Construction of pilot scale lignocellulosic ethanol plants requires considerable financial support through grants and subsidies. On 28 February 2007, the U.S. Dept. of Energy announced $385 million in grant funding to six cellulosic ethanol plants.[31] This grant funding accounts for 40% of the investment costs. The remaining 60% comes from the promoters of those facilities. Hence, a total of $1 billion will be invested for approximately 140 million gallon capacity. This translates into $7/annual gallon in capital investment costs for pilot plants; future capital costs are expected to be lower. Corn to ethanol plants cost roughly $13/annual gallon capacity.[32][33]
The quest for alternative sources of energy has provided many ways to produce electricity, such as wind farms, hydropower, or solar cells. However, about 20% of total energy consumption is dedicated to transportation (i.e., cars, planes, lorries/trucks, etc.)[34] and currently requires energy-dense liquid fuels such as gasoline, diesel fuel, or kerosene. These fuels are all obtained by refining petroleum. This dependency on oil has two major drawbacks: burning fossil fuels such as oil may contribute to global warming; and for net-consuming countries like the United States, importing oil creates a dependency on oil-producing countries.
As of 2007, ethanol is produced mostly from sugars or starches, obtained from fruits and grains. In contrast, cellulosic ethanol is obtained from cellulose, the main component of wood, straw and much of the structure of plants. Since cellulose cannot be digested by humans, the production of cellulose does not compete with the production of food, other than conversion of land from food production to cellulose production. The price per ton of the raw material is thus much cheaper than grains or fruits. Moreover, since cellulose is the main component of plants, the whole plant can be harvested. This results in much better yields per acre up to 10 tons, instead of 4 or 5 tons for the best crops of grain.[citation needed]
The raw material is plentiful. Cellulose is present in every plant, in the form of straw, grass, and wood. Most of these "bio-mass" products are currently discarded. It is estimated that 323 million tons of cellulose containing raw materials that could be used to create ethanol are thrown away each year. This includes 36.8 million dry tons of urban wood wastes 90.5 million dry tons of primary mill residues 45 million dry tons of forest residues and 150.7 million dry tons of corn stover and wheat straw.[35] Transforming them into ethanol using efficient and cost effective hemi(cellulase) enzymes or other processes might provide as much as 30% of the current fuel consumption in the United States and probably similar figures in other oil-importing regions like China or Europe.[citation needed]
Moreover, even land marginal for agriculture could be planted with cellulose-producing crops like switchgrass, resulting in enough production to substitute for all the current oil imports into the United States.[36]
Paper, cardboard, and packaging comprise a substantial part of the solid waste sent to landfills in the United States each day, 41.26% of all organic municipal solid waste (MSW) according to California Integrated Waste Management Board's city profiles. These city profiles account for accumulation of 612.3 tons daily per landfill where an average population density of 2,413 per square mile persists. Organic waste consists of 0.4% Manures, 1.6% Gypsum Board, 4.2% Glossy Paper, 4.2% Paper Ledger, 9.2% Wood, 10.5% Envelopes, 11.9% Newsprint, 12.3% Grass & Leaves, 30.0% Food Scrap, 34.0% Office Paper, 35.2% Corrugated Cardboard, and 46.4% Agricultural Composites, makes up 71.51% of land fill. All these except Gypsum Board contain cellulose that can be transformable into cellulosic ethanol[35] because they are the leading cause of methane plumes. Methane, a greenhouse gas, is 21 times more potent than carbon-dioxide[37].
Reduction of the disposal of solid waste through cellulosic ethanol conversion would reduce solid waste disposal costs by local and state governments. It is estimated that each person in the US throws away 4.4 lb (2.0 kg) of trash each day, of which 37% contains waste paper which is largely cellulose. That computes to 244 thousand tons per day of discarded waste paper that contains cellulose.[38] The raw material to produce cellulosic ethanol is not only free, it has a negative cost i.e., ethanol producers can get paid to take it away[39].
The environmental company Wise Landfill Recycling Mining[40] expects to start generating cellulosic ethanol product from trash early 2008.[41]. Their method also boasts of being not merely carbon neutral, but oil independent.[42]
In June 2006, a U.S. Senate hearing was told that the current cost of producing cellulosic ethanol is US $2.25 per US gallon (US $0.59/litre). This is primarily due to the current poor conversion efficiency.[citation needed] At that price it would cost about $120 to substitute a barrel of oil (42 gallons), taking into account the lower energy content of ethanol. However, the Department of Energy is optimistic and has requested a doubling of research funding. The same Senate hearing was told that the research target was to reduce the cost of production to US $1.07 per US gallon (US $0.28/litre) by 2012. "The production of cellulosic ethanol represents not only a step toward true energy diversity for the country, but a very cost-effective alternative to fossil fuels. It is advanced weaponry in the war on oil, said Vinod Khosla, managing partner of Khosla Ventures, who recently told a Reuters Global Biofuels Summit that he could see cellulosic fuel prices sinking to $1 per gallon within ten years.
University of Massachusetts at Amherst researchers have developed a streamlined technique which uses "catalytic fast pyrolysis" (heating to 400-600 degrees C followed by rapid cooling) and zeolite as a catalyst to produce cellulosic ethanol in about 60 seconds. They estimate improvements in the process should be able to generate ethanol at the equivalent of $1-$1.70/gal of gasoline. As of April 2008, the process has only been developed to work at laboratory scales.
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Today, there is only a small amount of switchgrass dedicated for ethanol production. In order for it to be grown on a large-scale production it must compete with existing uses of agricultural land, mainly for the production of crop commodities. Of the United States 2 billion acres of land, 33% are forestland, 26% pastureland and grassland, and 20% crop land. A study done by the U.S. Departments of Energy and Agriculture in 2005, determined whether there were enough available land resources to sustain production of over 1 billion dry tons of biomass annually to replace 30% or more of the nations current use of liquid transportation fuels. The study found that there could be 1.3 billion dry tons of biomass available for ethanol use, by making little changes in agricultural and forestry practices and meeting the demands for forestry products, food, and fiber.[44] A recent study done by the University of Tennessee reported that as many as 100,000,000 acres (400,000 km²)(154 thousand sq. miles ) of cropland and pasture will need to be allocated to switchgrass production in order to offset petroleum use by 25 percent.[45]
Currently, corn is easier and less expensive to process into ethanol in comparison to cellulosic ethanol. The Department of Energy estimates that it costs about $2.20 per gallon to produce cellulosic ethanol, which is twice as much as ethanol from corn. Enzymes that destroy plant cell wall tissue cost 30 to 50 cents per gallon of ethanol compared to 3 cents per gallon for corn.[46] The Department of Energy hopes to reduce this cost to $1.07 per gallon by 2012 to be effective. However, cellulosic biomass is cheaper to produce than corn, because it requires fewer inputs, such as energy, fertilizer, herbicide, and is accompanied by less soil erosion and improved soil fertility. Additionally, nonfermentable and unconverted solids left after making ethanol can be burned to provide the fuel needed to operate the conversion plant and produce electricity. Energy used to run corn-based ethanol plants is derived from coal and natural gas. The Institute for Local Self-Reliance estimates the cost of cellulosic ethanol from the first generation of commercial plants will be in the $1.90-$2.25 per gallon range, excluding incentives. This compares to the current cost of $1.20-$1.50 per gallon for ethanol from corn and the current retail price of over $3.00 per gallon for Regular Gasoline (which is subsidized and taxed).[47]
One of the major reasons for increasing the use of biofuels is to reduce greenhouse gas emissions.[48] In respect to gasoline, ethanol burns cleaner with a greater efficiency, thus putting less carbon dioxide and overall pollution in the air. Additionally, only low levels of smog are produced from combustion.[49] According to the U.S. Department of Energy, ethanol from cellulose reduces green house gas emission by 90 percent, when compared to gasoline and in comparison to corn-based ethanol which decreases emissions by 10 to 20 percent.[45] Carbon dioxide gas emissions are shown to be 85% lower than those from gasoline. Cellulosic ethanol contributes little to the greenhouse effect and has a five times better net energy balance than corn-based.[49] When used as a fuel, cellulosic ethanol releases less sulfur, carbon monoxide, particulates, and greenhouse gases. Cellulosic ethanol should earn producers carbon reduction credits, higher than those given to producers who grow corn for ethanol, which is about 3 to 20 cents per gallon.[46]
It takes 1.2 gallons of fossil fuel to produce 1 gallon of ethanol from corn. This total includes the use of fossil fuels used for fertilizer, tractor fuel, ethanol plant operation, etc. Research has shown that 1 gallon of fossil fuel can produce over 5 gallons of ethanol from prairie grasses, according to Terry Riley, President of Policy at the Theodore Roosevelt Conservation Partnership. The United States Department of Energy concludes that corn-based ethanol provides 26 percent more energy than it requires for production, while cellulosic ethanol provides 80 percent more energy.[45] Cellulosic ethanol yields 80 percent more energy than is required to grow and convert it.[50] The process of turning corn into ethanol requires about 1,700 gallons of water for every 1 gallon of ethanol produced. Additionally, each gallon of ethanol leaves behind 12 gallons of waste that must be disposed.[51] Grain ethanol uses only the edible portion of the plant. Expansion of corn acres for the production of ethanol poses threats to biodiversity. Corn lacks a strong root system, therefore, when produced, it causes soil erosion. This has a direct effect on soil particles, along with excess fertilizers and other chemicals, washing into local waterways, damaging water quality and harming aquatic life. Planting riparian areas can serve as a buffer to waterways, and decrease runoff.
Cellulose is not used for food and can be grown in all parts of the world. The entire plant can be used when producing cellulosic ethanol. Switchgrass yields twice as much ethanol per acre than corn.[45] Therefore, less land is needed for production and thus less habitat fragmentation. Biomass materials require fewer inputs, such as fertilizer, herbicides, and other chemicals that can pose risks to wildlife. Their extensive roots improve soil quality, reduce erosion, and increase nutrient capture. Herbaceous energy crops reduce soil erosion by greater than 90%, when compared to conventional commodity crop production. This can translate into improved water quality for rural communities. Additionally, herbaceous energy crops add organic material to depleted soils and can increase soil carbon, which can have a direct effect on climate change.[52] As compared to commodity crop production, biomass reduces surface runoff and nitrogen transport. Switchgrass provides an environment for diverse wildlife habitation, mainly insects and ground birds. Conservation Resource Program (CRP) land is composed of perennial grasses, which are used for cellulosic ethanol, and may be available for use.
Ok, so what do we have. Given gas prices and current biofuels, this will become profitable around 2013-2014. I'm willing to wait. It won't raise the price of food... unless you can strip off the bark of a tree and eat it. Plus it comes from biological garbage! If market prices are going to shape energy usage, then these should be a no-brainer.
