1. Introduction
Proposed Solution
Utilization of Woody Biomass
Jose Alcala, Nicholas Busse, Hugh Van Camp, Thomas Peev, Diego Trejo
University of California, Merced
We determined the cost of the entire project (see breakdown below), and
the production rate required to pay off the project after 1 year.
Assuming a 40 hour work week, and 48 weeks per year, and a pellet price of
$225/ton, the investment can be paid back within a year with a production
rate of about 2 tons of wood pellets per day.
Cost Analysis
Examples showing a) woody biomass found pile, b) wood chips c) manufactured pellets and d) a tree drum chipper.
Wood U Inc. is determined to produce sustainable, high-quality products
from renewable resources, which will enhance the nature of all our lives.
Being conscious of renewable resources, we strive to protect our national
forests and communities by serving as a model for sustainable forest man-
agement.
We want to make an ecologically sustainable product from woody biomass
that is commercially viable, quickly to produce, and not damaging the forest
ecosystem. We propose the production of wood pellets from woody bio-
mass, using a mobile pellet press assembly.
We proposed wood pellets, which will be sold at the market price of
$225 per metric ton.
To produce the pellets, we have designed a mobile pellet press assem-
bly which turns wood chips into pellets; the design concept fits in a
shipping container and can be transported anywhere.
The woodchips, however, have to be dehydrated since minimal mois-
ture content is allowed for pellet production.
A prototype at a reduced scale was built, which successfully justified
the design of the dryer and confirmed the assumptions.
Economic analysis has shown that the whole investment can be paid
off within a year if the daily pellet production is at 2.53 metric tons per
days.
Design: Mobile Pellet Press Assembly
The mobile pellet press assembly turns wood chips into wood pellets at a rate
of 1 metric ton per hour. The assembly consists of a hopper, drying chamber,
Hammermill, auger, storage bin and pellet mill:
• Hammermill receives dried wood chips and pulverizes them to sawdust size
• An auger is a screw conveyor transporting the sawdust to the storage bin
• The pellet mill presses saw dust material into 6-10 mm diameter pellets
CAD Model of the mobile pellet press assembly.
Prototype: Drying Chamber
blblah blah figure for dryer
The wood chips delivered have a too high moisture content to be
turned into pellets. We propose the design of a drying chamber which
can dry the required amount of woody biomass at a fast rate, enabling
the required production rate. The prototype, pictured above, is able to
dry the woody biomass at the required time, meeting our design require-
ents for the full scale dryer.
References
Acknowledgements
Hopper
Steel
150 kg
1.17 x 1.24 x 1.66 m3
$312
Shipping Container
Steel
285 kg
6.10 x 2.44 x 2.44 m3
$2,650
Hammermill
RLH-240
Capacity: 1 ton/hr
Power: 7.5 kW
285 kg
1.61 x 1.18 x 1.68 m3
$4,000
Pellet Mill
ZLSP 400B R-Type
Capacity: 0.44 tons/hr
Power: 30 kW
550 kg
1.24 x 0.92 x 1.50 m3
$1,975
Storage Bin
Capacity: >1 ton
Stainless Steel
100 kg (empty weight)
0.90 x 0.90 x 1.00 m
$600
Screw Conveyor/ Auger
Capacity: 1.1 tons/hr
Carbon Steel
Power: 3 kW
250 kg (empty weight)
3.20 x 0.13 m3 (L x D)
$750
Conclusion
We would like to thank our Faculty advisor Dr. Robert Rice, and Cap-
stone advisor Dr. Ashley Martini.
Thank you to our sponsor contact at TCEDA Larry Cope, Sherri Bren-
nan and Randy Hanvelt.
Special thanks go to Dave Horack, Michael Pickard, Jim Junette,
Dr. Valerie Leppert and Dr. Christopher Viney.
Around 80% of Tuolumne County is
covered by the Stanislaus National
Forest. Annually, the forest dies at a
rate of 80 million board-feet, which
turns into woody biomass. 50%-70%
of the woody biomass is a high-prior-
ity fire risk. The fires fueled by woody
biomass lead to hydrophobic soils
and drastically change the ecosystem.
300 bone dry tons of woody biomass burning within 4
hours. Source: DOI: 10.3733/ca.v069n03p142
Breakdown of investment cost. Values were determined using current market price and above stated assumptions.
$33,968
81.6%
$7,654
18.4%
$4,162
3.5%
$57,600
48.1%
$16,320
13.6%
$41,621
34.8%
Pellet Press Assembly Dryer Maintenance Labor Operational
• “Woody Biomass Utilization” Internet:
www.fs.fed.us/woodybiomass/whatis.shtml.[Accessed: 15-Feb-2016]
• S. Baker, et. al. “Forest biomass diversion in the Sierra Nevada:
Energy, economics and emissions”, California Agriculture vol. 69,
pp. 142-149, Jul-Sep 2015
• Jurandir Primo. “ASME Section I & Section VIII
Fundamentals.”http://www.pdhcenter.com/courses/m398/m398co
ntent.pdf, 2012 [Accessed: 01-Apr-2016].
• E. M. Bilek et al. “Fuel to Burn: Economics of Converting Forest
Thinnings to Energy Using BioMax in Southern Oregon.” [Accessed:
15-April-2016]