Catalytic cracking of Pachira aquatica Aubl. oil: PY-GC/MS study using HZSM-5.
Munguba oil; flash pyrolysis; bio-aromatics; renewable hydrocarbons
In an energy transition context, investment in renewable energy plays a crucial role in mitigating greenhouse gas emissions, reducing air pollution and protecting against the effects of climate change. In this sense, the oil extracted from the seeds of the fruit of Pachira aquatica Aubl. (PAA), known as Munguba, proves to be an excellent source of biomass for the production of renewable biofuels. Its composition has significant amounts of saturated acids, especially palmitic acid (C16:0), along with the unsaturated oleic (C18:1) and linoleic (C18:2) acids. The objective of this study is to characterize biomass from PAA with a focus on evaluating its energy potential for the production of second generation biofuels and valuable products for the chemical industry. The ash, moisture, volatile contents and lignocellulosic components were consistent with previous studies carried out on seeds of the same species. Furthermore, a satisfactory oil yield was observed through mechanical extraction, along with remarkable thermal stability, withstanding temperatures of up to 250 °C. To assess the feasibility of using this oil in the production of biofuels, comprehensive analyzes were carried out, including ash characteristics, density, viscosity and determination of indices such as acidity, iodine, saponification, peroxides and refraction. During conventional analytical pyrolysis of the oil, there was predominantly the formation of aliphatic hydrocarbons in the C7-C18 range, and a low amount of oxygenated compounds. In catalytic pyrolysis using HZSM-5, a significant reduction in oxygenated compounds and the predominance of aliphatic hydrocarbons were observed, covering the range of C7-C14 at 300 °C, and the range of C4-C13 at 500 °C. At both catalytic bed temperatures, a high yield of aromatic compounds was noted, including benzene, toluene, ethylbenzene and xylene (BTEX), which are products of great interest to the chemical industry. HZSM-5 is widely used for this purpose due to its ability to promote the decarbonization, decarbonylation, deoxygenation and aromatization of structures, due to its acidic properties and porous structure. These results point to the significant potential for applying PAA seed oil to obtain biofuels and bioproducts.