From sludge to fuel

    An alternative energy expert at Temple University says what we send down our drains could be processed and used to power farm equipment and heavy machinery.

    (Photo: / CC BY-ND 2.0)


    The budding biodiesel industry is mostly fueled by vegetable seeds such as soybeans and canola. But Philadelphia researcher David Kargbo says green experts are looking for alternatives to those petroleum alternatives.

    Kargbo: You know, energy is everywhere. And sometimes where we get the energy from can be very expensive, and also not good for the environment. Therefore we have to look for other means, and one of them is right in front of us, which is using sewage sludge.

    Sludge that smelly, soupy stuff that comes from sewage treatment plants is rich with energy-packed lipids and can be processed into biodiesel fuel.

    Kargbo is a scientist with the U.S. Environmental Protection Agency.

    Biodiesel from sludge doesn’t burn any cleaner, but Kargbo says extracting more biodiesel from sludge means relying less on food crops for fuel.

    Scientists already know how to make the switch, but there are several hurdles to mass production.

    The U.S. government gives sizeable tax credits for biodiesel made from vegetable seeds; the incentives for sludge biodiesel are less generous.

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