Guys this is only 4 pages of a 25 page report from the international fuel symposium of 2005 on fuel production efficiency. Unfortunately the graphs would not reproduce.
Alky has a positive fuel production to btu required while fossil fuels have a negative.
Someone is lying about alky production costs and efficiency and I believe we can make alky far cheaper and far more efficiently that gas but those numbers will never be common knowledge because then the oil companies (who control the world) will be exposed.
I will try and post the whole report as a web link so you can read it. This one is from 2005 and a new report is scheduled this year. I can e-mail the whole report to those that want it in pdf format.
The following is from the report:
The energy and environmental effects of using fuel ethanol in the United States have been debated since the inception of the fuel ethanol program in 1980. Over the past 25 years, more than 20 studies were published regarding the so-called “energy balance” of corn ethanol. In those studies, energy balance is usually defined as the energy in a gallon of ethanol minus the total
fossil energy input (including the energy in coal, natural gas, and petroleum) consumed to make that gallon of ethanol. Several studies conducted in the late 1970s and 1980s concluded that corn ethanol resulted in a negative energy balance. But the majority of more recent studies — with the
exception of a few studies conducted by Pimentel and his co-authors (see Figure 15) — have concluded that corn ethanol indeed has a positive energy balance. Since the 1980s, researchers in the Center for Transportation Research at Argonne National Laboratory have conducted life-cycle analyses of the energy and emission effects of transportation fuels for DOE. In 1995, with DOE’s support, Argonne began to develop the GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model — a life-cycle model for transportation fuels and vehicle technologies. The model contains more than 85 transportation fuel pathways, including four for fuel ethanol (corn dry milling, corn wet milling, woody cellulosic, and herbaceous cellulosic). The GREET model and its documentation are posted on Argonne’s GREET web site (
Argonne Transportation Research GREET/index.html). There are now more than 2,000 registered GREET users worldwide. Since 1997, Argonne has applied, updated, and upgraded the GREET model to evaluate fuel ethanol’s energy and emission effects relative to those of petroleum gasoline. In 1997, Argonne published its findings from an ethanol analysis conducted for the State of Illinois (Wang et al.
1997). With DOE support, Argonne continued its efforts to analyze the effects of fuel ethanol (Wang et al. 1999a; Wang et al. 1999b). In 2003, with support from the State of Illinois, Argonne analyzed the potential effects of blending ethanol into diesel (Wang et al. 2003). This paper presents Argonne’s updated energy and GHG emission results for fuel ethanol; these results were generated by using the most current version of the GREET model.
Energy Balance of Fuel Ethanol As discussed, energy balance is defined as the energy content of a unit of the energy product minus the fossil energy inputs used to make it. Calculations of fossil energy inputs include all
key activities used in the production of the energy product. The GREET model can estimate energy inputs required to produce transportation fuels, including ethanol. Although GREET does not explicitly present energy balance values for different transportation fuel products, its intermediate results do contain information about the energy balance values. Figure 2 shows the key activities that are included in energy balance calculations for both cornbased
ethanol and petroleum gasoline in the GREET model. For corn ethanol, GREET includes fertilizer production, fertilizer transportation from plants to farms, corn farming, corn transportation from farms to ethanol plants, ethanol production, and ethanol transportation from ethanol plants to refueling stations. For petroleum gasoline, GREET includes petroleum recovery,
petroleum transportation from oil fields to petroleum refineries, gasoline production in refineries, and gasoline transportation from petroleum refineries to refueling stations.
As Figure 2 shows, GREET simulations indicate that 0.74 million (mm) Btu of fossil energy is consumed for each million Btu of ethanol available at refueling stations. Thus, Argonne’s GREET simulations show a positive energy balance value for corn ethanol. On the other hand, 1.23 million Btu of fossil energy is consumed for each million Btu of gasoline available at refueling stations, so production of gasoline has a negative energy balance value. Note that in
GREET calculations, the energy used to produce a fuel, as well as the energy contained in the fuel, are taken into account. For example, for a kWh of electricity used, GREET takes into account the 3,412 Btu contained in that kWh and the energy loss in electric power plants to produce that kWh of electricity. The same applies for other energy products, such as gasoline,
diesel, natural gas, etc. Why does corn ethanol have a positive energy balance while petroleum gasoline’s energy balance is negative? The difference is primarily caused by the definition of the energy balance calculations: the energy in an energy product minus the fossil energy used to produce that
product. In the corn ethanol case, the feedstock for ethanol production is corn; the energy needed for corn plat growth (through photosynthesis) is solar (not fossil) energy. Solar energy is not considered in the energy balance calculation because solar energy is renewable and is not subject
to resource depletion (unlike fossil energy). In the case of petroleum gasoline production, the feedstock is petroleum; the Btu in the petroleum used to produce gasoline is taken into account in the energy balance calculation.
Figure 2. Activities Included in Energy Balance Calculations for Corn Ethanol vs. Petroleum Gasoline
Figure 3 presents energy balance calculations for U.S. electricity generation. The United States generates 54% of its electricity from coal, 14% from natural gas, 1% from oil, 18% from nuclear energy, and the remaining 13% from other sources, such as hydro-power. Figure 3 shows that, for U.S. average electricity, 2.34 million Btu of fossil energy is consumed for each million Btu of electricity available at a wall outlet. Fossil-fuel-powered electric plants have an energy conversion efficiency of about 35%. Thus, fossil electric power plants in the United States may require 2.96 million Btu of fossil energy per 1 million Btu of electricity generated. The fossil energy requirement of 2.34 million (rather than 2.96 million Btu) shown in Figure 3 for U.S. average electricity generation is due to the fact that a significant amount of U.S. electricity is generated from nuclear energy and hydro-power, which are not taken into account in fossil energy requirement calculations.
U.S. Electricity Generation: 2.34 mm Btu Fossil Energy Input Figure 3. Calculation of Fossil Energy Balance of U.S. Electricity Generation Thus far, we have addressed energy balance results for corn ethanol, petroleum gasoline, and U.S. average electricity. Figure 4 further summarizes the energy balance results for these three energy products plus cellulosic ethanol and coal. Of the five energy products, only cellulosic and corn ethanol have positive energy balances because solar energy is the ultimate energy feedstock for ethanol production. The huge positive energy balance for cellulosic ethanol is attributable to little use of fertilizer during farming of cellulosic biomass (compared with corn farming) and use of the unfermentable portion of biomass in cellulosic ethanol plants to generate steam and
electricity. Based solely on the results presented in Figure 4, gasoline production and electricity generation— both of which have large negative fossil energy balance values — should be eliminated. This obviously wrong conclusion is caused by the deficiency of fossil energy balance values
themselves. By adding all fossil Btus together, energy balance calculations fail to address the fact that different energy products have very different qualities and uses. For example, while electricity suffers a large negative energy balance, it is a high-quality energy product that we depend upon heavily to meet our daily needs. In practice, there is no energy product that can be substituted in most of applications in which we use electricity. Similarly, gasoline is a premium transportation fuel for use in internal combustion engines. We cannot — and should not — make energy choices solely on the basis of the energy balance values of individual energy products.
Yet energy balance values have mistakenly been made a focal point in ethanol policy debates. Key Technical Issues for Corn Ethanol An objective evaluation of corn ethanol’s energy and environmental effects should take into
account key technical issues, including improvements in the energy efficiencies of key production activities and proper treatment of ethanol’s co-products. Of the activities that comprise the corn ethanol production pathway, nitrogen fertilizer production, corn farming, ethanol production, and co-products of ethanol plants are key factors in determining energy and
emission results for corn ethanol. Each of these factors is discussed in the following paragraphs.
Nitrogen Fertilizer Production Corn farming requires intensive nitrogen fertilizer use. Wang et al. (2003) examined recent trends in the energy intensity required for nitrogen fertilizer production. Because of the dramatic increase in natural gas prices in North America in recent years, many North American nitrogen fertilizer plants shut down. Consequently, the United States increased its nitrogen fertilizer imports. Nitrogen fertilizer plants that have recently been built outside of North America have higher energy efficiencies than the old North American plants. GREET simulations take into account recent improvements in the efficiency of nitrogen fertilizer production.
Corn Farming The United States has about 80 million acres of corn farms that produce more than 11 billion bushels of corn a year. Over the past 100 years, the U.S. corn yield per acre has increased nearly 8 times — to over 140 bushels per acre (Perlack et al. 2005). However, the increase in per-acre
corn yields before 1970s resulted from increased application of chemicals, especially nitrogen fertilizer, to corn farms. While the high chemical inputs helped per-acre corn production, they did not help corn yield per unit of fertilizer input, which is directly related to corn ethanol’s energy and emission effects. Figure 5 shows the change in corn productivity — defined as bushels of corn per pound of nitrogen, phosphate, and potassium fertilizer used — over the past 40 years. This index relates directly to the effect of corn productivity on corn ethanol’s energy and emission effects. As the chart shows, since the mid-1980s, corn productivity has increased by about 70%. Because of efforts such as precision farming and better corn varieties offered by seed companies, those in the agricultural community expect that the upward trend in corn productivity will continue in future years.
Energy Use in Ethanol Plants
Both wet and dry milling ethanol plants are used to produce fuel ethanol in the United States. In wet milling ethanol plants, corn oil, gluten, and other high-value products are produced with ethanol. In dry milling plants, ethanol is produced through fermentation of starch, and the residues from fermentation become high-protein distillers’ dry grains and solubles (DDGS),
which are used as animal feeds. Wet milling plants are much larger than dry milling plants and require larger capital investment. Prior to 2000, more ethanol was produced from wet than from dry milling plants. But now, more ethanol is produced from dry milling plants. Ethanol plants in operation in the 1980s usually had high energy use per gallon of ethanol produced. Energy cost is the second-largest cost item (after corn feedstock) for ethanol plant
operators. For economic reasons, ethanol plant design/engineering firms and plant operators have made efforts to reduce energy use in ethanol plants and to increase ethanol yield per bushel of corn. As a result, ethanol yield has been increased from less than 2.5 gallons per bushel of corn in the 1980s to 2.7 gallons in 2005, and the energy use per gallon of ethanol produced has been significantly reduced. Figure 6 shows that, over the past 20 years, per-gallon energy use has been reduced by more than 20% in wet milling plants and by more than 40% in dry milling plants. Efforts are continuing to increase ethanol yield in corn ethanol plants, and there is new interest in using crop residues in place of natural gas or coal to fuel the plants. These efforts will continue to help corn ethanol’s energy and emission results.
Mikey
