An apparatus and method for purifying a raw hydrogen gas stream of chloramines and chlorine is provided. The explosive chloramines compounds can be effectively captured by the carbon adsorbent without accumulating on the carbon surface. Rather, the chloramines are converted via decomposition, into non-explosive products with catalytic effect of the carbon material. Chlorine reacts with impregnated reducing agent on the carbon surface to form the solid products, which can be adsorbed on the carbon surface. The purified hydrogen gas contains little to no trace of chloramines and chlorine impurities, thereby making the hydrogen gas suitable for liquid hydrogen production.

The invention relates to a process for producing ethylene glycol and/or ethylene carbonate, said process comprising contacting at least a portion of a recycle gas stream comprising an alkyl iodide impurity with a guard bed system positioned upstream of an ethylene oxide reactor to produce a treated recycle gas stream, wherein the guard bed system comprises silver on alumina; contacting a feed gas stream comprising ethylene, oxygen and at least a portion of the treated recycle gas stream with an epoxidation catalyst in the ethylene oxide reactor to produce an epoxidation reaction product comprising ethylene oxide; and contacting at least a portion of the epoxidation reaction product comprising ethylene oxide with an aqueous absorbent in the presence of an iodide-containing catalyst in an absorber to produce an aqueous product stream comprising ethylene carbonate and/or ethylene glycol and the recycle gas stream comprising the alkyl iodide impurity.

A process for purifying a feed gas stream containing at least 90% of CO.sub.2, at least 20% RH and at least one impurity chosen from chlorinated, sulfur-bearing, nitrated or fluorinated compounds is provided. The process includes a) subjecting the feed gas stream to catalytic oxidation producing a stream containing at least one of HCl, NOx, SOx or hydrofluoric acid; b) maintaining the temperature of the gas stream above the highest value between the dew points of water and the acid(s) contained in the gas; c) removing at least a part of the acid impurities by bringing the gas stream into contact with a corrosion-resistant heat exchanger to condense the acid compounds while regulating the temperature of the gas stream exiting below the dew point of water; and d) separating the acid condensates with a corrosion-resistant separator in such a way as to produce a CO.sub.2-enriched gas stream.

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.

An apparatus and method for purifying a raw hydrogen gas stream of chloramines and chlorine is provided. The explosive chloramines compounds can be effectively captured by the carbon adsorbent without accumulating on the carbon surface. Rather, the chloramines are converted via decomposition, into non-explosive products with catalytic effect of the carbon material. Chlorine reacts with impregnated reducing agent on the carbon surface to form the solid products, which can be adsorbed on the carbon surface. The purified hydrogen gas contains little to no trace of chloramines and chlorine impurities, thereby making the hydrogen gas suitable for liquid hydrogen production.

A method for treating the waste stream from a purified terephthalic acid (PTA) process is provided. The method comprises contacting a waste stream containing carbon monoxide (CO), volatile organic compounds (VOCs), and methyl bromide with a catalyst comprising a first base metal catalyst supported on an oxygen donating support that is substantially free of alumina, and at least one second base metal catalyst.

Disclosed is a system for integrally treating a composite waste gas including nitrogen oxides (NO.sub.x and N.sub.2O), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and perfluorinated compounds (PFCs). The system includes a first wet processor configured to wash and adsorb dust including gases, SO.sub.x, and ash dissolved in water, a decomposing reactor configured to receive waste gas processed in the first wet processor and process nitrogen oxides (NO.sub.x and N.sub.2O), fluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and perfluorinated compounds (PFCs) in the waste gas, and a second wet processor configured to receive the waste gas processed in the decomposing reactor and wash and adsorb the received waste gas. The system can efficiently treat a large amount of composite waste gas.

Systems and methods for purifying a carbon dioxide gas mixture are disclosed. A carbon dioxide purification and in liquefaction unit integrated with an external hydrocarbon dosing system is used to purify a mixture that includes (1) primarily carbon dioxide and (2) other material including an organic chloride and other organic hydrocarbons. The organic chloride in the mixture may be substantially removed via controlling the amount of the organic chloride reacted in the reactor of the carbon dioxide purification and liquefaction unit. The controlling of the organic chloride content is executed by the external hydrocarbon dosing system. The external hydrocarbon dosing system is configured to maintain a temperature of the effluent from the reactor within a predetermined range via controlling the flow rate of the external hydrocarbon into the mixture.

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.