Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

The invention relates to a gas scrubbing process for purifying crude synthesis gas with methanol as a physical absorption medium, wherein an acid gas comprising at least hydrogen sulfide (H.sub.2S) is produced. The acid gas is produced in a hot regenerator arranged downstream of an absorption apparatus and subsequently separated from gaseous methanol in an acid gas separator by cooling and condensation. The acid gas separator has a condensation region and an absorption region, wherein both regions are separated from one another by a gas-permeable tray. This has the result that impurities such as hydrogen cyanide and/or ammonia outgassing from a first acid gas substream are not reabsorbed in the condensation region of the acid gas separator, thus avoiding an accumulation of impurities in the hot regenerator or other parts of the gas scrubbing plant. The invention further relates to an acid gas separator and to the use of the acid gas separator according to the invention in a process according to the invention.

This disclosure relates to improved methods for alkali metal cyanide production, particularly to improved methods for sodium cyanide production. The improved method of producing sodium cyanide involves the step of contacting hydrogen cyanide with an aqueous solution of sodium carbonate or of a mixture of sodium carbonate and sodium bicarbonate to produce a sodium cyanide solution.

A device for processing waste is described herein that comprises an ion generator, a furnace chamber, a heat exchanger, a pollution control system, and a chimney. The ion generator converts atmospheric air into an ionized gas and the furnace chamber thermally decays the waste by combining the waste with a product of an interaction of the ionized gas and heat generated by the furnace chamber. The heat exchanger cools the excess gas. A wet scrubber system removes heavy metals and/or acid gases from the cooled excess gas to generate scrubbed excess gas, and a fixed bed coke system detoxifies the scrubbed excess gas by converting carbon monoxide, water, and steam in the scrubbed excess gas to carbon dioxide and hydrogen, and removing remaining acid gas, a remaining heavy metal, and/or a remaining dioxin from the scrubbed excess gas. The chimney transfers remaining scrubbed excess gas out of the device.

In a process for treating a carbon dioxide-rich gas (1) containing water, the treatment by compression and/or washing and/or drying of the gas produces acidified water (W1, W2, W3, W4, W7) which is sent to a cooling circuit (W8, W10).

The present invention relates to a process for producing an aqueous solution containing chlorine dioxide from gaseous chlorine dioxide and from an aqueous phase. The invention additionally relates to an apparatus for producing an aqueous solution containing chlorine dioxide and/or for carrying out the process of the invention. Finally, the invention also relates to the use of an apparatus according to the invention for carrying out a process according to the invention. In the following, all statements made in respect of the process of the invention also apply correspondingly to the apparatus of the invention and the use according to the invention, and vice versa, unless indicated otherwise in the individual case.

A process for recovering nitric acid or salts thereof, comprising: contacting, in the presence of water, an water-immiscible ionic liquid of the formula [A.sup.+][X.sup.−], wherein [A.sup.+] represents a phosphonium or ammonium cation and [X.sup.−] represents a counter anion which is NO.sub.3.sup.−, an halide anion displaceable by NO.sub.3.sup.−, or both, with a fluid which contains HNO.sub.3 and at least one more mineral acid, or precursors of said acids, and partition, under mixing, said acids between aqueous and organic phases and form nitrate-loaded ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z>0.25 where Z indicates a molar amount of nitrate held in the ionic liquid beyond the positions occupied by the nitrate counter ions; separating the so-formed mixture into an organic phase comprising a nitrate-loaded ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z>0.25 and an aqueous phase consisting of a nitrate-depleted aqueous solution that contains the other mineral acid(s); stripping the nitric acid from said nitrate-loaded ionic liquid to create an aqueous nitrate solution and regenerate ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z≥0 with reduced nitrate loading, or unloaded [A.sup.+][NO.sub.3.sup.−].sub.z=0 ionic liquid.

An absorption column including at least one external heat exchange circuit for cooling or heating the absorption liquid, including one or more serially connected heat exchangers, wherein the junction of the pipeline for withdrawal of the absorption liquid from the column is disposed above the junction of the pipeline into the first heat exchanger in the flow direction, wherein the pipeline also includes a dumped bed.

Apparatus and methods are disclosed. The apparatus comprises: an abatement chamber of an abatement apparatus which treats an effluent stream from a semiconductor processing tool to provide a combusted effluent stream having effluent particles; and a first atomiser located downstream of the abatement chamber, the first atomiser being configured to produce droplets having a droplet size based on a particle size of the effluent particles to be removed from the combusted effluent stream. In this way, the atomizer may produce droplets which combine with or adhere to the effluent particles which assists in the removal of the effluent particles from the combusted effluent stream.

A long-effect self-cleaning negative-pressure ejector at least comprises a suction chamber, a jet pipe and a flushing member. A side wall of the suction chamber has at least one suction port for communicating with a first fluid pipeline. An exit port of the jet pipe is disposed in the suction chamber and ejects a second fluid so that a negative pressure is generated in the suction chamber, a first fluid in the first fluid pipeline obliquely enters the suction chamber, and a first included angle is between a direction in which the first fluid being sucked into the suction chamber and an ejection direction of the second fluid. The flushing member optionally provides a third fluid to flush the suction chamber and/or the first fluid pipeline. At least one air jet nozzle is disposed on the first fluid pipeline to inject gas into the first fluid pipeline.