Executive Summary : | The increasing use of biodiesel has led to a significant increase in the production of glycerol, a major by-product. Glycerol is readily available from various sources, including cellulose via hydrogenolysis, fermentation processes involving yeast, bacteria, and algae, and as a by-product during the transformation of feedstock into fine chemicals like perfumes, fragrances, and pharmaceuticals. It is considered a useful "waste" due to its nontoxic and biodegradable nature and its green non-volatile solvent properties. Glycerol is also used as a fuel, source of hydrogen, and precursor to several synthetically useful raw materials. One such transformation involves the generation of hydrogen and the production of lactic acid (LA), which is valuable synthetic feedstock found in food, pharmaceuticals, fine chemicals, cosmetics, and poly lactic acid (PLA). Traditional fermentation and heterogeneous catalysis have limitations, but homogeneous catalysis for glycerol to lactic acid conversion has shown good reactivity and selectivity.
The current proposal aims to enhance catalytic efficiency and accomplish this reaction in a recyclable fashion. It proposes using the by-product hydrogen in a tandem step, involving carbon-dioxide hydrogenation to formic acid, using a pincer-M catalyst. This approach utilizes abundant greenhouse gas carbon dioxide and readily available waste glycerol in the presence of recyclable pincer catalysts based on inexpensive metals like iron to produce highly valuable lactic acid (LA) and formic acid (FA), which have a large global market. |