The magical world of
BIOENERGY
Social and political implications as well as some science
Emily J. May
Energy Alternatives
February 28, 2007
What is Bioenergy?
 Bioenergy is:
“energy derived from recently living material
such as wood, crops, or animal waste.” (versus
decayed materials that comprise fossil fuels)
 Can be burned directly for heat or converted to
biofuels such as biodiesel or ethanol.
 Currently approx 1 million Mtoe, projected to
double in 25 years
1% of cumulative investment
Come On Baby Light My Fire:
A Brief History of Biofuels
Humans have derived energy from organic
matter for millennia.
wood and animal dung
Grass fuel for animals as agriculture and
domestication began.
Animal fat candles- Industrial Revolution
Traditional Biomass
Burning of wood, animal dung and plant
matter
Common in developing countries as a
primary energy source
Provides 48 EJ to world primary energy
(approximate figure)
The Path to Prosperity?
“Haiti might be able to supply the Dominican Republic with
biofuels while strengthening its own economy and mitigating the
increased greenhouse gases that can accompany economic
development. [Haiti] has a large agrarian citizenship, a eastern
neighbor eager for biofuels, and a consistent mandate from the
international community to increase standard-of-living. Haiti…may
be able to strengthen its ravaged economy by helping a neighbor
decrease its use of fossil fuels - which can only be good for an
island poised to suffer from the adverse effects of climate change.”
http://www.haitiinnovation.org/node/308?gclid=CI6TqJq0zYoCF
SZfQAodyW-UdA
“New” Biomass
Produced on a large commercial scale in
industrialized nations- 7% primary energy
Provides 9 EJ (2%) of world primary
energy
Energy Crops: Plants that are grown
specifically for use as biofuels
Organic Wastes: byproduct of direct uses
of biomass, eg. agriculture.
Energy Crops
Woody crops: trees harvested for biofuel
Europe, U.S. and Australia
Agricultural crops
most common are sugar cane and maize for
conversion into liquid fuels
Plants such as sunflowers and soybeans are
grown for the oil in their seeds’ conversion to
biodiesel
ETHANOL
U.S.
101 plants- 4.8 billion gallons/year
2005- 4 billion gallons used = 1.2 fewer cars (?)
 Brazil
 PRO-ALCOOL is the world’s biggest biomass
system.
Vehicles run on “gasohol” (26% ethanol)
Developed during economic hardship, saved
over $40 billion
Organic Wastes
Wood Residues: byproduct of plantation
thinning
Temperate Crop Wastes: unused portion
of wheat, maize and corn crops; over a
billion tonnes/year. 15-20 EJ
Tropical Crop Wastes: sugar and rice, 18
EJ.
Animal Wastes: anaerobic digestion of
manure can be converted to fuel
Organic Waste Cont.
Municipal Solid Waste
Landfill Gas
anaerobic digestion of biological material
produces landfill gas which has been used
since the 1970s. Has low efficiency.
Commercial and Industrial waste
How Does It All Work?
Solid biomass
Combustion produces heat energy and CO2.
 Gaseous fuels
Anaerobic digestion: disgester enables bacteria
to break down matter, creating heat.
Gasifier: hot steam and oxygen + volatiles and
char= producer gas
How Does It All Work? Cont.
Liquid Fuels
Pyrolysis: heating bio material to extract volatile
components, then condensed, made into bio-oil.
Approx. half the energy of crude oil
Synthesis: gasification produces syngas (CO
and H2), condensed into liquid.
Fermentation: sugars converted to alcohol by
organisms such as yeast.
Bioenergy in the US
Cheap petroleum has consistently
destroyed US bioenergy market
second to Windpower in renewables
3% of US energy consumption
ethanol and biodiesel currently in use
Future: biomass to produce plastics and
chemicals
US Biofuel Prices
Biodiesel:.50/litre
Ethanol
maize: .23/litre
wood: .62/litre
Crude oil, Feb 2007: .60/litre
Focus of the US DOE Biomass Program:
An Impressively Convoluted Diagram (no questions please)
Bioenergy in Burlington
The McNeil Biomass Plant
 conventional wood-burning plant that has been
in operation since 1984
Uses biogasification: converts organic fuels into
“clean” gas
McNeil uses 200 tons of locally produced wood
per day!
But is it sustainable?
70% from low quality trees and forest
residue
25% is byproduct of local sawmills
5% recycled urban wood waste
Burlington’s McNeil
Biomass Plant
catalytic system cleans
gas, compress gas,
sends through turbine
Emissions are 1/100 of
the permitted federal
level
50 MW capacity:
1/10 size of Vermont
Yankee but still enough
power for all of
Burlington
Bioenergy in Belize
2002 Johannesburg World Summit
Central American Commission on Environment
and Development
Feasibility of bioenergy in Belize by NGOs
GBEP (2006): bioenergy to developing
nations
Belize has no Clean Development
Mechanism (Kyoto Protocol)
No large-scale bioenergy production
Freedom from Fossil Fuels!
Biofuels “should
generate no more
heat and create
no more carbon
dioxide than
would have been
formed in any
case by natural
processes.” (106)
BUT WAIT!
What about those conversion efficiencies?
The low conversion efficiency of biomass
to bioenergy is almost as hard to justify as
a war for oil
“air-dry mass of plant matter produced
annually on an area of one hectare can be
as little as one tonne.” (112)
This produces only 15 GJ/hectare/year!
Burning Bush
 “Twenty by Ten” introduced in the 2007 State of
the Union address proposes a decrease of fossil
fuel use in 10 years by replacing 15% with
biofuels and increased fuel efficiency of cars by
5%
 Biofuel production must increase fivefold
 Seeks $3.6 billion for the research and
development of new fuels using "everything from
wood chips, to grasses, to agricultural wastes"
“Addicted to Biofuels”?
 When demand for biofuels exceeds a
sustainable production rate, bioenergy is no
longer a viable energy source.
 high level of energy and resource input
 "All the fossil fuels that are used in the
production of corn, in the fertilizers and in the
fuel, in the ploughs and transportation and so on
and in the distillation process, it becomes almost
a very dirty fuel.” –Kurt Davies, Greenpeace
USA
Sources cited

Bioenergy: US Department of Energy. http://www.energy.gov/energysources/bioenergy.htm

“Q&A: Bush’s Energy Reforms” 24 Jan, 2007. http://news.bbc.co.uk/2/hi/americas/6293805.stm

“US Ethanol Production.” http://www.ksgrains.com/ethanol/useth.html

Boyle, Godfrey. Renewable Energy: Power For a Sustainable Future. Oxford Press 2004,
Glasgow.

Lallement, Dominque. “The Role and Significance of Latin America in Global Energy Markets.”
Amsterdam, 19 Dec. 2006.

Nurmi, Dr. Marrku. Central American Carbon Finance Guide. September 2004.
http://www.greenstream.net/content/Projects/carbono_en.pdf?from=204215008731975

Riley, Kate M. 27 Feb, 2007.

Valenti, Michael. “Preaching to the converted.” Mechanical Engineering, 2001.
http://www.memagazine.org/backissues/membersonly/dec01/features/preaching/preaching.html
Questions?
Consult your book.