Lignin as alternative fuel: an estimate of the thermal energy generation potential from brazilian crops

Abstract

Looking for alternatives to promote the diversification of the Brazilian energy grid through the utilization of renewable fuels, this forecasting study evaluates the potential to generate thermal energy from lignins extracted of several crops in the period 2015–2021. The estimates were carried out taking into account two biomass particle size distributions (ranged between 105–500 µm and 1000–2000 µm) and two extraction methods (Klason and Willstatter) to assess the lignin yields obtained from five well-known Brazilian crops. Results revealed that lignins obtained from the sugarcane bagasse, wood chips, and corn straw would have the highest potential to provide thermal energy when data of lignin yields, higher heating values, and crops production are considered. The estimate suggests that in 2021 this alternate fuel could supply more than 1320 × 106 GJ yr−1 of thermal energy from the five crops analyzed, owing to the expected increase of the acreage and production for the most crops studied here in the next years. Recognizing that more studies are still needed, mainly in terms of economic feasibility, results of this work warn about possible additional benefits in developing the large-scale production of second-generation ethanol (via hydrolysis), in which lignin fractions from several crops could be separated and recovered for using them as new energy resource. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 717–722, 2017.