• Energy Research

Renewable energy sources have become an urgent worldwide concern due to the impacts of global warming. Globally, biofuels can significantly reduce greenhouse gas emissions, which are major contributors to global warming. The use of biofuels has the potential to transform the energy landscape while mitigating the adverse effects of traditional fossil fuels. This study examines the water features, biochemical compositions, and fatty acid profiles among various plant species. The results reveal significant variations in water features as a consequence of the relative water content and water potential of each seed. Also, we note that some non-edible species like A. blanchetii, C. procera, E. oleracea, P. juliflora, M. oleifera, and J. curcas have good attributes that confer a biofuel-like species. These attributes are high in oil content and have a good profile content of long-chain polyunsaturated fatty acids (LC-PUFAs), ranging from 35% to 80% among the different oilseeds. Fatty acid profiling reveals distinct compositions among the plant species. Stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2) were the principal oils in A. blanchetii, J. curcas, P. juliflora, M. oleifera, and S. tuberosa compared to other species. M. oleifera stands out with a high linoleic acid (C18:1) content, while C. maxima, J. curcas, and P. juliflora are even higher (C18:2). A principal component analysis (PCA) and Pearson correlations analysis also confirmed that alternative oilseeds exhibited similarities to standard oilseeds and have the potential to replace them for biofuel production. These findings demonstrate the potential of non-conventional oilseeds for sustainable biofuel production. By unlocking their global potential, we can advance towards mitigating environmental impacts and fostering a sustainable biofuel industry.

The discovery of alternative fuels that can replace conventional fuels has become the goal of many scientific researches. Biodiesel is produced from vegetable oils through a transesterification reaction that converts triglycerides into fatty acid methyl esters (FAME), with the use of a low molecular weight alcohol, in different reaction conditions and with different types of catalysts. Titanium dioxide has shown a high potential as heterogeneous catalyst due to high surface area, strong metal support interaction, chemical stability, and acid–base property. This review focused on TiO2 as heterogeneous catalyst and its potential applications in the continuous flow production of biodiesel. Furthermore, the use of micro reactors, able to make possible chemical transformations not feasible with traditional techniques, will enable a reduction of production costs and a greater environmental protection.

The production of biodiesel at the industrial level is mainly based on the use of basic catalysts. Otherwise, also acidic catalysis allowed high conversion and yields, as this method is not affected by the percentage of free fatty acids present in the starting sample. This work has been useful in assessing the possible catalytic pathways in the production of fatty acid methyl esters (FAMEs), starting from different cooking waste oil mixtures, exploring particularly acidic catalysis. It was possible to state that the optimal experimental conditions required concentrated sulfuric acid 20% w/w as a catalyst, a reaction time of twelve hours, a temperature of 85 °C and a molar ratio MeOH/oil of 6:1. The role of silica in the purification method was also explored. By evaluating the parameters, type of catalyst, temperature, reaction time and MeOH/oil molar ratios, it has been possible to develop a robust method for the production of biodiesel from real waste mixtures with conversions up to 99%.

Novel triphenylamine (TPA)-based organic dyes were synthesized and assessed for their performance in dye-sensitized solar cells (DSSCs). In the dyes considered the TPA group and the cyanoacetic acid have the role of electron-donor and -acceptor, respectively, whereas a thienyl-fluoro-phenyl-substituted was introduced as ?-linker to improve the dye performance in DSSCs. Experimental characterizations empasize that the presence of electron withdrawing substituents in the linker close to the electron-acceptor moiety leads to a more efficient intramolecular photoinduced charge transfer. In fact, photovoltaic experiments reveal that the DSSCs based on the thienyl-o-fluoro-phenyl substituted dyes yield a better solar-energy-to-electricity conversion efficiency.

Glycerol is a valuable by-product in the biodiesel industries. However, the increase in biodiesel production resulted in an excess production of glycerol, with a limited market compared to its availability. Precisely because glycerol became a waste to be disposed of, the costs of biodiesel production have reduced. From an environmental point of view, identifying reactions that can convert glycerol into new products that can be reused in different applications has become a real necessity. According to the unique structural characteristics of glycerol, transformation processes can lead to different chemical functionalities through redox reactions, dehydration, esterification, and etherification, with the formation of products that can be applied both at the finest chemical level and to bulk chemistry.

Biodiesel was produced via transesterification reaction catalyzed by acids, bases, enzymes or supercritical fluids. The catalysis was homogeneous or heterogeneous and the process could be carried out in batch or using a continuous flow process. Microreactors allowed us to obtain better control of the experimental variables, such as temperature, pressure and flow rate, carrying out the reactions in safe conditions, avoiding exothermic and dangerous processes. The synthetic methodologies in continuous flow, combined with other technologies as microwave irradiation or ultrasounds, led to complete automation of the process with an increase in efficiency, also applicable on an industrial scale.