The present invention provides a photocatalytic composition comprising: a photocatalyst; and an adsorbent material.

The present invention provides an energy-efficient method and apparatus that can achieve exhaust gas abatement with a minimum use of diluent nitrogen gas. More specifically, the present invention is directed to a method and apparatus for exhaust gas abatement under reduced pressure, in which an exhaust gas supplied from an exhaust gas source via a vacuum pump is decomposed by heat of a high-temperature plasma under a reduced pressure.

In the method for scrubbing a chemical from a medium, wherein the improvement comprises the steps of using a carbide derived carbon to adsorb the chemical which may later be released by heating. The carbide derived carbon may be a powder, a fiber, a solid foam, a mesh, or other solid form. The carbide derived carbon can adsorb a chemical in the gaseous, liquid, particulate, or aerosol phase.

The system and method spatially predict the condensation of water and acid from the flue gas in the condensing heat exchanger installed in fossil power plant flue gas treatment system or similar environment. By modifying the operational conditions, the heat exchanger can control rates and areas of condensations. The system and method adjust either the cooling water temperature or the flowrate ratio of flue gas to cooling water to control the condensation rates of water or acids. The system and method also estimate actual coverage areas to apply for anti-corrosive coating onto the tube or duct surfaces to resist corrosion due to acid condensation. The system and method also optimize or customize condensation rates of water and acids in boiler flue gas under operating conditions given at a power plant.

Extractive agent compounds are disclosed, with exemplary compounds having Formula (I):

##STR00001##

wherein R.sup.a and R.sup.b are independently selected from the group consisting of an oxygen radical, a hydrogen radical, and a hydrocarbyl radical having from about 1 to about 20 carbon atoms, and wherein R.sup.2-R.sup.6 are independently selected from the group consisting of halo, a hydrogen radical, and a hydrocarbyl radical having from about 1 to about 20 carbon atoms, and further wherein at least two of R.sup.2-R.sup.6 are halo. Also disclosed are extractive distillation processes, comprising distilling a liquid mixture comprising ethylbenzene, a further C.sub.8 aromatic compound, and an extractive agent compound as described herein. The extractive agent contributes to improved separability of ethylbenzene from the further C.sub.8 aromatic compound. The separability may be quantified in terms of increasing relative volatility of ethylbenzene to the further C.sub.8 aromatic compound or may alternatively be quantified in terms of a competitive factor, D, as described herein.

A method for providing renewable natural gas (RNG) includes removing hydrogen sulfide and/or carbon dioxide from biogas to provide partially purified biogas, which may be stored in a mobile storage tank. The partially purified biogas is transported to a biogas upgrading facility, at least partially by truck, rail, or ship. At the biogas upgrading facility, the partially purified biogas is further purified to provide the RNG, which can be injected into a distribution system (e.g., natural gas grid) and/or provided for use in transportation.

Sorbent compositions, comprising a solid sorbent, a dispersive agent, and optionally a capture agent for enhanced wet-Flue Gas Desulfurization (wFGD) or wet scrubber unit function in a flue gas pollutant control stream is disclosed. The sorbent composition may include a sorbent with a dispersive agent, designed to enhance the dispersion of the sorbent in an aqueous sorption liquid of a wet scrubber unit, and therefore may be especially useful in EGU or industrial boiler flue gas streams that include one or more wet scrubber units. The sorbent composition may also include a capture agent useful in sequestering mercury and bromine, as well as other contaminants that may include arsenic, selenium and nitrates.

An environment control system utilizes oxygen and humidity control devices that are coupled with an enclosure to independently control the oxygen concentration and the humidity level within the enclosure. An oxygen depletion device may be an oxygen depletion electrolyzer cell that reacts with oxygen within the cell and produces water through electrochemical reactions. A desiccating device may be g, a dehumidification electrolyzer cell, a desiccator, a membrane desiccator or a condenser. A controller may control the amount of voltage and/or current provided to the oxygen depletion electrolyzer cell and therefore the rate of oxygen reduction and may control the amount of voltage and/or current provided to the dehumidification electrolyzer cell and therefore the rate of humidity reduction. The oxygen level may be determined by the measurement of voltage and a limiting current of the oxygen depletion electrolyzer cell. The enclosure may be a food or artifact enclosure.

An apparatus for capturing CO.sub.2 from flue gas includes (a) an absorber, (b) a stripper, (c) a heat exchanger, (d) an amine absorbent circulating through the absorber, the stripper and the heat exchanger, (e) a water washing unit downstream from the flue gas outlet of the absorber, and (f) an electrochemical cell. The electrochemical cell is connected to the water washing unit and is adapted to adsorb and decompose nitrosamine compounds present in liquid separated by the water washing unit.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stability at high-reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica-to-alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.