Analyzing uncertainty in a comparative life cycle assessment of hand drying systems
Name
11367_2013_606_ReferencePDF.pdf
Size
260.54 KB
Format
Adobe PDF
Checksum (MD5)
cb112100afc4c24b108bdd2b9c71424d
Author(s)
Gregory, Jeremy
Montalbo, Trisha Mae
Kirchain, Randolph E.
Date Issued
June 2013
Journal
International Journal of Life Cycle Assessment
Publisher
Springer Berlin Heidelberg
Citation
Gregory, Jeremy R., Trisha M. Montalbo, and Randolph E. Kirchain. "Analyzing uncertainty in a comparative life cycle assessment of hand drying systems." International Journal of Life Cycle Assessment 18:8 (2013), pp.1605-1617.
Version
Author's final manuscript
Abstract
Purpose:
The goal of this study is to evaluate and compare the environmental impact (with a focus on global warming potential) of five hand drying systems: hands-under (HU) dryers, high-speed hands-under (HSHU) dryers, high-speed hands-in (HSHI) dryers, cotton roll towels, and paper towels. Another objective is to incorporate uncertainty into this comparative life cycle assessment (LCA) as a means of understanding the statistical robustness of the difference between the environmental impacts of the hand drying systems.
Methods:
We conducted a life cycle assessment in accordance with the ISO 14040/14044 standards using data primarily from publicly available reports. As part of the study, we performed a parameter uncertainty analysis for multiple scenarios to evaluate the impact of uncertainty in input data on the relative performance of products. In addition, we conducted a probabilistic scenario analysis of key drying system parameters in order to understand the implications of changing assumptions on the outcomes of the analyses.
Results and discussion:
The scope of the analyses enabled us to draw robust conclusions about the relative environmental performance of the products. We can say with a high degree of confidence that the high-speed dryers have a lower impact than paper towels and cotton roll towels. Differentiating the performance of the hand dryers requires being more specific about framing assumptions. Under certain conditions, the HSHI dryer is expected to have a lower impact than the HU and HSHU dryers. However, under other conditions, one cannot say that the HSHI dryer is clearly better than the other dryers. We cannot differentiate the performance between the HU dryer, cotton roll towels, and paper towels.
Conclusions: This work demonstrates the importance of going beyond traditional uncertainty analyses for comparative LCAs that are used for assertions of relative product environmental impact. Indeed, we found instances where the conclusions changed as a result of using the probabilistic scenario analysis. We outline important elements that should be included in future guidance on uncertainty analyses in comparative LCAs, including conducting parameter and scenario uncertainty analyses together and then using the outcomes to guide selection of parameters and/or choices to analyze further.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Massachusetts Institute of Technology. Engineering Systems Division
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1007/s11367-013-0606-0
