As pressure grows to make Europe into a low carbon economy, Susan Birks looks at what UK manufacturing sites are doing to improve resource efficiency
The chemicals sector accounts for some 22% of UK industrial process emissions, the Carbon Trust stated at a recent Resource Efficiency conference organised by Envirowise, and the pharmaceutical industry is seen as no small player within that group. Drug production involves many energy-intensive processes: drying, evaporation and distillation. It also is a heavy user of HVAC equipment.
Pressure from governments and environmental agencies to make industry leaner and cleaner, along with diminishing UK landfill space and escalating energy prices, is galvanising the sector into action, forcing a change in behaviour. The conference highlighted various approaches to cutting energy and waste, some of which are covered here, and introduced many of the organisations that can direct companies to how and where savings can be made.
For example, for UK businesses with energy bills of £50,000 or above, The Carbon Trust will carry out a site survey and advise on energy savings. For Bespak, a supplier of drug delivery technologies with an energy bill of £1.1m a year, this meant the installation of mechanical droplet vaporisers, rationalisation of compressed air usage, use of variable speed drives on air handling units and of temperature and humidity controls.
The Carbon Trust survey suggested that these changes would produce a potential annual saving for Bespak of £260,000 - a quarter of its energy bill.
Astra Zeneca had a £24m energy bill for its Cheshire sites. The company has reduced its energy usage by specifically targeting HVAC systems. It estimated that 60-70% of energy consumption at its UK research and manufacturing sites was associated with the HVAC systems necessary to keep the plants clean and protect employees from potentially toxic drug materials.
The company's first step was to monitor the energy consumption. It invested in 380 electricity meters, 26 steam meters, three water meters and three nitrogen meters. It then embarked on a rolling programme of HVAC optimisation works. It plans to invest a further £1.3m but expects a payback in less than five years.
At its new r&d facility in Macclesfield, the company is applying Variable Air Volume fume hood control and heat recovery. This should use 15% of the energy per fume hood of the facility it replaces.
prevention first
Environmental team leader at Dow Corning, Mike Squire, says his company now focuses on cleaner process designs for prevention of waste, as an estimated 75% of total life-cycle costs of products are determined at the design stage.
The company has eliminated or minimised hazardous waste at its joint Dow Chemical and Corning manufacturing site in Barry, South Wales using the "waste hierarchy" approach (fig. 1). Prevention is top of the hierarchy, and with this in mind, Dow has replaced solid catalyst with liquid catalyst, eliminating hazardous waste in the form of solid catalyst filter cartridges and saving more than £10,000 a year.
A second example was the elimination of cyclohexane solvent use, achieved by substituting the hazardous raw material with a non-hazardous one. This eliminated VOCs from plant vent and also eliminated drum handling and hazardous drum waste.
By forming a "symbiotic" relationship with companies operating on its boundaries, the company was also able to feed its waste chlorosilanes to others for use as a raw material. The waste HCl gas was then fed back as raw material to Dow Corning. This led to a 23% reduction in raw material methyl chloride costs and also obviated the need for shipments of hazardous wastes.
Minimisation is the next best process in the waste reduction hierarchy. By changing its purging technique and achieving a 10-fold increase in the life of fixed bed molecular sieve, the company made a 10-fold saving in raw material costs and reduced its hazardous waste volumes.
Under reuse or recovery, Squire said that sewered HCl acid was being recovered for reuse in its processes. This produced a further 11% reduction in raw material costs and also meant a minimisation of water treatment neutralisation. This translated into lime raw material savings and cut calcium filter cake waste to landfill.
Supplier of bulk APIs and excipients, Shasun Pharma Solutions, has made an annual saving of £132,000 at its 42-acre site in Dudley, UK, through regular waste reviews on every routine manufacturing process. The site, comprising process development labs, a flexible pilot plant and three major production facilities, has 450m3 of cGMP reactor capacity and its own biological waste-water treatment facility.
The review process involves an around-a-table audit involving employees and outsiders, followed by a walk-the-process audit, with the objective of identifying and reducing or eliminating waste. The audit covers all raw materials put into the process, including solvents and catalysts, as well as packaging, utilities and energy.
Technical manager for manufacturing at Shasun, Jon Cummins, says the company uses "the "toddler technique - why?, why?, why?, why?, why?"
This method of questioning how and why they do things has led to significant savings. He gave an example:
- Q: "Why do we run the scrubbers on this process?"
- A: "To prevent air emissions",
- Q: "What air emissions?"
- A: "None really, there are no acidic materials present, the alcohol solvent is contained by condensation (-15°C) and is environmentally harmless anyway".
- Q: "So why do we use the scrubber?
- A: "We always use a scrubber if it's available!"
The company agreed not to use the scrubber and to review scrubber use on its other processes. This scrubber usage review made annual savings of:
water (purchase & disposal costs) £820
18% caustic soda solution £105
electricity bill £1,100 plus
operator time for scrubber operations
analyst time (caustic content analysis).
The same question is put by the process manager to current reaction conditions, reagents, proportions, solvent use, temperature and pressure profiles, and process wastes.
For example, during one main manufacturing process, a reaction quench solvent used was an alcohol. Lab studies showed that a cheaper alcohol worked as well as the more expensive alcohol in current use. Yield, quality and process time were unaffected by the change but the company made an annual saving of £59,000.
A third example considered the disposal route for an acetone waste: Why was it disposed of as cement fuel? The company found the original low volume of production had meant recovery was not viable. But that volume of production had since increased, making recovery a viable option. Better use of a waste stream achieved an annual saving of £5,200.
By relocating a distillation operation and investing in a more efficient still, the company reduced liquid fuel oil costs, saving £6,000 a year. The transfer via a hard pipe meant no more drum usage or manual handling or forklift truck transfer between plants. The drum cost-saving was £13,000 a year.
Finally, each batch uses a precious metal-based catalyst in a coupling reaction. This generates one drum of solid waste (200kg containing around 360g of precious metal). The original route of disposal was incineration. Now the waste is repackaged for return to the catalyst manufacturer for recovery of metal. As a result, the company gets paid, giving an annual saving £7,000.
professional advice
There are many organisations in the UK that have been set up to help companies find and facilitate such savings. The National Industrial Symbiosis Programme (NISP) is one such group. Funded through the UK Department for Environment, Food and Rural Affairs, NISP engages separate industries and organisations in material exchange to achieve a mutually beneficial competitive advantage.
As the NISP's Mick Fanning put it: "One man's waste is another's raw material". Not exclusive to a particular resource, waste can include raw materials, energy, logistics, human resources, water and investment. Available to UK businesses regardless of size or turnover, NISP has gained more than 8,000 members since 2005.
Trade bodies such as the ABPI also play their part in helping the industry tackle waste by facilitating exchange of best practices between members. Mike Murray, head of manufacturing and environment at the ABPI, said that in particular the organisation's EH&S Group continues to investigate the possibility of Climate Change Agreements for the pharmaceutical sector and to review the future developments in respect of emissions trading.
Envirowise, another UK government-funded organisation, has successfully driven savings throughout the pharma sector but it is looking to make more. In addition to organising seminars on the topic of resource efficiency and waste reduction, it offers free specialist advice for UK-based companies. It can help provide an action plan to focus manufacturers" effort, identify where valuable resources may be saved, give practical advice on how to make changes and sources of further assistance..