Water and Effluent Treatment Magazine
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NOVEMBER 2016 WET NEWS 13 TECHKNOW • Exelys is a continuous rather than a batch process • The Exelys reactor can treat more than three times the amount of sludge solids • The reactor volume is used for 100% of the time by comparison with a batch reactor • Exelys can handle higher sludge concentrations than batch systems NEED TO KNOW 1 The Billund Biorefinery wastewater treatment facility anaerobically co-digests 4,200 tonnes a year of domestic and industrial organic waste together 2 Future plans include producing odour-free organic fertiliser, and eventually, phosphorus fertilisers and biodegradable bioplastics 3 Billund's biogas production generates three times the energy requirements of the plant itself 4 The biorefinery has received worldwide plaudits for innovation and sustainability THE VERDICT "Billund BioRefinery is an example of people continuously striving to do better, develop new products and come up with solutions that improve the environment in Denmark and the rest of the world" Kirsten Brosbøl, former environment minister, Denmark NOVEMBER 2016 WET NEWS 13 SUPPORTED BY WASTEWATER 2017 CONFERENCE & EXHIBITION INFRASTRUCTURE | NETWORKS | TREATMENT | INNOVATION 31 JANUARY | BIRMINGHAM book now events.wwtonline.co.uk/ wastewater The only event with all WASCs represented The largest single-day showcase of wastewater-specific case studies, innovation and thought-leadership under one roof Choose your focus: wastewater Infrastructure & networks conference wastewater treatment conference David black Senior director, Water 2020 Ofwat nevil muncaster Director of asset management Yorkshire Water steve wilson Director of wastewater services D ŵr Cymru Welsh Water mark worsfold Director of asset management South West Water Lawrence Gosden Managing director – wastewater services Thames Water kate Zabatis Head of environment policy & regulation United Utilities Luke de Vial Head of water resources Wessex Water Peter Vale Technical lead – innovation Severn Trent Water EXPERT SPEAKERS INCLUDE: EXPERT SPEAKERS INCLUDE: ● Prepare your business for AMP7 and long-term investment priorities ● Improve collaboration with customers, retailers and manufacturers to reduce FOG ● Build resilience to flooding and optimise existing wastewater assets ● Apply lessons from Europe's largest privately- funded infrastructure project ● Align investment decisions with Water 2020 and the evolving competitive landscape ● Implement innovative strategies to drive efficiencies in treatment works ● Extract more commercial value from sludge ● Reduce damage, inefficiency and cost in pollutant removal FOLLOW US @WWTlive #wastewater SPONSORED BY than a batch process. This means that the reactor volume is used for 100% of the time by comparison with a batch reactor which, because it is cyclic control, effectively operates at only about 30-40% utilisation, and with less concentrated sludge. As a result, the Exelys reactor can treat more than three times the amount of sludge solids compared to a similar sized batch reactor. Continuous operation means that the steam demand is constant, which improves boiler efficiency and since Exelys™ can handle higher sludge concentrations than batch systems, the steam demand per tonne of dry solids is lower. The early installations were called LD configuration (for Lysis followed by Digestion) and more recently Veolia has installed some DLD (that is Digestion followed by Lysis and then a second stage Digestion) and DL (Digestion followed by Lysis with a recycle loop) plants. All these configurations have their place. There are also options for how the resulting biogas is used. You can burn all of it in a CHP plant and use the waste heat to heat the digester, or you can use some of the biogas to fire a boiler for heating the digester and the rest for running the CHP plant. You can even pass all the biogas to the CHP plant and fire the boiler with imported natural gas, oil or biofuel crops. It all depends on the relative costs of imported fuel and electricity and the feed-in tariff for electricity generation. The best solution for any given works will depend on site specific conditions and the individual economics based on sludge quantity and quality, footprint and the utilisation of the biogas. n Mike Froom is business development director at Veolia Water Technologies. Billund BioRefinery features an array of advanced technologies The plastic carriers are a key element of the MBBR technology