How Gold Can Recycle Biofuel Waste into Useful Additive

Gold nanoparticles serve as catalysts for obtaining valuable chemical products based on glycerol. Scientists from Tomsk Polytechnic University and their international colleagues are developing gold catalysts to recycle one of the main byproducts of biofuel production. The obtained products are in high demand in medicine, agriculture, cosmetic industry and other sectors.

“Today the production of biofuels is an important area in many countries. They can be obtained from a great variety of biomasses. In Latin America, it is orange and tangerine peel as well as banana skin. In USA biofuels are produced from corn, in the central part of Russia and Europe – from rape (Brassica napus). When processing these plants into biofuels a large amount of Glycerol is formed. It's esters constitute the basis of oils and fats. Glycerol is widely used in cosmetic industry as an individual product. However, much more glycerol is obtained in the production of biofuels – many thousands of tonnes a year. As a result, unused glycerol merely becomes waste,” described the problem Alexey Pestryakov, head of department of physical and analytical chemistry. “Now, a lot of research groups are engaged in this issue as to how to transform excess glycerol into other useful products. Along with our foreign colleagues, we offered catalysts based on Gold nanoparticles.”

The authors of the research note that catalytic oxidation on gold is one of the most effective techniques to obtain from glycerol such useful products as Aldehydes, esters, carboxylic acids and other substances.

“Thus, unused glycerol after being processed will further be applied,” summed up Pestryakov.

Gold catalysts are super active. They can enter into chemical reactions with other substances at room temperature (other catalysts need to be heated), in some case even under zero. However, gold can be a catalyst only at the nano level.

“If you take a piece of gold, even very tiny, there will be no chemical reaction. In order to make gold become chemically active, the size of its particle should be less than two nanometers. Only then it gets its amazing properties,” explained the scientist.

Unlike their counterparts, the gold catalysts developed at TPU are more stable (they retain their activity longer).

“A great challenge in this area is that gold catalysts are very rapidly deactivated, not only during work but even during storage. Our objective is to ensure their longer shelf life. It is also important to use oxygen as an oxidizer since toxic and corrosive peroxide compounds are often used for such purposes,” said Petryakov.