Biomass plant reduces carbon emissions for University of British Columbia
Programmable automation controllers, human-machine interfaces (HMIs), and a historian at a combined heat and power (CHP) plant from Nexterra supplied more than 12% of the steam for University of British Columbia (UBC) Vancouver. In the first year of operation, the facility with a biomass plant retrofit displaced more than 115,000 MMBtu of natural gas, reducing greenhouse-gas (GHG) emissions by 6,000 tons per year, the equivalent of taking 1,250 cars off the road; better performance is expected. The facility is part of UBC’s "Campus as a Living Laboratory" initiative.
The UBC Vancouver campus is a city unto itself. The community includes over 50,000 students, faculty, and residents who work, learn, and live on the 1,000-acre campus. Until 2012, the university relied on its natural-gas-fueled central heating plant to produce heat for the campus and purchased electricity from BC Hydro for its electrical grid. As a leader in sustainability, the university is committed to reducing its GHG emissions. In 2009, UBC embarked on designing and building a CHP plant on campus, running on renewable fuels.
In 2007 UBC met its Kyoto targets for GHG emission reductions. To set aggressive goals for further GHG emission reductions, the university developed a Climate Action Plan that same year. Under the plan, UBC committed to reducing its current emissions by one-third between 2007 and 2015. By 2050, the university wants to be carbon neutral.
Adding to these challenges, UBC was expecting its campus size to grow substantially due to increased enrollment and research activity. To accommodate this increase, the university planned to add several million square feet of buildings, all of which would need heat and power.
UBC not only wanted to reduce its own GHG emissions, but it also wanted to become a hub for innovative renewable energy technologies that could be adopted by communities. In British Columbia, public institutions like the university have been subject to a provincial carbon tax since July 2007.
"As a community, we wanted to become a true leader in sustainability. If we couldn’t reduce our energy use and GHG emissions, how could we expect others to?" said Brent Sauder, director of strategic initiatives at UBC. "We also wanted to take advantage of our aggressive GHG commitments to drive innovation and new technologies within our own community."
As a first step in reducing its emissions, the university identified the buildings or technologies that were emitting GHG. UBC completed a campus-wide study of all GHG emissions. The largest single point of emissions turned out to be the campus’s central heating plant, which provided heat to laboratories, classroom buildings, and residences. University leaders decided they needed to augment the building’s gas-burning system with a biomass system using renewable biomass fuels to produce heat for the campus.
The university began a search for an energy-system supplier that understood the unique energy requirements of the campus, as well as how to deliver renewable energy systems in an urban campus. Nexterra Systems Corp., a Vancouver-based developer and supplier of advanced gasification systems for projects in Canada and the U.S., responded to the university’s search. Nexterra offered its significant technical expertise and also worked with UBC to secure funding for the project from Canadian and British Columbian government agencies and private organizations.
Nexterra designed, developed, and installed the CHP facility that operates on woody biomass—clean wood waste (such as pallets and construction debris) and residues from wood manufacturing.
Woody biomass arrives at the facility by the truckload two to three times per day. Any oversized or nonwoody materials are removed automatically with an integrated screen and magnet system. A gasifier converts the biomass into a clean, combustible synthesis gas or "syngas."
The new Bioenergy Research and Demonstration Facility (BRDF) at UBC is the first CHP system in North America to use Nexterra’s proprietary gasification system combined with the company’s unique syngas clean-up technology. The BRDF produces engine-grade syngas capable of running an internal combustion engine, producing heat and power.
2 operating modes
The system has two main operating modes: a commercial thermal mode and a demonstration CHP mode. In thermal mode, an oxidizer burns the syngas, and the hot flue gas is directed through the boiler to produce steam. The steam is used to heat campus buildings through the university’s existing distribution system. In demonstration mode, syngas is conditioned to remove impurities, then cooled and filtered, to generate both heat and electricity. The syngas is then injected into the high-efficiency, internal combustion engine that runs the generator, producing electricity distributed throughout the UBC campus via the existing power grid.
The system also recovers the engine heat and exhaust to generate additional steam for campus heating. Controlling the process is as critical as the process itself.
Two programmable automation controllers (PACs) manage the system’s control. The facility operator can monitor operations and proactively correct any issues on a system and machine level via human machine interface (HMI) software. In addition, historian software reports facility data to the Nexterra server where the company can support the facility’s operations in real time.
With the controllers’ integrated platform and single programming environment, the on-site facility operator has fewer spare parts to maintain. The platform’s tight operational control enables the system to process biomass with the required precision, while still meeting the university’s ambitious emission-reduction goals.
The interconnectivity and wide acceptance of these technologies have "Allowed us to become very efficient at implementing solutions," said Quamar Jutt, electrical and controls manager for Nexterra. "We’re able to focus our resources on improving our key offerings, such as the CHP system, instead of translating programs from platform to platform."
The platform’s openness also helped ease integration with an engine via an EtherNet/IP network from ODVA. Three motor control centers (MCCs), connected with ac drives, provide plant-wide motor control.
12% of steam requirements
Since operations began in September 2012, the BRDF has provided an average of 12% of the campus’s annual steam requirements. The system has successfully reduced GHG emissions by displacing fossil fuel used to produce steam. In addition, air emissions have been consistently well below and/or at permitted levels.
In the first year of operation, the facility displaced over 115,000 MMBtu of natural gas. This reduced GHG emissions by 6,000 tons per year-the equivalent of taking 1,250 cars off the road. As operators become more comfortable with the system, the numbers will continue to grow.
Today the BRDF is a successful part of UBC’s "Campus as a Living Laboratory" initiative. Inside the facility’s research lab, students and faculty complete their own alternative-energy source projects. The plant attracts tours at a nearly nonstop rate-more than 1,000 people visited in the first two years to learn about new forms of clean and sustainable power generation. The university and Nexterra will continue to explore advancing the facility’s technology even further. Potential areas include converting the clean syngas into advanced biofuels, renewable hydrogen, and other products.
The results mentioned above are specific to UBC’s use of the products and services selected in conjunction with other products; specific results can vary.
– Darcy Quinn is from Nexterra Systems; edited by Mark T. Hoske, content manager, Control Engineering, firstname.lastname@example.org.
- University of British Columbia retrofits biomass plant technology to its combined heat and power (CHP) plant to reduce carbon emissions.
- Controls and automation, including PLCs, HMIs, and historian, reduce greenhouse gas emissions by 6,000 tons per year.
- UBC gives tours at the facility, part of a "Campus as a Living Laboratory" initiative.
What processes can benefit from retrofitting new controls to improve performance?
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