Improved glycerol dehydration through hierarchical beta zeolite

The increasing production of biodiesel has led to a surplus accumulation of glycerol as a byproduct, making its valorization essential for the sustainable development of the biodiesel industry, aiming for economic and environmental benefits. The dehydration of glycerol represents a promising alternative in the quest for higher value-added products, such as acrolein and acetaldehyde. Innovatively, hierarchical beta zeolite with uniform mesopores is reported in glycerol dehydration. The use of ammonium hydroxide (NH4OH) as an alkaline agent combined with the cetyltrimethylammonium bromide (CTAB) surfactant efficiently promoted the generation of uniform mesopores. Variations in the concentration of NH4OH and amount of CTAB significantly impacted the textural properties of the zeolitic materials and allowed for increasing the amount of Lewis acid sites. Hence, hierarchical beta zeolite allows to achieve superior specific activity in the dehydration of glycerol, reaching 93% of conversion, with acrolein (70%) and acetaldehyde (22%) as the main products. Zeolite Beta hierarchization strengthens Lewis acid concentration. Surfactants in hierarchization improve textural and acidity properties differently. Hierarchical Beta zeolite enhances the catalytic activity in glycerol dehydration.