Biomass questions and answers
A look at the landscape in next-generation non-food biofuels.
What is biomass?
Biomass refers to plant material that can be harvested for energy. Any plant can be used for its biomass.
If any plant can be used for energy, why is corn the most common?
Corn was used to make nearly all of the eight billion gallons of ethanol that the U.S. produced in 2008. Corn was part of the first generation of plants used to create biofuels because it could be turned into ethanol using technology that already existed to convert plant starch to alcohol.
What can we use besides corn?
Second-generation biofuels are now being produced from crops that can't be used for food—plants such as giant cane (Arundo donax) and other perennial grasses. Selectively harvested biomass from forestry materials is also being converted into forms of bioenergy.
Which of those second-generation sources are most likely to be environmentally and economically sustainable?
The future of biomass energy will likely come from a variety of feedstocks situated in the regions most suited to growing each of them. Expect to see a patchwork of fast-growth trees and grasses spread around the country, says John Erickson, assistant professor and environmental agronomist at the University of Florida.
How many acres will be needed to meet the demand for alternative fuels?
The Energy Independence and Security Act of 2007 requires that by 2022 the United States use 36 billion gallons of renewable fuels, of which 16 billion gallons are supposed to come from cellulosic sources such as trees, grasses, weedlike energy crops and non-edible parts of plants.
The total acreage of giant cane needed to create 16 billion gallons of ethanol—assuming a yield of 13.4 tons of giant cane per acre and 91 gallons of ethanol per ton of biomass—is 13.1 million.
To completely replace the annual U.S. gasoline consumption would require about 170 million acres of Arundo, or just under half a football field per person per year. By comparison, corn is currently grown on about 87 million acres in the United States.
Why aren’t more biofuels on the market now?
The technology needed to turn cellulosic material into biofuel is still in the early stages of development. Cellulosic ethanol differs from ethanol in that it requires an extra step called cellulosis, which is the breaking down of cellulose into sugars. According to Norman Smit, the director of communications and education at the Biofuels Center of North Carolina, until there is a conversion process that has proven economic models, farmers will not be persuaded to grow energy crops.
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John Bonitz
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... This is informative but really neglects the "bird in hand." Biomass for electricity is proven technology, economically viable, and cost-competitive with new coal -- the typical default for Southern electric utilities. It also has much less air pollution emissions than average coal-fired plant, and none of the toxic mercury. Biomass for electricity (aka biopower) is the renewable energy source we have in greatest abundance here in North Carolina and other Southeastern states. Biopower brings more jobs than any other renewable energy - about 9 jobs per MW. Conservative estimates are that NC has enough sustainable biomass resource to feed 1,000 to 2,000 MW of biopower plant capacity. These plants are small, community scale, typically less than 50MW in size. Craven County Wood Energy in New Bern, NC is a great example, having a 19 year operating history. http://www.ccwe.net/ Biopower isn't a silver bullet: We need massive investments in energy efficiency, solar electric, solar thermal, wind power, small low-impact hydroelectric, etc. But biopower can play an important role as baseload electricity. The trouble is that the regulated electric monopolies don't like biopower because it is a distributed energy source: It's not centralized like coal and nuclear. Progress and Duke would prefer to run a few 1,000MW coal or nuclear plants rather than a few dozen biopower plants. They also prefer to buy coal from a handful of suppliers, whereas biomass must be bought from hundreds of forest owners, farmers, loggers, sawmills, etc. North Carolina's economy bleeds $2 billion every year in coal purchases, with 10% coming from foreign countries. These coal dollars leave our state, sapping our economy. Investing in renewable energy, including biopower, helps us keep this money in-state, recirculating and re-invigorating our local economies. Partly for this reason, here in NC we have a mandate for the utilities to buy renewable energy (Senate Bill 3, the Renewable Energy Portfolio Standard or REPS). But the utilities are not buying biopower, even though many biopower companies have offered it. It's cost-competitive, clean, renewable, and available today. Why aren't the utilities doing it? |
football tickets
said:
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... We should use corn because 1/2 a football field per person is alot of land. We would rather have some football tickets so i can go to a game. |
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