TERU Focus Report - Bioenergy Facility Tour
Woody Biomass to Energy Field Tour, November 17, 2010: Big, Small & Tiny
November 20, 2010 -- Michael Theroux
Orchestrated by the Center for Forestry, University of California Berkeley, 30 plus
people boarded a bus in Lincoln and got a chance to see a variety of facilities up close that convert woody
biomass into combined heat and power (CHP). Nominal buy-in included lunch; the rest was sponsored by the
California Association of Resource Conservation and Development (RC&D) Councils, UC Berkeley Cooperative
Extension, USDA Forest Service State and Private Forestry, Central Sacramento Valley RC&D and the California
Biomass Collaborative. Representatives from each organization and agency participated, making for informative
The tour started at the Sierra Pacific Industries (SPI) sawmill in Lincoln, with a thorough
guided exploration of the saw mill and the direct biomass combustion cogeneration facility. Our tour guide
explained that the SPI Lincoln mill is one of the most diverse and busiest lumber mills right now in the US,
taking in vast amounts of pine, cedar and fir (no redwood) and turning out every shape and size of lumber
“sticks”, from 1” x 4” slats to massive support beams. 20-foot piles of fine sawdust dry in the sun between the mill works and the co-gen operations.
Four-story tall stacks of logs are kept wet to reduce splitting by spraying with water that is reclaimed and
continuously recycled in a closed loop flow. The operation of the plant requires 6 to 7 megawatts of
electricity (MWe), about one third of the 20 MWe continuously generated on-site through direct combustion of
biomass feedstock. Daily economics dictate whether to use site sawdust for bioenergy or ship north for sale to
pulp and paper mills. At tour time, 90% of the fuel comes from regional agriculture, purchased by SPI at about
$36 per bone dry ton (bdt) and coming into the plant at “field moisture” of 30% to 50%, about a truck an hour.
Unlike most California bioenergy facilities, SPI Lincoln uses little urban wood waste, perhaps one truck a
day. Heat from the biomass combustion makes steam, which drives an Alstom turbine and an ABB generator. The
entire operation is constantly monitored electronically for emissions, with all data sent directly to the Air
Pollution Control District.
Mid-day, we visited the converted metal
ag-products storage building on the Wallace Ranch in Woodland that now houses the Woodland Biomass Research
Center, home of West Biofuels since 2007. The sub-commercial scale research and
development systems are now in “Phase II - Pilot-Plant Demonstration”. The systems were shut down for tar
removal at the time of the tour, and everything smelled faintly of
“Liquid Smoke”. Standing perhaps 30’ tall were a pair of inter-connected retorts, a reformer and a
regenerator. The reformer circulates super-heated sand to heat biomass to drive off combustible synthetic gas.
The second regenerator uses the carbon char from the reformer as fuel to re-heat the sand. Since the syngas is
produced without air or oxygen, it contains very little nitrogen (abut 4% NOx), and is rich in hydrogen,
usually around 25%. The current testing phase runs the syngas from the 75 bdt fluidized bed dual allothermic
(no air) steam gasification system into an internal combustion engine, producing around 3 MWe from wood chips.
West Bioenergy plans to later test various locally sourced feedstocks, primarily wheat and rice straw, grass
straw, tomato residues, grape pumice, and urban green waste. In the long-term, coproduction of food and fuel
is envisioned. Research will then shift focus to use of the Fischer/Tropsch process to catalytically convert
the syngas to liquid fuels.
The afternoon found us on the west side of
Davis near Winters, motoring through the organic walnut orchard to the Dixon Ridge Farms walnut processing facilities. There, tall stacks of
walnut shells await conversion to heat. The well-packaged biomass gasification system developed by
Community Power Corporation (CPC) out of Colorado sits at one end of
an impressively large open-span metal warehouse. This is
biopower unit, the 50 kilowatt (kWe) “BioMax
50”. Producer gas from the gasifier primarily replaces the use of propane in the processing plant for product
drying, and to run an off-the-grid adsorption chiller for product cold storage. The equipment is fully automated
and computer monitored; CPC can watch and adjust operations at any time. CPC’s website shows that the
demonstration unit has over 18,000 run-time hours, with over 14,000 hours producing electricity and an
additional 4,000-plus run for strict heat production, summing to better than 1,266,000 kilowatt hours (kWhrs).
Dixon Ridge Farms hope in the future to increase the number of modules, eventually producing all of the heat
they need and an excess of electricity for sale. CPC is also working on conversion of their syngas to liquid
fuels, which could replace diesel for the farm’s equipment.
Representatives from each site provided
detailed information on each technology and responding to all of our questions. Special kudos go to Rob Williams
(UC Davis), John Shelly and Gareth Mayhead (UC Berkeley) for their planning and facilitation of the tour. The UC
Berkeley Center for Forestry’s next event is a Woody Biomass to Energy Workshop, scheduled for December 2, 2010 in
Ukiah, Mendocino County; registration is now open through the Center’s website.
© Teru Talk by JDMT, Inc 2010. All rights
You are free to reprint and use this report as long as
no changes are made to its content or references and credit is given to the author, Michael Theroux.