Two stories from the last few days address biofuels and their prospects for replacing more of the gasoline we use to power our vehicles. One provides evidence for what could be a biofuel champion; the other compares 26 contenders in search of an environmental winner.
The more recent — and somewhat sensational — story is about a study that appeared in the Proceedings of the National Academy of Sciences this week. A BBC headline about it blares ‘Grass biofuels cut CO2 by 94%.’ The study, led by M.R. Schmer and K.P. Vogel of the U.S. Department of Agriculture (USDA) and the University of Nebraska, estimated that ethanol made from switchgrass (a prairie weed) would produce 540 percent more energy than it takes to create the ethanol, and would cut CO2 by the aforementioned amount, compared to petroleum fuels.
The research study lasted five years and studied 10 farms that grew the switchgrass. The big catch, however, is that nobody has yet figured out how to make ethanol from switchgrass in a commercially viable way, so the researchers had to estimate the energy gains. The USDA and some private companies are working on technology to distill cellulosic ethanol (for example, from switchgrass), but that could be years away, according to this story on Time.com.
It’s easier to make ethanol from corn and sugar cane — and that’s where most of our ethanol comes from today. But these have a total environmental impact that’s worse than fossil fuels, according to an article in the Jan. 4 issue of Science magazine.
In that article, ‘How Green Are Biofuels?’, Jörn P. W. Scharlemann and William F. Laurance examine another recent study (R. Zah, et al., 2007) that measured 26 biofuels against gasoline, diesel and natural gas. This study used two criteria to compare the fuels: Total environmental impact and greenhouse gas emissions (both relative to gasoline). “Total environmental impact” included natural-resource depletion and damage to human health and ecosystems.
The results: Corn and sugarcane used to make ethanol both had a higher environmental impact than gasoline, as did soy diesel. Ethanol made from grass had a lower environmental impact than gasoline and reduced greenhouse gas emissions by nearly 70 percent. Fuels made from biowaste and recycled cooking oil also scored well.
Scharlemann and Laurance point out some problems with the Zah study and they note that some second-generation biofuels (like switchgrass) are promising from a cost-benefit point of view. They encourage governments to look beyond energy and greenhouse gas considerations and take into account the full environmental impact of each biofuel, before supporting them.
Non-food plants like switchgrass seem to be the best biofuel option, if we can devise ways to turn them into ethanol efficiently. Using food crops such as corn, sugar and soy for fuel has an economic downside — when we take some of these crops off of the market, prices go up for those foods. There can also be indirect consequences, such as people razing more of the Amazon in South America to grow soy, because soy prices have spiked, because a significant amount of U.S. farmers have switched from growing soy to growing corn (for ethanol).
I guess the thing to do is to engineer our cars to get the highest mpg possible, while at the same time investing in new technology to efficiently convert non-food crops such as switchgrass into ethanol.
What do you think? Post your comments here.
How is it that when these calculations are made, no mention is made of the impact of being at the mercy(or lack of)of the middle east and other foreign fuel supplies. Just the fact that as a Nation we need this for our security and economy is reason enough to put the same effort that was used to get us to the moon, to find an efficient way to produce fuel from switchgrass.
Keep in mind that high-yield production of any crop requires the addition of nitrogen in the form of ammonia to the soil. Most of our ammonia fertilizers now are products of the petroleum industry. In addition, there will be a lot of fuel expended planting, tending and harvesting the agri-product. Add to that the energy used to dry and process the material.
I think it would be prudent to let the market and unfettered innovation “solve” the energy crisis. If we depend on government to “help” us, we will be broke, cold and hungry.
Yes, alternative fuels can help reduce our reliance on petroleum from all sources, including the Middle East. Conservation can also help some. Renewable energy sources can also chip in. We’ll have to see exactly how much these measures can reduce our consumption of petroleum (and coal).
As for Benjamin’s concerns, the BBC story about the switchgrass study has some answers for you. The energy inputs in the study do includ “nitrogen fertiliser, herbicides, diesel and seed production.” The study estimated its results by assuming that a biorefinery would be used to process the grass and make ethanol; this refinery would run, in part, on “biomass residue” from the plants themselves, not totally on fossil fuels the way our corn-to-ethanol plants currently work.
Also, “Although the process to produce ethanol from switchgrass was more complex than using food crops such as wheat or corn, the so-called “second generation” biofuel could produce much higher energy yields per tonne because it utilised the whole plant rather than just the seeds.”
The researchers concluded that ethanol made from switchgrass would create 88 percent fewer greenhouse gas emissions than corn ethanol.
Switchgrass does seem promising, although there are some assumptions in the study that don’t exist yet — the biorefinery being the big one.
This type of research, done by both the federal government and a university, is one way that innovation happens. I think we’ll need all types of innovation to solve our energy and climate problems.
Dan, Are you ready for more information about reducing emissions? Please contact me.
I totally agree that using human consumable farm products is not a good idea. We should look to products such as switch grass as much more useful imputs. We also need to look for ways to reduce our consumtion of petroleum products. By using synthetic oils with their longer change intervals we could reduce our consumption. We should also consider vehicles that get better fuel milage to help reduce our level of consumption.
Hi Dan!
I just found you and you have posted on one of my pet subjects. Somewhere someone’s got
it wrong. A big fuss is made about the merits of re-cycling cooking oil. BUT governments are worried about the health effects of obesity!
Whilst networking recently I was introduced to someone who was supposed to be aligned
with my ethos. Wrong! She and her husband are growing miscanthus and turning it into biofuel. Oh, says I, you must be farming on marginal land. (I presumed that little else useful could grow there) . Oh no, says she we we’re not making enough in arable so we changed to this, with the subsides it is much more profitable. Fortunately the organiser stood up to speak before I could explode.
Why not visit my blog and leave a comment. I think we are on the same wavelength.
Bye for now
Ecoanne
Save energy today. Tomorrow my be too late.
Biofuel - one of the best that the people can do right now for the ecology! Its very important problem and we must solve it immidietly… For the next generations… but in our country this idea isnt popular for now… hope that soon this situation change!
The price of energy, in particular fossil fuel, is historically high and seems set to increase. Fuel bills - whether for the home or for the car - take up an ever-increasing proportion of people’s budgets. Fuel saver
I found this blog by accident looking for recipes blogs but AMEN! Couldn’t be a more important subject right now with fuel prices the way they are!
My brother and I attended a paid seminar, way back in the 1980’s (long before it was the buzz word of the day), given by a gentleman who made his own ethanol from sugar beets. His pretense was that sugar beets are much easier to grow can convert than corn or sugar cane and they could be grown in many types of soil that may not be conducive to growing cane or corn. Any comments on why sugar beets do not seem to get any mention in today’s proponents?
Great job.