The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.

A gas scrubber may include an absorption apparatus configured for receiving a gas and absorbing the gas in an absorption medium, as well as an evaporation apparatus configured for evaporating at least a part of the liquid that is introduced. The absorption apparatus may have an introduction apparatus for the gas, an apparatus for circulating the absorption solution that has reacted with the gas, a discharge apparatus for at least a part of the absorption solution that has reacted with the gas, and a cooling system for the circulating absorption solution. The absorption apparatus and the evaporation apparatus can be connected via a heat exchanger such that heat content of the absorption solution that has reacted with the gas is used at least in part for the evaporation.

An absorbent for selective removal of hydrogen sulfide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I) ##STR00001##
in which R.sub.1 and R.sub.2 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl, with the proviso that at least one R.sub.4 and/or R.sub.5 radical on the carbon atom bonded directly to the nitrogen atom is C.sub.1-4-alkyl or C.sub.1-4-hydroxyalkyl when R.sub.3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol. The absorbent allows a defined H.sub.2S selectivity to be set at pressures of the kind typical in natural gas processing.

The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.

Systems and methods are provided for reclaiming CO.sub.2 from air. The method includes absorbing solar radiation using a special photovoltaic panel, the H-SPV, which is so designed that the heat absorbed by the H-SPV is conducted to the back of the H-SPV to the substrate, and there it is cooled by the airstream behind it. A second supporting panel is included to provide enclosure for the heated air that rises between the two panels by the chimney effect, the heated air between the at least two plates will rise by the chimney effect, sucking in more air to be heated, wherein the air includes CO.sub.2, chemically removing the CO.sub.2 from the heated air, using a coolant liquid, wherein the coolant liquid in a heat exchanger, when in contact with the CO.sub.2 in the heated air, forms a bicarbonate, and releasing air that has had the CO.sub.2 chemically removed.

A process for preparing sulfuric acid may involve melting elemental sulfur in a melting stage to give molten sulfur. Sulfuric acid is subsequently produced from the molten sulfur. Further, sulfur-containing offgases formed in the melting stage may be subjected to oxidation in a supplementary oxidation stage in which sulfur-containing components of the offgases are oxidized to sulfur dioxide. The process may further involve processing the sulfur dioxide to give at least one reaction product. The melting stage may be operated without emissions by processing all of the offgases from the melting stage. An apparatus may be employed for carrying out such a process.

A process of removing contaminants and concentrating wastewater includes delivering wastewater from a source of wastewater to a hydrogen sulfide removal device, mixing an oxidant with the filtered wastewater in the hydrogen sulfide removal device to produce a hydrogen sulfide lean effluent, delivering the hydrogen sulfide lean effluent to a direct contact concentrator. and evaporating a portion of the hydrogen lean effluent in the direct contact evaporator to produce a slurry and an exhaust gas.

This disclosure provides an integrated system and method for producing purified water, hydrogen, and oxygen from contaminated water. The contaminated water may be derived from regolith-based resources on the moon, Mars, near-Earth asteroids, or other destination in outer space. The integrated system and method utilize a cold trap to receive the contaminated water in a vapor phase and selectively freeze out water from one or more volatiles. A heat source increases temperature in the cold trap to vaporize the frozen contaminated water to produce a gas stream of water vapor and volatiles. A chemical scrubber may remove one or more volatiles. The integrated system and method utilize ionomer membrane technology to separate the water vapor from remaining volatiles. The water vapor is delivered for crew use or delivered to an electrolyzer to produce hydrogen and oxygen.

An air purification and recirculation system positioned within an animal rearing/sheltering facility. The system draws untreated air into an elongated air treatment apparatus having a dust scrubbing section, an ammonia scrubbing section, and acid scrubbing section, configured so that the treatment sections are positioned in series. At the end of the air treatment process, the treated air is exhausted back into the animal rearing facility so that the air is circulated within the facility. Acid and water used during the air treatment process are continuously recycled and directed back through the scrubbers in the air treatment apparatus.

A liquid hydrocarbon desulfurization system having at least one processing unit, and preferably an initial and an end processing unit. Each processing unit having a reactor assembly and a sorption system. An aqueous system directs aqueous into the reactor assembly together with liquid hydrocarbon, wherein the two are mixed using shear mixers. An adsorbent system provides adsorbent to the sorption column to adsorb the oxidized sulfur resulting through the mixing of the liquid hydrocarbon with the aqueous. A system having multiple processing units is disclosed, as well as systems for transferring adsorbent and providing aqueous. A plurality of methods is likewise disclosed.