Water and Effluent Treatment Magazine
Issue link: https://read.utilityweek.co.uk/i/867569
SEPTEMBER 2017 WET NEWS 17 INSIGHT Renewable energy I ncreasing pressure on food and drink businesses to access alternative, cleaner sources of energy, for commercial and environmental reasons, extends across the supply chain. Not only for production processes but also for the transport of raw materials and finished products. Generating biogas from factory process residues, provides an effective on-site solution with an additional benefit – it can also facilitate the supply of recycled water. Following the 2015 Paris THE CONCEPT • Clearfleau's on-site bio-energy plants can discharge cleansed water for possible re-use • Cleansed water is one of the three outputs from the on-site digestion process, with biogas and bio-solids • COD load reduction in the digester can exceed 98% NEED TO KNOW 1 Generating clean energy from process residues is one way of promoting better water management 2 Clearfleau is exploring whether cleansed water after AD can be further polished, using reverse osmosis 3 the agri-food sector must become more efficient to supply products in a more water-sustainable way THE VERDICT "Recycling of cleansed water, to enable production sites to reduce net water consumption, should be part of the government's clean growth strategy" Richard Gueterbock, Clearfleau COP21 Climate Change Convention, leading food and beverage sector multi-nationals made commitments to change their practices. CEOs of companies like Unilever and Nestlé signed a statement of intent, stating that they: "Want the facilities where we make our products to be powered by renewable energy, with nothing going to waste, as corporate leaders, we have been working hard toward these ends, but we can and must do more." With global food companies setting ambitious targets for reducing their emissions and pressure to develop a more circular economy, European firms, large and small, should be trying to match them. Some British companies that have installed on-site bio-energy plants are already benefiting from cost savings, while reducing their environmental impact and making their sites more efficient. Taking a circular economy approach requires innovative production solutions which can also address issues like net water use across the food chain, from farm to retail shelf. On-site anaerobic digestion replaces traditional aerobic solutions for handling energy-rich processing residues and can allow cleansed water to be re-used. It can provide a cost-effective treatment option for residues, offering an attractive return on investment, with many wider benefits: • Energy – bio-energy generated on site cuts fossil fuel use, increasing energy efficiency • Emissions – replacing fossil fuels with bio-energy, reduces the site's carbon emissions • Water use – a•er digestion, cleansed water fit for river discharge can be re-used on site • Land fertility – residual bio- solids provide nutrients for crops (e.g. grain for distilleries) • Efficiency – extracting value from residues offers a zero- waste approach. Converting industrial washwaters and discarded process residues (that add to costs on many manufacturing sites) into biogas, can transform effluent treatment from a cost burden to a source of revenue. • Putting the grey matter into reducing water-footprint More businesses are considering how they can generate renewable energy from their process residues. This should extend to using grey water recycling to curtail their water footprint, says Clearfleau's Richard Gueterbock. The new AD plant under construction in East Anglia The AD plant on the Speyside distillery discharges clean water to river