A start-up method for heating a selective catalytic reduction (SCR) module in a hybrid propulsion system of a vehicle. An internal combustion engine is in fluid communication with an exhaust aftertreatment system having an exhaust. An SCR module is disposed in the exhaust passage downstream of the engine and an electric motor. The method includes operating the engine in a start-up mode with a torque restriction on the engine, allowing the SCR module to convert NOx emission; supplying a surplus amount of a reducing agent to the exhaust gas at a position between the engine and the SCR module, the surplus amount of the reducing agent being larger than a required amount of reducing agent for converting NOx emission from the engine; heating said SCR module to a working temperature; and terminating the start-up mode.

Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO.sub.3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO.sub.2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.

A catalytic reaction apparatus includes a coating composition for a catalyst and a catalyst portion to which the coating composition is applied, wherein the coating composition includes 1 to 15 parts by weight of tungsten, 1 to 15 parts by weight of vanadium, 35 to 55 parts by weight of titanium and 30 to 45 parts by weight of oxygen. This apparatus is configured to prevent a decrease in catalytic reaction efficiency in a specific temperature environment, thereby maximizing versatility.

Provided is a combustion system using a catalyst having better denitration efficiency at low temperatures, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent. This combustion system comprises: a combustion device that combusts fuel; an exhaust path through which flows exhaust gas generated from the combustion of fuel in the combustion device; a dust collection device that is arranged on the exhaust path and collects soot/dust in the exhaust gas; and a denitration device that is arranged on the exhaust path and removes nitrogen oxides from the exhaust gas by means of a denitration catalyst, wherein the denitration device is arranged downstream of the dust collection device on the exhaust path, and the denitration catalyst contains vanadium oxide, has a carbon content of 0.05 wt % or more, and has a defect site in which oxygen deficiency occurs in a crystal structure.

A process for production of elemental sulfur from a feedstock gas including from 15% to 100 vol % H2S and a stream of sulfuric acid, the process including: a) providing a Claus reaction furnace feed stream substoichiometric oxygen with respect to the Claus reaction, b) directing to a reaction furnace zone operating at elevated temperature such as above 900° C., c) directing to a sulfuric acid evaporation zone downstream said reaction furnace zone, d) cooling to provide a cooled Claus converter feed gas, e) directing to contact a material catalytically active in the Claus reaction, f) withdrawing a Claus tail gas and elemental sulfur, g) directing to a Claus tail gas treatment plant, with the associated benefit of a process involving injection of sulfuric acid in a sulfuric acid evaporation zone allowing high temperature combustion of said feedstock gas, including impurities, without cooling from evaporation and decomposition of sulfuric acid.

A process and a process plant for production of elemental sulfur from a feedstock gas including from 15 vol % to 100 vol % H2S and a stream of sulfuric acid, the process including a) providing a Claus reaction furnace feed stream with a substoichiometric amount of oxygen, b) directing s to a reaction furnace operating at elevated temperature, c) cooling, d) directing to contact a material catalytically active in the Claus reaction, e) withdrawing a Claus tail gas and elemental sulfur, f) directing to a means for sulfur oxidation, g) directing to contact a material catalytically active in SO2 oxidation to SO3, h) converting to concentrated sulfuric acid, i) recycling to the Claus reaction furnace, wherein an amount of combustibles, in the Claus tail gas, is oxidized in the presence of a material catalytically active in sulfur oxidation, at an inlet temperature below 400° C.

The present disclosure is directed to a catalytic composite that comprises porous supported catalyst particles durably enmeshed in a porous fibrillated polymer membrane. The supported catalyst particles are composed of at least one metal or metal oxide catalyst dispersed on a porous support substrate. In some embodiments, the porous fibrillated polymer membrane is perforated or otherwise contains mechanically formed holes therein. The supported catalyst particles have a large particle population based, at least in part, a D90 value greater than 60 microns. The catalytic membrane composite may be used in filtration applications to remove air-polluting substances such as SOx, NOx, dioxin/furan, CO, and others and convert them into non-polluting or less-polluting gas components. Additionally, the catalytic article may be in the form of a filter bag, a honeycomb, a monolith or any other suitable geometrically structured forms.

A wall-flow honeycomb catalyst for dust removal and low-temperature denitrification of flue gas, and a preparation process thereof are provided. The catalyst is prepared from the following raw materials in parts by weight: calcined titanium dioxide: 30 to 60 parts; crude titanium dioxide: 30 to 50 parts; boehmite: 3 to 5 parts; fused silica powder: 2 to 4 parts; binder: 0.5 to 2 parts; lubricant: 0.5 to 2 parts; vanadium-molybdenum composite oxide: 5 to 10 parts; and water: 150 to 200 parts; and the vanadium-molybdenum composite oxide is obtained by dissolving ammonium metavanadate and ammonium molybdate in an oxalic acid solution and spray-drying a resulting solution. The preparation process of the catalyst of the present disclosure is simple and low in cost.

An aftertreatment system includes a first exhaust gas path, a second exhaust gas path, and a selector valve configured to divert exhaust gas between the first exhaust gas path and the second exhaust gas path based on a temperature of the exhaust gas. The aftertreatment system also includes a controller programmed to control the selector valve such that the selector valve diverts at least a portion of the exhaust gas to the first exhaust gas path when the temperature of the exhaust gas is equal to or less than a predetermined temperature threshold and the selector valve diverts the exhaust gas to the second exhaust gas path when the temperature of the exhaust gas is greater than the predetermined temperature threshold. The first exhaust gas path includes a heater configured to heat the exhaust gas received in the first exhaust gas path.

Disclosed herein are methods and systems for the removal of volatile organic compounds, carbon monoxide and nitrogen oxides from off-gas, which systems comprise a source of ammonia, means for introducing ammonia into a catalytic article having an SCR functionality; a catalytic article having both an oxidation and an SCR functionality, the catalytic article comprising a catalyst substrate and a catalyst composition comprising at least one platinum group metal and/or at least one platinum group metal oxide, at least one oxide of titanium and at least one oxide of vanadium, wherein the washcoat is located in and/or on the walls of the catalyst substrate: means for measuring the amount of NO.sub.x and/or the ammonia slip between the outlet end of the catalytic article and the stack or at the stack, at least one carbon monoxide source, and means for introducing carbon monoxide into the catalytic article.