scholarly journals Improving Robustness of LCA Results Through Stakeholder Engagement: A Case Study of Emerging Oil Sands Technologies

Author(s):  
Sylvia Sleep ◽  
Zainab Dadashi ◽  
yuanlei chen ◽  
Adam R. Brandt ◽  
Heather L. MacLean ◽  
...  

Life cycle assessments can help to inform decision-making about greenhouse gas (GHG) emission reduction opportunities but are often not embraced by stakeholders associated with industries where study results are highly scrutinized and often contentious. This project was motivated by stakeholder interest in understanding open source life cycle models (the Oil Production Greenhouse Gas Emissions Estimator, OPGEE, and the Petroleum Refinery Life Cycle Inventory Model, PRELIM) and how accurately they can estimate emissions for existing oil sands projects and emerging technologies. We evaluate the robustness of these models and improve them using data from three existing oil sands projects (mining + upgrading, mining + dilution, and steam assisted gravity drainage, SAGD, + dilution). The models are then applied to estimate the GHG emissions reduction potential for two emerging in situ oil sands technologies. We find that, when boundaries are aligned, OPGEE can generate upstream GHG emissions estimates for the projects modeled within 1-4% of company reported GHG emissions data. Extending the boundary to include indirect (life cycle) emissions can lead to a doubling in upstream GHG emissions intensity. The two emerging technologies evaluated in the study can reduce upstream emissions by 14-19% compared to a SAGD project operating at the same reservoir, or 1.4-1.9% on a well-to-wheel basis. This work contributes a revised process of conducting LCAs that includes stakeholder input throughout and results in more robust and transparent estimations of emissions from deploying existing and emerging technologies.<br>

2020 ◽  
Author(s):  
Sylvia Sleep ◽  
Zainab Dadashi ◽  
yuanlei chen ◽  
Adam R. Brandt ◽  
Heather L. MacLean ◽  
...  

Life cycle assessments can help to inform decision-making about greenhouse gas (GHG) emission reduction opportunities but are often not embraced by stakeholders associated with industries where study results are highly scrutinized and often contentious. This project was motivated by stakeholder interest in understanding open source life cycle models (the Oil Production Greenhouse Gas Emissions Estimator, OPGEE, and the Petroleum Refinery Life Cycle Inventory Model, PRELIM) and how accurately they can estimate emissions for existing oil sands projects and emerging technologies. We evaluate the robustness of these models and improve them using data from three existing oil sands projects (mining + upgrading, mining + dilution, and steam assisted gravity drainage, SAGD, + dilution). The models are then applied to estimate the GHG emissions reduction potential for two emerging in situ oil sands technologies. We find that, when boundaries are aligned, OPGEE can generate upstream GHG emissions estimates for the projects modeled within 1-4% of company reported GHG emissions data. Extending the boundary to include indirect (life cycle) emissions can lead to a doubling in upstream GHG emissions intensity. The two emerging technologies evaluated in the study can reduce upstream emissions by 14-19% compared to a SAGD project operating at the same reservoir, or 1.4-1.9% on a well-to-wheel basis. This work contributes a revised process of conducting LCAs that includes stakeholder input throughout and results in more robust and transparent estimations of emissions from deploying existing and emerging technologies.<br>


2021 ◽  
pp. 53-59
Author(s):  
Dennis G. A. B. Oonincx

Abstract This chapter discusses the environmental impact of insect rearing. Direct greenhouse gas (GHG) emissions from insects used as feed or food are discussed and data from life cycle assessments (LCAs) on commercially farmed insects are discussed per species. The relevance of the utilized feed on the environmental impact of insects and their derived products, including suggestions to lower this impact are also discussed. It is concluded that land use associated with insect production generally seems low, compared to conventional feed and food products. The EU (expressed as fossil fuel depletion) of insect production is often high compared to conventional products. To a large extent this is because several LCAs have been conducted for systems in temperate climates, which require extensive climate control.


2016 ◽  
Vol 113 (48) ◽  
pp. E7672-E7680 ◽  
Author(s):  
Ian J. Laurenzi ◽  
Joule A. Bergerson ◽  
Kavan Motazedi

In recent years, hydraulic fracturing and horizontal drilling have been applied to extract crude oil from tight reservoirs, including the Bakken formation. There is growing interest in understanding the greenhouse gas (GHG) emissions associated with the development of tight oil. We conducted a life cycle assessment of Bakken crude using data from operations throughout the supply chain, including drilling and completion, refining, and use of refined products. If associated gas is gathered throughout the Bakken well life cycle, then the well to wheel GHG emissions are estimated to be 89 g CO2eq/MJ (80% CI, 87–94) of Bakken-derived gasoline and 90 g CO2eq/MJ (80% CI, 88–94) of diesel. If associated gas is flared for the first 12 mo of production, then life cycle GHG emissions increase by 5% on average. Regardless of the level of flaring, the Bakken life cycle GHG emissions are comparable to those of other crudes refined in the United States because flaring GHG emissions are largely offset at the refinery due to the physical properties of this tight oil. We also assessed the life cycle freshwater consumptions of Bakken-derived gasoline and diesel to be 1.14 (80% CI, 0.67–2.15) and 1.22 barrel/barrel (80% CI, 0.71–2.29), respectively, 13% of which is associated with hydraulic fracturing.


2008 ◽  
Vol 57 (11) ◽  
pp. 1683-1692 ◽  
Author(s):  
Andrea Tilche ◽  
Michele Galatola

Anaerobic digestion is a well known process that (while still capable of showing new features) has experienced several waves of technological development. It was “born” as a wastewater treatment system, in the 1970s showed promise as an alternative energy source (in particular from animal waste), in the 1980s and later it became a standard for treating organic-matter-rich industrial wastewater, and more recently returned to the market for its energy recovery potential, making use of different biomasses, including energy crops. With the growing concern around global warming, this paper looks at the potential of anaerobic digestion in terms of reduction of greenhouse gas (GHG) emissions. The potential contribution of anaerobic digestion to GHG reduction has been computed for the 27 EU countries on the basis of their 2005 Kyoto declarations and using life cycle data. The theoretical potential contribution of anaerobic digestion to Kyoto and EU post-Kyoto targets has been calculated. Two different possible biogas applications have been considered: electricity production from manure waste, and upgraded methane production for light goods vehicles (from landfill biogas and municipal and industrial wastewater treatment sludges). The useful heat that can be produced as by-product from biogas conversion into electricity has not been taken into consideration, as its real exploitation depends on local conditions. Moreover the amount of biogas already produced via dedicated anaerobic digestion processes has also not been included in the calculations. Therefore the overall gains achievable would be even higher than those reported here. This exercise shows that biogas may considerably contribute to GHG emission reductions in particular if used as a biofuel. Results also show that its use as a biofuel may allow for true negative GHG emissions, showing a net advantage with respect to other biofuels. Considering also energy crops that will become available in the next few years as a result of Common Agricultural Policy (CAP) reform, this study shows that biogas has the potential of covering almost 50% of the 2020 biofuel target of 10% of all automotive transport fuels, without implying a change in land use. Moreover, considering the achievable GHG reductions, a very large carbon emission trading “value” could support the investment needs. However, those results were obtained through a “qualitative” assessment. In order to produce robust data for decision makers, a quantitative sustainability assessment should be carried out, integrating different methodologies within a life cycle framework. The identification of the most appropriate policy for promoting the best set of options is then discussed.


Author(s):  
Ching-Shin Norman Shiau ◽  
Scott B. Peterson ◽  
Jeremy J. Michalek

Plug-in hybrid electric vehicle (PHEV) technology has the potential to help address economic, environmental, and national security concerns in the United States by reducing operating cost, greenhouse gas (GHG) emissions and petroleum consumption from the transportation sector. However, the net effects of PHEVs depend critically on vehicle design, battery technology, and charging frequency. To examine these implications, we develop an integrated optimization model utilizing vehicle physics simulation, battery degradation data, and U.S. driving data to determine optimal vehicle design and allocation of vehicles to drivers for minimum life cycle cost, GHG emissions, and petroleum consumption. We find that, while PHEVs with large battery capacity minimize petroleum consumption, a mix of PHEVs sized for 25–40 miles of electric travel produces the greatest reduction in lifecycle GHG emissions. At today’s average US energy prices, battery pack cost must fall below $460/kWh (below $300/kWh for a 10% discount rate) for PHEVs to be cost competitive with ordinary hybrid electric vehicles (HEVs). Carbon allowance prices have marginal impact on optimal design or allocation of PHEVs even at $100/tonne. We find that the maximum battery swing should be utilized to achieve minimum life cycle cost, GHGs, and petroleum consumption. Increased swing enables greater all-electric range (AER) to be achieved with smaller battery packs, improving cost competitiveness of PHEVs. Hence, existing policies that subsidize battery cost for PHEVs would likely be better tied to AER, rather than total battery capacity.


2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Ching-Shin Norman Shiau ◽  
Jeremy J. Michalek

We pose a reformulated model for optimal design and allocation of conventional (CV), hybrid electric (HEV), and plug-in hybrid electric (PHEV) vehicles to obtain global solutions that minimize life cycle greenhouse gas (GHG) emissions of the fleet. The reformulation is a twice-differentiable, factorable, nonconvex mixed-integer nonlinear programming (MINLP) model that can be solved globally using a convexification-based branch-and-reduce algorithm. We compare results to a randomized multistart local-search approach for the original formulation and find that local-search algorithms locate global solutions in 59% of trials for the two-segment case and 18% of trials for the three-segment case. The results indicate that minimum GHG emissions are achieved with a mix of PHEVs sized for 25–45 miles of electric travel. Larger battery packs allow longer travel on electrical energy, but production and weight of underutilized batteries result in higher GHG emissions. Under the current average U.S. grid mix, PHEVs offer a nearly 50% reduction in life cycle GHG emissions relative to equivalent conventional vehicles and about 5% improvement over HEVs when driven on the standard urban driving cycle. Optimal allocation of different PHEVs to different drivers turns out to be of second order importance for minimizing net life cycle GHGs.


2021 ◽  
Vol 7 ◽  
Author(s):  
C. E. Andersen ◽  
F. N. Rasmussen ◽  
G. Habert ◽  
H. Birgisdóttir

Buildings play a vital role in reaching the targets stated by the Intergovernmental Panel on Climate Change to limit global warming to 1.5 degrees. Increasing the use of wood in construction is a proposed upcoming strategy to reduce the embodied greenhouse gas emissions of buildings. This study examines existing life cycle assessments of wooden buildings. The aim is to investigate embodied greenhouse gas emission results reported, as well as methodological approaches applied in existing literature. The study applies the protocol for Systematic Literature Reviews and finds 79 relevant papers. From the final sample, the study analyses 226 different scenarios in-depth in terms of embodied emissions, life cycle assessment method, life cycle inventory modelling and biogenic carbon approach. The analysis shows that the average reported values of embodied greenhouse gas emissions of wooden buildings are one-third to half of the embodied emissions reported from buildings in general. Additionally, from the analysis of the final sample we find that the majority of wooden building life cycle assessments apply similar methods and often leave out biogenic carbon from the assessment or simply do not declare it. This implies that the focus on variability in the different methods applied in wooden building life cycle assessments needs to be increased to establish the relationship between methodological choices and embodied emissions of wooden buildings. Further, transparency and conformity in biogenic carbon accounting in life cycle assessments is essential to enhance comparability between life cycle assessment studies and to avoid distortions in embodied GHG emission results.


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