Sustainable synthesis of acetals from glycerol as potential additives for biofuels under solvent-free conditions

SANTOS, ANA LUÍZA QUINTÃO; ROMANELLI, GUSTAVO PABLO; SATHICQ, ÁNGEL GABRIEL; FERNANDES, SERGIO ANTONIO; CASTRO, GABRIEL ABRANCHES DIAS; PALERMO, VALERIA

Reaction Chemistry & Engineering

Royal Society of Chemistry

Año: 2022 vol. 7

2058-9883

Acetals formed from glycerol find applications in several areas, being their use as fuel additives the most promising, since it results in the total integration in the biodiesel chain and eliminates one of the obstacles to its production. In order to convert glycerol into acetals, the use of p-sulfonic acid calix[4]arene supported on silica CX4SO3HSi(n) and heating microwave-assisted was proposed, and the quantitative analysis was performed by 1H NMR. The effects of the main reaction parameters were evaluated, such as temperature, reaction time and amount of catalyst heterogeneous, using benzaldehyde and glycerol as model substrates. From the optimized conditions 0.5 mmol of glycerol, 0.5 mmol of benzaldehyde, 5% wt of the catalyst CX4SO3HSi(n), at 110 °C in 20 min, the generality of the reaction was evaluated, obtaining twelve products with yields ranging from 6 to 99%. The important aspects of this protocol are the solvent-free reaction, water as a sole waste, metal-free and shorter reaction times.