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History and economics of cellulosic ethanol
Thomas Jeffries
Specialized Library AssociationChicago, Illinois
July 17, 2012
If we are to survive as a society we must find a way to convert
our fossil energy capital into the means for renewable energy
income.
R. Buckminster Fuller
Biofuels have been under development for 200 years
Ethanol production from wood is much older than many think.The chemistry has not changed.Biotechnology has provided new impetus.Emphasis increased during wars and times of fuel shortage.
Earliest attempts - 1819
Henri Braconnot (1819) treated wood with cold 91.5% sulfuric acid, and fermented the sugar
French chemist elected member of the Paris Académie des Sciences in 1823 Braconnot, H. 1819. Gilbert's
Annalen der Physik, 63:348-371
Commercialization in Europe - 1855
Arnould (1854) used 110 parts of concentrated sulfuric acid per 100 parts of wood and obtained 80 to 90% of wood in solution
Melsens (1855) used 3 to 5% sulfuric acid under pressure at 180°C
Pelouze (1855) erected a factory for the recovery of ethanol from wood in Paris
Von Demuth, R. 1913. Zeitschr. F. angew Chemie Aufsatzteil 1913, 26:786-792
The Simonsen process (1894-1898)
First comprehensive examination of engineering parametersUsed dilute acid under high pressure 15 minute hydrolysis, 0.5% sulfuric acid, 9 atm steam (≈180°C). Yielded 26.5% sugar on a dry wood basisProduced 7.6 L ethanol/100 kg wood
Kressmann studied dilute acid hydrolysis at FPL from 1910 to 1922
Need for ethanol in synthetic rubber synthesisExcess wood residues accumulated at sawmills ($0.50 per ton)Raw material cost was ≈ 2 cents per gallon of ethanol.Sugars from softwoods were about 70 percent fermentable while those from hardwoods were 30 percent fermentable by yeast.
First US commercialization in 1910 by the Standard Alcohol Company
Built a cellulosic ethanol plant in Georgetown, South Carolina to process waste wood from a lumber mill Later built a second plant in Fullteron, LouisianaEach produced 5,000 to 7,000 gal ethanol per day from wood wasteBoth were in production for several years
Robert Rapier Sep 10, 2009Sherrad EC & Kressman FW (1945) Review of Processes in the United States Prior to World War II. Industrial and Engineering Chemistry 37(1):5-8
Problems with pentoses and sugar degradation
Foth noted in 1913 that the unfermentable sugars in hydrolysates mainly come from pentosansThe pentosans are completely converted to pentoses in the first cookGlucose was degraded by acid at high temperatures
Foth, G. 1913. The recovery of alcohol from wood. Chemiker Zeitung 37(120), p. 1221
From 1916 to 1922, FPL took acid hydrolysis to the pilot scale
Settling tank, Single effect evaporator,
Hydroextractor
Hydrolyzer
Evaporator, Condenser
These findings led to the percolation process
Hemicellulosic sugars (xylose , arabinose) are hydrolyzed rapidly – but then break down in the acidCellulosic sugars (glucose) are hydrolyzed more slowly and are more stableUse a percolation process with rising acidity and temperature to extract
Madison Wood Sugar process - 1943
Developed in response to need for ethanol for the synthesis of synthetic rubber.
Based on the Scholler process in which dilute acid is percolated over a bed of wood chips.
Differs in that dilute acid is percolated initially at a lower temperature then at progressively higher temperatures until only lignin remains.
Sugars are collected in a series of tanks, neutralized with CaO and fermented.
Development of the Scholler process
Following World War II, scientists modified the German Sholler process for use in the United StatesJ.A. Hall directed pilot plant studies at the Dow Chemical Company plant in Marquette, Michigan and Vulcan Copper and Supply Co. at Cincinnati Ohio.Designed a pilot plant to produce 11,500 gal of ethanol/day (4 million gallons/year)
Based on Douglas fir (lowest xylan)0.4 to 0.85% sulfuric acid6 hour hydrolysis; 8:1 L:S ratio50 to 150 psig; 298-366°FYield of 52 gallons per ton (2% beer)
Vulcan Wood to ethanol plant, Springfield Oregon, 1945Designed by Ray Katzen Operated by Jerry Saeman“The plant did run and made ethanol but had lots of problems.”… “Low concentration of sugar; lots of organic matter ran down the river; no alternative to that…”
Jerome Saeman, May 1, 2003
Tars, calcium sulfate made a hard scale and lining in pumps and valves requiring cleaning and maintenance
Ray Katzen, May 6, 2003
Constructed in 1944 operated until 1946: met target of 15,000 gal/day, 50 gal per ton
History doesn’t repeat itself…
“To render automotive transportation independent of fuel imports and to produce domestically this fuel in the desired quantities, are the questions to be faced from the national point of view” -- Meunier 1922
1 bushel of corn yielded 2.4 gal EtOH in 1922Cost about $0.27/gal prior to WWI
Today one bushel of corn yields 2.75 gal EtOHCosts about
But it rhymes…
One ton of sawdust yielded about 12 to 20 gal EtOH/ton in 1922
“If the manufacturing cost of producing ethyl alcohol from wood can be reduced to the same figure or nearly the same figure as that for making it from grain or molasses, there will be a large margin in favor of producing the alcohol from wood waste.” -- F.W. Kressman, USDA Bulletin No. 983, 1922, p. 2.
Today, one ton of sawdust could yield ≈70-90 gal of ethanol
The maximum theoretical yield is 110-140 gal
We have made much progress with cellulosics
Enzymatic saccharification of celluloseReese, Siu and Levinson - 1950
Cellulase is not a single enzyme but a complexC1, Cx hypothesis (later replaced with endo/exo)
Reese organized and chaired an ACS symposium in Washington, DC on cellulase in 1962Katz and Reese produced 30% glucose from 50% cellulose in 1968Second ACS symposium on cellulase in Atlantic City 1969Natick symposium on “Enzymatic Conversion of cellulose 1975
Early contributors to cellulose enzymatic saccharificationKendall King
Virginia Polytechnic
Geoffery HalliwellRowett Res. Institute
Kazutosi NisizawaTokyo University
Karl Erick ErickssonSwedish Forest Products Laboratory
Keith SelbyShirley Institute
Ellis CowlingYale School of Forestry
Nobuo ToyamaMiyazaki University
Tarun K. GhoseIndian Institute, New Delhi
Mary MandelsNatick Lab
Development of Trichoderma reesei
QM6a first isolated from deteriorated shelter from Bougaineville Island at the end of WW2Originally identified as T. viride; in 1977 recognized as T. longibrachiatum named T. reesei by Simmons in 1977Produces a complete extracellular cellulase complexScheduled for complete genome sequencing by DOE in 2003
QM6A
QM9123 1969
QM9414 1971
TK041 1977
MCG77 1977
Linear accelerator
Linear accelerator
UV -Kabicidin
UV
M7
NG14
C-30
MCG80
1976
1977
1978
1980
UV
nitrosoguanidine
UV
UV -Kabicidin
Development of hyper secreting strains
Bland Montenecourt and Doug Eveleigh developed RutC30Looking for carbon catabolite resistance - discovered hyper-secreting strainUsed oxgall extract and phosphon D as colony restriction agentsBlocked phospholipid production
Discovery of pentose fermenting yeasts
Wang and Schneider - NRC, Canada
Fermentation of D-xylulose (1980)Clete Kurtzman - USDA, NRRL
Fermentation by P. tannophilus (1981)C.S. Gong - Purdue University
Candida sp. Mutant (1981)Tom Jeffries - FPL
Aerobic conversion by C. tropicalis (1981)
The virtual community -1981-1982
First international computer conference on biotechnology for fuels and chemicals; Organized through IEA
One of the very first computer conferences.
Initiated by Swedish innovator; coordinated by John Black, University of Western Ontario
Brought together researchers from around the world to exchange information on bioconversion for renewable fuels and chemicals
Sweden, Canada, Japan, United States, Soviet Union, India, France, Mexico, Brazil (et al.)
Metabolic engineering - 1984
Lonnie IngramMetabolic engineering of Escherichia coliPET operon -- from Zymomonas mobilis
Min Zhang, Steve PicataggioMetabolic engineering of Z. mobilis Pentose metabolic genes from E. coli
Accelerating forces
Enzymes from uncultured organismsIn-vitro recombinationDirected evolutionPathway optimizationGenome-wide expression analysisMetabolic modelingPetroleum prices
Source: U.S. Energy Information Administration Annual Energy Review, Table 5.21.¹ Composite of domestic and imported crude oil.² In chained (2005) dollars, calculated by using gross domestic product implicit price deflators. See "Chained Dollars" in Glossary.
19681970
19721974
19761978
19801982
19841986
19881990
19921994
19961998
20002002
20042006
20082010
0
10
20
30
40
50
60
70
80
90
100
U.S. Refiner Acquisition Cost¹ of Crude Oil, 1968-2010
Nominal Real²
Dollars
per
Barr
el
Average in 2011 - $111
Arab-IsraeliConflict 1973
Iranian hostageCrisis 11/79-1/81
Peak oil 2005?
Collapse of oilcartel 1980-86
Ethanol production has tracked with petroleum price
1984 1990 1996 2002 2008 20140
2000400060008000
10000120001400016000
Grain ethanol (10^9) gal
11/14/84 1/31/93 4/19/01 7/6/090
20
40
60
80
100
120
140
U.S. Crude Oil ($/bbl)
The greenhouse effect has been recognized for 185 years
Joseph Fourier discovered greenhouse effect in 1827John Tyndall discovered in 1861 that H2O and CO2 were largely responsible
Svante Arrhenius showed the role of CO2 in 1896 and he and Chamberlin recognized the feedback effect with water by 1905
Projected surface temperature of the globe in 150 years
Nine of the world's 10 warmest years since records began were in the 1990s, including.Temperatures in the 1990s were 0.33 C higher than in 1961-90 and 0.7 C higher than those at the turn of the century
We are already seeing the effects of global change
Each decadeSpring comes 5 days earlier Animal and plant ranges move 6 km further north
Ice thinning in arctic and alpine glaciersVegetation changes in arctic
Temperature correlates closely with CO2 levels395 ppm
Regional emissions
commitment from existing energy
and transportation infrastructure
Regional emissions
normalized by regional population
Regional emissions
normalized by regional GDP
Future CO2 Emissions and Climate Change from Existing Energy Infrastructure Steven J. Davis, et al. Science 329, 1330 (2010)
Global emissions of CO2 have an intergenerational effect
The last and the current generation contributed approximately two thirds of the present day CO2-induced warming.
Global mean temperatures would increase by several tenths of a degree for at least the next 20 years even if CO2 emissions were immediately cut to zero.
Friedlingstein and Solomon, 2005 PNAS 102(31):10832–10836
Solid line shows contribution to CO2 by each “generation” continuing at same rateDotted line shows contribution if CO2 emissions were immediately stopped
CO2 is rising at a faster rate than seen in 400,000 years
Domestication Of first plants
Biofuels can reduce CO2 production
Ethanol, methane and biodiesel are the most immediate bioenergy sourcesEthanol and biodiesel recovered in processingMethane recovered from feedlot operationsGreatly reduces CO2 emissions
Summary of energy efficienciesFuel Energy yield
Net Energy (loss) or gain
Gasoline 0.805 (19.5 %)
Diesel 0.843 (15.7 %)
Ethanol 1.34 34 %
Biodiesel 3.20 220 %
Source: Minnesota Department of Agriculture
Biofuels account for ≈7% of the US automotive and light truck fuel supply
>14 billion gallons of ethanol/yrVirtually all derived from grainEthanol can be blended at up to 10% by vol.Has only 2/3 the energy content of gasoline
Production of ethanol from corn is reaching unsustainable levels
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
20
09
20
10
0
3,000
6,000
9,000
12,000
15,000
U.S. Production, Consumption, and Trade* of Fuel Ethanol
Production Net Imports Consumption
Mill
ion
Ga
llon
s E
tha
no
l
1986
1989
1992
1995
1998
2001
2004
2007
2010
0
3,000
6,000
9,000
12,000
15,000
-
9
18
27
36
45
U.S. Corn Production and Use for Fuel Ethanol
Production Used for Ethanol PercentYear
Mill
ion
Bu
sh
els
Co
rn
Pe
rce
nt
co
rn u
se
d f
or
eth
an
ol
CTL = coal to liquids; GE = grain ethanol; CE = cellulosic ethanol; BTL = biomass to liquids; Gas = gasoline
Cellulose to ethanol reduces CO2 emissions
Isobutanol could provide 12% of US automotive and light truck fuels
> 14 billion gallons of ethanol annuallyVirtually all derived from grain (corn)Ethanol can be blended at up to 10% by vol.
Has only 2/3 the energy content of gasoline
Equivalent to 7%
Isobutanol can be blended at 16% by vol
Has ¾ the energy content of gasoline
Production from cellulosics is essential for market expansionDomestic biomass resource is sufficient
Wheat straw and forest residues are potentially the most economical feedstocks
Feedstock WTA WTPPrice gap
($/dry ton)Price gap
($/gal)Corn stover 92 25 67 0.96Alfalfa 118 26 92 1.31Switchgrass 117 26 90 1.29Miscanthus 110 27 84 1.20Wheat straw 75 27 49 0.70SR woody crops 89 24 65 0.93Forest Residues 78 24 54 0.77
Source: National Research Council, 2011 Renewable Fuel Standard (prepublication)
WTA = willing to accept; WTP willing to pay
Implicit subsidy required for cellulosic ethanol at $111/bbl oil
The US produces large amounts of biomass annually
Basic advances are needed in cellulase saccharification and biocatalyst researchMore funding for basic energy research is desperately needed“Competitive funding for basic research in plant biology by all federal agencies totals only about 1% of the National Institutes of Health’s budget”
Chris Somerville Science 312:1277 (2 JUNE 2006)
Barriers to commercialization
Cellulose is recalcitrant and requires large amounts of enzymes to produce sugarLignin occludes polysaccharides and inhibits enzymatic hydrolysis of carbohydratesEnergetically expensive and corrosive chemical pretreatments are required. Yeast currently used in large-scale ethanol production cannot efficiently ferment sugars other than glucose.
Why are we doing this work?
Ethanol fuels can help alleviate global warming
Wood and agricultural residues are available
Metabolic engineering can increase ethanol production