Summary Biodiesel is one of the most widely used alternative fuels to reduce exhaust emissions and the use of conventional fossil fuels. It can be synthesized from a transesterification reaction from vegetable oils or animal fats in the presence of homogeneous or heterogeneous catalysts. Some drawbacks of using homogeneous catalysts increased attention to heterogeneous catalysts for biodiesel production. Recently, heterogeneous catalysts derived from biomass have risen to the forefront of biodiesel production due to their sustainability, economical and eco‐friendly nature. In addition, they are easily recovered and constitute an alternative to eliminate biomass residues. This review highlights several biomass sources used as precursors for the production of heterogeneous catalyst. Furthermore, methods for preparing heterogeneous catalysts, the reaction mechanisms, catalyst advantages and drawbacks, their performance in biodiesel production, as well as the methodologies developed for their effective recovery are discussed in detail. Among lignocellulosic biomass‐based precursors, the paper takes into account those based on biochar, ash, carbonaceous substrate, and seed oil cake. Those catalysts obtained by both preparation methods (calcination and activation) have good catalytic activity for waste cooking oil or neat oils. Biomass ash or biochar‐based catalysts are also promising routes in biodiesel synthesis, but significant reductions in catalyst load, reaction time, temperature, and methanol‐to‐oil ratio must be reached.

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The production and use of terpene-based fuels represents a renewable source of energy in the transportation sector, especially in the aviation sector. The literature on the conversion of terpenes into valuable compounds is not new but has been based on the production of products for cosmetics and pharmaceutics. Several established chemical routes are also a way to develop drop-in fuels. The present work explores all the main chemical processes that can transform terpenes into more valuable fuels or additives, focusing on the use of heterogeneous catalysis, catalyst type, operating conditions, and reaction performance. α-pinene is the most studied catalyst, since it is the main component of turpentine. Isomerization is the most frequently applied chemical pathway used to enhance fuel properties, and a wide group of heterogeneous catalysts have been reported, with sulphonic acid resin catalysts, transition metals, alumina, and silicates being the most used. This work also explores the current production and commercialization of terpenes, as well as the challenges for their use as fuels at a commercial scale. The future challenge is to discover new catalysts or to improve the performance of the current products and reduce production costs. The feasibility of the production and commercialization of terpene-derived fuels is also linked to oil prices.

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La simulación de procesos desempeña un papel importante para el desarrollo de nuevas tecnologías y permite la asistencia en el diseño, operación y optimización de plantas. En la presente investigación se simularon mediante DWSim los procesos de transesterificación del aceite de Jatropha curcas y la gasificación de la corteza de su fruto. En la simulación del proceso de producción de biodiesel se emplearon cinco etapas: preparación del metóxido, transesterificación, recuperación del alcohol, separación del glicerol, lavado y purificación del biodiesel. La simulación del proceso de gasificación se realizó mediante un modelo estequiométrico teniendo en cuenta las reacciones fundamentales presentes en las etapas de pirólisis, combustión y reducción que ocurren en un gasificador en corriente descendente. Los productos obtenidos de la transesterificación mostraron altos rendimientos: 11% de glicerol y 98% de biodiesel. La composición del gas de síntesis de la gasificación se correspondió con las reportadas en la literatura. Se obtuvo un flujo volumétrico de gas de 92,38 m3/h con un poder calórico inferior de 5,67 MJ/Nm3, con un 72% de eficiencia del proceso. Debido a las limitaciones encontradas en la simulación del proceso de gasificación, se realizó una validación en Aspen Plus que mostró igualdad de resultados entre ambos simuladores.