7884079487

Picmcntcl/Problemy Ekorozwoju/Problcms of Sustainable Dcvclopmcnt 2/2012,15-22

Table 3. Inputs per 1000 liters of 99.5% ethanol pro-_duced from com."_

Inputs	Quantity	Kcal x 1000	Dollars $
Com grain	2.690 kg"	2.106^b	634.14
Com transport	2.690kg^b	264^c	27.63^d
Water	7.721 L°	46'	3.86^s
Stainlcss Steel	3 kg'	42'	8.52“
Steel	4 kg'	40^s	2.39“
Cement	8 kg'	ll^s	1.86'
Steam	2.564.764 kcal¹	2.362'	59.94*-
Electricity	395 kWli¹	2,863'	26.38
95% ethanol to 99.5%	9 kcal/L¹"	9^m	40.00
Sewage effluent	20 kg BOD"	69^b	6.00
Distribution	331 kcal/L*¹	331	375.00
TOTAL		8.143	$ 1185.72

a) Output: 1 liter of ethanol = 5,130 kcal (Low heating value). The mean yield of 9.5 L pure EtOH per bushel has been obtained from the industiy-reported ethanol sales minus ethanol imports from Brazil. both multiplied by 0.95 to account for 5% by vol-ume of the #14 gasoline denaturant. and the result was divided by the industiy-reported bushels of córa inputs to ethanol plants (See: http://petroleum.berkel ey. edu/patzek/BiofuelQ A/Materials/TrueCostofEtO H.pdf (Patzek. 2006).

c) Calculated for 144 km roundtrip.

d) Pimentel et al., 2009.

e) 7.7 liters of water mixed with each kg of grain.

f) Pimentel et al„ 2009.

g) Pimentel et al.. 2009.

h) 4 kWh of energy reąuired to process 1 kg of BOD (Blais et al.. 1995; Illinois Com. 2004).

i) Estimated from the industiy reported costs of $85 million per 65 million gallons/yr diy grain plant amortized over 30 years. The lotal amortized cost is S43.6/1000L EtOH, of which an estimated $32 go to Steel and cement.

j) Patzek. 2008.

k) Calculated based on coal fuel. Below the 1.95 kWli/gal of denatured EtOH in South Dakota, see j).

l) $0.07 per kWh (USCB, 2004-2005).

m) 95% ethanol conyerted to 99.5% ethanol for addition to gasoline (T. Patzek, personal conununication. Uniyersity of Califomia. Berkeley. 2004).

n) 20 kg of BOD per 1000 liters of ethanol produced (Martinelli. 2009).

p) Newton, 2001.

q) DOE. 2002.

r) Johnson et al., 2007

s) Venkatarama and Jagadish. 2003.

I) Lin and Echkhoff. 2009.

u) Steel Mili. 2010.

v) Concrete Products. (2010).

for the production of 1 liter of ethanol. and the disposal of this relatively large amount of sewage effluent comes at an energetic. econotnic. and envi-romnental cost.

The production of a liter of 99.5% ethanol. includ-ing the energy to produce the com. reąuires 158% morę fossil energy than the energy present in 1 liter of ethanol and costs $1.19 per liter ($4.48 per galion) (Table 3). The com feedstock reąuires morę than 26% of the total energy input. In this analysis. the total cost. including the energy inputs for the fermentation/distillation process and the appor-tioned energy costs of steam. electricity. and stain-less Steel tanks and other industrial materials is significant (Table 3).

Net Energy Yield

The largest energy inputs in cmaize-ethanol production are com feedstock production energy, steam energy. and electricity used in the fermentation and distillation process. The total energy input to produce a liter of ethanol is 8,14.3 kcal (Table 3). However, a liter of ethanol has an energy value of only 5,130 kcal. Based on a net energy loss of 3,013 kcal of ethanol produced. 58% morę fossil energy is expended than is produced as ethanol.

Economic Costs

Current maize ethanol production technolog) uses morę fossil fuel and costs substantially inore to produce in dollars than its energy yalue is worth on the market. Without the morę than $12 billion an-nual federal and State goyemment subsidies. U.S. ethanol production would be reduced or cease. confirming the basie fact that ethanol production is uneconomical and does not provide the U.S. with any net energy benefit (Koplow and Steenblik. 2008).

Federal and State subsidies for ethanol production that total morę than $12 billion/year for ethanol are mainly paid to large corporations (Koplow and Steenblik. 2008), while maize farmers are receiving a minimum profit per bushel for their maize (Pimentel and Patzek. 2008). Senator McCain reports that direct subsidies for ethanol. plus the subsidies for maize grain. amount to 79C per liter (McCaia 2003).

About 80% of the ethanol in Brazil is also heayily subsidized (Berg. 2004). Even with heavy subsidies. about half of the fuel burned in autos in Brazil is gasoline. only about 50% is ethanol (Berg. 2004). Sugar subsidies have a major impact on ethanol production from sugarcane.

If the production cost of a liter of ethanol were added to the tax subsidy cost. then the total cost for a liter of ethanol would be $1.54. The mean Wholesale price of ethanol was almost $1.00 per liter without subsidies. Because of the relatiyely low energy content of ethanol. 1.6 liters of ethanol have the energy equivalent of 1 liter of gasoline. Thus. the cost of producing an amount of ethanol eąual a liter of gasoline is about $2.33 ($8.82 per galion of gasoline). This is morę than the 53p per liter, the current cost of producing a liter of gasoline. The subsidy per liter of ethanol is 60 times greater than