UEET 101 Emerging Technology
Energy Engineering Unit
Biofuels
Presented By
Pradip Majumdar
Professor
Department of Mechanical Engineering
Northern Illinois University
DeKalb, IL 60115
What is Biofuel?
• Biofuels are solid, liquid, gas fuels derived from recently dead
biological materials.
• They are distinguished from the fossil fuels, which are formed
from long dead biological materials over a long period of
time.
• Biofuels can be produced theoretically from any biological or
organic carbon-source materials:
- Most common being the photosynthetic plant
- and other plant-derived materials such woodchips,
trash etc.
• They essentially recycle existing carbon in the atmosphere
rather than releasing any new carbon from fossil fuels.
- because plants used in the production of the fuel
removed carbon dioxide from the atmosphere.
• In theory they are endlessly renewable.
Common Bio-fuel Production
• There are two common strategies for bio-fuel production:
1. Grow crops high in starch (Corn and maize) or grow
crops high in sugar (sugar cane, sugar beet and
sweet sorgum) and then use yeast fermentation to
produce Ethyl Alcohol or Ethanol.
- The most common bio-fuels are in the form of
ethanol.
2. Grow plants that contain high amount of
vegetable oil such as oil palm, soy bean,
algae.
- when these oils are heated, their viscosity is
reduced and they can be burned directly in a
diesel engine.
or
- they can be chemically processed to
produce fuels such as biodiesel.
• Wood and its byproducts can also be converted
into biofuels such as wood gas, methanol and
ethanol fuel.
Problems with Ethanol-Biofuel
• Currently, ethanol is produced primarily from food grade
materials such as such corn and souya.
• It uses a energy-intensive process that may not
save a lot of fossil fuel.
• Study shows that USA can not produce enough
ethanol from corn to meet its demand.
• Current rush to produce ethanol from food grade
material lead to global food shortage and increased food
price.
Alternate Technology to Produce
Ethanol
New research is focused on to develop more efficient
processes to make ethanol from wider range of non-food
grade biomass.
The key elements of a biomass is the cellulose that
gives plant cells their strong walls.
The process involves converting cellulose into sugar
and then sugar into ethanol:
Cellulose Sugar Ethanol
Conversion Process
• One of the recent effort is to turn any carbon-rich organic
material into a gas and then into liquid fuel.
• Potential source for this carbon-rich organic biomass
- Pine tress
- Wood Chips
- Trash (Municipal solid waste
- Farming residues (cornstalks)
- timber residues (unusable parts of logged trees)
• Challenge is to cheaply transport these leftovers to the
ethanol plants.
• How about leaves, small limbs, waste woods (forest
leftovers)?
Conversion Process
Conventional Approach
Gas
Biomass
Problem removing
Nitrogen Nitrogen
Oxygen (If air is used)
(Expensive) or Air
• Syngas is a mixture of mostly
New Approach Carbon monoxide and hydrogen
(By Range Fuels and Coskata)
• Syngas is generally converted into
liquid fuel ethanol by means of a
Biomass
Syngas
Ethanol catalyst (Range Fuels)
Steam • Newer approach involves no use
of catalyst and but use bacteria to
ferment the syngas into ethanol.
• The amount of ethanol produced in processes with
chemical catalyst is around 70-80 gallons per ton.
• Bacteria-based process may produce 100 gallon
per ton - this process makes more ethanol rather than other
products such as butanols, propanol,
hexanol, octanol and other alcohols.
Some Practical Issues
Main challenge is to design a system that gives steady supply of
ethanol from any biomass.
Sorting out trash is a major huddle – practical issues
- Plastic and bald tires are ideal use.
Range Fuels system is currently designed for wood chips.
- pretty uniform in size
- no need for sorting process (taking out bad stuffs such as
batteries)
Use of garbage is quite challenging and may be risky for initial
trials.
- There may not be enough of it ( ???)
- Municipal solid waste is less than 10 % of all the available
biomass.
- Is sorting process worthwhile?
Prospects of Biofuels
• Need to develop more efficient ethanol production
process from non-food grade biomass.
• Need to develop infrastructures for packaging and
transporting biomass waste to ethanol plant in a
economical manner.
• Estimated current cost of ethanol is $2.10 per gallon.
• Projected cost is $1.33 per gallon by 2012 with in-
progress in technologies.
• Can we reach $1.00 per gallon (Target) ?
• Future for biofuel cars – May be!
Some National and International
Issues
• Mitigation of carbon emission levels
• Oil prices
• Food vs. fuel
• Deforestation and soil erosion
• Impact on water resources
• Energy balance and eficiency
Energy Animations
Biomass Program
EERE: Biomass Program Home Page
EERE: Biomass Program Home Page
BP
www.bp.com