VOC Emissions from Manufacturing Processes
Summary and conclusions
As summary parts of the text from the project article in the publication "Ny Viden", issued by the Danish EPA are reproduced.
VOC-reduction - step by step - is possible
The lacquer and paint industry is able to reduce the emission of VOC’s (volatile organic compounds) to the working environment and the external environment. This is documented in a report describing methods for mapping, preparation and assessment of solution proposals as well as preparation of final action plans. Reduction can take place through product development and changed planning of production including training of employees. However, in many situations there is a need for technical initiatives. As use for assessment hereof a catalogue has been prepared with different emission limiting initiatives and expected efficiency and economy has been assessed.
New requirements for the lacquer and paint industry
Background and purpose
The lacquer and paint industry in Denmark consists of approx. 20 manufacturers of paints as well as approx. 10 manufacturers of glue and sealing compounds.
Under the auspices of the EC, two directives have been adopted which will become important for the environmental work within the paint industry.
EC-directive 1999/13/EC of 11 March 1999 makes a request for reduction of the VOC emission from among others the companies within this industry. The directive shall be implemented in the Danish legislation in March 2001 at the latest. For the actual companies this will mean requests for documentation and set-up of action plans with a view to meet specified requirements for emission from point sources and diffuse sources.
EC-directive 96/61/EC of 24 September 1996 about integrated prevention and abatement of pollution is implemented in Denmark with a new order regarding approval of listed activities, The Danish Ministry of Environment and Energy’s ministerial order no. 807 of 25 October 1999 (Miljø- og Energiministeriets bekendtgørelse nr. 807 af 25. oktober 1999). The ministerial order, clarifying the requirements for statement with regard to use of best accessible technique (BAT), will acquire an importance for companies in the situation of approval and by reassessment of approvals formerly issued.
In 1994-1995 the Danish Paintmakers’ Association made a review of the possibilities for using cleaner technology within the lacquer and paint industry. Report regarding this review has previously been published/issued as Trade Information for the lacquer and paint industry no. 5, 1996 from the Danish EPA (Brancheorientering for lak- og farveindustrien nr. 5, 1996 fra Miljøstyrelsen).
In continuation of the review in 1994-1995 the Danish Paintmakers’ Association has completed a project with assessment of technical possibilities for reducing VOC emissions from manufacturing processes within the lacquer and paint industry. The aim is to demonstrate the possibilities being used and how the industry can work with the way of presenting the problems. Employees from Fichtner GmbH & Co. KG in Germany and Carl Bro a|s in Denmark have been consultants on the project.
The target group of the project is companies within the lacquer and paint industry as well as the environmental authorities. The purpose has been to introduce possibilities for initiatives at existing companies. More far-reaching initiatives primarily being possible in connection with a new establishment are beyond this project.
The possibility of implementing the project is created by financial support from the Danish EPA.
Collecting of relevant experiences
The project
The main stress will be laid on method description for review, setting-up and assessment of solutions as well as the final action plan. As use for this work a catalogue has been elaborated with emission limiting initiatives. The catalogue describes solutions to different parts of the process with information of expected efficiency and economy.
There is a brief description of possibilities for reduction through product development and planning of production including training and education of employees.
A number of companies in Germany among suppliers of equipment and manufacturers have kindly placed information, material and experience at our disposal for the project,
Two Danish companies Teknos Technology A/S and Akzo Nobel Decorative Coatings A/S have participated in a group of experts having followed the project.
The Danish EPA, the Danish Directorate for National Labour Inspection SiD (the General Workers Union in Denmark), the Association of County Councils in Denmark and the Danish Paintmakers’ Association have been represented in a steering committee.
Increase of demands
Main conclusions
In order to understand the way of presenting the problems it is important to look at the contents of the new VOC-directive.
The directive concerning reduction of the VOC-emission means for the lacquer and paint industry that companies with a consumption of VOC larger than 100 tons/year shall:
 | Prepare documentation through emission review |
| Describe the development up to the situation in 2007 |
| Identify and describe initiatives meeting the demands of the directive |
| Establish initiatives to an extent as circumstances may require |
The emission requirements for the companies in the lacquer and paint industry are shown in table 1.
Table 1
Limit value in EC-directive 1999/13/EC of 11 March 1999.
Consumption of VOC, |
Emission limit (point sources), |
Limit for diffuse emissions, % |
Limit for total emissions, % |
100-1,000 > 1,000 |
150 150 |
5 3 |
5 3 |
Note:
| Emission limit cannot be compared directly with the values in the Air Instruction (Luftvejledningen, the Danish EPA, 06/90), as this states mg substances per m3. |
| The directive means that a company has to meet either the emission limit together with limit for diffuse emissions or limit for the total emissions (emission limit for point sources can then be exceeded) |
The VOC emissions can be grouped depending on how they leave the production facilities:
| Part of wastewater to sewer or through internal purifying plant |
| Part of solid waste to external disposal |
| Emission to the atmosphere, directly or as residues after air cleaning |
The emissions to the atmosphere are of major importance and at the same time is efficient reduction possible here. The primary sources for emissions are:
| Tank facility, filling and storage |
| Filling of raw materials to production plant |
| Processes in mixing vessels etc. |
| Filling of semi-finished products and finished products |
| Diffuse exhaust from production equipment |
| Cleaning of equipment |
In connection with set-up of action plans and combination of solutions it is necessary to separate different airflows after air volume and concentration of VOC. The separation can be used by choice of appropriate handling of each airflow. Concentrated flows can possibly be incinerated with limited use of support fuel. A solution with collection of all airflows could cause the fact that a considerable volume with low concentration of VOC had to be incinerated by means of continuous supply of support fuel.
It is important to emphasise the importance of the fact that the concrete action plans have to be elaborated on the basis of the conditions at the individual companies.
However, it is also important to stress that the manufacturers should plan a long-term strategy for development of new products aiming at reducing the VOC emission, partly during production and partly at the customer. The strategy is planned on the basis of interplay between the demands of the market, suppliers of raw materials and the manufacturer.
VOC reduction - step by step
Instruction
The general steps in the work with emission reduction are:
| Establishment of detailed emission register |
| Assessment in relation to requirements from authorities |
| Planning of scenarios for reduction |
| Choice of best combination of initiatives |
| Set-up of action plans |
| Follow-up and reporting |
The steps are described in the report advising how the work can be initiated.
As there are several partial flows and processes having to be reviewed by measurement of VOC the report recommends that measurements to a large extent are carried out as TOC-measurements (Total Organic Carbon) with transportable measuring equipment (FID - Flame Ionisation Detector). Measurements should to the extent required be calibrated with traditional measurements with collection of VOC on active carbon tubes and subsequently laboratory analysis.
In connection with the work with scenarios, action plans and subsequently follow-up an EPI-figure (Environmental Performance Indicator) is introduced:
EPI = [Q (kg VOC/year)] / [Cr x Production (tons/year)]
EPI can be influenced by changing the emission (Q) or by changing the character of the raw materials in use (Cr - a weighted C-value). It shall be noted that a Cr -value is a theoretical value in principle to be used only for not odour-regulated substances with same toxicological effect. EPI can be used on each individual company, however it cannot be used directly as standard of comparison between companies. The use of EPI brings both the size of the emission and the substitution of dangerous solvents to less dangerous solvents into focus. EPI can be used as environmental indicator informing about the development of the environmental performance of the company and as such may enter as a management parameter in an environmental management system. The practical making-up of EPI is carried out on the basis of production data compared to experience figures from emission measurements for single processes and/or on the basis of mass balances.
An example of reporting of development based on EPI-figures is shown in figure 1.
Figure 1
Example of development in EIP-figures over time and by implementation of action plans.
Emission limiting initiatives
Catalogue
The catalogue of emission limiting measures is based on production activities and partial activities indicated in figure 2.
Figure 2
Typical partial activities within the lacquer and paint industry.
An overview of each element of the catalogue is stated in table. The importance for emission from point sources and diffuse emission is indicated with arrows:
| ê | Reduction of VOC concentration |
| î | Slight reduction of VOC concentration |
| ì | Slight increase in VOC concentration |
| é | Increase of VOC concentration |
Table 2
Emission limiting initiatives and their importance for diffuse emissions and point
sources.
MEASURES |
Diffuse emissions |
Point source emissions |
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5.1 Unloading system for feedstock dosing and tankfarms |
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ê |
ê |
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ê |
ê |
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5.2 Dissolver and reactor |
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ê |
ì |
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ê |
ì |
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î |
ì |
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î |
ì |
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ê |
ê |
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ê |
ì |
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ê |
ê |
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ê |
é |
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ê |
é |
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- |
î |
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5.3 Holding store for mobile bins |
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î |
- |
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MEASURES |
Diffuse emissions |
Point source emissions |
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5.4 Dosing station for mobile production bins |
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î |
ì |
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ê |
ì |
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ê |
ì |
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ê |
ì |
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5.5 Mills for fine dispersing |
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î |
ì |
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î |
ì |
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5.6 Finish tanks |
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ê |
ì |
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5.7 Filter systems |
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ê |
ì |
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5.8 Filling systems |
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î |
ì |
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5.9 Rinsing basin |
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ê |
ì |
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ê |
ì |
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5.10 Cleaning of mobile production bins |
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ê |
ê |
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ê |
ê |
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ê |
î |
For each category of production equipment the character of the emission is stated together with description of initiatives with assessment of efficiency and economy.
Moreover the catalogue contains an appendix with photos of a number of initiatives.