Year-end Sale % OFF 
Abstract
Modeling the life cycle of fuel pathways for cellulosic ethanol (CE) can help identify logistical barriers and anticipated impacts for the emerging commercial CE industry. Such models contain high amounts of variability, primarily due to the varying nature of agricultural production but also because of limitations in the availability of data at the local scale, resulting in the typical practice of using average values. In this study, 12 spatially explicit, cradle-to-refinery gate CE pathways were developed that vary by feedstock (corn stover, switchgrass, and Miscanthus), nitrogen application rate (higher, lower), pretreatment method (ammonia fiber expansion [AFEX], dilute acid), and co-product treatment method (mass allocation, sub-division), in which feedstock production was modeled at the watershed scale over a nine-county area in Southwestern Michigan. When comparing feedstocks, the model showed that corn stover yielded higher global warming potential (GWP), acidification potential (AP), and eutrophication potential (EP) than the perennial feedstocks of switchgrass and Miscanthus, on an average per area basis. Full life cycle results per MJ of produced ethanol demonstrated more mixed results, with corn stover-derived CE scenarios that use sub-division as a co-product treatment method yielding similarly favorable outcomes as switchgrass- and Miscanthus-derived CE scenarios. Variability was found to be greater between feedstocks than watersheds. Additionally, scenarios using dilute acid pretreatment had more favorable results than those using AFEX pretreatment.
Highlights
Electronic supplementary material The online version of this article contains supplementary material, which is available to authorized users.The life cycle production of second-generation cellulosic ethanol (CE) and its environmental impacts are less studied and more uncertain than that of first-generation corn grain ethanol
The analysis has extended our analysis to the biorefinery, with the application of two contrasting pretreatment options—ammonia fiber expansion (AFEX) and dilute acid (DA)—as well as two different co-product allocation methods for corn stover production, yielding 16 CE production scenarios that were compared using four impact category metrics: net energy ratio (NER), global warming potential (GWP), acidification potential (AP), and eutrophication potential (EP)
This study used the most local data available for each process in the cradle-to-refinery gate life cycle of CE pathways, though spatial variation was generally found to be subtle across the watersheds of the ninecounty area of the Michigan regionally intensive modeling Area (RIMA)
Summary
Electronic supplementary material The online version of this article (doi:10.1007/s12155-016-9774-7) contains supplementary material, which is available to authorized users.The life cycle production of second-generation cellulosic ethanol (CE) and its environmental impacts are less studied and more uncertain than that of first-generation corn grain ethanol. Feedstock options include agricultural and forestry residues as well as dedicated bioenergy crops [1] Factors such as the resource inputs required to Bioenerg. The efficiency of a pretreatment method in yielding sugars for fermentation, as well as the material and energy input needed in the process, can alter the comparative advantage of one feedstock over another and introduces additional uncertainty. Understanding these life cycle processes and their impacts is critical because of their significant effect on the sustainability of a particular pathway [4]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
