Coatings solvent abatement

Papasavva et al. [36] showed diagrams of auto paint lines that indicated abatement on the solvent-borne primer/surfacer ovens, on the heated flashed zone after waterborne basecoat application, and on the solvent-bome clearcoat oven. The abatement equipment included a carbon concentrator, which is likely a device for solvent vapor adsorption on activated carbon. A collection efficiency of 90% was reported. The abatement equipment also included a system for oxidizing the vapors to form water and carbon dioxide. These units were called reactive thermal oxidizers (RTOs) [36], and their destruction efficiency was reported to be 95%. For the various scenarios discussed in Section 6.7.2, the abatement efficiencies were reported to range from 52.3 to 62.5%. Emissions from powder coatings ovens are expected to be so low that abatement is not needed, and calculations with and without powder coating oven abatement gave the same results for VOC emission [36]. 

No information was provided concerning techniques for the abatement of VOC-emissions. The lack of information on abatement techniques and associated emission levels made it impossible to formulate a BAT eonclusion. Techniques for the reduction of VOC-emissions related to coating processes (as applied to cores and moulds) may be found in the BREF on Surface Treatment Using Solvents. 

Figure 6.7 shows how the emission of solvent from a typical coating process can be reduced using three different technologies - conventional paint with end-of-pipe abatement, an alternative water-based paint and... 

The elimination of organic solvents in the application of coatings, saturants, sealants and adhesives, and its importance in environmental pollution abatement and worker health and safety, has already been identified in connection with aqueous polyurethane latex and polyurethane... 

The dryer provides heat to volatilize the solvent and a means to carry the solvent away from the coating. Efficient hardware is used to minimize energy costs. The dryers may be equipped with the appropriate pollution abatement devices to meet both OSHA and EPA standards. Dryers commonly use hot air both to provide heat and to carry away the solvent. The air may be heated by steam or by heat exchange with flue gases. Flue gases from the combustion of natural gas maybe used directly in place of hot air. Infrared radiant energy from gas combustion or electric resistance heaters is sometimes used. Conduction heat transfer from heated... 

In general, many VOC generating processes operate in lean (excess air) environments and thus abatement involves oxidation. When large amounts are present it is sometimes economical to recover them for recycling since many are used as solvents. For chemical plants such as painting or coating operations, alcohols, paraffinic and... 

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