A 10.3 MW biomass gasification facility in Birmingham, England, will use waste wood to produce a synthetic gas that will then be oxidized to produce heat. Steam from this process will drive a condensing turbine. Wikimedia Commons
A new facility will power 17,000 homes and be fueled entirely with discarded wood products that were formerly placed in landfills.
March 4, 2014—Site preparation work is under way on a 10.3 MW biomass gasification facility in Birmingham, England, that will be fueled entirely by such waste wood products as discarded furniture, kitchen cabinets, packing material, and construction waste.
The £47.8-million (U.S.$65.7-million) plant has been in development since 2012. The project’s developers recently secured financing, including funding from the U.K. Green Investment Bank, a bank established by the government to fund projects that help the nation meet ambitious sustainability goals. The United Kingdom is seeking to reduce greenhouse gas emissions by 34 percent by 2020 and generate 15 percent of all its energy from renewable sources.
“The government has put in place a series of financial incentives to encourage renewable deployment,” said Ian Miller, the operations director, waste and energy, for MWH Treatment, a division of MWH Global that is based in in the United Kingdom, in written answers to questions posed by Civil Engineering online. MWH is delivering the project for Birmingham Bio-Power Ltd., under what is called an engineer/procure/construct (EPC) contract. “These incentives make renewables viable,” Miller explained. “Government requires electricity supply companies to provide a certain amount of their power from renewable sources, which they can provide themselves or buy from renewables producers.”
The plant will be developed on a tight site approximately 4 km southeast of Birmingham’s city center in a mixed industrial and residential zone. It will take up approximately two acres of a five-acre factory parcel owned by Webster & Horsfall, a storied wire producer that was a pioneer in transatlantic telegraph cable.
“The site is quite congested and an awkward shape,” noted Miller. “The resultant building and structures had to be laid out to fit the site, allowing for a safe and efficient traffic flow for [trucks] delivering the waste wood feedstock.”
Engineering challenges weren’t limited to the constricted, irregular site, Miller noted. “In process engineering terms, there was a lot of work to do to optimize the overall design to arrive at a financially attractive and fundable project.” The plant is designed to be eligible for 1.9 renewable obligations certificates (ROCs) per MWh. The ROCs are a type of currency that energy producers in the U.K. can purchase and spend to meet sustainability targets if their own portfolios don’t include renewable energy facilities.
Other engineering challenges included the historic preservation of canals that date to the city’s early industrial period, and the relocation of a 1,500 mm diameter sewer that had been in place and operational since the Victorian period.
The plant gasifies waste wood to produce a synthetic gas—or syngas. This syngas is then oxidized to produce heat, which is used to create steam in the plant’s boiler. The steam then drives a fully condensing turbine that is coupled to a generator that produces 11 KV of power at around 10.3 MW, Miller said.
The complex gasification process uses discarded wood to
generate electricity. (The steam generator and turbine are not
shown.) The facility will be housed in a single steel-framed,
one-story building with a three-story office wing. Fitting the
plant onto a tight site in a busy area was one of the key
challenges of the project. © Nexterra Systems Corporation
The facility will be housed in a single steel-framed, one-story building with a three-story office wing. The facility is divided into four main functional areas: wood waste receiving and storage, gasifier hall, a process area that contains the plant’s boiler, and a steam turbine area.
“Because it uses waste material, there are not the same sustainability issues as there are with virgin biomass material,” Miller explained. “The waste feedstock will contain some paints, resins, glues, and the like. Because it is defined as a waste, the emissions from the facility will be continuously monitored to ensure they meet strict EU Waste Incineration Directive limits.”
The plant is projected to consume approximately 67,000 metric tons of waste wood per year over the course of a 20-year life span, all of which would have otherwise been destined for a landfill. Employing gasification technology developed by Nexterra Systems Corporation, of Vancouver, British Columbia, Canada, the plant will power more than 17,000 homes when it becomes operational in 2016.
This is the first biomass gasification project funded by the U.K. Green Investment Bank, and developers said they hope it serves as a demonstration of the technology’s potential.
Miller said that biomass is a renewable sector that is likely to grow within the U.K. energy market. The government’s ambitious renewable-energy targets anticipate that biomass will provide 18 percent of both its renewable power and its renewable heat target by 2020.