Inexpensive Ni-based catalysts can afford comparable performance to costly precious metal formulations in the conversion of fat, oil, or greases (FOG) to fuel-like hydrocarbons via decarboxylation/decarbonylation (deCO_x). While the addition of certain metals has been observed to promote Ni-based deCO_x catalysts, the steady-state performance of bimetallic formulations must be ascertained using industrially relevant feeds and reaction conditions in order to make meaningful comparisons. In the present work, used cooking oil (UCO) was upgraded to renewable diesel via deCO_x over Ni/Al₂O₃ promoted with Cu, Fe, or Pt in a fixed-bed reactor at 375 °C using a weight hourly space velocity (WHSV) of 1 h⁻¹. Although all catalysts fully deoxygenated the feed to hydrocarbons throughout the entire 76 h duration of these experiments, the cracking activity (and the evolution thereof) was distinct for each formulation. Indeed, that of the Ni-Cu catalyst was low and relatively stable, that of the Ni-Fe formulation was initially high but progressively dropped to become negligible, and that of the Ni-Pt catalyst started as moderate, varied considerably, and finished high. Analysis of the spent catalysts suggests that the evolution of the cracking activity can be mainly ascribed to changes in the composition of the metal particles.

In the present paper, an integrated continuous process of biodiesel manufacturing is proposed using Aspen Plus simulator for different feedstocks. Majority of the reported simulation models in literature are design models for new processes by fixing some level of equipment performance such as the conversion in reactor. Most models assume the feed oil as pure triglycerides or some fatty acids and the biofuel as pure ester. In order to optimize the production of biodiesel, similarity with reality is necessary. For this purpose, this work uses thermophysical property estimation of glycerides, rigorous reaction kinetics, phase equilibrium for separation and purification units, and prediction of essential biodiesel fuel qualities. Detailed operating conditions, equipment designs, and properties of feed and products were obtained. The reactions and parameters kinetics were applied to represent both methanolic and ethanolic transesterification of the biodiesel production. An evaluation of optimal operating conditions (time, temperature, alcohol: oil ratio) for a CSTR reactor was determined. The optimal conversion was achieved at a temperature of 60 °C, 6.00 mol/mol alcohol-oil ratio and 2.0 h residence time when used methanol transesterification reaction as 88.19, 93.77, 89.43, and 89.25%, respectively for sunflower, soybean, palm and macauba oil, on the other hand 86.09, 80.26, 76.54, and 76.39% for transesterification ethanolic. Most of the biodiesel obtained from the simulations presented adequate according to the specifications of the D6751, ANP 45, and EN 14214 standards. Finally, the model proposed can be used for improving operations conditions, new products design and help economic analysis in continuous processes of biodiesel production.

Macauba (Acrocomia aculeata) is a good source of vegetable oil in tropical America. Its fruits are highly suitable for biodiesel, cosmetics and food production owing to the high quality of its oil. However, the influence of maturity and harvest region on the quality of oils is not known. Thus, the chemical composition and physicochemical properties oils extracted from the macauba palm fruit at two regions of Minas Gerais and different maturity stage were investigated. C16:0 and C18:1 were the most abundant fatty acids in the mesocarp oil. C12:0, C14:0, C16:0, and C18:1 prevailed in the kernel oil. The High-Resolution Gas Chromatography analysis revealed triacylglycerols (TGs) with equivalent carbon numbers (CN) ranging between 28 and 54. TGs composed of long-chain fatty acids prevailed in the mesocarp oil (CN52 and CN54). On the other hand, the kernel showed a more complex lipid profile, containing TGs with CN between 30 and 54. The lipid content in the oils increased significantly with the ripening of the fruit and the harvest regions. Furthermore, changes in physicochemical properties were observed for both oils depending on the stage of maturity and harvest point. Macauba oils can be used in several industries, such as food and cosmetics. Thus, for its best use, the physicochemical properties of greatest interest should be evaluated in order to identify the ideal cultivation region and maturity stage.

Pesquisas com foco no desenvolvimento de processos de produção de biocombustíveis têm aumentado significativamente nos últimos anos, principalmente por questões ambientais e econômicas. A busca por matérias-primas de baixo custo, bem como o desenvolvimento de modelos de simulação capazes de prever as condições da produção e as propriedades dos componentes, podem ser o caminho para aumentar o desempenho desses processos. O conhecimento propriedades termofísicas dos componentes da alimentação é crucial para que os resultados sejam similares aos reais. Assim, o objetivo deste trabalho foi avaliar métodos de estimativas de propriedades termofísicas, a fim de desenvolver uma base de dados dos compostos dos óleos vegetais e recomendar os métodos adequados com base na precisão e consistência dos dados obtidos. Ao final deste trabalho recomendou-se o modelo mais viável para cada propriedade avaliada, comparando-se os valores estimados aos dados experimentais disponíveis na literatura.