Can crops replace oil?

The yields of crops has to increase dramatically for biofuels to make sense. It currently takes around 3 tonnes of wheat to produce 1 tonne bioethanol via fermentation. That is using grain, rather than the whole wheat, from seed to root and is probably only sustainable in fairly limited quantities of bioethanol production.

Why? mostly because if the US would starve. Now these sums are as rough as a badgers’ behind but…

Taking the averages US gasoline consumption for September this year and converting this to tonnes/year with a rule of thumb found in The Economist World Measurement Guide (paper, I know but it was printed in 1980 (page 134)) that 1 barrel/day is 50 tonne/year. If September’s consumption is average then the US will use between 462 million tonne and 472 million tonne/year gasoline. The US Department of Agriculture (USDA) estimates in its March 2006 year book that this year there will be 41m US acres under wheat, producing around 2105m bushels (equivalent to 57m ton grain). Even if we malted, brewed and distilled all of this, we’re talking about 19m tonne ethanol. That’s not quite enough to make a 5% blend with gasoline. Even if we diverted the whole world’s supply of vegetable oil estimated at 106.82 million tonnes in 2005, by the USDA in its march yearbook (Its in spreadsheet 48, if you get that far).
Even if it were a drop-in replacement for gasoline, which it isn’t, we’re going to be way short. While the lack of margarine, would be good news for the butter lobby, this would be offset by the black market in Fried Food that would inevitably spring up.
Which is why people are interested in using the whole of the wheat from the seed to the root. Which is why people are interested in biomass,things like weeds, though whether we’d be better burning them and generating electricity from the steam you could make is something I’ll be looking at later.

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4 Responses to Can crops replace oil?

  1. C. Scott Miller 5 October, 2006 at 3:32 pm #

    I prefer to leave food crops for human and livestock feeding. But I applaud the current U.S. ethanol industry which is currently only using “surplus” food crops for producing ethanol.

    One of the themes of this blog is the need to think broadly about what can be used as feedstock. We all know sugar cane and corn for sugar fermentation. We (including developing countries that don’t have corn or sugar cane) have begun thinking about grain, switchgrass, and other “energy crops” for enzymatic hydrolysis. I believe syngas fermentation will prove the most universal technology for cleanly producing ethanol because it feeds on anything that has carbon in it including:

    • agricultural waste – corn stover, rice straw, damaged crops (like spinach this year);
    • forestry waste;
    • urban trash, plastics, auto fluff, tires, sewage, and other waste.

    If that is not enough biomass feedstock, you can blend in sulfurous coal and other fossil fuels which, through gasification, can be used to transfer heat to electricity while their otherwise harmful emissions are scrubbed and converted into ethanol.

  2. john richardson 8 October, 2006 at 4:34 am #

    Some of the logic driving the ethanol industry could indeed be as rough as Simon’s proverbial badger’s backside.

    You cannot help thinking that all the fuss about ethanol, and biofuels in general, is driven to some extent by companies wanting to look good, to improve their environmental image in the eyes of investors, rather than necessarily making sensible and long-term choices about what’s good for either their company or our dear old, soon-to-be departed planet.

    Take the obscene amounts of grain needed to produce ethanol in sufficient quantities, for example. Wouldn’t it be better to wait for the new biomass technologies to come along? Why invest in what could soon be redundant technology, ie all the ethanol refineries being built in the US?

    Widen the picture out, and what about the demand for Asian palm oil for biodiesel production? Could yet more rainforests be destroyed in Sumatra to plant palm oil for biodiesel and what’s the net environmental impact? I am sitting here in Singapore breathing in the pollution from this year’s forest-clearing season in Indonesia; every year, Indonesia burns the soft wood to get at the hard wood at the heart of the forests, but the firest invariably rage out of control. This year is no exception, with most of the logging illegal. Could next year’s haze over Southeast Asia be even worse as greedy businessmen, with an eye for the quick buck or rupiah, clear the forests to plant more palm oil? Will the net effect of all the these burning trees, minus the benefits of more bidiesel production, be negative for the environment?

    Food security remains an issue for the majority of Asians who still live on less than $1 a day. What would diverting agricultural land to palm-oil production mean for food security? Hunger usually equals social, political and economic damage, and lots of carbon dioxide released from burning buildings.

    How much does the whole biofuels debate hang on the search for a quick buck at the expense of a distanced evaulation of the overall benefits for the environment?

    Can market forces alone be trusted to allow the industry to make the right choices?

  3. deputyeditorecn 9 October, 2006 at 8:17 pm #

    It is a moot point about the desire of companies to look good and the need for food in developing countries.

    It would be more than obscene if we satisfied people’s demand for motor fuel by starving those in devloping world. That is why Malaysia’s moratorium on palm oil to biofuel projects should be welcomed.

  4. john richardson 10 October, 2006 at 11:41 am #

    But does Malaysia’s moratorium also apply to planting palms trees for exporting palm oil for biodiesel production overseas? I imagine it would be hard to legislate against the palm-oil industry, as end-use will vary depending on market conditions, eg, between biodiesel and oleochemicals.

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