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Switchgrass
From CopperWiki
Switchgrass once fed millions of bisons in North America. Soon it may help fuel millions of cars and trucks, spin power turbines, and supply chemicals to American industries. In the olden days these tall, native grasses of the prairie were vital to North America’s ecology and now may prove equally vital to its economic future.
Governments both in the EU and the US view switchgrass, once considered an “obstacle to progress”, as a plentiful and low-cost alternative to corn or sugarbeets for making the next generation of biofuels.
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[edit] Switchgrass Produces Ethanol
When distilled switchgrass produces ethanol, an alcohol that fuels vehicles. As much as 96 gallons of ethanol can be produced from each ton of dry switchgrass. Currently ethanol is blended at a ratio of 15 percent to 85 percent of gasoline and sold as E-85. Switchgrass also grows fast, absorbs the solar energy, and turns this energy into cellulose. Ethanol is extracted from cellulose by means of distillation.
To make ethanol from corn, about seven-tenths of a gallon of fossil energy, oil or natural gas is required to make every gallon of fuel. This is only a small improvement in terms of greenhouse gases. But on the other hand, for every gallon of ethanol made from cellulose like switchgrass only a tiny amount of fossil material is used.
[edit] Less Energy Input. Less Greenhouse Gas
Brazil makes ethanol from sugarcane and runs an automobile fleet with it. The climatic conditions in the US don’t permit cultivation of sugarcane. So the emphasis so far had been on making ethanol from corn. But corn competes with food, both for humans and livestock. Also a huge amount of energy is required to plant, fertilize, de-pestify, grow, and harvest corn.
Switchgrass on the other hand does not compete with food. For irrigation fossil fuel is required by tractors to spread fertilizer and fuel the pumps that irrigate fields. Switchgrass production requires less fossil fuel as it is resistant to drought and requires little fertilizer. Studies have shown that switchgrass produces 540 percent more energy than the energy needed to produce it and convert it to ethanol. This means that switchgrass biofuel generates nearly five-and-a-half times the amount of energy that was invested in creating it.
Less energy input also results in 94 percent reduction of greenhouse gas emissions in the process of creating switchgrass biofuel compared with the amount of carbon dioxide that would have been released by burning the same amount of oil.
[edit] To Reduce US Dependence on Foreign Oil
The groundwork has been laid by a team of US economists, energy analysts, plant physiologists and geneticists for this new source of renewable energy which would reduce America’s dependence on foreign oil and curb emissions of the greenhouse gas carbon dioxide.
Currently many farmers are growing switchgrass as forage for livestock or as a ground cover to control erosion. Only minor changes would be required to cultivate it as energy crop. Switchgrass does not require replanting for at least 10 years and can be harvested as cash crop annually or semi-annually. And because of its multiple uses - as an ethanol feedstock, as forage, as ground cover - switchgrass crop can always be put to good use.
[edit] Switchgrass Profile
Switchgrass has one of the highest potentials for use as a biofuel feedstock crop mainly because it can tolerate almost any soil type and grows well under a wide range of climatic conditions, from floods to droughts. Switchgear only needs to be planted once, not annually. Also switchgrass could be grown on marginal farmland not suited to high value crops like corn and soybeans.
Switchgrass can be of two types. The low land type grows up to 12 feet while the upland types are 5 to 6 feet tall. Big and tough, switchgrass has stems as thick and strong as hardwood pencils. It is a valuable soil protection cover crop, binds loose soils and provides valuable wildlife habitat. It is capable of producing high yields with very low application.
The stems and roots of switchgrass reach into the deeper parts of the soil to hold on to it, and in the process stop soil erosion. Planted along wetlands and steambanks, these grasses filter out pesticides and prevent these dangerous chemicals from entering the water supply. While fossil fuels release huge amounts of carbon dioxide into the atmosphere, switchgrass removes CO2 from the air and puts these back in the soil
[edit] Home Heating Fuel of the Future
With rise in energy crops homeowners are looking for alternative energy sources for home heating. Scientists see switchgrass as a new and cheaper way to heat your home. Agricultural fiber is a potential source of energy that can be pelletized through conventional pelleting plants and burned in pellet stoves to heat homes.
Switchgrass can be densified into a pelletized biofuel and used for space heating purposes with a close couple gasifier pellet stove.
Research work is under way in US and Canada for development of biofuel pellets made from switchgrass for use in space heating applications. Once pelletized, switchgrass has the potential to displace oil, natural gas, and electricity used for heating fuel. This will particularly help the rural economy as there will be significant reduction in heating costs as well as greenhouse gasses.
[edit] Pellet Stoves and Furnaces
Gasifier pellet stoves and furnaces have emerged as energetically efficient, economical, and convenient energy transformation pathway for converting switchgrass into energetically efficient, economical, and convenient energy transformation pathway. These furnaces can burn switchgrass pellets just the way wood pellets are burnt and provide fuel conversion efficiencies and particulate emissions in the same range as modern oil furnaces.
It is estimated that an acre of switchgrass made into pellets will heat an average American home for a whole year. These pellets have the potential to reduce fuel heating costs and greenhouse gas emissions by approximately 30% and 90% respectively compared to heating oil systems
[edit] REFERENCES:
- Switchgrass-based ethanol may yield 540 percent more energy
- Grass Biofuel Pellets
- Is Switchgrass a Viable Energy Crop?
- Home Heater?
- Switchgrass ethanol
