Transcript Wood Chemistry PSE 406/Chem E 470

What is “hot” in bioenergy?
Agenda
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Feedstock
» Algae
» MSW
» Woody biomass
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Research areas
Review
Background
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Uses for algae
» Nutrition
– Nori, dulse, kombu
– Supplements – spirulina, chorella
» Cosmetics
» Fertilizer
» Pigments
Bioproducts
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Biodiesel
» Algae biodiesel has superior cold-weather
properties
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Vegetable oil
Bioethanol
Butanol
Methanol
Hydrogen
Requirements
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Light
CO2
Water
Inorganic nutrients
» Vary depending on algae
» Nitrates, phosphates, iron, trace elements
Farming methods
Photosynthetic surface area
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Surface area to volume ratio (SVR)
» Open (pond) system: 3-4 m2/m3
» Closed system
70-100 m2/m3
» 3D matrix system
1500-2000 m2/m3
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Surfaces
»
»
»
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Polycarbonate (best)
Acrylic
Glass
Polymer film
Process
Biodiesel
CO2
Nutrients
Algae biomass
production
Water, nutrients
Biomass
Extraction
recovery
Oil
Biomass
Bioethanol
Animal feed
Algae species
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Many different species can be used
Different species for fresh or salt water
» Scenedesmus dimorphus
– High yield but needs constant agitation
» Botryococcus braunii
– Produces long chain hydrocarbons, up to 86% of weight
– Thought be responsible for fossil fuel deposits
» Chlorophyceae spp.
– Produce starch granules
Productivity
NREL
Challenges
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“High yield photoefficiency”
» As biomass increases light access is blocked
» Use small diameter tubes
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High capital costs
Contamination by invasive species
Water must be maintained at constant temp.
Not enough CO2 in atmosphere for exponential
growth
Disadvantages
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Transfers CO2 – doesn’t eliminate it
» Captured CO2 from coal plants is released by cars
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Could slow progression towards alternative energy
sources which might reduce CO2 levels
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High water usage
Nutrient sourcing
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Production
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PetroSun: Rio Hondo, Texas
» 1100 acres of saltwater ponds
» 4.4 million gallons oil/year
» 110 million pounds biomass/year
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Solix
» 0.4 acre pilot plant using CO2 from brewery
» Flexible plastic reactors – 50x300 ft
» Predict 8000 gal/acre/year
Players
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Greenfuel Technologies Corp.
PetroSun
Solix
Algaelink
Solazyme
Valcent
Conclusions
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Cost of “alg-oil” becoming more reasonable as
oil prices rise
Best constructed in tandem with a CO2
producer
Promising “piece of the puzzle” for future
transportation fuels
Converting Washington
Lignocellulosic Urban Waste to
Ethanol
Objective
Develop and assess processes to produce bioethanol
from cellulosic urban waste
•Process Development
•Techno/economic analysis
•Life Cycle Assessment
Municipal Solid Waste
Municipal Solid Waste
LOTS OF CELLULOSE
Mixed Waste Paper
Yard Waste
Synthetic Garbage
Municipal solid waste (Part A)
1) Separation
Mixed Waste Paper
Yard waste
Synthetic garbage
2) Pretreatment
Acid hydrolysis
Steam explosion
Acid hydrolysis
Acid hydrolysis
210°C, 10 min, 3%SO2
3) Enzymatic hydrolysis
Cellulose to glucose 86%
Xylan to xylose 62%
4) Fermentation
3) Enzymatic hydrolysis
4) Fermentation
3) Enzymatic hydrolysis
Cellulose to glucose 41%
Xylan to xylose 36%
3) Enzymatic hydrolysis
Cellulose to glucose 89%
Xylan to xylose 87%
4) Fermentation
4) Fermentation
Cellulose to glucose conversion (%)
Enzymatic hydrolysis (MSW)
100
Yard waste (SO2)
Yard waste (NaOH)
Municipal solid waste
Paper waste
90
80
70
60
50
40
30
20
10
0
0
10
20
30
40
Time (hours)
50
60
70
Woody biomass
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Grows slow
Difficult to break down and fractionate
compared to agricultural biomass
How much can we take out of the forest?
» Forest thinning
» Forest fires
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Ecosystem
How caw we collect it?
Competition from pulp and paper industry
Research areas (1)
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Pretreatment
Hydrolysis
Fermentation
Co-products
Research areas (2)
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Techno-economical analysis
Life cycle analysis (LCA)
Infrastructure
Bioethanol, biodiesel, biobutanol as new fuels
for engines
New biofuels
What else?
Review