A flue gas stream arising from fossil fuel fired sources containing nitrogen oxide contaminants is conveyed through an exhaust duct into a quencher. In the quencher aqueous medium is sprayed into contact with the flue gas stream. The quenched flue gas stream is mixed with ozone distributed at a high velocity in a sub-stoichiometric amount for partial oxidation of NO.sub.xto form NO.sub.2 and prevent the formation of N.sub.2O.sub.5. The flue gas containing NO.sub.2 is absorbed into an acidic medium of a wet scrubber to form nitrous acid. In the scrubber the nitrous acid is mixed with selected compounds of ammonia to decompose the nitrous acid for release of nitrogen. With this process the consumption of ozone and the operating costs associated therewith eliminate the requirement to dispose of nitrate recovered from the scrubber purge stream.

A separation material and method for separating and recovering a target gas from a mixed gas including the target gas and a hydrocarbon gas that has the same number of carbon atoms as the target gas, the target gas being a hydrocarbon gas having 2 or 4 carbon atoms and a carbon-carbon double bond. This gas separation material includes: a metal complex containing a 2,3-pyrazinedicarboxylic acid; an ion of at least one type of metal (M); and an organic ligand (B) capable of bidentate coordination to the metal ion represented by general formula (1) or general formula (2), where (M), formula (1) and formula (2) are as defined herein. The metal complex has a composition represented by M.sup.2+.sub.2A.sup.2.sub.2B where M.sup.2+ is the ion of the metal (M), A.sup.2 is a 2,3-pyrazinedicarboxylate dianion and B is the organic ligand (B) capable of bidentate coordination to the metal ion.

An absorption medium includes compressed coir particles having been compressed from an uncompressed state at a volume to volume ratio of greater than 3:1, but less than 15:1, and having been ground to a grind size of 1/25 inches to inch.

An air pollution control system includes: a desulfurization device which removes sulfur oxides in a flue gas generated from a boiler; a cooler which is provided at the downstream side of the desulfurization device, decreases a flue gas temperature and enlarges a particle diameter of SO.sub.3 mist contained in the flue gas through cooling or heating the flue gas by a temperature adjustment means for adjusting a gas dew point temperature of the flue gas; and a CO.sub.2 recovery device which includes a CO.sub.2 absorber bringing CO.sub.2 in the flue gas into contact with the CO.sub.2 absorbent so as to remove CO.sub.2 therefrom and a regenerator recovering CO.sub.2 by dissociating CO.sub.2 from the CO.sub.2 absorbent and regenerating the CO.sub.2 absorbent, wherein the flue gas is cooled by a cooling unit so as to enlarge the SO.sub.3 mist in the flue gas.

A fertilizer product is produced by a method of removing sulfur from flue gas. The method includes: introducing a flue gas stream to a wet scrubber; contacting the flue gas stream with a liquid nitrogen reagent in the wet scrubber that deposits in a bottom portion of the wet scrubber as a liquid fraction and possibly contacting the liquid fraction from the wet scrubber with an oxidizing gas; discharging reacted liquid nitrogen product from the wet scrubber that contains sulfur removed from the flue gas stream and that comprises a nitrogen and sulfur enriched fertilizer solution; and discharging flue gas exhaust from the wet scrubber.

According to embodiments disclosed herein, a method for absorption and desorption of CO.sub.2 may comprise absorbing CO.sub.2 onto an absorbent solution comprising a CO.sub.2-depleted amidoxime compound, wherein absorbing CO.sub.2 onto the absorbent solution comprising the CO.sub.2-depleted amidoxime compound may comprise contacting the absorbent solution with a gas comprising CO.sub.2 at a first temperature to form an absorbent solution comprising a CO.sub.2-enriched amidoxime compound; and then desorbing the CO.sub.2 from the absorbent solution comprising the CO.sub.2-enriched amidoxime compound, wherein desorbing the CO.sub.2 from the absorbent solution comprising the CO.sub.2-enriched amidoxime compound may comprise heating the absorbent solution comprising the CO.sub.2-enriched amidoxime compound to a second temperature greater than the first temperature to remove at least a portion of the CO.sub.2 from the CO.sub.2-enriched amidoxime compound and form the CO.sub.2-depleted amidoxime compound, wherein the second temperature is less than or equal to 80 C.

An acid gas absorbing mixture and a process for the removal of acid gases from gaseous mixtures containing them, such as natural gas, air and flue gases and an absorbent mixture usable for the removal of acid gases from gaseous mixtures containing them includes at least one diol of general formula R(OH).sub.2 having a normal boiling point equal to or greater than 100 C.; at least one organic base having a pK.sub.b (in water) lower than or equal to 3; and a polar aprotic solvent having a dielectric constant at 25 C. greater than or equal to 30, a viscosity at 25 C. lower than or equal to 40 cP (centipoise). The organic base/diol weight ratio is lower than or equal to 0.6, and the aprotic solvent/diol weight ratio is between 0.05 and 0.6.