an NOx removal efficiency of the at least one filter medium after removal of deposits.

Catalyst regeneration processes that include measures for controlling emissions generated during the regeneration are described. The present invention further relates to catalytic processes for producing various chlorinated aromatic compounds that include provisions for controlling emissions during catalyst regeneration.

Catalyst regeneration processes that include measures for controlling emissions generated during the regeneration are described. The present invention further relates to catalytic processes for producing various chlorinated aromatic compounds that include provisions for controlling emissions during catalyst regeneration.

Various aspects disclosed relate to a catalyst particle for catalyzing the production of syngas from carbon dioxide and methane. The catalyst particle includes a metal oxide substrate. The substrate includes a particulate nickel phase. An exposed surface of the catalyst particle includes at least some of the particulate nickel phase. Additionally, the exposed surface is substantially nonporous.

Various aspects disclosed relate to a catalyst particle for catalyzing the production of syngas from carbon dioxide and methane. The catalyst particle includes a metal oxide substrate. The substrate includes a particulate nickel phase. An exposed surface of the catalyst particle includes at least some of the particulate nickel phase. Additionally, the exposed surface is substantially nonporous.

Disclosed is a method for partially regenerating a catalyst for methanol and/or dimethyl ether-to-olefin. The method comprises: introducing a mixed gas into a regenerated region containing a catalyst to be regenerated, and subjecting same to a partial regeneration reaction to obtain a regenerated catalyst, wherein the mixed gas contains water vapor and air; and in the regenerated catalyst, the coke content of at least part of the regenerated catalyst is greater than 1%. The method utilizes the coupling of a mixed gas of water vapor and air to activate a deactivated catalyst, selectively eliminate part of a coke deposit in the catalyst to be regenerated, and obtain a partially regenerated catalyst for methanol-to-olefin. Another aspect of the present invention is that further provided is a method for methanol and/or dimethyl ether-to-olefin by using the partially regenerated catalyst for methanol-to-olefin regenerated by means of the method.

Disclosed is a method for partially regenerating a catalyst for methanol and/or dimethyl ether-to-olefin. The method comprises: introducing a mixed gas into a regenerated region containing a catalyst to be regenerated, and subjecting same to a partial regeneration reaction to obtain a regenerated catalyst, wherein the mixed gas contains water vapor and air; and in the regenerated catalyst, the coke content of at least part of the regenerated catalyst is greater than 1%. The method utilizes the coupling of a mixed gas of water vapor and air to activate a deactivated catalyst, selectively eliminate part of a coke deposit in the catalyst to be regenerated, and obtain a partially regenerated catalyst for methanol-to-olefin. Another aspect of the present invention is that further provided is a method for methanol and/or dimethyl ether-to-olefin by using the partially regenerated catalyst for methanol-to-olefin regenerated by means of the method.

A process for regenerating a catalyst containing ruthenium or ruthenium compounds, which includes, optionally at elevated temperature, subjecting the catalyst to a hydrogen halide treatment, particularly a gas stream comprising hydrogen chloride, under non-oxidative conditions and, optionally at reduced temperature, to at least a two-stage oxidative post-treatment. The catalyst may have been poisoned by sulfur compounds. After the removal of sulfur, the catalyst is subjected to an oxidative post-treatment.

A process prepares an oxygen carrier for a chemical looping process including providing a material A having a first transition metal and/or an oxide of the first transition metal. The first transition metal is selected from chemical element groups 6-11 of the Periodic System. Material A is subjected to a reaction with H2 to reduce the first transition metal and/or oxide to form a reduced material B. Material B is treated with a salt solution of a second transition metal selected to have a standard reduction potential larger than the first transition metal. A portion of the first transition metal in the reduced material B is replaced by the second transition metal. A molar ratio of the first transition metal with respect to the second transition metal in material B ranges between 2:1 and 100:1. An oxygen carrier is obtained with the method and is regenerated using steam.

A process prepares an oxygen carrier for a chemical looping process including providing a material A having a first transition metal and/or an oxide of the first transition metal. The first transition metal is selected from chemical element groups 6-11 of the Periodic System. Material A is subjected to a reaction with H2 to reduce the first transition metal and/or oxide to form a reduced material B. Material B is treated with a salt solution of a second transition metal selected to have a standard reduction potential larger than the first transition metal. A portion of the first transition metal in the reduced material B is replaced by the second transition metal. A molar ratio of the first transition metal with respect to the second transition metal in material B ranges between 2:1 and 100:1. An oxygen carrier is obtained with the method and is regenerated using steam.