Biofuels – the bad and the good!

Photo Credit jurvetson

The Guardian revealed today that it has obtained a World Bank report claiming that biofuels are responsible for 75% of the recent surge in food prices – far more than was previously thought.

Rising food prices have pushed 100m people worldwide below the poverty line, estimates the World Bank, and have sparked riots from Bangladesh to Egypt.

The report was being withheld, it seems to avoid embarrassing President Bush because it directly contradicts his claims that plant-derived fuels contribute less than 3% to food-price rises.

The report author, Don Mitchell, is an internationally-respected senior economist at the World Bank and has done a detailed, month-by-month analysis of the surge in food prices. This approach allows for a much closer examination of the link between biofuels and food supply than was possible in previous reports.

Dr Mitchell’s report

argues that production of biofuels has distorted food markets in three main ways. First, it has diverted grain away from food for fuel, with over a third of US corn now used to produce ethanol and about half of vegetable oils in the EU going towards the production of biodiesel. Second, farmers have been encouraged to set land aside for biofuel production. Third, it has sparked financial speculation in grains, driving prices up higher.

However, the news on biofuels isn’t all bad. There are some biofuels which don’t cause massive food price increases, and while I’m not a huge fan of biofuels (burning them produces CO2 still, don’t forget), they are a renewable resource.

They have, in the case of algae for example, the potential to be used in large-scale carbon sequestration projects. Large vats of algae could have the exhaust from power plants bubbled through them. The algae would feed on the CO2 and along with light convert the carbon into biofuel – recycling the carbon if you will.

Long term we need to get off the carbon economy but algal biofuels (which are not produced on viable farmland) look like a reasonable short-term way of reducing our CO2 emissions.


  1. Jason Etheridge says

    Isn’t the whole point of biofuels that, in theory, they’re carbon neutral? That is, while burning them does produce CO2, it should produce no more than was incorporated during the life of the plants that made that fuel?

    Biofuels aren’t inherently bad because they emit CO2 when burned. The problem is that the current production (e.g., ethanol from corn) isn’t carbon neutral (fossil fuels are needed in the process), they’re apparently more polluting than regular petrol, and (worst of all) they force up the price of food by creating a (subsidised) demand for food crops.

    An algae-based production method is ideal: biofuels can be produced that are truly carbon neutral. We can then have biofuels that are effective substitutes for use in aircraft and cars than can be delivered using the existing infrastructure, and don’t require modification of engine design. The ideal solution, if its production can be scaled up to the required level.

    The bottom line is that there’s no need to “get off the carbon economy”, as long as the CO2 produced is an even exchange with what’s incorporated.

  2. says

    Tom, A couple of questions re the algae.
    1. Is there much of a difference between bubbling the exhast gas through the algae and just growing the algae elsewhere? Where the CO2 is released makes no difference. I know the plants will take up more CO2 in a CO2 rich environment but I would guess that the extra energy required to cool the gas the bubble it through the algae would offset the simpler system of just putting the algae in a pond?
    2. How is the algae locking up the CO2? Will it not be released again when the biofuel is used or when the remains are composted or fed to animals? Maybe it could go through a biochar system – that might lock it up.

  3. Brian Miles says

    Regarding growing algae on power plant exhaust (I’m assuming coal or natural gas here), I’m no expert on CCS let alone the carbon cycle, but if you combust biofuels made from said algae, I don’t think any CO2 is being sequestered in the end. Now you might be getting more energy per unit of CO2 emitted into the atmosphere, not to mention the convenience of a liquid fuel, but you’re not keeping CO2 out of the atmosphere when all is said and done.

    You are in a sense piggybacking on the fossil carbon, which might not be a bad way, in the short- to medium-term, to reduce the carbon footprint of liquid fuels. Now if this algae process proves to be energetically and economically profitable for fossil fuel power plants, it would be interesting to try it on a wood-fired plant. Here you’d be piggybacking on “renewable” carbon, so you would be closing a loop, tapping a previously wasted byproduct of this form of centralized energy production.

  4. says

    @Phoebe, thanks for the questions and apologies for the delayed response but am just back from hols and am catching up!

    1. You are absolutely correct that it makes no difference where the CO2 is released but why would you need to expend energy to cool the gas to bubble it through the algae? Surely the CO2’s heat would be used to heat water and thereby turn the heat into a benefit, not a cost.
    2. You are again correct that the CO2 isn’t locked up indefinitely this way. What turning it into a fuel does is reduce the amount of fossil fuel burned for transportation, so we get more energy for less CO2 released. But I agree that fundamentally we need to move totally off the carbon economy. This is a stepping stone, a short-term solution to help us get there.

    @Brian, see my comments to Phoebe above re sequestration. I love the idea though of wood-fired piggybacking! Excellent.