Evaluation of Jerusalem artichoke as a sustainable energy crop to bioethanol: energy and CO2eq emissions modeling for an industrial scenario

Abstract

An alternative to the sugar/starch-based crops bioethanol is lignocellulosic biomass, but its utilization to biofuels is still not economically viable. In this context, an increasing interest has arising on the search for specific energy crops that do not require arable lands and are not water intensive, such as Jerusalem artichoke (JA). So, this work consisted on the cultivation of JA on those agricultural conditions and its further evaluation as a sustainable feedstock towards bioethanol. Two strategies of producing bioethanol were evaluated pointing out for the consolidated bioprocessing with the Zygosaccharomyces bailii Talf1 yeast as the best approach for further scale-up, based on energy data analysis and ethanol productivity. Different industrial scenarios were outlined and compared for overall CO2eq emissions and energy consumption per liter of ethanol (LEtOH), using adequate criteria on a cradle-to-gate approach. With no land-use change, no biogenic and no co-products credits, the comparison of the overall energy consumption and CO2eq emissions (100% process) from JA ethanol (9 MJ/LEtOH; 679 g CO2/LEtOH) with sugarcane/sugar beet ethanol (42/29 MJ/LEtOH; 731/735 g CO2/LEtOH) and with gasoline refinery (15 MJ/LEtOH eq; 1154 g CO2/LEtOH eq), highlights the JA as an alternative feedstock to be a focus of ethanol research for gasoline blends.