A process for combined removal of siloxanes and sulfur-containing compounds from biogas streams, such as streams from landfills or anaerobic digesters, comprises heating the biogas stream and optionally mixing it with air, feeding the gas to a first filter unit with high temperature resistance, injecting a dry sorbent into the first filter unit to capture siloxanes present in the gas, recycling part of the exit gas from the first filter unit to the inlet thereof for the sulfur-containing compounds to be captured by the dry sorbent or optionally to a second filter unit inlet for the sulfur-containing compounds to be captured by a sulfur-specific sorbent and recovering clean gas from the first or optionally from the second filter unit.

A method for the purification of a raw gas stream by selective catalytic oxidation, in which organic and inorganic sulfur compounds, halogenated and non-halogenated volatile organic compounds are selectively oxidized without substantially oxidizing the lower hydrocarbons and the sulfur containing compounds present in the gas to sulfur trioxide and excess of oxygen is removed by oxidation of lower alcohols, ethers or hydrogen added to the raw gas stream upstream the catalytic oxidation.

Oxygen is removed from a gas feed such as a landfill gas, a digester gas or an industrial CO.sub.2 off-gas by heating the feed gas, optionally removing siloxanes and silanols from the heated feed gas, optionally removing part of the sulfur-containing compounds in the heated feed gas, injecting one or more reactants for oxygen conversion into the heated feed gas, carrying out a selective catalytic conversion of any or all of the volatile organic compounds (VOCs) present in the gas, including sulfur-containing compounds, chlorine-containing compounds and any of the reactants injected, in at least one suitable reactor, and cleaning the resulting oxygen-depleted gas. The reactants to be injected comprise one or more of H.sub.2, CO, ammonia, urea, methanol, ethanol and dimethyl ether (DME).

An apparatus and method for wet cleaning a gas stream has a housing with a gas inlet and a gas outlet, wherein, in the housing, there is at least a first washing segment that serves to clean the gas stream with a washing liquid and that is arranged in the flow path of the gas stream. Inside the housing of the apparatus, there is at least one fan that regulates air pressure along the flow path of the gas stream. A bypass channel for bypassing the flow path through the at least one washing segment as well as a regulator that is arranged in the bypass and that serves to discharge the gas stream being conveyed via the bypass channel are arranged inside the housing.

A vacuum pump with abatement function which can prevent contamination of a process chamber without allowing products generated by exhaust gas treatment to flow back to the process chamber, and can reduce the amount of gas to be treated without allowing a purge gas and a diluent gas to be contained in an exhaust gas, and thus can achieve energy saving by reducing the amount of energy required for the exhaust gas treatment in an abatement part is disclosed. The vacuum pump with abatement function includes a vacuum pump to which at least one abatement part for treating an exhaust gas is attached. The vacuum pump comprises a dry vacuum pump having a pair of multistage pump rotors each of which comprises a plurality of rotors arranged on a rotating shaft, and the at least one abatement part is connected to an interstage of the multistage pump rotors.

A vacuum pump with abatement function which can prevent contamination of a process chamber without allowing products generated by exhaust gas treatment to flow back to the process chamber, and can reduce the amount of gas to be treated without allowing a purge gas and a diluent gas to be contained in an exhaust gas, and thus can achieve energy saving by reducing the amount of energy required for the exhaust gas treatment in an abatement part is disclosed. The vacuum pump with abatement function includes a vacuum pump to which at least one abatement part for treating an exhaust gas is attached. The vacuum pump comprises a dry vacuum pump having a main pump capable of evacuating gas from an atmospheric pressure and a booster pump for increasing an evacuation speed of the main pump, and the at least one abatement part for treating the exhaust gas is connected between the main pump and the booster pump.

A vacuum pump with abatement function is used for evacuating a chamber of a manufacturing apparatus. The vacuum pump with abatement function includes a vacuum pump having a discharge port to which one or more abatement parts for treating an exhaust gas discharged from the vacuum pump to make the exhaust gas harmless are attached. The one or more abatement parts are selected, depending on the amount and kind of the exhaust gas discharged from the vacuum pump, from plural kinds of abatement parts which have different treatment types of exhaust gas and/or different treatment amounts of exhaust gas.

An apparatus for exhaust gas abatement under reduced pressure includes a reaction tube having, in an interior thereof, an exhaust gas treatment space in which an exhaust gas supplied from an exhaust gas source via a vacuum pump is heated by an electric heater or excited by a plasma for decomposition and/or reaction treatment. The apparatus also includes a downstream vacuum pump connected to an exhaust gas outlet located downstream of the reaction tube to reduce a pressure in a region located downstream of an outlet of the vacuum pump and including the interior of the reaction tube. The downstream vacuum pump is a water-sealed pump. The apparatus further includes a water-washing unit for washing a downstream end of an exhaust gas flow path in the reaction tube with washing water. The washing water supplied by the water-washing unit is reused as seal water for the downstream vacuum pump.

A detoxifying device 100 having an inner wall 104 that forms a flow passage 103 through which treatment gas flows includes a first piping 130 that forms a part of the flow passage 103, a replaceable piping section 170 that forms a part of the flow passage 103 at the position downstream of the first piping 130, and is connected thereto for sprinkling the cleaning water to remove the solid product adhering to the inner wall 104, and a second piping 150 that forms a part of the flow passage 103 at the position downstream of the piping section 170, and is connected thereto.

A system for chemical vapor densification includes a reaction chamber having an inlet and outlet; a trap; a conduit fluidly coupled between the outlet of the reaction chamber and the trap; a cryogenic cooler fluidly coupled to the trap though a frustoconical conduit; a first exit path from the cryogenic cooler that vents hydrogen gas to an exhaust; and a second exit path from the cryogenic cooler that recirculates silane and hydrocarbon-rich gas back to the inlet of the reaction chamberand a related method places a substrate in the reaction chamber; establishes a sub-atmospheric pressure inert gas atmosphere within the reaction chamber; densifies the substrate by inputting virgin gas into the reaction chamber; withdraws effluent gas from the reaction chamber; extracts silane and hydrocarbon-rich gas from the effluent gas; and recirculates the silane and hydrocarbon-rich gas back to the reaction chamber.