A combustion system for ships operated at low cost is provided. A combustion system 1 for ships includes an internal combustion engine 20 that burns fuel, an exhaust line L2 through which exhaust gas flows, the exhaust gas being generated through combustion of the fuel in the internal combustion engine 20, an exhaust heat recovery device 40 that is disposed in the exhaust line L2 and that recovers exhaust heat from the exhaust gas discharged from the internal combustion engine 20, and a denitration device 50 that is disposed in the exhaust line L2 and that removes nitrogen oxide from the exhaust gas using a denitration catalyst. The denitration device 50 is disposed downstream from the exhaust heat recovery device 40 in the exhaust line L2. 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 regenerated spent hydroprocessing catalyst treated with a chelating agent and having incorporated therein a polar additive.

A regenerated spent hydroprocessing catalyst treated with a chelating agent and having incorporated therein a polar additive.

The present invention discloses a process for recovery and regeneration of rare earth metals or salts thereof used as catalyst and which is conveniently integrated within the overall flow sheets of manufacturing dialkyl carbonates. Alkyl carbamate, alcohol and a rare earth metal salt as catalyst selected from the lanthanide series are added in a reactor to afford dialkyl carbonate. The rare earth metal catalyst is selected from samarium, cerium, lanthanum, neodymium, ytterbium, europium and gadolinium. Ammonia is added to a portion of the reaction mixture to precipitate the catalyst and the separated deactivated catalyst is dissolved in acid to afford regenerated catalyst, e.g., in triflic acid in the case of samarium triflate catalyst.

The present invention discloses a process for recovery and regeneration of rare earth metals or salts thereof used as catalyst and which is conveniently integrated within the overall flow sheets of manufacturing dialkyl carbonates. Alkyl carbamate, alcohol and a rare earth metal salt as catalyst selected from the lanthanide series are added in a reactor to afford dialkyl carbonate. The rare earth metal catalyst is selected from samarium, cerium, lanthanum, neodymium, ytterbium, europium and gadolinium. Ammonia is added to a portion of the reaction mixture to precipitate the catalyst and the separated deactivated catalyst is dissolved in acid to afford regenerated catalyst, e.g., in triflic acid in the case of samarium triflate catalyst.

A process for ex-situ treatment of a catalyst that contains at least one hydrogenating phase, and at least one amorphous silica-alumina or a zeolite that contains acid. The process includes: a stage for introducing nitrogen by contact at a temperature that is less than 100 C., with at least one basic nitrogen-containing compound that is ammonia or a compound that can be decomposed into ammonia, the compound being introduced at a rate of 0.5-10% by weight (expressed in terms of N), and a sulfurization/activation stage with a gas that contains hydrogen and hydrogen sulfide at a temperature of at least 250 C., with this stage being carried out before or after the stage for introducing said nitrogen-containing compound, and optionally drying the catalyst that is obtained. This treatment allows a rapid, effective start-up on the hydrocracking unit.

A process for ex-situ treatment of a catalyst that contains at least one hydrogenating phase, and at least one amorphous silica-alumina or a zeolite that contains acid. The process includes: a stage for introducing nitrogen by contact at a temperature that is less than 100 C., with at least one basic nitrogen-containing compound that is ammonia or a compound that can be decomposed into ammonia, the compound being introduced at a rate of 0.5-10% by weight (expressed in terms of N), and a sulfurization/activation stage with a gas that contains hydrogen and hydrogen sulfide at a temperature of at least 250 C., with this stage being carried out before or after the stage for introducing said nitrogen-containing compound, and optionally drying the catalyst that is obtained. This treatment allows a rapid, effective start-up on the hydrocracking unit.

The present invention relates to a method for reactivating an anthraquinone hydrogenation catalyst for the preparation of hydrogen peroxide, comprising at least one step of bringing said catalyst into contact with an aqueous solution comprising ammonia. The invention also relates to the use of an aqueous ammonia solution for reactivating an anthraquinone hydrogenation catalyst for the preparation of hydrogen peroxide.

The present invention relates to a method for reactivating an anthraquinone hydrogenation catalyst for the preparation of hydrogen peroxide, comprising at least one step of bringing said catalyst into contact with an aqueous solution comprising ammonia. The invention also relates to the use of an aqueous ammonia solution for reactivating an anthraquinone hydrogenation catalyst for the preparation of hydrogen peroxide.

Present invention relates to a novel process for upgrading a residual hydrocarbon oil feedstock having a significant amount of Conradson Carbon Residue (concarbon), metals, especially vanadium and nickel, asphaltenes, sulfur impurities and nitrogen to a lighter more valuable hydrocarbon products by reducing or minimizing coke formation and by injecting fine droplets of oil soluble organo-metallic compounds at multiple elevations of the riser with varying dosing rates.