Vancouver-based Nexterra Systems Corp. has built a solid
reputation North of the border for making gasification systems that use woody
biomass to create a syngas, which is then combusted to produce steam. Now, five
years after an unsuccessful foray into the American markets and cogeneration,
the nearly decade-old company is making its second attempt in the Lower 48.
Commercial operation of the gasification system at the U.S.
Department of Energy’s Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tenn.
began in July after completing a rigorous 30-day endurance test and third-party
emissions tests. The biomass plant provides heat for the ORNL campus with a
capacity of 60,000 lbs/hr (17.5 MWth).
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| Diagram explaining Nexterra's gasification process. Courtesy: Nexterra Systems Corp. |
Nexterra uses an updraft partial oxidation gasification system on a fixed bed. Their website says their systems range from 2-40 MWth or 2-15 MW. Running at 20-30% of stoichiometric air puts Nexterra in line with other partial ox gasification systems in the market such as ICM.
The company reports that thermal conversion occurs at
1500-1800 degrees Fahrenheit and that the syngas exits the gasifier at 500-700
degrees, which implies cooling for gas cleanup, most likely to condense the
tars. The syngas can be combusted along with the resulting flue gas for the
generation of steam.
Nexterra currently has five operating systems in Canada,
including its project at Tolko Industries Plywood Mill, which has been running
continuously since 2006. After an unsuccessful attempt at moving into the
American market with a project at University of South Carolina, Nexterra was
able to install a turnkey gasification system at the University of Northern
British Columbia in May 2011. The biomass gasification system uses locally
sourced wood waste to produce a combustible gas that is directed through a
boiler to provide hot water for the campus.
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| Courtesy: Nexterra Systems Corp. and Biomass Magazine. |
Although some, particularly in the Southern U.S. might
remember the debacle at South Carolina that caused the campus to shut down a
$20 million facility after three years, many may not have the whole story. While Nexterra did provide the gasifier
and oxidizer, Johnson Controls Inc., out of Wisconsin, was in charge of design,
engineering and fuel control. After almost three dozen previous shutdowns in
the first two years of operation, a piece of sheet metal shot across the power
plant in 2009, resulting in USC calling for an independent safety review before
allowing staff to return to work. The plant was permanently closed in March
2011.
Darcy Quinn of Nexterra said the incident gave the company
valuable experience in deciding to pursue projects where it could have full
control and provide a turnkey system rather than piecing different components
together.
Nexterra was selected for the University of Montana’s $16
million biomass boiler project that we wrote about in A Tale of Two Cities,
earlier this year. The project was later cancelled due to “deteriorating
discourse.”
The company has just announced a partnership with Stopford
Projects Ltd. to develop waste-to-energy projects in the United Kingdom. In the
meantime, the company is busy working on facilities at the University of
British Columbia and the US Veterans Affairs Medical Center.
Better BTU Take: Nexterra
has built some steam (pun intended) by facilitating successful projects in
Canada before making a second attempt in the U.S. We like the transparency of
its website but didn’t see anything about cost and have heard whisperings that
would make them fairly expensive.
One interesting note is that the only project that has
failed is also the only one in which the gasification system would be creating
heat and power. Since the problem seems to lie with Johnson Controls, we don’t
know if we can surmise much from that but thought it was interesting to point
out. We also think it’s interesting that Nexterra chose to work with Johnson
Controls again on the DOE ORNL project after the company let them down in South
Carolina. The company seems to have made good inroads in the U.S. with its
second project already in the works and will be interested to see how it fares
overseas.
For Further Reading:
Nexterra
and Stopford Sign Strategic Alliance Agreement to Develop
Energy-From-Renewable-Waste Projects in the U.K. – Cogeneration & On-Site
Power Production (Sept. 4, 2012)
Nexterra
Energy-from-Renewable-Waste Gasification Systeam at the US DOE's Oak Ridge
National Labratory Commences Full Commercial Operation – Nexterra Systems
Corp. (July 24, 2012)
South
Carolina Biomass Explosion Raises Questions About Safety of UM Project – By
Chelsi Moy, The Missoulian (Oct. 16,
2011)
