Today’s chemical industry relies on oil to make everything from plastics to detergents to medications. Scientists say wood waste is a more sustainable alternative.
They recently demonstrated the possibilities by manufacturing succinic acid using wood waste and bacteria. They showed that the process could be significantly cheaper or considerably more eco-friendly than conventional oil-based methods.
Succinic acid is added to fuel and lubricants to protect motors from corrosion. It goes under the name of E 363 in the food industry, where it is used as an acidifier and flavor enhancer. It’s also used to manufacture vitamins, medication, solvents, crop protection products, polymers, and aromatic substances for perfumes.
To manufacture succinic acid using bacteria, the scientists needed glucose (grape sugar) as the raw material. It can be extracted from sugar beet or sugar cane, but wood is also an option.
“Cellulose, found in wood, can be converted to glucose by adding acid,” explains Merten Morales, a PhD student at ETH Zurich and lead author of the study.
The scientists compared the method of manufacturing succinic acid from sugar beet or from wood waste. In terms of cost effectiveness, environmental impact, and safety, the differences were negligible. They considered the total energy required for manufacture, including grey energy (which also covers the indirect energy required to manufacture primary products, infrastructure and waste management), as a measure of the environmental impact.
“If it is possible to use wood waste—in other words, waste from the forestry industry—that is what we should do,” says Morales. “Then there is no competition with the food supply chain.”
The new method could apply to the paper industry. One waste produce—an alkaline solution that contains cellulose—is not currently recycled, but would be an ideal source of glucose.
“The European paper industry could once again hope to compete with strong competition overseas if it succeeded in recycling waste products and selling them with added value,” says Morales.
The study appears in the journal Energy and Environmental Science.
Source: ETH Zurich