Move Over Ethanol And Biodiesel, Biopetrol Is In The Pipeline
Here’s a development that might (and I stress “might”) shake up the biofuels industry. A team led by Professor Mark Mascal at the University of California, Davis has developed a method of making petrol (gasoline)-like fuels from cellulosic waste – things like straw, corn stalks, and green municipal waste – maybe even old newspapers. If it makes it through to market, it could be a game-changer
The liquid biofuels scene has been dominated by ethanol and biodiesel. Biodiesel mostly comes from oil crops. Current ethanol production is mainly based on sugar cane and corn. In both cases only a relatively small amount of the plant – the oil from seeds or the sugar crystalised from the juice – are used to make fuel.
One great hope has been that the cellulose that makes up the bulk of a plant can be broken down into its constituent sugar, glucose, and used to make ethanol. This means that straw, wood chips and a range of plant materials can be used as feedstock. Some cellulosic ethanol pilot plants are operating, but the fossil fuel industry isn’t quaking in its boots just yet.
Another issue is the requirement to modify engines, to varying degrees, to run on biofuel. Most petrol vehicles run quite happily on up to 10% ethanol, but that’s hardly the route to a truly sustainable fuel source. And ramp the ethanol up much above 10% and the engines need modification. If a plant-based petrol alternative that can go straight into current refuelling infrastructure and vehicles can be developed, it’s going to be much easier to transition to a renewable fuels future.
It’s early days, of course, but a couple of things stand out as far as the UC Davis development is concerned. One is that, unlike the enzymatic processes used in cellulosic ethanol production, the UC Davis process is entirely chemical. The cellulose is used to make levulinic acid, and doesn’t need to be converted to sugars first. Secondly, Mascal says that levulinic acid can be made in high yield, and points out that the starting materials are cheap.
For now it’s a case of “watch this space” as we wait to see how the new kid on the biofuels block shapes up.