The environmental performance of pretreatment technologies for the bioconversion of lignocellulosic biomass to ethanol. (November 2019)

• Record Type: Journal Article
• Authors: Smullen, Emma; Finnan, John; Dowling, David; Mulcahy, Patricia
• Is Part Of: Renewable energy. Volume 142(2019)
• Page Start: 527
• Page End: 534
• Publication Date: 2019-11
• Subjects: LCA -- Switchgrass -- Ethanol production -- Environmental impact; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2019.04.082
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Ethanol production from switchgrass has the potential to reduce life cycle GHG emissions by 77–97% relative to petroleum based fuels. This study examines the environmental performance of the chemical pretreatment process employed during lignocellulosic conversion to ethanol in an effort to minimise the environmental impact of pretreatment processing techniques. The study quantifies the impact of four pretreatment chemical processes employing sodium hydroxide, ammonia, methanol and sulphuric acid on five environmental indicators, in order to identify the pretreatment process with the lowest environmental impact. Using SimaPrò life cycle assessment software the emissions output to air, soil and water contributing to the environmental parameters: global warming potential (GWP), eutrophication, acidification, photochemical oxidation demand and marine and human ecotoxicity were assessed. Pretreatment employing methanol exhibited the lowest GWP of the four chemicals analysed, with the highest GWP values observed for sodium hydroxide. In general, emissions output varied significantly between all four pretreatment chemicals when compared using selected environmental parameters. Pretreatment employing methanol was identified as having the lowest environmental. Highlights: Pretreatments H2 SO4 and NaOH measured the highest level of emissions to GWP, EP, POD, MEP and HEP environmental receptors. The lowest chemical contributor of emissions varied depending on the impact category in question. NH3 and CH3 OH have the lowest impact on air, soil and water, with CH3 OH having the lowest environmental impact on GWP. This result is significant as it shows that the use of methanol in the pretreatment process will minimise GHG emissions.