Don’t drag your Christmas trees to the curb just yet. Research at the University of Sheffield, United Kingdom, and the University of Valladolid, Spain, has found that pine needles could be turned into renewable fuels and new products.
According to a press release from the University of Sheffield, 7 million Christmas trees end up in landfill in the U.K. each year. Not only is this costly, but each tree will release 16 kg of greenhouse gases as they decompose, producing methane gas, which is 25 times more potent than carbon dioxide.
Earlier research found that the chemical structure of pine needles could be broken down into a liquid product (bio-oil), which could be used in the production of sweeteners, paint, adhesives and vinegar and a solid by-product (bio-char), which could be used in other industrial chemical processes.
“With these results, this study sets a new strategy for CO2 and residual biomass valorisation (the process of reusing waste materials and converting them into more useful products) to produce renewable fuels and value-added chemicals, using only water as a solvent and producing a simultaneous reaction that simplifies the process and makes it more efficient,” says María Andérez-Fernández, a University of Valladolid PhD student, who was visiting the University of Sheffield’s department of chemical and biological engineering at the time much of the research was conducted.
The study looked at using different waste materials — sugar cane as well as pine needles — and concluded although sugar cane worked more effectively, refineries could use mixed biomass feedstock at different times of the year when different waste products are more abundant, for example, using pine needles in January.
“This could create a challenge in the process design, as currently refineries use feedstock that is constant throughout the year. So, if what you are feeding in as your reactants change throughout the year, this would have to be built in. But it’s a place we would like to get to so that in January, we are using the millions of pine needles readily available rather than them going to landfill,” says Dr. James McGregor, senior lecturer in the department of chemical and biological engineering at the University of Sheffield.