Concern about global warming and the high consumption of fossil fuels has led some countries to seek and invest in new energy sources that are efficient and less polluting. Among these alternatives, hydrogen fuel cells are a potential solution that can generate clean energy. Due to the industrial production of hydrogen being carried out by steam reforming of methane, which uses non-renewable raw material and is endothermic (resulting in high energy costs), the autothermal reform of ethanol has been presenting itself as an interesting technology, as it combines a renewable raw material with the reactions of reform (endothermic) and partial oxidation (exothermic), thus achieving energy self-sufficiency in the process of converting ethanol to hydrogen. Despite the various studies referring to the autothermal reform of ethanol, to our knowledge, no article has presented a detailed review of the main advances made in recent years for this process. Thus, this review presents the main results for the autothermal reform of ethanol, in recent years, in three main areas: Catalysts, Reactor Design and Modeling / Simulation. This work identified that the greatest advances have been made in the development of new catalysts and the design of reactors, while the modeling/simulation area still has few studies to efficiently describe the thermodynamics of the autothermal reform of ethanol.

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Biodiesel is a renewable and biodegradable biofuel, generally produced by the fatty materials transesterification. Due to its importance in the diversification of the energy matrix of countries, various studies have been carried out to improve its production process. One of the technologies developed is the use of co-solvents in the process. The co-solvents decrease the mass transfer resistance between the oil and the alcohol during the chemical reaction. In this paper, a review of the literature on the biodiesel production using co-solvents was presented. The research gathered information about various studies that are relevant to the theme, aiming to show the state of the art, the substances most used as co-solvents, and the conditions of the process variables that result in high yields of fatty acid methyl esters (FAME). In the homogeneous basic catalysis of vegetable oils, potassium hydroxide is the most used catalyst. Its range of application normally varies from 0.5% to 1.8% in relation to the mass of oil. The reaction time may vary from 10 minutes to 2 hours, the temperature from 25 °C to 100 °C, the molar ratio (MR), from 3:1 to 12:1, and the amount of 30% (w/w) co-solvent, or in some cases up to 0.7:1 co-solvent to alcohol molar ratio.