The VOC Solvent Emissions Directive ­ an industry perspective

Citation

Dobson, I. (1999), "The VOC Solvent Emissions Directive ­ an industry perspective", Pigment & Resin Technology, Vol. 28 No. 2. https://doi.org/10.1108/prt.1999.12928baf.001

The VOC Solvent Emissions Directive ­ an industry perspective

The VOC Solvent Emissions Directive ­ an industry perspective

Ian DobsonVOC manager at BP Chemicals Ltd and Chairman of the European Solvent VOC Co-ordination Group (ES-VOC-CG), a cross industry forum representing solvent using industries, manufacturers of products containing solvents and solvent producers

Keywords Emissions, Environment, Solvents

Introduction

In this article the author reviews the status of the VOC Solvent Emissions Directive which is nearing adoption by the European Union's legisiative bodies. He looks at why the Directive is required and considers how it will affect over 30 industry sectors using solvents in many vital manufacturing processes and how these industries can act to cut emissions.

The proposed VOC Solvent Emissions Directive, which aims to cut VOC emissions by 67 per cent by 2007 compared to 1990 levels, moved one step closer to adoption on 23 March 1998 when Europe's Council of Environment Ministers reached a Common Position on the proposal.

The proposed Directive is now being translated into the 11 official EU languages before it goes back to the European Parliament for its second reading. The Directive is then likely to be formally adopted by the Council by the end of 1998 without further significant changes.

Each Member State government will be obliged to put national legislation into place within two years to achieve the Directive's requirements. They will be able to adopt the requirements exactly as set out in the Directive, or adopt more stringent requirements ­ indeed each State's decision will depend on the type of national regulations already in place to cut VOC emissions.

Compliance will undoubtedly be challenging and costly for some 400,000 enterprises in the 30 industry sectors affected by the proposals, but time and flexibility have been built in so that compliance should be achievable by 2007.

Why a Directive?

The proposed Directive, published in 1996, is a component of the European Commission's air quality strategy which includes a range of proposed and adopted Directives such as those within the Auto Oil programme and the Integrated Pollution Prevention Control (IPPC) Directive. There are overlapping requirements between the IPPC, the VOC Solvent Emissions Directives and existing national legislation in some Member States, so it is encouraging that a flexible approach for national implementation has been agreed by the Council of Ministers.

It is widely accepted that organic molecules in the lower atmosphere are involved in chemical reactions which under certain weather conditions can lead to summertime smog creation. However, the problem is not by any means entirely caused by solvents. On an annual basis approximately 24 per cent of Europe's VOCs (volatile organic compounds) come from solvents use ­ other major sources are from natural vegetation, transport and power generating combustion processes, and the percentage of each varies both geographically and seasonally according to the amount of natural vegetation versus industry. Furthermore, natural emissions are at their highest precisely under the weather conditions which cause summertime smog. When these factors are considered, the overall "weighted" contribution from solvents to summertime smog is around 10 per cent.

Air quality standards in Europe have been constantly improving for several years now. Indeed, 1996 data show that in most parts of Europe, air quality targets were not exceeded. Where they were, this rarely happened for more than five days in the year. Nevertheless, in a number of urban areas, targets were exceeded for between five and ten days so industry and European Commission attention is focused on reducing these occasions still further. It must be remembered, however, that ground level ozone creation is, to a large extent, a geographical phenomenon. In the Mediterranean countries levels of natural VOCs are so high that when NOx is present they react and create ozone regardless of the levels of man-made VOCs.

Taking these points together we see the driving force for this Directive is for the solvents sector to make a further contribution to help minimise Europe's summertime smog.

Who uses solvents and how will they be affected by the Directive?

Many industries from diverse sectors rely on solvents in critical manufacturing processes, for example to extract food oils, recrystallise pharmaceuticals and achieve controlled evaporation of paints and inks, to name just three examples.

Over four million tonnes of solvents are used in Western Europe annually, almost half of which is used by paints and coatings manufacturers, but significant proportions are also used by the pharmaceuticals, cleaning, adhesives and printing inks industries. A large number of industries will therefore be affected by the proposed Directive, because solvents are used in key processes such as coating, cleaning and degreasing, which are essential across most industrial sectors. The trade associations of affected industries have been involved, as part of ES-VOC-CG, in discussions at EU level, to ensure comprehensive industry representation in the debate surrounding the Directive's development.

As it currently stands, the proposed Directive aims to cut VOC emissions from solvent using installations by 67 per cent by 2007 compared to 1990 levels. It will affect some 400,000 enterprises, over 90 per cent of which are small and medium sized enterprises, involving 10 million employees ­ clearly a very wide-ranging proposal.

The Directive's proposals allow for economic growth ­ thresholds have been set to avoid excessive costs for smaller enterprises and any capital invested previously to reduce emissions will be recognised and protected. It will credit efficiency improvements as well as emissions reductions ­ encouraging industries to look at all methods of reducing VOC emissions to the atmosphere and allowing them the choice to pick the best for their industry.

This is a critically important aspect, as it supports innovation and ensures that most cost-effective solutions can be achieved on a plant-by-plant basis. Even within an industry sector, the needs of a given operator vary widely depending on many factors, including scale, variety of products, age and geography of the site.

The Directive's main impact on industry will come through compliance. New plants will be required to comply with the Directive immediately and existing plants within a certain time lag. Emission limit values will be set depending on the sector. Tables I and II summarise the main requirements, by sector, contained in the Directive as it currently stands. Sectors will be able to make use of a reduction scheme which allows for creative solutions to emission control by a combination of different methods. Industries will also need to comply with some monitoring and reporting requirements.

What can affected industries do to reduce VOC emissions?

Significant progress to reduce VOC emissions has already been made. Today, industry is twice as efficient per unit of production compared with the 1970s. This Directive will build on top of what has been achieved to date.

However, solvents' use in many applications is critical and in the majority of cases they cannot be replaced. Industry is looking at low-solvent alternatives ­ to help solvent users comply with targets, however, even where alternatives exist, environmental benefits must be balanced with performance costs.

Good housekeeping measures can help start off the process of VOC emission reduction. Using less solvents, accompanied by technical innovations, can have a significant impact. For example, high volume, low pressure spray guns allow paint to be more precisely targeted, reducing overspray and creating better resource efficiency. Other examples include changes to resin technology for coatings. For example, replacing 100 microns of alkyd with ten microns of polyurethane yields a more durable surface with much less solvent, despite both being solvent-based paints.

Using coloured primer inside car boots avoids the necessity of a top coat, saving paint and hence emissions ­ an example of one of the creative ways that emissions can be reduced while still getting the benefits from using solvents.

Abatement technologies such as thermal oxidisers will be used by many industrial processes to capture solvent emissions after use. For example, BP Chemical's flexible packaging site uses solvent-based inks to print on plastics and is currently installing a thermal oxidation unit which will reduce VOC emissions from 950 to only 20 tonnes a year. Such equipment is often the most cost effective solution to meet the target emissions for medium to large solvent users.

In some instances, where very large amounts of one solvent type are used, VOCs can be collected and reprocessed. For example, isopropanol used in pharmaceutical synthesis can sometimes be redistilled and turned into car windscreen de-icer.

Low solvent technologies are also being developed and used successfully in certain applications. High solid and water-based paints are examples of low solvent options which still rely on some solvent to ensure performance. An excellent example is the internal coating of tin cans. Water-based epoxy resins formulated using glycol ethers achieve better coverage inside the can and lower emissions. This is one of the very specific cases where water-based coatings perform better and are more cost-effective.

Reducing solvent content needs to be balanced with functional performance. If a substitute product is less durable it will require earlier replacement and greater maintenance, resulting in increased resources which may negate environmental benefit. Assessing the pros and cons is a complex procedure, but if done properly, then the results can be quite illuminating. For example, a recent life cycle analysis of solvent-based paint used to protect the Humber Bridge against a harsh marine environment provided strong evidence of the long-term environmental benefits of solvent-based coatings in maintenance applications. Substitution to a water-based coating in this particular application would require stripping and cleaning old paint from the structure and re-painting every five years, adding a substantial environmental burden in terms of mineral ores and particulates and landfill requirements. Therefore, substitution of solvents can also result in substitution of environmental impacts.

Overall costs are high and in some sectors technologies are extremely challenging. Costs will vary widely according to sector. For example, a cost analysis by the UK DTI demonstrates that large scale abatement could reduce emissions in the region of 100 ECU per tonne per year. This is in contrast to the most marginal aspects of the Directive, for example, substitution to water-based car paints, which could cost well over 10,000 ECU per tonne per year.

Overlap with IPPC

This Directive becomes important for sites large enough to be covered by the Integrated Pollution Prevention Control (IPPC) Directive. Many industries are covered by both. Key elements of IPPC include the emphasis on best available techniques, measures to control water pollution and energy efficiency. It makes some VOC solutions less obvious for larger industries who will not be able to substitute one problem for another. The European Commission has endeavoured where possible to harmonise the timescales between these two Directives.

Conclusions

There is no doubt that the Directive will have an impact on a wide range of solvent-using industries, however, the time necessary to achieve these developments has been set aside, so that by 2007, industries should be able to comply with the emission regulations. Solvents manufacturers are committed to working with industry partners to achieve the best cost efficiency possible for emission monitoring and abatement techniques to enhance improvements already made. Managed responsibly, solvents do not present an environmental risk and within the framework of this Directive will continue to offer their performance benefits to a wide variety of industries.