Driven by sawdust (Day 196)

Back in 2006, a campaign was launched to plant one billion trees every year. In the first five years alone, over 12 billion were planted, and the campaign rolls on today.

The Billion Tree campaign is now managed by the United Nations Environment Agency and efforts like these have had an important role to offset the billions of trees cut down every year.

Of course, all this wood processing creates sawdust and there’s a long list of uses for this by-product including fuel briquettes, animal bedding, mushroom growing, soil amelioration, ‘smoking’ food, building products and more.

One of the latest development involves researchers at Katholieke Universiteit Leuven (KU Leuven) in Belgium, the Leibniz-Institute for Solid State and Materials Research in Dresden, Germany, and the chemical engineering department at the California Institute of Technology in USA.

They have managed to convert sawdust into building blocks for gasoline.

Using what they say is a new chemical process, they were able to convert the cellulose in sawdust into hydrocarbon chains. These hydrocarbons can be used as an additive in gasoline, or as a component in plastics.

Cellulose is the main substance in plant matter and is present in all non-edible plant parts of wood, straw, grass, cotton and old paper.

KU Leuven’s Bert Lagrain, says: “This is a new type of bio-refining, and we currently have a patent pending for it. We have also built a chemical reactor in our lab; we feed sawdust collected from a sawmill into the reactor and add a catalyst – a substance that sets off and speeds the chemical reaction.

“With the right temperature and pressure, it takes about half a day to convert the cellulose in the wood shavings into saturated hydrocarbon chains, or alkanes.

“Essentially, the method allows us to make a ‘petrochemical’ product using biomass – thus bridging the worlds of bio-economics and petro-chemistry.”

The team have been able to produce an intermediary product that requires one last simple step to become fully-distilled gasoline. It can be used as a green additive – a replacement for a portion of traditionally-refined gasoline.

KU Luevens also believe their product has possible applications that go beyond gasoline, including ethylene, propylene and benzene – the building blocks for plastic, rubber, insulation foam, nylon, coatings, and other products.

Chemical engineers often talk about having a balanced energy mix. For countries that don’t have their own crude oil reserves or shale gas, sometimes the choices are limited.  Hydrocarbon derived from plant waste that doesn’t compete with crops, may provide a viable alternative.

More details about their work can be found online in Energy & Environmental Science.