Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

Integrated Life Cycle Framework for Evaluating the Sustainability of Emerging Drop-In Replacement Biofuels

Zaimes, George G. (2017) Integrated Life Cycle Framework for Evaluating the Sustainability of Emerging Drop-In Replacement Biofuels. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

PDF (Updated Version of Thesis)
Updated Version

Download (6MB) | Preview


Mounting concerns over energy independence and security, oil supply volatility and price, and anthropogenic-derived climate destabilization are driving the strategic development of low-carbon biofuels. Recently, second generation biofuels—fuels derived from non-food biofeedstocks including: perennial grasses, short rotation woody crops (SRWCs), and microalgae have gained significant interest from scientific and political actors due to their potential for reduced life cycle greenhouse gas (GHG) emissions relative to baseline petroleum fuels, and fungibility with existing transportation infrastructure and vehicles fleets. However, the environmental sustainability of these second generation biofuels and their capacity to meet U.S. regulatory biofuel mandates remains uncertain, and a point of scientific inquiry.

This work investigates the sustainability of emerging second-generation drop-in replacement hydrocarbon biofuels, utilizing sustainability metrics and methodologies derived from multiple disciplines including life cycle assessment, industrial ecology, statistics, thermodynamics, and process modeling. This novel interdisciplinary life cycle framework is applied to study the environmental sustainability of several distinct emerging drop-in replacement biofuel platforms including: (1) cultivation of microalgae in open raceways ponds and hydro-processing of algal-oil to renewable diesel, (2) fast pyrolysis of perennial grasses and hydro-upgrading of bio-oil to green gasoline, and (3) multistage torrefaction of SRWCs and catalytic upgrading to hydrocarbon biofuels. Traditional process-based Life Cycle Assessment (LCA) and hybrid Ecologically-based Life Cycle Assessment (EcoLCA) models are developed to assess the degradation of ecological good and services, environmental impacts, and resource intensity of producing drop-in replacement biofuels. Rigorous process modeling and statistical analysis is performed to quantify key sustainability metrics including energy return on investment and life cycle GHG emissions for producing hydrocarbon biofuels under different combinations of biofeedstocks, fuel upgrading pathways, and coproduct scenarios, and to determine if renewable fuel(s) meet compliance with life cycle GHG emissions reductions thresholds set by U.S. federal regulatory programs. This interdisciplinary approach captures broader environmental externalities and unintended consequences of biofuel production that are outside the purview of traditional process design, and allows for holistic understanding of the potential tradeoffs, challenges, and broad-based impacts of emerging biofuels prior to their widespread commercialization—information that is pivotal for guiding the sustainable development of the nascent biofuels industry.


Social Networking:
Share |


Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Zaimes, George G.ggz2@pitt.eduggz2
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee MemberBilec, Melissambilec@pitt.eduMBILEC
Committee MemberLandis, Amy
Committee MemberRadisav, Vidicvidic@pitt.eduVIDIC
Thesis AdvisorKhanna, Vikaskhannav@pitt.eduKHANNAV
Date: 1 February 2017
Date Type: Publication
Defense Date: 22 June 2016
Approval Date: 1 February 2017
Submission Date: 28 November 2016
Access Restriction: 1 year -- Restrict access to University of Pittsburgh for a period of 1 year.
Number of Pages: 373
Institution: University of Pittsburgh
Schools and Programs: Swanson School of Engineering > Civil and Environmental Engineering
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Life Cycle Assessment, Process Design, ASPEN, Pyrolysis, Exergy, Emergy, EROI, GHG emissions, Carbon Footprint, Climate Change, RFS2, EISA, Energy Policy, Microalgae, Switchgrass, Miscanthus, Woody Biomass, Sustainability, Biofuel, Bioenergy, Biomass
Date Deposited: 01 Feb 2017 20:09
Last Modified: 01 Feb 2018 06:15


Monthly Views for the past 3 years

Plum Analytics

Actions (login required)

View Item View Item