A big thank you goes out to the land down under for giving the world another great reason for making wine – biofuel. University of Adelaide researchers have found that the solid waste left over from wine-making could make a competitive biofuel.
Their recent research, which was published in the scientific journal Bioresource Technology, has demonstrated that up to 400 litres of bioethanol can be produced by fermentation of a tonne of grape marc (the leftover skins, stalks and seeds from wine-making).
Wine production leaves several hundred thousands tonnes of grape marc waste in Australia, and a whopping 13 million tonnes globally. Wineries generally have to pay to dispose of this waste so finding a use for it will help improve the bottom line of many.
“This is a potentially economic use for what is largely a waste product,” says Associate Professor Rachel Burton, Program Leader with the Australian Research Council (ARC) Centre of Excellence in Plant Cell Walls in the School of Agriculture, Food and Wine.
Researcher Kendall Corbin analysed the grape marc from two popular varieties, cabernet sauvignon and sauvignon blanc. She found that most of the carbohydrates found in the grape marc could be converted directly into ethanol through fermentation, yielding up to 270 litres per tonne of grape marc. Pre-treating the grape marc with acid and enzymes increased this yield to 400 litres a tonne.
The leftover product from this process can be used as animal feed or fertilizer.
“Using plant biomass for the production of liquid biofuels can be difficult because of it structurally complex nature that is not always easily broken down,” says Ms Corbin.
“Grape marc is readily available, can be sourced cheaply and is rich in the type of carbohydrates that are easily fermented.”
Associate Professor Burton says: “We’ve shown that there is a potential new industry with the evolution of local biofuel processing plants to add value to the grape for an environmentally friendly biofuel.”
Thanks to these researchers, we have another reason to enjoy a glass of wine.
Tracey is an accountant and entrepreneur with a passion for nature. This passion is what spurred her interest in renewable energy, and the rest is history as they say. Tracey is a principal in Energy Think Group, the publisher of Solar Thermal Magazine and Tek-Think. She is also the principal at Women's Financial Help Desk. She spends her free time in the outdoors with her horses and dogs. She loves to travel.