The present invention discloses a method and system of recovering elemental sulfur and regenerating the catalyst for a sulfur-deposited catalyst, including immersing the sulfur-deposited catalyst in the ammonium sulfide solution, the leaching reaction under normal pressure and temperature, replacing the ammonium sulfide solution and immersing again for extraction for the same time; collecting the leachate of the two steps, conducting gas stripping of the elemental sulfur by adopting the high-temperature nitrogen gas, condensing the tail gas of gas stripping, subjecting to a purification treatment and then discharging, with the liquor condensate being the ammonium sulfide solution. Finally, the solid in the leachate is filtered, washed and dried after the gas stripping to obtain the elemental sulfur; and the washing and drying of catalysts that has been subjected to the two times of immersion and extraction obtain the regenerated catalysts.

The present invention discloses a method and system of recovering elemental sulfur and regenerating the catalyst for a sulfur-deposited catalyst, including immersing the sulfur-deposited catalyst in the ammonium sulfide solution, the leaching reaction under normal pressure and temperature, replacing the ammonium sulfide solution and immersing again for extraction for the same time; collecting the leachate of the two steps, conducting gas stripping of the elemental sulfur by adopting the high-temperature nitrogen gas, condensing the tail gas of gas stripping, subjecting to a purification treatment and then discharging, with the liquor condensate being the ammonium sulfide solution. Finally, the solid in the leachate is filtered, washed and dried after the gas stripping to obtain the elemental sulfur; and the washing and drying of catalysts that has been subjected to the two times of immersion and extraction obtain the regenerated catalysts.

Honeycomb bodies and methods for treating a honeycomb bodies that include a skin surrounding a matrix of cells, the skin and the matrix of cells comprising a porous inorganic material. Methods include applying a buffer solution to only the porous inorganic material of the skin and coating the porous inorganic material of the skin with an oxide slurry. The oxide slurry includes an oxide or a precursor of the oxide configured to increase the isostatic strength of the honeycomb body. After treatment, the honeycomb body may be dried.

Honeycomb bodies and methods for treating a honeycomb bodies that include a skin surrounding a matrix of cells, the skin and the matrix of cells comprising a porous inorganic material. Methods include applying a buffer solution to only the porous inorganic material of the skin and coating the porous inorganic material of the skin with an oxide slurry. The oxide slurry includes an oxide or a precursor of the oxide configured to increase the isostatic strength of the honeycomb body. After treatment, the honeycomb body may be dried.

A combustion system operated at low cost is provided. A combustion system 1 includes a combustion device 10 that burns fuel, an exhaust line L1 through which exhaust gas flows, the exhaust gas being generated through combustion of the fuel in the combustion device 10, an air preheater 30 that is disposed in the exhaust line L1 and that recovers heat from the exhaust gas, and a denitration device 40 that is disposed in the exhaust line L1 and that removes nitrogen oxide from the exhaust gas using a denitration catalyst. The denitration device 40 is disposed downstream from the air preheater 30 in the exhaust line L1, and the denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more.

A combustion system operated at low cost is provided. A combustion system 1 includes a combustion device 10 that burns fuel, an exhaust line L1 through which exhaust gas flows, the exhaust gas being generated through combustion of the fuel in the combustion device 10, an air preheater 30 that is disposed in the exhaust line L1 and that recovers heat from the exhaust gas, and a denitration device 40 that is disposed in the exhaust line L1 and that removes nitrogen oxide from the exhaust gas using a denitration catalyst. The denitration device 40 is disposed downstream from the air preheater 30 in the exhaust line L1, and the denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more.

This invention describes a novel and efficient processing scheme that can be used to transform a vacuum residue feedstock into 0.5 wt % sulfur bunker fuel that fulfills the specifications required by the International Maritime Organization (IMO).

This invention describes a novel and efficient processing scheme that can be used to transform a vacuum residue feedstock into 0.5 wt % sulfur bunker fuel that fulfills the specifications required by the International Maritime Organization (IMO).

There is provided a method for recycling a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A method for recycling a denitration catalyst includes a step of spraying an aqueous solution with a pH of 7 or more onto a used denitration catalyst while the denitration catalyst is set in a denitration device to remove a surface of the denitration catalyst. The denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more. The denitration catalyst after recycling is used for denitration at 200 C. or lower.

There is provided a method for recycling a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A method for recycling a denitration catalyst includes a step of spraying an aqueous solution with a pH of 7 or more onto a used denitration catalyst while the denitration catalyst is set in a denitration device to remove a surface of the denitration catalyst. The denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more. The denitration catalyst after recycling is used for denitration at 200 C. or lower.