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This study investigates the life cycle GHG emissions of jet fuel produced via the hydroprocessed esters and fatty acids (HEFA) pathway from canola grown in western Canada, with a focus on characterizing regional influences on emissions. We examine the effects of geographic variations in soil type, agricultural inputs, farming practices, and direct land use changes on life cycle GHG emissions. We utilize GREET 2016 but replace default feedstock production inputs with geographically representative data for canola production across eight western Canadian regions (representing 99% of Canada's canola production) and replace the default conversion process with data from a novel process model previously developed in ASPEN in our research group wherein oil extraction is integrated with the HEFA‐based fuel production process. Although canola production inputs and yields vary across the regions, resulting life cycle GHG emissions are similar if effects of land use and land management changes (LMC) are not included; 44–48 g CO2e/MJ for the eight regions (45%–50% reduction compared to petroleum jet fuel). Results are considerably more variable, 16–58 g CO2e/MJ, when including effects of land use and LMC directly related to conversion of lands from other uses to canola production (34%–82% reduction compared to petroleum jet fuel). We establish the main sources of emissions in the life cycle of canola jet fuel (N‐fertilizer and related emissions, fuel production), identify that substantially higher emissions may occur when using feedstock sourced from regions where conversion of forested land to cropland had occurred, and identify benefits of less intense tillage practices and increased use of summerfallow land. The methods and findings are relevant in jurisdictions internationally that are incorporating GHG emissions reductions from aviation fuels in a low carbon fuel market or legislating carbon intensity reduction requirements. [ABSTRACT FROM AUTHOR]

Vehicle lightweighting reduces fuel cycle greenhouse gas (GHG) emissions but may increase vehicle cycle (production) GHG emissions because of the GHG intensity of lightweight material production. Life cycle GHG emissions are estimated and sensitivity and Monte Carlo analyses conducted to systematically examine the variables that affect the impact of lightweighting on life cycle GHG emissions. The study uses two real world gliders (vehicles without powertrain or battery) to provide a realistic basis for the analysis. The conventional and lightweight gliders are based on the Ford Fusion and Multi Material Lightweight Vehicle, respectively. These gliders were modelled with internal combustion engine vehicle (ICEV), hybrid electric vehicle (HEV), and battery electric vehicle (BEV) powertrains. The probability that using the lightweight glider in place of the conventional (steel-intensive) glider reduces life cycle GHG emissions are: ICEV, 100%; HEV, 100%, and BEV, 74%. The extent to which life cycle GHG emissions are reduced depends on the powertrain, which affects fuel cycle GHG emissions. Lightweighting an ICEV results in greater base case GHG emissions mitigation (10 t CO 2 eq.) than lightweighting a more efficient HEV (6 t CO 2 eq.). BEV lightweighting can result in higher or lower GHG mitigation than gasoline vehicles, depending largely on the source of electricity. [ABSTRACT FROM AUTHOR]

Large scale, low cost, and low carbon intensity hydrogen production is needed to reduce emissions in the energy and transportation sectors. We present a techno-economic analysis and life cycle assessment of natural gas pyrolysis technologies for hydrogen production, with carbon black (CB) as a co-product. Four designs were considered based on the source of heat to the pyrolysis system, the combustion medium, and use of carbon capture (CC) technology. The oxygen-fired-CB design with CC is the most attractive from financial and environmental perspectives, superior to a conventional steam methane reformer (SMR) process with CC. The estimated pre-tax minimum hydrogen selling prices for the pyrolysis technologies range between $1.08/kg and $2.43/kg when natural gas (NG) costs $3.76/GJ. Key advantages include near-zero onsite GHG emissions of the oxygen-fired-CB design with CC and up to 41% lower GHG emissions compared to the SMR + CC process. The results indicate that natural gas pyrolysis may be a feasible pathway for hydrogen production. • Commercial scale hydrogen production via natural gas pyrolysis pathways is explored. • Options for handling the carbon black product are examined. • Low-carbon hydrogen of $1.7/kgH 2 outperforms the SMR hydrogen at similar conditions. • Cradle to gate GHG emissions between 1.8 and 4.6 kgCO 2 eq/kgH 2 is computed. [ABSTRACT FROM AUTHOR]

Conventional cost-effectiveness calculations ignore the implications of greenhouse gas ( GHG) emissions timing and thus may not properly inform decision-makers in the efficient allocation of resources to mitigate climate change. To begin to address this disconnect with climate change science, we modify the conventional cost-effectiveness approach to account for emissions timing. GHG emissions flows occurring over time are translated into an 'Equivalent Present Emission' based on radiative forcing, enabling a comparison of system costs and emissions on a consistent present time basis. We apply this 'Present Cost-Effectiveness' method to case studies of biomass-based electricity generation (biomass co-firing with coal, biomass cogeneration) to evaluate implications of forest carbon trade-offs on the cost-effectiveness of emission reductions. Bioenergy production from forest biomass can reduce forest carbon stocks, an immediate emissions source that contributes to atmospheric greenhouse gases. Forest carbon impacts thereby lessen emission reductions in the near-term relative to the assumption of biomass 'carbon neutrality', resulting in higher costs of emission reductions when emissions timing is considered. In contrast, conventional cost-effectiveness approaches implicitly evaluate strategies over an infinite analytical time horizon, underestimating nearer term emissions reduction costs and failing to identify pathways that can most efficiently contribute to climate change mitigation objectives over shorter time spans (e.g. up to 100 years). While providing only a simple representation of the climate change implications of emissions timing, the Present Cost-Effectiveness method provides a straightforward approach to assessing the cost-effectiveness of emission reductions associated with any climate change mitigation strategy where future GHG reductions require significant initial capital investment or increase near-term emissions. Timing is a critical factor in determining the attractiveness of any investment; accounting for emissions timing can better inform decisions related to the merit of alternative resource uses to meet near-, mid-, and long-term climate change mitigation objectives. [ABSTRACT FROM AUTHOR]

• This study integrates LCA and energy simulation on a visual programming interface. • 16,128 envelope variants are studied exploring passive EEMs on walls, windows, and roofs. • This study considers projected future climate and GHG intensity of energy sources. • The application of energy efficiency measures may increase total GHG emissions. • Studying embodied emissions is critical when highly efficient HVAC systems are used. The building industry has been developing measures for reducing operational emissions in the fight against climate change. Some of these well-intentioned measures may result in higher embodied emissions, potentially more than offsetting reductions achieved during operation. This research evaluates the effectiveness of different levels of application of five passive energy efficiency measures to reduce life cycle greenhouse gas (GHG) emissions in high-rise residential buildings in Toronto, Canada, while considering projected future climate and GHG intensity of energy sources. Through combining and automating life cycle assessment and energy simulation on a visual programing interface, the study evaluates 16,128 envelope variants, examining 56 wall, 12 roof, 6 window assemblies and 4 window-to-wall ratios (WWRs). Decreasing the WWR is found to be the most effective measure to reduce total envelope related GHG emissions (by about 28%). Increasing wall and roof insulation with GHG intensive materials (e.g., extruded polystyrene [XPS]), and increasing spandrel wall insulation potentially augment total emissions, depending on the scenario. Higher trade-offs between embodied and operational emissions are found when highly efficient electric HVAC systems are implemented (e.g., heat pumps). Results demonstrate it is imperative to assess both embodied and operational emissions during the design process of building envelopes to effectively reduce GHG emissions. [ABSTRACT FROM AUTHOR]

The first Feed-in-Tariff (FiT) program in North America was recently implemented in Ontario, Canada to stimulate the generation of electricity from renewable sources. The life cycle greenhouse gas (GHG) emissions and economics of electricity generation through anaerobic digestion (AD) of household source-separated organic waste (HSSOW) are investigated within the FiT program. AD can potentially provide considerable GHG emission reductions (up to 1 t CO2eq/t HSSOW) at relatively low to moderate cost (-$35 to 160/t CO2eq) by displacing fossil electricity and preventing the emission of landfill gas. It is a cost-effective GHG mitigation option compared to some other FiT technologies (e.g., wind, solar photovoltaic) and provides unique additional benefits (waste diversion, nutrient recycling). The combination of electricity sales at a premium rate, savings in waste management costs, and economies of scale allow AD facilities processing >30,000 t/yr to be cost-competitive against landfilling. However, the FiT does not sufficiently support smaller-scale facilities that are needed as a transition to larger, more economically viable facilities. Refocusing of the FiT program and waste policies are needed to support the adoption of AD of HSSOW, which has not yet been developed in the Province, while more costly technologies (e.g., photovoltaic) have been deployed. [ABSTRACT FROM AUTHOR]

The article focuses on greenhouse gas emissions coming from municipal solid waste facilities. In the authors' case study, they used four waste emissions quantification methods that include the Intergovernmental Panel on Climate Change and the U.S. Environmental Protection Agency Waste Reduction Model on greater Toronto, Ontario's waste disposal data. They discovered that the IPCC2006 method was the way to evaluate the effectivity of waste management programs.

Renewable and low carbon fuel standards being developed at federal and state levels require an estimation of the life cycle carbon intensity (LCCI) of candidate fuels that can substitute for gasoline, such as second generation bioethanol. Estimating the LCCI of such fuels with a high degree of confidence requires the use of probabilistic methods to account for known sources of uncertainty. We construct life cycle models for the bioconversion of agricultural residue (corn stover) and energy crops (switchgrass) and explicitly examine uncertainty using Monte Carlo simulation. Using statistical methods to identify significant model variables from public data sets and Aspen Plus chemical process models, we estimate stochastic life cycle greenhouse gas (GHG) emissions for the two feedstocks combined with two promising fuel conversion technologies. The approach can be generalized to other biofuel systems. Our results show potentially high and uncertain GHG emissions for switchgrass-ethanol due to uncertain CO2 flux from land use change and N2O flux from N fertilizer. However, corn stover-ethanol, with its low-in-magnitude, tight-in-spread LCCI distribution, shows considerable promise for reducing life cycle GHG emissions relative to gasoline and corn-ethanol. Coproducts are important for reducing the LCCI of all ethanol fuels we examine. [ABSTRACT FROM AUTHOR]

Abstract: Over the last 30 years the use of light weight, inexpensive, and durable plastics in automobiles has nearly tripled on a per vehicle basis. Although this has created benefits such as increased fuel efficiency and associated lower CO2 emissions, the growing disposition of plastics from end-of-life vehicles has put increasing pressure on North American landfill capacity. Financial and life cycle assessment models were developed and applied to the current and proposed recycling business operations of AADCO Automotive Incorporated (AADCO), a leading Canadian automotive dismantling company. By applying both kinds of models, two key questions are addressed. First, how much is it expected to cost AADCO to participate in a start-up automotive plastics recycling network? and second, by estimating greenhouse gas emissions and energy requirements, is recycling automotive plastics actually better for the environment compared to manufacturing virgin plastic resin within the boundaries set forth in this case study? The present study concluded that the proposed recycling network would reduce greenhouse gas emissions and energy requirements by nearly 50% when compared to the current operations at AADCO (equating to a reduction of 1063tonnes of CO2(eq) and 18TJ, respectively). However, in spite of the environmental benefits, the magnitude of the added costs for AADCO to participate in the post-consumer automotive plastics recycling network resulted in an unprofitable value proposition for the company. [Copyright &y& Elsevier]

Canada's ratification of the Kyoto Protocol has focused attention on the importance of accurately estimating emissions of greenhouse gases (GHG) from all sectors. An inventory of emissions of greenhouse gases from Canadian municipal wastewater treatment plants was prepared using a life-cycle approach. Both on-site emissions at the treatment facility due to the biological processes used and fossil fuels consumed for energy and heat and upstream emissions related to off-site production and transmission of fuels and the off-site production of electricity for the plant were included. For the year 2000, the on-site methane (CH4) emission rate from Canadian municipal wastewater treatment facilities was estimated at 1600 Mg/year. The total on-site emission rate of carbon dioxide (CO2) was estimated at 669 100 Mg/year, but the estimated total CO2 equivalent emissions rose to 1 048 500 Mg/year once upstream emissions were included. Clear abatement strategies related to more efficient energy use and energy recovery can be identified once accurate GHG emissions inventories are in place. [ABSTRACT FROM AUTHOR]

This study provides an empirical assessment of energy use and greenhouse gas (GHG) emissions associated with high and low residential development. Three major elements of urban development are considered: construction materials for infrastructure (including residential dwellings, utilities, and roads), building operations, and transportation (private automobiles and public transit). Two case studies from the City of Toronto are analyzed. An economic input–output life-cycle assessment (EIO-LCA) model is applied to estimate the energy use and GHG emissions associated with the manufacture of construction materials for infrastructure. Operational requirements for dwellings and transportation are estimated using nationally and/or regionally averaged data. The results indicate that the most targeted measures to reduce GHG emissions in an urban development context should be aimed at transportation emissions, while the most targeted measures to reduce energy usage should focus on building operations. The results also show that low-density suburban development is more energy and GHG intensive (by a factor of 2.0–2.5) than high-density urban core development on a per capita basis. When the functional unit is changed to a per unit of living space basis the factor decreases to 1.0–1.5, illustrating that the choice of functional unit is highly relevant to a full understanding of urban density effects. [ABSTRACT FROM AUTHOR]

To support more sustainable development of a region, decision support tools must consider local and global systems level impacts on the economy, environment, and society. Through the development and application of "economic input–output water resources" models for Beijing, China for the years 1985, 1990, and 1992, historical trends related to the economy structure and its water use are investigated. The study finds that the economy of Beijing and water use are highly concentrated in agriculture and heavy industry, but this intensive water use is indirectly reflected in the production of most other goods and services throughout the economy because of the interrelationships among various sectors of the economy. In spite of progress during the time period observed (e.g., between 1985 and 1990 the output of the economy doubled, but water consumption increased only 12% partly because of a significant increase in the price of water in 1988) and given the seriousness of water resources issues in the region, it is critical that future regional development make progress toward a more water-efficient economic system. [ABSTRACT FROM AUTHOR]

We examine the possibilities for a "greener" car that would use less material and fuel, be less polluting, and would have a well-managed end-of-life. Light-duty vehicles are fundamental to our economy and will continue to be for the indefinite future. Any redesign to make these vehicles greener requires consumer acceptance. Consumer desires for large, powerful vehicles have been the major stumbling block in achieving a "green car". The other major barrier is inherent contradictions among social goals such as fuel economy, safety, low emissions of pollutants, and low emissions of greenhouse gases, which has led to conflicting regulations such as emissions regulations blocking sales of direct injection diesels in California, which would save fuel. In evaluating fuel/vehicle options with the potential to improve the greenness of cars [diesel (direct injection) and ethanol in internal combustion engines, battery- powered, gasoline hybrid electric, and hydrogen fuel cells], we find no option dominates the others on all dimensions. The principles of green design developed by Anastas and Zimmerman (Environ. Scl. Technol. 2003, 37, 94A-101A) and the use of a life cycle approach provide insights on the key sustainability issues associated with the various options. [ABSTRACT FROM AUTHOR]

We examine the life cycle implications of a wide range of fuels and propulsion systems that could power cars and light trucks in the US and Canada over the next two to three decades ((1) reformulated gasoline and diesel, (2) compressed natural gas, (3) methanol and ethanol, (4) liquid petroleum gas, (5) liquefied natural gas, (6) Fischer–Tropsch liquids from natural gas, (7) hydrogen, and (8) electricity; (a) spark ignition port injection engines, (b) spark ignition direct injection engines, (c) compression ignition engines, (d) electric motors with battery power, (e) hybrid electric propulsion options, and (f) fuel cells). We review recent studies to evaluate the environmental, performance, and cost characteristics of fuel/propulsion technology combinations that are currently available or will be available in the next few decades. Only options that could power a significant proportion of the personal transportation fleet are investigated.Contradictions among the goals of customers, manufacturers, and society have led society to assert control through extensive regulation of fuel composition, vehicle emissions, and fuel economy. Changes in social goals, fuel-engine-emissions technologies, fuel availability, and customer desires require a rethinking of current regulations as well as the design of vehicles and fuels that will appeal to consumers over the next decades.The almost 250 million light-duty vehicles (LDV; cars and light trucks) in the US and Canada are responsible for about 14% of the economic activity in these countries for the year 2002. These vehicles are among our most important personal assets and liabilities, since they are generally the second most expensive asset we own, costing almost $100 000 over the lifetime of a vehicle. While an essential part of our lifestyles and economies, in the US, for example, the light-duty fleet is also responsible for 42 000 highways deaths, and four million injuries each year, consumes almost half of the petroleum used, and causes large amounts of illness and premature death due to the emissions of air pollutants (e.g. nitrogen oxides, carbon monoxide, hydrocarbons and particles).The search for new technologies and fuels has been driven by regulators, not the marketplace. Absent regulation, most consumers would demand larger, more powerful vehicles, ignoring fuel economy and emissions of pollutants and greenhouse gases; the vehicles that get more than 35 mpg make up less than 1% of new car sales. Federal regulators require increased vehicle safety, decreased pollution emissions, and better fuel economy. In addition, California and Canadian regulators are concerned about lowering greenhouse gas emissions. Many people worry about the US dependence on imported petroleum, and people in both countries desire a switch from petroleum to a more sustainable fuel.The fuel-technology combinations and vehicle attributes of concern to drivers and regulators are examined along with our final evaluation of the alternatives compared to a conventional gasoline-fueled spark ignition port injection automobile.When the US Congress passed laws intended to increase safety, decrease emissions, and increase fuel economy, they did not realize that these goals were contradictory. For example, increasing safety requires increasing weight, which lowers fuel economy; decreasing emissions generally decreases engine efficiency. By spending more money or by reducing the performance of the vehicle, most of the attributes can be improved without harming others. For example, spending more money can lighten the vehicle (as with an aluminum frame with greater energy absorbing capacity), improving performance and safety; a smaller engine can increase fuel economy without diminishing safety or increasing pollution emissions, but performance suffers; modern electronics have improved performance, fuel economy, and lowered emissions, but have increased the price of the vehicle. However, low price and performance are important attributes of a vehicle. To resolve these contradictions, regulators in the US and Canada need to specify the desired tradeoffs among safety, emissions, fuel economy, and cost, and a single agency needs to be designated in each country to oversee the tradeoffs among the regulators’ attributes and those desired by consumers.We discuss methods needed to evaluate the attractiveness of vehicles employing alternative fuels and propulsion systems including:

We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C[sub2]H[sub5]OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C[sub2]H[sub5]OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output lifecycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are... [ABSTRACT FROM AUTHOR]

Studies the environmental implications of alternative-fueled automobiles. Reduction of greenhouse gases; Energy density of alcohol fuels; Importance of fuel formulation for gasoline and diesel; Importance of consumer behavior on fuel selection.

Addressing the "slum challenge" is essential for urban sustainability and the capacity of cities to provide a minimum quality of life to their residents. To present policy-makers with data to inform strategies to improve the lives of marginalized urban residents, this paper reviews quantitative indicators on slum infrastructure, and demonstrates analyses they can facilitate. First, we review 122 studies on slum infrastructure and report frequently assessed quantitative indicators; access to municipal services is among the most prevalent appearing in 25%–50% of the studies. We then assess how these indicators can increase our understanding of slum settlements, analysing access to services in slums vs the remaining urban population for a subset of cities (Sao Paulo, Rio, Lima, Johannesburg, Mumbai, and Hyderabad). Significant gaps exist between the communities, especially when per capita indicators are compared. Finally, we analyse how these indicators can be used to scope the challenges of achieving universal access to basic services (e.g. water, electricity, and water collection) by 2030. The results show that large infrastructure investments or conservation efforts are needed, especially for solid waste collection and water provision in Mumbai and Hyderabad. Additional work is needed to address data gaps to enable informed policy-making. • Systematic review of quantitative studies of slum infrastructure across the globe. • Access to municipal services among most prevalent indicators in slum infrastructure literature. • Lack of data on consumption patterns and other urban infrastructure indicators for slums. • Huge gap in basic infrastructure access and use patterns between slums and non-slums. • Developing cities require large infrastructure investments to attain universal access to services in 2030. [ABSTRACT FROM AUTHOR]

Presents information on the assessment of the environmental and energy implications of midsized automobile, by performing a life-cycle inventory analysis that emphasized manufacture and use phases. Type of model used in the assessment; Concerns surrounding the entire life cycle of an automobile from a manufacture to use to disposal; Information on life-cycle analysis; Reference to previous studies on life-cycle analyses.

Presents a reply and discussion on issues related to the article 'Life-Cycle Analysis (LCA) of Alternative Automobile Fuel/Propulsion Technologies'. Discrepancies in the life-cycle inventory; Criticisms over how the study was conducted; Defense of article authors over how study was conducted.

Aluminum is one of the most used metals of modern civilization, but its production is responsible for multiple adverse environmental impacts mostly due to aluminum smelting and alumina refining. Previous life cycle assessments (LCAs) have aggregated alumina refining into a single global process even though refining processes are highly spatially differentiated and alumina is highly traded. Our work improves on existing LCAs of primary aluminum by including temporal and spatial differentiation in alumina refining and aluminum smelting and trade of alumina and primary aluminum ingots. We build country‐level impact factors for primary aluminum ingot production and consumption, with the spatial distributions of environmental impacts, from 2000 to 2017, by combining a trade‐linked multilevel material flow analysis with LCA using six midpoint categories of the ReCiPe method. Climate change impacts of primary aluminum production range from 4.5 to 33.6 kg CO2 eq./kg. We then estimate the life cycle production‐ and consumption‐based environmental burdens of primary aluminum ingot by country. High spatial variations exist among impact factors of primary aluminum production. Aggregating the alumina refining processes into a single process may cause important deviations on the impact factors of primary aluminum ingot production (up to 38% differences in climate change impacts). Finally, we estimate the climate change impacts of worldwide primary aluminum production at 1.2 Gt CO2 eq. in 2017 and untangle their spatial origins, localized at 70% in China. Overall, we show the importance of spatial differentiation for highly traded products that rely on highly traded inputs and offer recommendations for LCA practitioners. This article met the requirements for a gold‐gold JIE data openness badge described at http://jie.click/badges. [ABSTRACT FROM AUTHOR]

Bio-based jet fuels are projected by the International Civil Aviation Organization (ICAO) to play a major role in meeting greenhouse gas emissions reduction targets. Recent literature has identified promising pathways for biojet fuel production, including several pathways approved by the ASTM International. Despite the importance of this topic, only a few studies have examined the financial metrics of biojet production, and different assumptions make it difficult to compare results. This paper evaluates and compares the financial viability of six key biojet fuel production pathways using appropriate biomass feedstocks. The pathways were analyzed from a technical and financial perspective, utilizing a common discounted cash flow approach and Monte Carlo analysis, considering internal (e.g. scale-up to commercial scale) and external (e.g. oil price) uncertainties. The hydroprocessed esters and fatty acids technology with oil feedstock had the most promising financial results, with an internal rate of return of over 26% and a 70% probability of exceeding the minimum attractive rate of return (MARR = 15%) even under the most pessimistic scenario. The next most attractive pathway was catalytic hydrothermolysis, which had favorable financial performance, but only under a scenario that assumed an oil price range of $93 to $140 per barrel. Pyrolysis and gasification with Fischer-Tropsch synthesis presented high financial risk under an oil price range of $50 to $93 per barrel and low technical development scenarios, whereas the alcohol-to-jet and direct-fermentation-to-jet technologies were found to be unlikely to achieve the MARR for any of the scenarios. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Highlights • The corn stover ethanol models from GREET and GHGenius were compared. • Life cycle greenhouse gas emissions from baseline models differed by 45 gCO 2 e MJ−1. • Key inputs and assumptions in the models were aligned and made identical. • Life cycle greenhouse gas emissions differed by 1.3 gCO 2 e MJ−1 after alignment. • Variations in emissions persisted for key inputs even after model alignment. Abstract This paper evaluates differences in life cycle greenhouse gas emissions of corn stover ethanol produced in the U.S. Midwest, as estimated by the life cycle-based software GHGenius 4.03a, GREET 2013, and GREET 2015. Life cycle assessments are not typically conducted using more than one software package, but comparisons such as the analysis in this paper provide a critical review of a fuel product system. In particular, differences in the data and assumptions become evident for life cycle stages of the same fuel product when compared between life cycle assessment software packages. Using default settings in the three software packages, life cycle greenhouse gas emissions predictions ranged from 2.75 to 47.8 gCO 2 equivalent per MJ of ethanol (gCO 2 e MJ−1), which presents a difference of as much as 45 gCO 2 e MJ−1. Assumptions regarding nitrogen fertilizer, land management, on/off-site enzyme production, and material/energy inputs included/excluded had substantial effects on life cycle greenhouse gas emissions. A consistent corn stover ethanol pathway using equivalent model assumptions and material/energy inputs was developed and implemented in each of the software packages, resulting in life cycle greenhouse gas emissions ranging from 40.7 to 42.0 gCO 2 e MJ−1. The difference in life cycle greenhouse gas emissions was considerably reduced to 1.3 gCO 2 e MJ−1 at most between software packages; however, individual emissions sources such as nitrogen fertilizer production, fertilizer application, corn steep liquor, glucose, sodium hydroxide, and biomass electricity still exhibit variation between software packages (e.g., up to 7.3 gCO 2 e MJ−1 E100 for equivalent glucose input), mainly due to different emissions factors data. Life cycle greenhouse gas emissions appeared consistent because emissions sources that vary between software packages offset each other. Differences in greenhouse gas emissions determined for corn stover ethanol point to the need to improve the life cycle modelling and replicability of life cycle studies on this biofuel pathway. Such inconsistencies are relevant in a carbon economy because the same product will have a different value in different jurisdictions as a result of differences in life cycle assessment software packages. [ABSTRACT FROM AUTHOR]

The paper presents techno-economic analyses and life cycle assessments (LCA) of the two major gasification processes for producing hydrogen from biomass: fluidized bed (FB) gasification, and entrained flow (EF) gasification. Results indicate that the thermal efficiency of the EF-based option (56%, LHV) is 11% higher than that of the FB-based option (45%), and the minimum hydrogen selling price of the FB-based option is $0.3 per kg H 2 lower than that of the EF-based option. When a carbon capture and liquefaction system is incorporated, the efficiencies of the EF- and FB-based processes decrease to 50% and 41%, respectively. The techno-economic analysis shows that at a biomass price of $100 per tonne, either a minimum price of $115/tonne CO 2e or a minimum natural gas price of $5/GJ is required to make the minimum hydrogen selling price of biomass-based plants equivalent to that of commercial natural gas-based steam methane reforming plants. Furthermore, the LCA shows that, biomass as a carbon-neutral feedstock, negative life cycle GHG emissions are achievable in all biomass-based options. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions associated with extraction of bitumen from oil sands can vary from project to project and over time. However, the nature and magnitude of this variability have yet to be incorporated into life cycle studies. We present a statistically enhanced life cycle based model (GHOST-SE) for assessing variability of GHG emissions associated with the extraction of bitumen using in situ techniques in Alberta, Canada. It employs publicly available, company-reported operating data, facilitating assessment of inter- and intraproject variability as well as the time evolution of GHG emissions from commercial in situ oil sands projects. We estimate the median GHG emissions associated with bitumen production via cyclic steam stimulation (CSS) to be 77 kg CO2eq/bbl bitumen (80% CI: 61-109 kg CO2eq/bbl), and via steam assisted gravity drainage (SAGD) to be 68 kg CO2eq/bbl bitumen (80% CI: 49-102 kg CO2eq/bbl). We also show that the median emissions intensity of Alberta's CSS and SAGD projects have been relatively stable from 2000 to 2013, despite greater than 6-fold growth in production. Variability between projects is the single largest source of variability (driven in part by reservoir characteristics) but intraproject variability (e.g., startups, interruptions), is also important and must be considered in order to inform research or policy priorities. [ABSTRACT FROM AUTHOR]

Battery-electric trucks (BET) are an alternative to diesel trucks and have the potential for lower life cycle greenhouse gas (GHG) emissions and total lifetime costs (TCO). This study compares a Class 6 medium-duty BET with a Class 6 medium-duty diesel truck. Vehicle fuel consumption is simulated for Toronto driving conditions, based on different drive cycles, operating temperatures and payloads. The base case results show the BET has lower life cycle GHG emissions and higher lifetime TCO than the diesel truck, but this does not hold across all conditions. GHG emissions of the BET are higher than those of the diesel truck under 100% payload in driving conditions with infrequent stops, while the results are less sensitive to operating temperature. The lifetime cost of the BET can be lower than that of the diesel truck in situations that have driving with frequent stops/starts and with low payloads and low battery and charging station costs. These variables also affect estimated GHG abatement costs, which are highly relevant as carbon pricing is being introduced in the province. [ABSTRACT FROM AUTHOR]

This study presents techno-economic analyses and life cycle assessments of four hydrogen production technologies using natural gas as a feedstock. Steam methane reforming, auto-thermal reforming and two innovative technologies: syngas chemical looping (SCL) and chemical looping reforming (CLR) are evaluated and compared. Thermodynamic analysis indicates that the CLR option can achieve the highest thermal efficiency (84%, LHV), even when CO 2 capture and liquefaction units are added. The financial analysis shows that the minimum hydrogen selling price of this system is 50%–90% of the price for the other technologies and finally, a carbon price of only $5/tonne CO 2 is required to make the CLR option (with zero direct carbon emissions) more financially attractive than SMR. While the analyses show that the CLR option is capable of achieving promising results there remain challenges to scale-up and commercialization of this technology including uniform flow distribution and reactivity of oxygen carrier. [ABSTRACT FROM AUTHOR]

This paper evaluates the financial viability of renewable jet fuel production, from two oilseed crops Camelina sativa (camelina) and Brassica carinata (carinata) and used cooking oil (UCO), by the hydrodeoxygenation pathway. A Monte Carlo analysis is performed to examine the robustness of the financial performance by taking into consideration key uncertain parameters, including capital cost, oil content of seeds, and prices of feedstocks, gas, electricity, water, meal co-product, and crude oil (indicator of fuel product prices). The Monte Carlo analysis revealed that under the conditions analyzed, the probabilities that the net present value would be positive are 29% for camelina, 18% for carinata and 8% for UCO, indicating that the three projects are risky for investors. Sensitivity analysis determined that the projects’ financial performance is highly sensitive to prices of fuel products and feedstocks. The impacts of two different hypothetical biofuel economic incentives were assessed: Carbon trading and tradable credits similar to the Renewable Identification Number (RIN). Income earned in the form of a RIN would have a large positive impact on the projects’ viabilities. By assuming an incentive of $0.20/L of renewable fuel, the probabilities that the NPV would be positive are 85% for camelina, 75% for carinata and 58% for UCO. [ABSTRACT FROM AUTHOR]

The focus of this work is to model the hydrodeoxygenation process to produce renewable jet fuel and co-products from low-input oilseeds, specifically camelina, carinata (non-edible oil) and used cooking oil (UCO), taking into account the fatty acid compositions by incorporating the stoichiometric hydrodeoxygenation reactions. This methodology provides insight into the effect of feedstock composition and hydrodeoxygenation reactions upon product yields, product distribution, hydrogen consumption and process utilities. The resulting product slates, hydrogen gas and utility demands are specific to each of the camelina, carinata and UCO feedstocks. The yield of kerosene-range alkanes ranged from 53 to 54% of the incoming oil, with 13–14% diesel range alkanes, 13–15% naphtha, and 7–9% liquefied petroleum gas, depending upon the fatty acid composition. The hydrogen consumption rate ranged from 26 to 30 kg per tonne of incoming oil, depending upon the degree of bond unsaturation. Thermal energy demand is 2.8 GJ/tonne oil when processing used cooking oil, versus 5.2 and 5.7 GJ/tonne of oil for carinata and camelina, respectively, owing to the additional energy required for oil extraction. Electricity demand was 73 kWh/tonne oil for UCO, versus 170 and 227 kWh/tonne oil for carinata and camelina. [ABSTRACT FROM AUTHOR]

The literature analyzes changes in vehicle attributes that can improve fuel economy to meet Corporate Average Fuel Economy (CAFE) standards. However, these analyses exclude either vehicle price, size, acceleration or technology advancement. A more comprehensive examination of the trade-offs among these attributes is needed, this case study focuses on technically feasible modifications to a reference 2012 vehicle to meet the 2025 fuel economy target. Scenarios developed to examine uncertainty in technology advancement indicate that expected technology cost reductions over time will be insufficient to offset the costs of additional fuel efficiency technologies that could be used to meet the 2025 fuel economy target while maintaining other vehicle attributes. The mid-price scenario results show the targeted 66% increase in fuel economy from 2012 to 2025 can be achieved with (i) a 10% ($2070) vehicle price increase (lightweight hybrid electric vehicle), (ii) a 31% (2.9 second) increase in the 0–97 km/h (60 mph) acceleration time (smaller engine), or (iii) a 17% (700 L) decrease in interior volume (smaller body) while maintaining other vehicle attributes. These results are consistent with those obtained using methods that generalize the US light-duty vehicle fleet, but are not a forecast of future vehicle attributes because combinations of less perceptible changes to vehicle price, acceleration and size would also be feasible. This study shows there are numerous ways that 2025 fuel economy targets can be met; therefore, the trade-offs quantified provide important insights on the implications of future CAFE standards. [ABSTRACT FROM AUTHOR]

Steam-treated pellets can help to address technical barriers that limit the uptake of pellets as a fuel for electricity generation, but there is limited understanding of the cost and environmental impacts of their production and use. This study investigates life cycle environmental (greenhouse gas (GHG) and air pollutant emissions) and financial implications of electricity generation from steam-treated pellets, including fuel cycle activities (biomass supply, pellet production, and combustion) and retrofit infrastructure to enable 100% pellet firing at a generating station that previously used coal. Models are informed by operating experience of pellet manufacturers and generating stations utilising coal, steam-treated and conventional pellets. Results are compared with conventional pellets and fossil fuels in a case study of electricity generation in northwestern Ontario, Canada. Steam-treated pellet production has similar GHG impacts to conventional pellets as their higher biomass feedstock requirement is balanced by reduced process electricity consumption. GHG reductions of more than 90% relative to coal and ∼85% relative to natural gas (excluding retrofit infrastructure) could be obtained with both pellet options. Pellets can also reduce fuel cycle air pollutant emissions relative to coal by 30% (NOx), 97% (SOx), and 75% (PM 10 ). Lesser retrofit requirements for steam-treated pellets more than compensate for marginally higher pellet production costs, resulting in lower electricity production cost compared to conventional pellets ($0.14/kW h vs. $0.16/kW h). Impacts of retrofit infrastructure become increasingly significant at lower generating station capacity factors, further favouring steam-treated pellets for both environmental and financial metrics. [ABSTRACT FROM AUTHOR]

This study evaluated the viability of n-butanol production integrated within a first and second generation sugarcane biorefinery. The evaluation included a deterministic analysis as well as a stochastic approach, the latter using Monte Carlo simulation. Results were promising for n-butanol production in terms of revenues per tonne of processed sugarcane, but discouraging with respect to internal rate of return (IRR). The uncertainty analysis determined there was high risk involved in producing n-butanol and co-products from ethanol catalysis. It is unlikely that these products and associated production route will be financially attractive in the short term without lower investment costs, supportive public policies and tax incentives coupled with biofuels’ production strategies. [ABSTRACT FROM AUTHOR]

Despite international efforts to increase the adoption of alternative fuel vehicles, global gasoline internal combustion engine vehicles (ICEV-Gs) sales are projected to remain strong for the coming decades, with electric vehicles (EV) sales remaining well below 50% under International Energy Agency projections for 2030. The current study analyzes the cumulative reduction of greenhouse gas emissions that can be obtained by 2050 from policies targeting these gasoline powered vehicles. The analysis is applied to the case of the U.S. light-duty vehicles (LDV) fleet, a representative country with a large LDV fleet and slow EV penetration; the work considers technological, decisional and behavioral solutions. Technological pathways include fuel economy improvements, vehicle lightweighting and a greater provision of ethanol blends. Decisional pathways include purchasing decisions related to vehicle size and relative (best-in-class) fuel economy among available models. Behavioral pathways include improvements in driving habits. This study demonstrates the transitional and complementary role to fleet electrification that ICEV-Gs can play to meet climate targets, starting from vehicle models in the market today. A scenario-based analysis confirms that effective and diverse mitigation pathways targeting ICEV-G decarbonisation may lessen the need for aggressive fleet electrification rates – reducing the required cumulative electric vehicle sales through 2050 by at least 10% and by as much as 98% under extreme scenarios in the U.S. The analysis also identifies the limit of the ICEV-G fleet decarbonisation at 40% of cumulative lifecycle emissions from 2021 to 2050 in a very optimistic scenario, suggesting that these measures can complement but not replace the need to develop alternative fuels and powertrains. • Examined GHG mitigation measures targeting gasoline vehicle (ICEV-G) technology • Higher efficiency, hybridization & downsizing help ICEV-Gs meet GHG targets • Such measures can reduce cumulative fleet GHG emissions through 2050 by 5 to 30% • Plausible ICEV-G measures can delay need for full electrification by 5–25 years • Effective policy requires both technological improvements and behavioral changes [ABSTRACT FROM AUTHOR]

Up to 500 litres of water may be consumed at the batching plant per cubic meter of ready mix concrete, if water for washing mixing trucks and equipment is included. Demand for concrete is growing almost everywhere, regardless of local availability of freshwater. The use of freshwater for concrete production exacerbates stress on natural water resources. In water-stressed coastal countries such as Israel, desalinated seawater (DSW) is often used in the production of concrete. However, the environmental impacts of this practice have not yet been assessed. In this study the effect of using DSW on the water and carbon footprints of concrete was investigated using life cycle assessment. Water footprint results highlight the benefits of using DSW rather than freshwater to produce concrete in Israel. In contrast, because desalination is an energy intensive process, using DSW increases the greenhouse gas intensity of concrete. Nevertheless, this increase (0.27 kg CO2e/m³ concrete) is small, if compared to the life cycle greenhouse gas emissions of concrete. Our results show that using untreated seawater in the mix (transported by truck from the coast) in place of DSW, would be beneficial in terms of water and carbon footprints if the batching plant were located less than 13 km from the withdrawal point. However, use of untreated seawater increases steel reinforcement corrosion, resulting in loss of structural integrity of the reinforced concrete composite. Sustainability of replacing steel with non-corrosive materials should be explored as a way to reduce both water and carbon footprints of concrete. [ABSTRACT FROM AUTHOR]

This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits. [ABSTRACT FROM AUTHOR]

Abstract: An integrated modelling approach is adopted to estimate microscale urban traffic emissions. The modelling framework consists of a traffic microsimulation model developed in PARAMICS, a microscopic emissions model (Comprehensive Modal Emissions Model), and two dispersion models, AERMOD and the Quick Urban and Industrial Complex (QUIC). This framework is applied to a traffic network in downtown Toronto, Canada to evaluate summer time morning peak traffic emissions of carbon monoxide (CO) and nitrogen oxides (NO x ) during five weekdays at a traffic intersection. The model predicted results are validated against sensor observations with 100% of the AERMOD modelled CO concentrations and 97.5% of the QUIC modelled NO x concentrations within a factor of two of the corresponding observed concentrations. Availability of local estimates of ambient concentration is useful for accurate comparisons of predicted concentrations with observed concentrations. Predicted and sensor measured concentrations are significantly lower than the hourly threshold Maximum Acceptable Levels for CO (31 ppm, ∼90 times lower) and NO2 (0.4 mg/m3, ∼12 times lower), within the National Ambient Air Quality Objectives established by Environment Canada. [Copyright &y& Elsevier]

Abstract: We evaluate the implications of a range of driving patterns on the tank-to-wheel energy use of plug-in hybrid electric vehicles. The driving patterns, which reflect short distance, low speed, and congested city driving to long distance, high speed, and uncongested highway driving, are estimated using an approach that involves linked traffic assignment and vehicle motion models. We find substantial variation in tank-to-wheel energy use of plug-in hybrid electric vehicles across driving patterns. Tank-to-wheel petroleum energy use on a per kilometer basis is lowest for the city and highest for the highway driving, with the opposite holding for a conventional internal combustion engine vehicle. [Copyright &y& Elsevier]

Abstract: Lignocellulosic ethanol holds promise for addressing climate change and energy security issues associated with personal transportation through lowering the fuel mixes’ carbon intensity and petroleum demand. We compare the technological features and life cycle environmental impacts of near- and mid-term ethanol bioconversion technologies in the United States. Key uncertainties in the major processes: pre-treatment, hydrolysis, and fermentation are evaluated. The potential to reduce fossil energy use and greenhouse gas (GHG) emissions varies among bioconversion processes, although all options studied are considerably more attractive than gasoline. Anticipated future performance is found to be considerably more attractive than that published in the literature as being achieved to date. Electricity co-product credits are important in characterizing the GHG impacts of different ethanol production pathways; however, in the absence of near-term liquid transportation fuel alternatives to gasoline, optimizing ethanol facilities to produce ethanol (as opposed to co-products) is important for reducing the carbon intensity of the road transportation sector and for energy security. [Copyright &y& Elsevier]

The potential supply of biomass feedstocks in the US and Canada is estimated using a static supply function approach. Estimated total biomass available at a price of $100 per metric ton is 568 million metric tons in the US and 123 million tons in Canada, which together can displace 23-45 billion gallons of gasoline. Sufficient biomass, mainly agricultural and mill residues, will be available at prices of around $50/ton to meet the advanced biofuel mandates of the US Energy Independence and Security Act of 2007. The estimates of agricultural residue supply are very sensitive to the assumed fraction of residues that can be sustainably removed from the field, and the potential of municipal solid waste as a feedstock depends on which components can be economically converted into liquid biofuels. [ABSTRACT FROM AUTHOR]

We examined life cycle environmental and economic implications of two near-term scenarios for converting cellulosic biomass to energy, generating electricity from cofiring biomass in existing coal power plants, and producing ethanol from biomass in stand-alone facilities in Ontario, Canada. The study inventories near-term biomass supply in the province, quantifies environmental metrics associated with the use of agricultural residues for producing electricity and ethanol, determines the incremental costs of switching from fossil fuels to biomass, and compares the cost-effectiveness of greenhouse gas (GHG) and air pollutant emissions abatement achieved through the use of the bioenergy. Implementing a biomass cofiring rate of 10% in existing coal-fired power plants would reduce annual GHG emissions by 2.3 million metric tons (t) of CO2 equivalent (7% of the province's coal power plant emissions). The substitution of gasoline with ethanol/ gasoline blends would reduce annual provincial light-duty vehicle fleet emissions between 1.3 and 2.5 million t of CO2 equivalent (3.5-7% of fleet emissions). If biomass sources other than agricultural residues were used, additional emissions reductions could be realized. At current crude oil prices ($70/barrel) and levels of technology development of the bioenergy alternatives, the biomass electricity cofiring scenario analyzed is more cost-effective for mitigating GHG emissions ($22/t of CO2 equivalent for a 10% cofiring rate) than the stand-alone ethanol production scenario ($92/t of CO2 equivalent). The economics of biomass cofiring benefits from existing capital, whereas the cellulosic ethanol scenario does not. Notwithstanding this result, there are several factors that increase the attractiveness of ethanol. These include uncertainty in crude oil prices, potential for marked improvements in cellulosic ethanol technology and economics, the province's commitment to 5% ethanol content in gasoline, the possibility of ethanol production benefiting from existing capital, and there being few alternatives for moderate-to-large-scale GHG emissions reductions in the transportation sector. [ABSTRACT FROM AUTHOR]

With increasing trade liberalization, attempts at accounting for environmental impacts and energy use across the manufacturing supply chain are complicated by the predominance of internationally supplied resources and products. This is particularly true for Canada and the United States, the world's largest trading partners. We use an economic input-output life-cycle assessment (ElO-LCA) technique to estimate the economy-wide energy intensity and greenhouse gas (GHG) emissions intensity for 45 manufacturing and resource sectors in Canada and the United States. Overall, we find that U.S. manufacturing and resource industries are about 1.15 times as energy- intensive and 1.3 times as GHG-intensive as Canadian industries, with significant sector-specific discrepancies in energy and GHG intensity. This trend is mainly due to a greater direct reliance on fossil fuels for many U.S. industries, in addition to a highly fossil-fuel based electricity mix in the U.S. To account for these differences, we develop a 76 sector binational EIO-LCA model that implicitly considers trade in goods between Canada and the U.S. Our findings show that accounting for trade can significantly alter the results of life-cycle assessment studies, particularly for many Canadian manufacturing sectors, and the production/consumption of goods in one country often exerts significant energy- and GHG-influences on the other. [ABSTRACT FROM AUTHOR]

We model a municipal solid waste (MSW)-to-ethanol facility that employs dilute acid hydrolysis and gravity pressure vessel technology and estimate life cycle energy use and air emissions. We compare our results, assuming the ethanol is utilized as E85 (blended with 15% gasoline) in a light-duty vehicle, with extant life cycle assessments of gasoline, corn-ethanol, and energy crop-cellulosic-ethanol fueled vehicles. We also compare MSW-ethanol production, as a waste management alternative, with landlilling with gas recovery options. We find that the life cycle total energy use per vehicle mile traveled for MSW-ethanol is less than that of corn-ethanol and cellulosic-ethanol; and energy use from petroleum sources for MSW-ethanol is lower than for the other fuels. MSW-ethanol use in vehicles reduces net greenhouse gas (GHG) emissions by 65% compared to gasoline, and by 58% when compared to corn-ethanol. Relative GHG performance with respect to cellulosic ethanol depends on whether MSW classification is included or not. Converting MSW to ethanol will result in net fossil energy savings of 397–1830 MJ/MT MSW compared to net fossil energy consumption of 177–577 MJ/MT MSW for landfilling. However, landfilling with LFG recovery either for flaring or for electricity production results in greater reductions in GHG emissions compared to MSW-to-ethanol conversion. [ABSTRACT FROM AUTHOR]

Abstract: The paper compares selected life cycle-based (well-to-wheel) studies of fuel/propulsion alternatives for light-duty vehicles with a focus on lignocellulose-derived fuels (hydrogen, Fischer Tropsch liquids, and ethanol). Inter- and intra-study comparisons are completed and analyses are conducted to account for the variability due to differing assumptions surrounding energy accounting and vehicle characteristics. For lignocellulose-derived fuels used in relevant propulsion systems, life cycle greenhouse gas emissions are on average 96% lower for hydrogen, 91% lower for Fischer Tropsch liquids and 86% lower for ethanol as compared to the reference gasoline pathway. Key issues found to impact study results are assumptions regarding feedstock characteristics, vehicle propulsion system efficiency, land use changes and associated carbon sequestration, nitrous oxide emissions due to agricultural practices, co-product allocation, energy accounting practices, and expected progress on commercial-scale fuel production processes and associated infrastructure. [Copyright &y& Elsevier]

Utilizing domestically produced cellulose-derived ethanol for the light-duty vehicle fleet can potentially improve the environmental performance and sustainability of the transport and energy sectors of the economy. A life cycle assessment model was developed to examine environmental implications of the production and use of ethanol in automobiles in Ontario, Canada. The results were compared to those of low-sulfur reformulated gasoline (RFG) in a functionally equivalent automobile. Two time frames were evaluated, one near-term (2010), which examines converting a dedicated energy crop (switchgrass) and an agricultural residue (corn stover) to ethanol; and one midterm (2020), which assumes technological improvements in the switchgrass-derived ethanol life cycle. Near-term results show that, compared to a RFG automobile, life cycle greenhouse gas (GHG) emissions are 57% lower for an E85-fueled automobile derived from switchgrass and 65% lower for ethanol from corn stover, on a grams of CO2 equivalent per kilometer basis. Corn stover ethanol exhibits slightly lower life cycle GHG emissions, primarily due to sharing emissions with grain production. Through projected improvements in crop and ethanol yields, results for the mid-term scenario show that GHG emissions could be 25-35% lower than those in 2010 and that, even with anticipated improvements in RFG automobiles, E85 automobiles could still achieve up to 70% lower GHG emissions across the life cycle. [ABSTRACT FROM AUTHOR]

Municipal wastewater treatment may lead to the emission of greenhouse gases. The current Intergovernmental Panel on Climate Change (Geneva, Switzerland) approach attributes only methane emissions to wastewater treatment, but this approach may overestimate greenhouse gas emissions from the highly aerobic processes primarily used in North America. To better estimate greenhouse gas emissions, a procedure is developed that can be used either with plant-specific data or more general regional data. The procedure was evaluated using full-scale data from 16 Canadian wastewater treatment facilities and then applied to all 10 Canadian provinces. The principal greenhouse gas emitted from municipal wastewater treatment plants was estimated to be carbon dioxide (CO2), with very little methane expected. The emission rates ranged from 0.005 kg CO2-equivalent/m³ treated for primary treatment facilities to 0.26 kg CO2-equivalent/m³ for conventional activated sludge, with anaerobic sludge digestion to over 0.8 kg CO2-equivalent/m³ for extended aeration with aerobic digestion. Increasing the effectiveness of biogas generation and use will decrease the greenhouse gas emissions that may be assigned to the wastewater treatment plant. [ABSTRACT FROM AUTHOR]

Alternative hydrogen production technologies are sought in part to reduce the greenhouse gas (GHG) emissions intensity compared with Steam Methane Reforming (SMR), currently the most commonly employed hydrogen production technology globally. This study investigates hydrogen production via High Temperature Steam Electrolysis (HTSE) in terms of GHG emissions and cost of hydrogen production using a combination of Aspen HYSYS® modelling and life cycle assessment. Results show that HTSE yields life cycle GHG emissions from 3 to 20 kg CO 2e /kg H 2 and costs from $2.5 to 5/kg H 2 , depending on the system parameters (e.g., energy source). A carbon price of $360/tonne CO 2e is estimated to be required to make HTSE economically competitive with SMR. This is estimated to potentially decrease to $50/tonne CO 2e with future technology advancements (e.g., fuel cell lifetime). The study offers insights for technology developers seeking to improve HTSE, and policy makers for decisions such as considering support for development of hydrogen production technologies. • Highlighting economic and environmental trade-offs of high temperature electrolysis. • Aspen HYSYS® modelling and life cycle assessment of high temperature electrolysis. • Emissions of 3–20 kgCO 2 e/kgH 2 and cost of $2.5–5/kgH2 are possible. • Carbon price of $50-$360 might been needed to make the process competitive with SMR. [ABSTRACT FROM AUTHOR]

Life cycle assessment (LCA) analysts are increasingly being asked to conduct life cycle‐based systems level analysis at the earliest stages of technology development. While early assessments provide the greatest opportunity to influence design and ultimately environmental performance, it is the stage with the least available data, greatest uncertainty, and a paucity of analytic tools for addressing these challenges. While the fundamental approach to conducting an LCA of emerging technologies is akin to that of LCA of existing technologies, emerging technologies pose additional challenges. In this paper, we present a broad set of market and technology characteristics that typically influence an LCA of emerging technologies and identify questions that researchers must address to account for the most important aspects of the systems they are studying. The paper presents: (a) guidance to identify the specific technology characteristics and dynamic market context that are most relevant and unique to a particular study, (b) an overview of the challenges faced by early stage assessments that are unique because of these conditions, (c) questions that researchers should ask themselves for such a study to be conducted, and (d) illustrative examples from the transportation sector to demonstrate the factors to consider when conducting LCAs of emerging technologies. The paper is intended to be used as an organizing platform to synthesize existing methods, procedures and insights and guide researchers, analysts and technology developer to better recognize key study design elements and to manage expectations of study outcomes. [ABSTRACT FROM AUTHOR]

Moisture-related microbial growth is a key factor contributing to food spoilage in developing countries. Dehydration or drying of food reduces the moisture content supporting this microbial growth, thereby addressing this problem. Hence the moisture content of food materials is a key factor influencing the quality of storage thereby reducing post-harvest loss and is thus very important for the farmers. Current moisture measurement techniques (both destructive and non-destructive) available do not take into account the inherent difficulties in the context of developing countries including the relatively high instrumentation cost, unreliable power supply, specificity of the measurement method to food type, and training and maintenance requirements, among others. This paper includes a review of the existing moisture content measurement methods followed by an evaluation of their applicability for this proposed application in developing countries. Key Findings and Conclusions : A few recently developed instruments show promise but there is little research on how small-scale farms and co-operatives in developing countries can achieve a safe standard for their dried foods. Of these, two potential methods, equilibrium relative humidity and infrared imaging, were identified as promising techniques, but further research and development would be needed to make them suitable for use in small-scale operations in developing countries. • Study presents review of common moisture content measurement methods. • Current techniques do not consider inherent difficulties in developing countries. • Analysis conducted to determine feasible methods for developing country applications. • Equilibrium relative humidity and infrared imaging identified as promising techniques. [ABSTRACT FROM AUTHOR]