Evaluation of ethanol concentration and yields from different types of macroalgae

Abstract

Energy consumption represents the main source of greenhouse gas emissions, which brings serious problems to the environment and human health. Biofuels are one of the significant renewable energy sources to reduce the environmental impact produced by these emissions, highlighting bioethanol extracted from biomass like macroalgae (due to their high amount of hydrolysable carbohydrates and low lignin content). The present article focuses on the evaluation of ethanol concentration and yield obtained from different types of macroalgae. For this purpose, a bibliographic review and a classification of the information according to the algae taxonomy (brown, green, and red) was conducted, followed by a comparison of the chemical composition, the yields, and the amount of ethanol produced from the algae. According to the results of the research, red algae presented a higher ethanol yield and concentration than those of algae from other species, positioning this taxonomy as the ideal one for the extraction of this fuel. However, this conclusion is not definitive, since red algae do not always obtain higher concentrations and yields than algae of other species. It is necessary to analyze other variables and conditions that establish the best scenario for ethanol production from macroalgae, such as pretreatment, hydrolysis, and fermentation.