1 potential of eichhornia crassipes for biomass refining jessica e. hronich, lealon martin, joel...
TRANSCRIPT
11
Potential of Eichhornia Crassipes for Biomass Refining
Jessica E. Hronich, Lealon Martin, Joel Plawsky, & Henry Bungay
November 7th, 2007
AIChE Conference 2007
22
Introduction
• Department of Energy goal:• 60 Bgal/yr ethanol by 20301
• Current production• 5.4 Bgal/yr blended into gasoline for 20062
• 129 Ethanol plants, and growing
• The need for diverse feedstocks• Corn grain can only meet 15% of transportation
needs1
• Cellulosic ethanol can fill remainder• Greater energy output/input ratio31U.S. DOE. 2006. Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda, DOE/SC-0095, U.S.
Department of Energy Office of Science and Office of Energy Efficiency and Renewable Energy (www.doegenomestolife.org/biofuels/).2 “Biofuels in the U.S. Transportation Sector” Energy Information Association, Oct. 15, 2007. (http://www.eia.doe.gov/oiaf/analysispaper/biomass.html#1)3 Bourne, J.K. “Green Dreams” National Geographic, 2007. (http://magma.nationalgeographic.com/ngm/2007-10/biofuels/biofuels-interactive.html)
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Feedstock Evaluation
• Ideal Attributes• Wide availability• Ease of cultivation• Frequent harvest
cycles• No / low competition
with food crops• Easy to process• Inexpensive
• Water hyacinth• Global invasive
nuisance weed• Growth can exceed
200 tons DM / ha / yr• 2 week harvest cycle• Aquatic plant• Low-tech processing• Millions of dollars
spent each year to remove / dispose
44
Process Description
• Cultivation• Harvest &
Collection• Pressing• Pretreatm
ent / Storage
• Hydrolysis / Fermentation
55
Cultivation
• Infested waterways• Removal credit• Developing countries
• Hyacinth cultivation (farms)• Unused commercial
ponds / lakes
66
Harvest & Collection
77
Harvest & Collection
• Novel cutter design• Simply slice mats
• Mat width design variable
• Length dependent on connectivity
• Use less energy than traditional harvesters
• Tow swaths of mats to shore
• Cut pattern to allow re-growth
Factory
88
Pressing
• Can remove approximately 97 wt% of the water
• Will decrease volume for silage
• Water will be processed (if necessary) and returned to lake
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Pretreatment / Storage
• Partial Anaerobic digestion• Approximately
14 days• Less energy
intensive
• Remove loose water
• Combine with storage to reduce costs
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Process Cost Estimation• Estimation allowed for multiple inputs to affect
overall cost per ton to produce• Referenced current
biomass-to-ethanol evaluations
• Manufacturing cost estimation for chemical process industry adapted for agribusiness plan1
• Key design parameters taken from literature, manufacturers, and best guesses
1Ulrich D, Vasudevan T, (2004) Chemical Engineering Process Design and Economics: A Practical Guide. Ulrich Publishing, 409-435
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Key Design Parameters
• Cultivation• Lake covered in 300
acres hyacinth• Located in United States• 100 ton dry matter / ha /
yr
• Harvest / Collection• Cut width of 3.5 m• Cut speed of 45 m / min• Harvested 8 hours / day
• Pressing• 97 wt% water removal• Power usage: 18HP/ton
fiber/hr
• Pretreatment / Storage• 14 days to digest
• Misc.• Labor ($10 / hr +
benefits)• Overheads• Taxes, insurance• Depreciation
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Cost Estimation
Depreciation ($1.07)
Labor ($10.64)
Utilities ($6.01)
Maintenance ($1.74)
Overheads ($5.21)
Taxes & insurance ($2.95)
Total Cost: $28 / ton of Total Cost: $28 / ton of dry matterdry matter
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Sensitivity Analysis
• Lowest possible cost• 1 harvester & 1
transport boat• Cut width
greater than 7m• Cut speed
greater than 45 m/min
• Operation most likely at 3.5 m and 45 m/min
Bio
mass
Cost
($
/dry
to
n)
Cut Speed (m/min) Cut W
idth
(m)
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Future Work
• Investigation of digestion process• Temperature• pH• Residence time
• Hydrolysis methods• Acid• Enzymatic
• Fermentation yields• Quality of biomass produced
• Application to other aquatic nuisance weeds
Photo courtesy of Willey Durden, USDA Agricultural Research Service, www.forestryimages.org; Image Number 0002100.
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Summary
• Water hyacinth as a feedstock• Rapid growth rate• Wide availability• Low cost
• Exportable low-technology process• Cost Estimation / Sensitivity Analysis• E. Crassipes is an economically viable biomass
feedstock• A blight on an ecosystem can be used as an economic
benefit • Cost competitive with other feedstocks (less than $40
per dry ton)
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Acknowledgements
• NSF IGERT fellowship• Rensselaer Chemical & Biological
Engineering• The Martin Group