The anaerobic Digestion and Biogas Association’s fourth annual trade show and conference — UK AD & Biogas 2013 — attracted a busy stream of visitors to Birmingham, England in early July, demonstrating a growing interest in this vibrant industry sector. The event included facility tours, conference sessions, workshops, free one-on-one consultations with industry experts, launch of ADBA’s new Practical Guide to AD (article to follow in a future issue of BioCycle), and a trade show.
This year’s event had a total of 240 exhibitors — primarily from the UK and Europe — representing digester manufacturers from small-scale to large-scale and all stages in between. Farm-fed and waste-fed technologies were represented alongside companies making or selling the valves, grinders, pumps, mixers, macerators and related engineering needed to operate a facility as well as the application equipment needed to utilize the biogas and digestate. Biomethane vehicles were on display, as were companies supplying control solutions to operational issues, as well as policy or planning advice. The Wales Centre of Excellence for Anaerobic Digestion, The Chartered Institution of Wastes Management and the Waste and Resources Action Programme (WRAP) all had a strong presence.
The event itself felt energetic and engaged. Over 100 anaerobic digestion plants have now been built in the UK (not counting the 146 operating in the water industry) and more are at earlier stages of development. “I am pleased to say that the growth in the UK AD industry in the last five years has indeed been hugely impressive,” says Charlotte Morton, ADBA’s Chief Executive. “The future potential is even more exciting still.” Some of the companies that exhibited are presented in this article.
Self-Contained, Micro AD
SEaB Energy’s compact anaerobic digestion systems can begin producing biogas, energy, a liquid fertilizer and mulch with as little as half a ton of incoming organic waste per day (150-250 tons/year). The design is scalable with a starting footprint the size of three 20-foot shipping containers, increasing to seven containers of the same size to handle around 3 tons/day (1,250 tons/year). Based on the outskirts of Southampton, UK, SEaB has developed two turnkey AD systems. The first, Muckbuster®, is best suited for manures and crop processing. Flexibuster™ is optimum for food waste and green wastes. A key advantage of these smaller on-site units is they minimize transportation costs for wastes from food processors, breweries, restaurants, farms and food retailers.
One installation at the University of Southampton Science Park (USSP) utilizes a mix of food waste, cooking oil and spent alcoholic drinks collected from Chilworth Manor Hotel, situated within the Science Park, along with the green waste generated by USSP. The digester produces an average of 46 m3/day of biogas, which fuels an 8 kW combined heat and power (CHP) unit that produces electricity for a nearby office building. Heat from the CHP unit goes into a research and development organization facility and liquid digestate is used on the landscaped grounds. Another unit is operating at Lancaster Brewery and a third is being installed at Catherston Stud Farm in Hampshire.
Last year, the USSP installation won the ADBA’s UK AD & Biogas Industry’s 2012 Best Micro AD Project (www.seabenergy.com
Compact Farm-Fed Plant Design
One of the most eye catching displays at this year’s UK AD&Biogas show was the scale model of the Biogest “PowerCompact” Micro Plant, designed to produce renewable heat and power from cattle slurry, feed leftovers and similar agricultural wastes on small to medium dairy farms, with or without use of energy crops. Perhaps it was just the clean simplicity of the green domed fermenter fronted by a green box the company calls the “Technology Container,” but it looked efficient. The container houses the CHP unit, heating system and the control room and the plant is reported to produce up to 100 kW/day of electricity at optimum feedstock mix ratios.
Biogest Energie is an Austrian company with long experience in designing and building wastewater treatment plants based on the sequencing batch reactor (SBR) system. Some years ago, it expanded into anaerobic digestion and now has around 80 AD plants across Europe, including Austria, the Czech Republic, Italy, Romania and Serbia. The standard plant is called the PowerRing and works with almost all substrates. Plant dimensions are based on recent studies carried out in Vienna aimed at making the biological degradation process more effective. The various standard designs have power outputs ranging from 170 to 4,000 kW. Low-volume or high-volume slurry modifications are available. Biogest recently expanded into the UK. “We are developing a small 100 kW plant for the dairy industry in the UK, which is being very well received,” says Nick Slater of Biogest UK Limited. “We are due to start building the first two plants in October.” www.biogest-ad.com