Catalytic pyrolysis of coconut oil with Ni/SBA-15 for the production of bio jet fuel

Abstract

Catalytic pyrolysis of vegetable oil is one of the potential routes to convert oil to drop-in biofuels, known as renewable hydrocarbons. In this paper, we explored catalytic pyrolysis of coconut oil using SBA-15 impregnated with Ni in proportions of 1% to 5% to produce sustainable aviation fuel. The catalysts were synthesized, calcined and then characterized by XRD, FTIR, SEM, and EDS. In order to better understand the behavior of this process, thermal and kinetic studies were carried out by thermogravimetry. The TG curves of vegetable oil with (10%) and without catalysts were obtained at heating rates of 5, 15 and 20 °C min⁻¹, in the temperature range between 30 and 600 °C. The kinetic parameters were calculated by the Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS) methods. In the kinetic study, lower heat rates promoted higher conversions and the KAS model suits the process. The results calculated for the OC sample using the two kinetic models showed an increase in the E_a energy as the conversion progressed to a certain point. Catalytic pyrolysis experiments were performed in a one-stage tubular reactor at 500 °C with a catalyst loading of 10 wt% on the basis of mass of oil. The catalyst with 5% Ni showed greater presence of hydrocarbons and greater formation of water, indicating that the deoxygenation process occurred through decarbonylation. With this, the present study was successful in the development of methodologies for obtaining hydrocarbons with a composition close to that of drop-in fuels, compared to the process carried out with vegetable oil in the absence of catalysts.