industry
NEWS EDI to unveil biomass digester system
California-based Environmental Developers Inc. plans to showcase a new biomass digestion system for the first time at Biomass Magazine’s Pacific West Biomass Conference & Expo being Jan. 11-13 in Sacramento, Calif. The company believes the process is three to 10 times faster than other digestion designs on the market. The Vacuum Retort Anaerobic Digestion system has been in development since 1977, after EDI President Herman Miller III initially observed an anaerobic digester. “Typically, its instrumentation was out of service and deep rust has penetrated everything ferrous in the vicinity, eaten up by the hydro-sulfurous acid products of raw digest gas,” he said. “Realizing the potential energy possibilities for anaerobics and the disastrous impediment of the hydrogen sulfide byproduct as well as its usefulness, I was intrigued and challenged into a new avocation of work and study, while building other people’s plant designs. Every solution highlighted another problem until 30 years and four or five patents later, we had VRAD.” At a typical plant, municipal solid waste (MSW) is weighed, sorted, crushed and ground as finely as possible. Miller said EDI has a design for a grinder that the company can build, but added that it would be more economical to buy a grinding system that is already in the market though none have yet met the system’s exact specifications. The MSW is hydrolyzed, enzymes are added and the material then goes through three digestion stages. Hydrogen sulfide and inert materials are removed. “The sodium sulfate and sodium bicarbonate byproducts are taken off as part of the gas separation process,” Miller explained.
“We end up with clean water, a certain amount of which is used for washing, hydrolization, fire protection and general cleanup around the plant.” The water is continually recycled, he added, leaving about 80,000 gallons per day for sale. “The pure biomethane and carbon dioxide products are put through two stages of compression,” Miller said. “The low-pressure stage (300 pounds per square inch) gas is used for mixing, pH control and to feed the high-pressure stage (3,000 pounds per square inch) gas that is bottled and sold, based on the highest and best use principle—to power electric cars, trucks and buses. Brazil and Argentina are already well into these vehicles, and they make the most sense on every count.” Miller said the most significant benefit of the VRAD process is its gas separation capability. “It not only allows us to sell a cleaner biomethane product with a higher Btu per cubic foot than pipeline natural gas, but also allows us to reduce greenhouse gasses and carbon emissions to zero,” he said. This offers a serious carbon credit advantage over other processes. We didn’t design the process with the carbon credit game in mind, it just made good sense.” As far as the cost is concerned, Miller said EDI expects it will take $35 million to get the first 1,000-ton-per-day plant on line. The plant would have a 10-acre footprint and generate a return on investment in five to seven years. —Anna Austin
UK company supplies palm kernel shells for biomass power A U.K. company originally focused on supplying materials for the solar industry has expanded to the biomass industry, providing wood chips, bamboo and palm kernel shells to customers on several eastern hemisphere continents. Opean Energy Managing Director Odera Ume-Ezeoke said the company has offices or partners in each country it sources biomass from, which includes Ghana and Indonesia. “We started out aiming to bridge the supply gap in the clean commodity market where there appeared to be a real problem tracking down reliable supplies of silicon for solar panel production,” she said. “Now, we’ve expanded our products to focus and solve similar problems in the biomass industry by physically trading to supply our clients with the biomass they seek.” Opean Energy was formed in 2005, Ume-Ezeoke said, but its focus on biomass didn’t begin until early 2009, when it began developing its supply chain. “In the fourth quarter of 2009 we started marketing our supplies,” she said. “We chose to expand from silicon to biomass because as clean commodities, the products shared a lot of similarities as bulk products focused on the production of clean power, and used by a mainly industrial client base. Our silicon background essentially gave us a jogging start in the industry.”
Opean supplies customers with bamboo pellets, wood chips and pellets, and palm kernel shells, a waste product of palm oil production. “Smaller quantities of items like bamboo, we have around 5,000 metric tons (5,500 tons) per month at present,” Ume-Ezeoke said. “For wood chips, pellets and palm kernel shells, we have a supply capacity of around 20,000 to 40,000 metric tons per month of each, either on a FOB (free on board) or CIF (cost insured freight) basis.” According to Opean Energy, on an annual basis there are 3.2 million tons of palm kernel shells available in Indonesia and 3.1 million tons in Malaysia. The shells compare favorably as a boiler fuel source due to their relatively high calorific value of 4,320 kilocalories per kilogram (16 Btu per 154 pounds), abundance of supply, ease of use and per tonnage cost. Palm kernel shells are versatile and have multiple uses, Ume-Ezeoke added. “It can be used in its natural form for fuel at power stations, as a clean alternative to coal, to form activated carbon or to pave roads. We’re reducing emissions of EU power stations by encouraging them to burn biomass instead of coal, and also promoting and enabling enterprise in developing countries where we source our biomass from.” —Anna Austin
1|2010 BIOMASS MAGAZINE 17