A team of researchers developed a new green process to produce vanillin from lignin, according to a study published in Angewandte Chemie International Edition.
The demand for vanillin (to make vanilla flavour) is much larger than what can be harvested naturally. There is a way to produce vanillin from petroleum, which is far less expensive than getting it from fermented vanilla pods.
A more environmentally- friendly alternative relies on lignin, a waste product of the wood pulping industry, but the process is not very efficient. A team of researchers from the Johannes Gutenberg University Mainz (JGU), Germany, have now managed todevelop a green oxidation method. The aim is to degrade lignin — seen as a worthless byproduct — to release vanillin. “We are confident that our sustainable, environmentally-friendly process can contribute towards an even larger scale production of vanillin,” said Professor Siegfried Waldvogel.
Vanilla is added to a variety of foods and drinks, not to mention perfume and even medication. Every year, several tens of thousands of tons of vanillin are produced by chemical means. This problem is that this process needs fossil raw materials and produces toxic waste products. Not surprisingly, researchers have been looking for a better way to produce vanillin. “We can avoid these problems by making vanillin from lignin, a component of wood,” said Waldvogel. “The electrochemical process we have now been working on for nearly 15 years enables us to obtain high-quality vanillin from the renewable resource wood employing an eco-friendly method.”
There is a current method using lignin, which uses copper as a catalyst. However, this process requires a complex and expensive purification step at the end of the reaction. In contrast, exposing the lignin to an electrical current raw is more cost-effective and does not result in the production of waste. “The yield we achieve with this process can be up to 6.2 percent by weight of lignin used, which is an outstanding result,” concluded Waldvogel.
Zirbes M, Grabl T, Neuber R et al. (2023) Peroxodicarbonate as a Green Oxidizer for the Selective Degradation of Kraft Lignin into Vanillin. Angewandte Chemie International Edition, https://doi.org/10.1002/anie.202219217