This technology relates to the enlargement by water condensation in a laminar flow of airborne particles with diameters of the order of a few nanometers to hundreds of nanometers to form droplets with diameters of the order of several micrometers. The technology presents several advanced designs, including the use of double-stage condensers. It has application to measuring the number concentration of particles suspended in air or other gas, to collecting these particles, or to focusing these particles.

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 chamber—and 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.

The invention relates to a method for producing dinitrotoluene, comprising the following steps: a) nitrating toluene with a mixture of nitric acid and sulfuric acid and subsequently separating a sulfuric-acid-containing aqueous phase that arises in the nitration, wherein a raw dinitrotoluene is obtained, b) washing the raw dinitrotoluene in a water wash with neutral and/or alkaline washing water, wherein a pre-cleaned dinitrotoluene, which contains at least water in addition to dinitrotoluene, is obtained after the washing water used in the last wash has been separated, and c) separating the water from the pre-cleaned dinitrotoluene, d) collecting the waste water from steps a), b), and/or c), e) optionally extracting the collected waste water from step d) with toluene and returning the thus obtained organic phase to step a), f) freeing the collected waste water from step d), or, if the optional step e) is performed, the extracted waste water from step e), of toluene in a toluene stripper, wherein a toluene-containing exhaust gas flow is obtained, g) feeding at least one exhaust gas flow from steps a), b), c), d), e), or f) into an exhaust gas condenser and removing the toluene contained in the at least one exhaust gas flow in said exhaust gas condenser, wherein the method comprises the following further step: h) feeding the exhaust gas flow arising in step g) after the condensing out of the toluene to a thermal exhaust air cleaning, wherein nitrogen is added to the exhaust gas flow to be fed to the exhaust gas condenser or to the exhaust gas flow leaving the exhaust gas condenser, wherein preferably a nitrogen concentration in the exhaust gas flow of at least 0.1 vol % is set, especially preferably of at least 0.5 vol %.

A process and system for treating a hydroprocessing unit effluent gas stream for recycling includes introducing the effluent gas stream into a hydrogen purification zone and recovering a hydrogen-rich gas stream and a liquid stream containing a mixture that includes C1 to C4 hydrocarbons and H.sub.2S which is then mixed with an oxidant and fed to an oxidation unit containing catalyst for conversion of the H.sub.2S to elemental sulfur vapors that is separated for recovery of the elemental sulfur, and recovering a sweetened mixture that includes C1 to C4 hydrocarbons. Alternatively, the hydroprocessing unit effluent gas stream containing H.sub.2S is cooled, contacted with a solvent to absorb the C1 to C4 hydrocarbons and H.sub.2S, with the hydrogen-rich stream being recovered for recycling to the hydroprocessing unit, and the rich liquid solvent being flashed to produce a lean solvent stream for recycling to the adsorption zone and a mixed gas stream that includes the C1 to C4 hydrocarbons and H.sub.2S that is passed to an oxidation zone and is reacted with an oxidant in the presence of a catalyst to complete the process as described above for the recovery of elemental sulfur and a mixture that includes the sweetened C1 to C4 hydrocarbons.

A system for heating water for an oil and gas well treatment system utilizing raw natural gas from an oil and gas well. The system includes a separation assembly to remove liquids from the raw natural gas, wherein at least a portion of heated water from a frac water heater is passed through the separation assembly to prevent freezing therein.

The disclosure provides for the separation and combustion of at least one hydrocarbon, oxygenate, sulfur compound, and or nitrogen compound, from industrial gas or gasification derived syngas to generate steam. A gasification process and a gas fermentation process may be integrated using tail gas from the fermentation process for the flame to combust tar and other compounds from the syngas generated by a gasification process. Integration may be achieved by removing tar and other compounds from industrial gas or gasification derived syngas using an adsorbent and regenerating the adsorbent using tail gas from the gas fermentation process. Tail gas enriched with the desorbed tar and other compounds may be used to generate steam in a steam boiler and the steam may be used for a variety of purposes including power generation to power, for example, a compressor of the gas fermentation process.

A methane destruction apparatus for capturing and converting fugitive methane gas emissions into carbon dioxide and water comprises a methane-capturing module for capturing the fugitive methane gas emissions and a methane conversion module for receiving captured methane from the methane-capturing module. The methane-capturing module includes a fugitive methane gas emission intake connected to an emissions line having a backpressure equal to 1 to 3 inches of water (249 to 746 Pa), a natural gas feed for feeding natural gas into the methane-capturing module, may include a relief vent for preventing overpressure within the methane-capturing module and a drain for draining liquids that have condensed within the methane-capturing module. The methane conversion module includes a conversion pad for catalytically converting the captured methane into carbon dioxide and water, a water vapour opening for outputting the water and a carbon dioxide opening for outputting the carbon dioxide.

Sweep-based gas separation processes for reducing carbon dioxide emissions from gas-fired power plants. The invention involves at least two compression steps, a combustion step, a carbon dioxide capture step, a power generate step, and a sweep-based membrane separation step. One of the compression steps is used to produce a low-pressure, low-temperature compressed stream that is sent for treatment in the carbon dioxide capture step, thereby avoiding the need to expend large amounts of energy to cool an otherwise hot compressed stream from a typical compressor that produces a high-pressure stream, usually at 20-30 bar or more.

Included are an ammonia synthesis column that synthesizes ammonia from a raw material gas, a discharge line that discharges a synthetic gas, a water-cooled cooler that cools the synthetic gas with a coolant, disposed in the discharge line, an ammonia separator into which a synthetic gas after cooling is introduced and which separates the ammonia gas and a liquid ammonia from each other, a raw material return line that returns a raw material gas containing the separated ammonia gas to the ammonia synthesis column side as a return raw material gas, and a compressor that compresses the return raw material gas, disposed in the raw material return line. An ammonia concentration in the return raw material gas is 5 mol % or more, and an ammonia synthesis catalyst that synthesizes the ammonia gas in the ammonia synthesis column is a ruthenium catalyst.

A method and a plant for producing liquid CO.sub.2 from flue gas as described with reduced energy consumption and a stable behavior.