New additive scrubs away NOx-ious gases.New additive scrubs away [NO.sub.x]-ious gases Flue-gas scrubbers to remove sulfur dioxide sulfur dioxide, chemical compound, SO2, a colorless gas with a pungent, suffocating odor. It is readily soluble in cold water, sparingly soluble in hot water, and soluble in alcohol, acetic acid, and sulfuric acid. ([SO.sub.2]) -- a leading source of acid rain -- are required today on most new utility and industrial boilers in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. . But the scrubbers that remove [SO.sub.2] don't trap nitrogen oxides ([NO.sub.x]) -- a poorly controlled contributor to both acid rain and smog ozone. Commercially available stack-gas technologies are available to tackle [NO.sub.x], but these are costly and subject to efficiency-robbing engineering problems (SN: 4/29/89, p. 271). Now, chemists at Lawrence Berkeley (Calif.) Laboratory have "lucked" onto what they say could prove a major engineering advance -- the discovery of a simple additive that allows existing [SO.sub.2] scrubbers to efficiently remove [NO.sub.x] as well. The most widely used [SO.sub.2] scrubbers are towering structures that bathe exiting stack gases in a mist of limestone and water. The water-soluble [SO.sub.2] dissolves into the mist, becomes neutralized neu·tral·ize tr.v. neu·tral·ized, neu·tral·iz·ing, neu·tral·iz·es 1. To make neutral. 2. To counterbalance or counteract the effect of; render ineffective. 3. , and rains down the scrubber tower, eventually flowing out the bottom. Because nitric oxide nitric oxide or nitrogen monoxide, a colorless gas formed by the combustion of nitrogen and oxygen as given by the reaction: energy + N2 + O2 → 2NO; m.p. −163.6°C;; b.p. −151.8°C;. (NO), which makes up about 95 percent of most [NO.sub.x] emissions, is not water soluble, it passes through this limestone/water slurry and out into the atmosphere -- unless, that is, yellow phosphorus (Chem.) the waxy yellow allotropic form of elemental phosphorus. See also phosphorus . See also: Phosphorus is added to the scrubbing mist. Phosphorus reacts with oxygen in the flue gas Flue gas is gas that exits to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, it refers to the combustion exhaust gas produced at power plants. to form ozone. This in turn reacts with NO to form water-soluble nitrogen dioxide nitrogen dioxide n. A poisonous brown gas, NO2, often found in smog and automobile exhaust fumes and synthesized for use as a nitrating agent, a catalyst, and an oxidizing agent. Noun 1. ([NO.sub.2]), Shih-Ger Chang and D.K. Liu explain in the Jan. 11 NATURE. The [NO.sub.2] can then dissolve into the slurry mist for removal in the same manner as the [SO.sub.2]. In one experiment, the researchers managed to remove all of the [SO.sub.2] and NO. If the patented technology performs as well in field tests as it did in the preliminary bench-scale experiments, it should offer a "tremendous, commercially economic improvement" over existing industrial options for removing [NO.sub.x], Chang says. |
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