Process Optimisation - A framework that can't be overlooked01 August 2005

By 2007/8, some 4,500 installations regulated by the Environment Agency under the Integrated Pollution Prevention and Control (IPPC) regime brought in by the EU IPPC Directive should finally have completed the permitting process. The listed activities in the directive include energy production, the processing of metals, minerals; chemicals; waste management; pulp and paper; textiles treatment; tanning; food production and intensive farming.Latest available figures (to February 2004) show that approximately 450 permits had been issued for Part A(1) processes. Part A(1) installations are regulated by the Environment Agency and usually relate to the largest, potentially most polluting operations.

For many companies seeking to get to grips with the permit regime and comply with the UK Regulations which implement the Directive (Pollution Prevention and Control (England and Wales) Regulations 2000), a visit to the Environment Agency website to seek further clarification is likely to be their first port of call. Yet many probably don't then turn to the detailed and comprehensive EU guidance which underpins the UK IPPC regime.

Known as BREFs, BAT Reference Documents have now been drawn up by the European Integrated Pollution Prevention and Control Bureau (EIPPCB) to create an EU-wide information exchange process between Member States on Best Available Techniques (BAT). Since 2001, thirty-plus of these sector-specific guides have been prepared, with over half of them formally adopted by the commission. While the BREF notes do not constitute binding requirements, competent authorities in the Member States must take account of them in their own determinations of BAT.

However, while the Environment Agency refers to the BREFs, the Environment Agency's own guidance to UK manufacturing sectors in no way reflects the breadth and depth of information they contain. For example, its UK guidance for delivering the PPC (IPPC) regulations in the pulp and paper sector states briefly that 'the quality, comprehensiveness and usefulness of the BREF is acknowledged. This guidance is designed to complement the BREF, The reader is advised to have access to the BREF'.

This doesn't really do justice to the 500-plus page document available for free - and in English - from the EIPPCB website. As a result, many potential users of the documents are probably failing to realise the scope of these comprehensive documents. The people responsible for day-to-day operations of their plants who would gain significant benefits from the guidance may simply not even be aware of its existence.

Delivering business benefits

So why should plant engineers take a look at the BREFs? The short answer is that the BREFs' specific focus on maximising resource efficiency, consumption and use of raw materials - including water and energy inputs - all now play an increasingly central role in process optimisation and, ultimately, the delivery of bottom-line business benefits. No resource and energy-intensive industrial sector can afford to ignore these issues or do the minimum possible to get by - the upward spiral of rising energy prices, the need to reduce CO2 emissions and the constraints of the Emissions Trading Scheme have put paid to that.

To take a short look at just three of the sectors covered by the BREFs where final documents or the latest drafts have recently been published will give some indication of the scope of this EU best practice guidance. First, the final draft of the Draft Reference on Best Available Techniques for the Surface Treatment of Metals and Plastics (STM), which was published in May 2005. While STM in itself does not form a distinct vertical sector, it provides a service to a wide range of industries which treat metals and plastics to change their surface properties: eg, for decoration and reflectivity, improved hardness and wear resistance, corrosion prevention and as a base to improve adhesion of other treatments. The STM industry plays a major role in extending the life of metals - for example, in automotive bodies and construction materials. It is also used in equipment that increases safety or reduces consumption of other raw materials. The BREF addresses both process-integrated and end-of-pipe techniques, with more than 200 techniques for pollution prevention and control discussed under 18 specific areas. These include general operational issues, such as:

- Utility inputs and their management to optimise electricity consumption
- The amount of energy and/or water used in cooling
- Drag-out reduction and control to minimise the amount of raw materials dragged out of process solutions by the workpieces and other ways of optimising raw material usage. (Poor process control can lead to overdosing which increases material consumption and losses to waste waters)

Comprehensive guidance

The BREF goes into considerable detail about a wide range of process techniques. For example, the retention of raw materials in process vats and minimisation of water use by controlling the drag-in and drag-out of process solutions. The guidance describes how this can be achieved by jigging and barreling workpieces to enable rapid draining, preventing overdosing of process solutions, and using eco-rinse tanks and multiple rinsing with countercurrent flows. A whole chapter is devoted to techniques necessary to increase process solution life, as well as preserving quality, by monitoring and maintaining solutions within specified limits.

A separate chapter is also devoted to emerging techniques - for example, the possibility of integrating surface treatments into the manufacturing production process and the use of a trivalent chromium substitute process for hard chrome plating via modified pulse current which has already started pre-production verification in three typical applications. The technical working group responsible for producing the BREF has suggested that its on-going work programme should cover key issues, such as the development of software for optimisation for a variety of processes.

The 672-page Draft BREF on the Large Volume Inorganic Chemicals (LVIC) - Solid and Others Industry, published in June, provides similarly detailed technique and process-specific guidance for plant optimisation, aimed at maximising resource use, both in terms of energy and raw material input and improving process efficiency in the LVIC sector. The BREF's thorough analysis and description of production processes, together with techniques for process optimisation throughout the large inorganic chemicals sector (including soda ash, titanium dioxide, carbon black, synthetic amorphous silica and inorganic detergent, food and feed phosphates), should be required reading for any LVIC plant engineer professional.

The section on soda ash production alone runs to some 64 pages, covering a wealth of topics which embrace applied processes and techniques, options for process optimisation and improvement, consumption of raw materials and utilities in the form of steam, process water, cooling water and electricity, energy management, energy conversion of primary fuels, energy saving in the process, heat recovery, energy minimisation and optimisation of the soda ash process to reduce CO2 emissions - to mention just a very few! Likewise, the section on titanium oxide includes comparison of a titanium oxide plant using the sulphate process route and the chloride process route, with a six-page analysis of lifecycle assessment in the titanium oxide industry.

Thorough examination

The BREF examines in detail a range of selected LVIC industry products. These include silicon carbide, zeolites, calcium carbide, carbon disulphide, ferrous chloride, ferric sulphate, iron oxide pigment, lead oxide, sodium perborate and sodium percarbonate, and thorough technical information of their individual production processes, applications, applied processes and techniques, and raw material and energy inputs and outputs. Again, the BREF also considers emerging technologies in the LVIC industry - ranging from innovations in the carbonation section of the soda ash plant, novel products and co-products in titanium oxide production, future developments in carbon black and potential new developments in furnace operation in silicon carbide production.

Finally, the newly published 682-page Final Draft Reference Document on Best Available Techniques in the Food, Drink and Milk (FDM) Industries likewise goes into the same level of detailed expert coverage. The BREF examines large-scale food production for the treatment and processing for the production of food products from animal raw materials (finished product production capacity (FPPC) greater than 75 tonnes per day), vegetable raw materials (FPPC greater than 300 tonnes per day) and treatment and processing of milk ( FPPC greater than 200 tonnes per day).
The BREF covers a wide range of production processes from across the FDM sector, including materials reception and preparation, size reduction, mixing and forming, separation techniques, product processing technology, heat processing, concentration by heat, processing by removal of heat, post-processing operations and utility processes. Within each of these categories, up to 14 unit operations are described in detail. Some 370 techniques are described generally and cover topics such as operational data and applicability, and cover both process-integrated and end-of-pipe techniques. The BREF describes techniques which are applicable in all FDM installations, ranging from operational practices - such as equipment and installation design, maintenance and a methodology for preventing and minimising the consumption of water and energy - to more technical aspects, such as production management, process control techniques and the selection of materials.

As in other BREF guidance, the FDM BREF emphasises the importance of giving priority to process-integrated techniques to prevent and reduce air and waste water emissions, drilling down to very detailed level at the use of very specific technology in some individual FDM sectors. Many of the Best Available Techniques recommended by the BREF, which are aimed at optimising operating conditions, achieve reduced energy consumption in the process - eg, by using multi-effect evaporators, optimising vapour recompression related to heat and power availability in the installation to concentrate liquids.

Flagging up potential savings

Once again, the BREF includes recommendations for developing future guidance, covering process descriptions, operating conditions, further opportunities for by-product valorisation to minimise waste generation and the costs of investing in, and operating, techniques, and their associated direct and indirect savings. Some 200 pages provide a thorough analysis of current consumption and emission levels of water, air emissions, solid output, energy and noise for a comprehensive range of preparation and production processes - from grinding, milling and crushing, mixing/blending, homogenisation and conching, forming/moulding and extruding, to fining, centrifugation and sedimentation, filtration, membrane separation, deodorisation by steam stripping, pasteurisation, freezing, dehydration, gas flushing and vacuum generation. It also looks in detail at process control techniques, including control temperature, flow and level, flow measurement and control, analytical measurement, use of automated water start/stop controls and use of control devices.

The BREFs, then, are not full of impenetrable EU gobbledygook. Rather, they contain solid, practical, technical information which any plant engineer could usefully apply or consider for their own manufacturing processes in the context of improving/ optimising process performance. It is difficult to convey the expertise, breadth and wealth of information these invaluable documents contain. The Environment Agency should give serious consideration to making all the BREFs available - whether in draft or final format - directly from its own website. It just might find that such promotion has a significant impact on improving environmental performance, making UK industry more cost-effective and efficient in the process. Readers who want to access this information now should visit the EIPPCB website at: www.eippcb.jrc.es and click on activities to download the guidance for their sector.

Elaine Coles is Head of Research at IMS Consulting (part of IMS Marketing Communications Group) and writes regularly on environmental and industrial issues

BREFS BY SECTOR

Cement and Lime production
Ceramics
Chlor-Alkali manufacture
Common waste water and waste gas treatment and management systems in the chemical sector
Cooling Systems
Economic and cross-media issues under IPPC
Emissions from storage of bulk or dangerous materials
Energy Efficiency
Ferrous Metal processing
Food, Drink and Milk processes
Glass manufacture
Intensive Livestock Farming
Iron and Steel production
Large Combustion Plant
Large Volume Inorganic Chemicals - Ammonia, Acids & Fertilisers
Large Volume Inorganic Chemicals - Solid & Others
Large Volume Organic Chemicals
Management of Tailings and Waste-Rock in Mining Activities
Monitoring systems
Non-Ferrous Metal processes
Organic fine chemicals
Polymers
Pulp and Paper manufacture
Refineries
Slaughterhouses and Animal By-products
Smitheries and Foundries
Speciality inorganic chemicals
Surface treatment of metals
Surface treatments using solvents
Tanning of hides and skins
Textile processing
Waste Incineration
Waste Treatments [Previously Waste Recovery/Disposal activities]

SOE

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.