Heliyon (Apr 2023)
Glycerol valorization using Colombian olivine as a catalyst
Abstract
The biodiesel industry currently generates large amounts of crude glycerol that are not marketed, thus accumulating, and causing environmental problems. This study evaluates the catalytic potential of Colombian olivine, using glycerol steam reforming to assess valorization alternatives for this by-product. The analyzed olivine was thermally treated at 1200 °C and reduced at 900 °C, then producing nanometer-sized Fe compounds. The catalyst was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, scanning electron microscopy (SEM), temperature-programmed reduction (TPR), and transmission electron microscopy (TEM). Calcined olivine increased glycerol conversion at 600 °C from 43% (without catalyst) to 96% with the formation of liquid-phase products such as aldehydes and carboxylic acids. In addition, syngas with H2/CO ratios of 1.1 and 1.5 was generated at reaction temperatures of 700 °C and 800 °C, respectively, with low CH4 content. Finally, it was established that olivine from Medellín, under the conditions used for glycerol steam reforming, is a viable and interesting alternative to valorize glycerol into gas- or liquid-phase products.