Emissions, volatile aromatics

Production (Source, Use, Shipment) and Emissions Volatile Aromatics from Coal and Lignite... 

The aim of the present study is the investigation of activity of the catalysts based on foam materials (foam metals and foam ceramics) in the processes of deep oxidation of volatile aromatic compounds and neutralization of gas emissions of enameled wire production. 

Every year, about 50 million t hydrocarbons are discharged into the atmosphere from refineries and automobile exhausts, about 20 million t from incineration plants, and about 20 million t from other man-made sources [10, 11], of which only part is aromatic. These emissions could contain some 10-20 million t volatile aromatics [12]. Another estimate is based on world emissions of hydrocarbons from stationary plants of 54 million t (USA 7-18 million t) and from mobile sources (transportation means) of 34 million t (USA 12-20 million t) [13]. It has also been calculated that world evaporation losses of hydrocarbons from the production and processing of petroleum amount to 44.7-68 million t (approx, one-quarter of this in refineries), and emissions from the combustion of by-products in the oil processing industry to 28 million t [5]. In these figures, too, the volatile aromatics naturally account for only a portion, perhaps one-fifth. 

Evaporative emissions from vehicle fuel systems have been found to be a complex mixture of aliphatic, olefinic, and aromatic hydrocarbons [20,24,33]. However, the fuel vapor has been shown to consist primarily of five light paraffins with normal boiling points below 50 °C propane, isobutane, n-butane, isopentane, and n-pentane [33]. These five hydrocarbons represent the more volatile components of gasoline, and they constitute from 70 to 80 per cent mass of the total fuel vapor [24,33]. 

Floating polyethylene spheres are capable of reducing volatile emissions by up to 90%. Polyethylene spheres are compatible with a broad range of compounds including inorganic acids and bases and most aromatic and aliphatic organic compounds.16... 

Gundel, L. A., K. R. R. Mahanama, and J. M. Daisey, Semi-volatile and Particulate Polycyclic Aromatic Hydrocarbons in Environmental Tobacco Smoke Cleanup, Speciation, and Emission Factors, Environ. Sci, Technol., 29, 1607-1614 (1995b). 

One of the major uses of activated carbon is in the recovery of solvents from industrial process effluents. Dry cleaning, paints, adhesives, polymer manufacturing, and printing are some examples. Since, as a result of the highly volatile character of many solvents, they cannot be emitted directly into the atmosphere. Typical solvents recovered by active carbon are acetone, benzene, ethanol, ethyl ether, pentane, methylene chloride, tetrahydrofuran, toluene, xylene, chlorinated hydrocarbons, and other aromatic compounds [78], Besides, automotive emissions make a large contribution to urban and global air pollution. Some VOCs and other air contaminants are emitted by automobiles through the exhaust system and also by the fuel system, and activated carbons are used to control these emissions [77,78],... 

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