VOC Emissions from Manufacturing Processes
1. Introduction
| 1.1 | Description of problem |
In the production and use of solvent-containing paints and coatings, substantial
quantities of VOCs are emitted to the surroundings. Therefore, for environmental
protection, measures must be implemented to reduce these emissions.
The best and most practical measure for reducing VOC emissions is substitution by alternative and less critical solvents. In this connection, water-based paints and coatings are gaining in importance. Where substitution of organic solvents is not possible, a further measure reduction of the proportion of organic solvents in the products may be considered, such as the development of so-called "high solids" coatings.
Nevertheless, for certain applications currently no substitution possibilities for organic solvents are foreseeable. For this reason, over both the short and medium terms, solvent-containing products will continue to be used. When manufacturing solvent-containing paints and coatings, VOCs are emitted at various points during the production process.
Prior to constructing costly air pollution purification plants, measures for reducing the emissions of VOCs as well as for reducing the volumetric flow should be implemented. Apart from these purely economic considerations, regarding the implementation of emission reduction measures, also other criteria like practicability (no negative effects on operation, access, etc.), ecology (abatement of solvent emissions), safety, and so on have to be taken into account.
To give manufacturers of solvent-based paints and coatings a basis for coming to a decision on new investments in production facilities and/or pollution abatement technology, the Danish Paintmakers Association has initiated the project:
"Cleaner technology in the lacquer and paint industry"
with one report concerned with "VOC emissions from manufacturing processes" and another report with "Water-based cleaning of mixing vessels and equipment".
The general aim of the project is to qualify the individual companies within the industry to plan and to implement technology in the manufacturing phase that is actually cleaner.
The results of the study "VOC emissions from manufacturing processes" are described in this report.
In the study "Water-based cleaning of mixing vessels and equipment"- the focus will be on the possibilities of using water-based cleaning of mixing vessels and equipment, and to provide companies with a sound basis when confronted with new investments in cleaner water-based technology. Both reports are available on the Internet - www.mst.dk - homepage of the Danish EPA (Danish versions) and on – www.fdlf.dk - homepage of the Danish Paintmakers’ Association (English versions).
The project period was from January 1999 to February 2000.
The project has been carried out by Fichtner · Carl Bro a|s, with the participation of representatives from the companies Teknos Technology A/S and Akzo Nobel Decorative Coatings A/S.
1.1 Description of problem
The application, and release, of volatile organic compounds can, due to their properties, cause harm to human health and/or contribute to local or trans-boundary formation of photochemical oxidants in the boundary layers of the troposphere, leading to environmental degradation.
To prevent, or mitigate, emissions of volatile organic compounds over the long term, in March 1999 the European Communities issued Directive 1999/13/EC of the Commission on the Limitation of Emissions of Volatile Organic Compounds, referred to in the following as the VOC Directive. This requires registration of all plants or plant components covered by this Directive. Furthermore, their operators must initiate measures, within the stated transition periods and as far as necessary, to prevent or reduce VOC emissions.
The purpose of the study
The purpose of this study is to identify measures integrated into the production process for cutting VOC emissions from point and diffuse sources specifically for enterprises manufacturing solvent-based paints and coatings, and to assess these under the aspects of efficiency and costs.
Process integrated measures mean technical and organizational measures for preventing emissions directly at their sources, or by means of which emissions are reduced, extracted and directed to treatment or disposal.
This is contrasted with post-production pollutant destruction and exhaust air clean-up, which is not the subject of this Study. Photos in Appendix B show an example of a postproduction cleaning plant.
Production units at interest
Particularly of interest in this connection are the following production units:
 | unloading stations for feedstocks |
| tankfarms |
| production equipment, like dissolvers, mills, finish tanks, filters, dosing stations |
| holding stores for mobile bins |
| rinsing basins for special tools |
| cleaning cabinets for mobile bins, drums and containers |
Measures for preventing and/or mitigating solvent-containing emissions can be classified under the following headings:
| process-integrated measures |
| product development |
| production planning |