Vol.:(0123456789) 1 3 Clean Technologies and Environmental Policy https://doi.org/10.1007/s10098-017-1480-4 ORIGINAL PAPER Life‑cycle assessment of bioethanol production from sweet sorghum stalks cultivated in the state of Yucatan, Mexico Patricia Aguilar‑Sánchez 1  · Freddy Segundo Navarro‑Pineda 2  · Julio César Sacramento‑Rivero 2  · Luis Felipe Barahona‑Pérez 3 Received: 10 May 2017 / Accepted: 16 December 2017 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Bioethanol is being promoted in Mexico to be used in a blend with gasoline. On the north of the Yucatan peninsula, bioetha- nol could be produced from sweet sorghum, as it can grow efciently on this land; it can be harvested 2–3 times in a year and possesses a better agronomical stability than sugarcane with low nitrogen requirements and high productivity. In this work, the potential environmental impacts and energy efciency of bioethanol production from sweet sorghum were evalu- ated using life-cycle assessment. Four scenarios were evaluated: scenario PI considered only bioethanol production from the stalk juice; scenarios PII and PIII added cogeneration from the dry-stalk biomass in single and combined cycle, respectively. Scenario PIV considered bioethanol production from both stalk juice and dry-stalk biomass. Scenario PI demanded more fossil energy than what was generated as bioethanol, while scenarios PII and PIII were fossil energy independent. Scenario PIII showed the higher net energy ratio (1.89) and a better environmental performance in all CML-IA baseline impact cat- egories. In terms of global warming potential, the scenario PIII showed a mitigation potential of 16% with respect to the fossil reference. In the categories where the sweet sorghum scenarios represented larger emissions than the fossil reference, it was due mainly to the use of fertilizers and the conventional energy consumption in the various processing steps of the biomass. Scenario PIV showed the highest energy demand and worst environmental performance due to large demands of energy and chemicals in the bagasse pretreatment step. Keywords Renewable energy · Biofuels · Cogeneration · Environmental impact · Energy ratio Abbreviations ADP Abiotic depletion potential AP Acidifcation potential ART Agroscope Reckenholz-Tänikon (research station) CED Cumulative energy demand CFC Chlorofuorocarbon CML Institute of Environmental Sciences of Lei- den University EP Eutrophication potential FAEP Freshwater aquatic ecotoxicity potential GHG Greenhouse gas GWP Global warming potential HTP Human toxicity potential IEE Intelligent Energy Europe LCA Life-cycle assessment MAEP Marine aquatic ecotoxicity potential NER Net energy ratio ODP Ozone layer depletion potential PI Scenario I—bioethanol production from juice PII Scenario II—bioethanol and electricity pro- duction by simple steam power plant PIII Scenario III—bioethanol and electricity pro- duction with combination cycle power plant PIV Scenario IV—bioethanol production from juice and bagasse * Luis Felipe Barahona-Pérez barahona@cicy.mx 1 Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias, Campo experimental San Martinito km 56.5, Carretera Federal México, 72000 Puebla, Mexico 2 Universidad Autónoma de Yucatán, Periférico Norte km 33.5, Tablaje Catastral No. 13615, Chuburna de Hidalgo Inn, 97203 Mérida, Yucatán, Mexico 3 Centro de Investigación Científca de Yucatán AC, Parque Científco Tecnológico de Yucatán, km 5 Carretera Sierra Papacal - Chuburná Puerto, 97302 Sierra Papacal, Yucatán, Mexico