Belgian researchers have developed a method that allows turning sawdust into building blocks for gasoline that could be used as an additive in plastics or fuel.
The innovative chemical process modifies cellulose, present in non-edible plant matter such as straw, grass, cotton or paper, by removing oxygen bonded to its hydrocarbon chains while preserving the chains' structure.
“This is a new type of bio-refining, and we currently have a patent pending for it,” said Bert Lagrain from the Centre for Surface Chemistry and Catalysis at the Catholic University of Leuven who led the research.
“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.
The team believes their invention would be particularly valuable for Europe, which doesn’t have abundant resources of oil. The hydrocarbon chains could be added into gasoline, replacing a portion of the fossil fuel. Unlike conventional energy crops, cellulose doesn’t compete for land use with food crops as it is basically a side product of any plant production.
“Essentially, the method allows us to make a ‘petrochemical’ product using biomass – thus bridging the worlds of bio-economics and petro chemistry,” Lagrain said.
The material can also be used to make chemicals such as ethylene, propylene and benzene – the building blocks for plastic, rubber, insulation foam or nylon.
“From an economic standpoint, cellulose has much potential,” said Professor Bert Sels. “Cellulose is available everywhere; it is essentially plant waste. It also produces chains of five to six hydrocarbon atoms – ‘light petrol’ in the technical jargon. We are currently facing shortages in this because it is becoming quite difficult and more expensive to distil these specific hydrocarbon chains from crude oil or shale gas.”
The research was described in an article in a recently published issue of the journal Energy & Environmental Science.