August 19, 2010
by PLANT Staff
Nexterra Systems Corp. has signed a multi-million dollar agreement with the University of British Columbia (UBC) to supply and install a biomass-combined heat and power (CHP) system at the university’s Vancouver campus—the first installation of its kind in North America.
Nexterra, a Vancouver-based developer and manufacturer of biomass gasification systems, said the deal follows three years of collaboration between Nexterra and GE’s Jenbacher gas engine division.
The new CHP system will convert urban wood waste into clean burning synthetic gas (syngas) using Nexterra’s proprietary gasification and syngas conditioning technologies.
The technology involves bottom-feeding wood waste into the centre of a dome-shaped, refractory lined gasifier and combustion air, steam and/or oxygen are introduced into the base of the fuel pile. Partial oxidation, pyrolysis and gasification occur at 815 to 980 degrees Celsius, converting the fuel into syngas and non-combustible ash. The ash migrates to the base of the gasifier and is removed intermittently through an automated in-floor ash grate.
The syngas will be directly fired into a GE internal combustion engine to produce two megawatts of electricity. Waste heat will be recovered from the engine to produce 9,000 lb/hour of low-pressure steam.
Nexterra said emissions from the system will be well below local air emissions limits and the system will have a conversion efficiency of more than 65 percent.
Wood fuel will come from tree trimmings and other wood waste diverted from landfill and provided by the City of Vancouver and other local companies.
Electricity generated by the new system will be distributed throughout the campus to meet a portion of UBC’s electricity demand. The steam produced will offset about 15 percent of the natural gas currently used by UBC for district heating.
The project, scheduled for commissioning in in the fourth quarter of 2011, will lower the university’s greenhouse gas emissions by 4,000 tonnes per year.