Transesterificação do óleo de milho para produção de biodiesel usando x_MoO3/MCM-41

Abstract

The Industrial Revolution in the 18th century brought rapid development of production techniques and new technologies. However, increased production and natural resource consumption led to negative impacts such as air pollution and global warming. In this context, countries are seeking to diversify their energy sources and reduce dependence on fossil fuels for both environmental and energy security reasons. Among renewable energy sources, biodiesel is considered the prime option. The most commonly used technology for biodiesel production is transesterification, involving the reaction between triglycerides and alcohol in the presence of a catalyst. Among heterogeneous solid catalysts, molybdenum oxide (MoO3) incorporated into the mesoporous molecular sieve MCM-41 stands out. The aim of this work is to evaluate biodiesel production via methylation transesterification of corn oil using catalyst x_MoO3/MCM-41, determining optimal reaction conditions through a 22+3PtCt factorial design. Initially, MCM-41 molecular sieve was obtained through a hydrothermal process and subsequently activated by calcination to remove the structural template. Subsequently, the ammonium heptamolybdate precursor was incorporated into the MCM-41 structure by pore volume saturation, at percentages (by mass) of 10, 15, and 20%. MoO3 under the MCM-41 molecular sieve was obtained through calcination activation. Thermograms demonstrated removal of the structural template and precursor salt decomposition. Diffractograms identified MCM-41 structural phases and formation of the catalyst structure with excessive MoO3. Adsorption/desorption isotherms revealed a characteristic type IV profile of mesoporous materials, and textural properties indicated MoO3 dispersion in MCM-41, affecting pore diameter. TPD demonstrated ammonia silica-molybdenum interaction, impacting catalyst acidity. The factorial design revealed that using the 10% MoO3 catalyst at 175°C converted 86.9% of triglycerides in corn oil into methyl esters. Density, viscosity, and acidity tended to align within established parameters at temperatures above 150°C. Statistical analysis confirmed that the reactive temperature variable significantly influenced the response factor (% of methyl esters), being the most influential factor on the response variable.