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[Display omitted] • The pH-swing cold capture chloralkali process improves energy efficiency threefold over the benchmark process. • Integrating pH-swing cold capture chloralkali in eFuel synthesis moves most of the energy consumption to the electrolyzer. • We attain ∼ 76 % carbon capture efficiency and 79.5 % overall process efficiency. Renewable Fuels of Non-Biological Origin (RFNBOs, a.ka. "eFuels") are drop-in replacements for fossil fuels in the "hard-to-abate" sectors, and utilise existing distribution and storage infrastructure, but suffer from low synthetic efficiency. In particular, the low efficiency and high energy consumption of hydrogen synthesis by freshwater electrolysis remains a problem to be addressed. In the current study, we explore the potential of saltwater electrolysis (chloralkali) for the synthesis of eFuels generally, and specifically eMethanol. The study explores the use of chlorinated water in carbonate-loop pH-swing "cold capture" of carbon dioxide, and the resulting synergetic integration of the chloralkali process in eFuel syntheses. Doing so eliminates the high energy consumption of the calciner and the slaker of the benchmarked carbonate-loop thermal-swing method. It is replaced with a spontaneous chemical process in which chlorine is neutralized in the presence of carbonates. This allows the simultaneous solution of "The Chlorine Problem" of saltwater electrolysis, and a lower overall energy consumption of direct air capture when combined with green hydrogen synthesis. The only limitation on the comparison is that a large amount of carbon dioxide is over-captured when using chloralkali. That is, the ratio of hydrogen generated to carbon dioxide captured is fixed by the stoichiometry of chloralkali and not that of the eFuel. This results in an excess of carbon captured and thus a carbon-negative eFuel. We examine one configuration of secondary revenue and use it to inform the marginal cost of CO 2 capture. In the system proposed by Aeon Blue Technologies (ABT), carbon dioxide is absorbed into caustic according to the standard method. Hydrogen gas is produced in a standard chloralkali electrolyzer, along with caustic for the contactor, and chlorine. Water oxidation by chlorine gives the strong acid, hydrochloric acid, and the weak acid, hypochlorous acid, which react directly with wet carbonate to release CO 2. H 2 and CO 2 react in a methanol reactor to produce eFuel. H 2 is the limiting reagent for eFuel synthesis, giving an excess of cold captured CO 2. Thus, the current study underscores significant advancements in renewable fuel synthesis, particularly eMethanol, and evaluates the carbon capture and energy efficiency of a novel method. The simulation indicates that the marginal energy cost for a tonne of CO 2 is ∼ 184kWh. This gives ∼ 76 % theoretical carbon capture efficiency and an overall process efficiency of 79.5 % (approximately a threefold improvement over the benchmark). The authors are unaware of a comparable method. The overall system yields a tonne of carbon-neutral e-methanol (eMeOH) while capturing an additional 3 tonnes of carbon dioxide, which means the modelled process captures over 300 % more carbon dioxide than is released upon combustion of the eFuel. In summary, this research contributes valuable insights into carbon-negative eFuel production, representing a significant scientific step in sustainable fuel production. [ABSTRACT FROM AUTHOR]

• Renewable natural gas (RNG) production through biomass gasification was assessed. • Six feedstocks (corn stover (CS), wheat straw, whole forest, forest residues, cow manure, and the organic fraction of municipal solid waste (OFMSW) were studied. • Data-intensive process models were developed to understand the mass and energy balances of the conversion process. • RNG production costs are lowest for the OFMSW and CS. • The lowest cost of RNG production, $6.28/GJ, is higher than natural gas price in North America. Renewable natural gas (RNG) from biomass can be used as an alternative to natural gas. However, there is limited understanding of the economic viability of RNG production from a wide range of feedstocks. In this study, a comprehensive comparative techno-economic assessment of RNG production via gasification from six biomass feedstocks with a wide range of moisture contents and characteristics was conducted. The feedstocks studied are corn stover (CS), wheat straw (WS), whole forest (WF), forest residues (FR), cow manure (CM), and the organic fraction of municipal solid waste (OFMSW). The RNG production plants were simulated and the simulation results were used to develop techno-economic models for each feedstock to estimate the production cost of RNG. The pathways were compared in terms of RNG yield, RNG production quantity, electricity generation, as well as RNG production costs and cost components. Sensitivity analyses were conducted on a wide range of factors and effect of including cardon credit on the production cost were studied. RNG production costs from the gasification of the OFMSW and CS were lower than those of other feedstocks at 6.28 $/GJ and 6.32 $/GJ, respectively. If the avoided cost (as a source of revenue) of landfilling of the OFMSW or carbon credit (minimum 90 $/t CO 2) is considered, the RNG production cost can be competitive with natural gas price (1.4 $/GJ). The information developed in study is critical for decision makers in policy formulation and investment decisions. [ABSTRACT FROM AUTHOR]

Forced-air cooling of apples is typically a unidirectional flow process which often leaves the apples downward of the flow passage at elevated temperatures causing non-uniform temperature distributions at the process end. Previously, package vent and flow parameter modifications have often been investigated to improve these non-uniform temperatures and cooling characteristics with more focus on cooling rate improvements rather than cooling uniformity. This work analyzed the effects of periodic airflow reversal on cooling characteristics (i.e., cooling rate, uniformity, and energy consumption) and highlighted the challenges faced while using it as an optimization strategy. Compared to conventional designs available in the market, an improved vent design is proposed and used for comparing different flow reversal strategies at three constant cooling velocities (i.e., 1 m/s, 2 m/s, and 3 m/s). Also, the overall heterogeneity index (OHI) based on surface heterogeneity maps and energy consumption based on fan power and seven-eighth cooling times (SECT) were used to quantify the whole process uniformity and conspicuously compare different strategies. The results show that the periodic flow reversal improves precooling time, energy consumption, and cooling uniformity within the package and fruit for all flow velocities. Especially for higher velocities (i.e., 3 m/s) generally preferred for faster cooling, a significant improvement (i.e., 43.89% reduction in OHI with three reversals) in cooling uniformity was observed with more flow reversals. In addition, it is observed that OHI calculations provide a superior understanding of the cooling uniformities and properly handle experimental irregularities when compared with the other methods, which might show different results for different experiments. Therefore, for a process with intermediately seizing or warming periods like the present study, OHI can be an appropriate choice to compare the cooling uniformities. Finally, some cooling strategies and guidelines for utilizing flow reversals are proposed to achieve more uniformities at different flow velocities. • Experimental analysis of precooling using periodic flow reversals was carried out. • Enhancement in cooling rates by flow reversals was demonstrated. • Cooling uniformity was compared using various tools for different cooling schemes. • Guidelines for changing cooling strategies using flow reversals were proposed. [ABSTRACT FROM AUTHOR]

• A small-scale locked-cycle piston press test to provide design information closed-circuit HPGR. • The test ware inspired by the Bond ball mill grindability test. • Piston Work Index describes the samples' resistance to HPGR comminution. • The test results were within ± 20% range of HPGR tests for a fine feed. The increased energy efficiency of HPGR-based circuits as an alternative to AG/SAG mill circuits has been well established. However, assessing the HPGR technology involves pilot-scale testing requiring large samples, which is expensive and may be prohibitive, particularly for early-stage projects. As a result, the uptake of HPGR technology has been slow, emphasizing the need for small-scale tests for sizing and selection. A reliable small-scale test for preliminary HPGR circuit design is essential in garnering the mining industry's interest in the broader adoption of HPGRs. Inspired by the Bond ball mill grindability test, a small-scale locked-cycle piston press test was developed to estimate the circulating load and circuit-specific energy consumption for closed-circuit HPGR operation. The test introduces the Piston Work Index, which describes the ore samples' resistance to HPGR comminution and can be subsequently used to estimate the HPGR circuit-specific energy consumption. The test results indicated that the circuit-specific energy and circulating load obtained from the small-scale piston press test were within the ± 20% range of the locked-cycle pilot scale HPGR tests for a fine feed representing quaternary stage HPGR application. [ABSTRACT FROM AUTHOR]

Despite improvements, the residential sector is one of most energy-intensive sectors in the world and is the third largest consumer of energy across Canada, and in Alberta in particular. This study investigates opportunities to improve energy efficiency and reduce greenhouse gas emissions (GHG) in the residential sector. A case study for Alberta is conducted. Energy modeling and scenario analyses are used to project future energy savings and greenhouse gas mitigation potential in the residential sector. Seventeen energy-saving options are identified in different residential subsectors, including space heating and cooling, water heating, appliances, and lighting. The long-term impacts (i.e., from 2013 to 2050) of these technologies in terms of energy savings and greenhouse gas mitigation potential are assessed using the Long-range Energy Alternative Planning model. For the evaluated options, more than 80% of GHG mitigation is achievable with negative GHG abatement cost. A GHG abatement cost curve is developed to assess the economic performance of various options. The results of the cost curve indicate that efficient lighting, efficient furnaces, and high efficiency appliances are the three areas in which the most GHG mitigation can be achieved at the lowest cost. The results provide invaluable insights to policy makers. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new concept of bifacial PV/PCM system developed and numerically investigated. • Bifurcated PCM enclosure design show higher thermo-electric performance. • New BIF PV/PCM system enhances the incident radiation utilization ability by 87%. • New BIF PV/PCM system overall system efficiency approaches to about 65% higher. A new concept of bifacial PV/PCM (BIF-PV/PCM) system with sandwiched thermal energy storage enclosure has been investigated that possesses 1.21 times power output density and 7.39 times total energy utilization density per unit land area compared to the conventional PV system. Based on the melting morphology and thermo-electric performance of the initially rectangular PCM enclosure, an optimized bifurcated non-rectangular design of the enclosure is proposed to enhance the incident radiation utilization ability by 87% more than a simple one PV/PCM system. Enhanced utilization of solar radiation manifests into 105% more melting compared to conventional PV/PCM system. With the strategic mirror reflection and bypassing the solar radiation towards the rear PV panel and strategic design of PCM enclosure to aid convection-driven melting, electric power output has been increased significantly (about 77%) compared to similar conventional PV/PCM system. The study revealed that overall system efficiency could approach about 74% if suitable strategies are adopted, as demonstrated in this paper. Results are discussed in terms of energy utilization efficiency, exergy efficiency, power conversion efficiency, tracking melting front morphology, and its effect on heat transfer characteristics, etc. This investigation has been carried out with the help of an experimentally calibrated numerical model that accurately mimics the melting morphology of PCM and other heat transfer characteristics of the system. The findings of this study would help design and develop a more efficient BIF-PV/PCM system to meet exponentially increasing energy needs. [ABSTRACT FROM AUTHOR]

The present work encompasses comparative analysis using numerical optimization for energetic and exergetic efficiencies of solar air heater having Winglet type roughness over the absorber surface.Therefore, it is very necessary to calculate effective as well as exergetic efficiencƴ for the proper estimation of energy utilization of solar air heater. The evaluation of these efficiencies is done by considering parametric design parameter and temperature rise parameters. A mathematical model based on the thermal, effective and exergy analysis for the solar air heater, is presented and its effect on the entire design parameter is examined. Using roughnesѕ parameter e.g. the relative roughness pitch of 8, angle of attack of 600, relative roughness width of 5 at the temperature rise parameter of 0.0125 m2K/W shows maximum enhancement of thermal, effective and exergetic efficiencies comprise of 2.12, 1.99 and 2.03 times over smooth plate. This comprehensive analysis can be very efficient and beneficial to get the design plot for the defined value of roughness parameter without advancing plenteous investment for really conducted experimentation and also providing the performance assessment of the solar air heater design. LCT approach typically used to visualize the exact distribution of temperature over the roughened surface in a rectangular duct using the winglet type vortex generator. On the basis of the above analysis the strategy behind this is to maximize the heat transfer rates and the required value of energetic and exergetic efficiencies are determined. [Display omitted] • Experimental work on solar air heater are presented to evaluate the heat transfer using Winglet type roughness element. • The comparative analysis on thermal, effective and exergetic efficiencies are presented. • The effect of energetic and exergetic efficiency as a function of temperature rise parameter and insolation are examined. • An optimum value on thermal, effective and exergetic efficiencies observed to be of 2.12, 1.99 and 2.03 times over smooth plate. [ABSTRACT FROM AUTHOR]

• Framework for optimal positioning of wireless charging facility for BEV. • Consider both system level social cost and energy consumed. • Introduce an efficient algorithm for solving black-box objective function. • Present a case-study using a County network. Dynamic wireless charging (DWC) offers a plausible solution to extending Battery Electric Vehicle (BEV) driving range. DWC is costly to deploy and thus its locations need to be optimized. This raises a question often encountered in practice for infrastructure investment: how to determine the optimal locations of DWC facilities in a network. In this paper, we propose a sequential two-level planning approach considering the objectives of both the public infrastructure planning agency and the BEV users. Two different planners' objectives namely, total system travel time and total system net energy consumption are considered. Besides these objectives, constraints such as agency budget, range reassurance, and equity in resource distribution are also addressed at the planner's level. For each objective, BEV drivers respond by choosing their preferred route based on the location of DWC facilities implemented by the planner. An effective solution algorithm is utilized that has the capability of solving relatively large-scale real-world networks within a reasonable computational time. The numerical experiment and case study results provide useful insights on optimally positioning DWC infrastructure to minimize societal cost and energy. [ABSTRACT FROM AUTHOR]

This review assesses biochar's potential as an electrode material for energy producing (microbial fuel cells (MFCs) and energy storage devices (supercapacitors, batteries). Conventional energy storage faces challenges due to resource scarcity, cost, and environmental impact. Biochar, derived from biomass using different processes like pyrolysis, hydrothermal treatment, and flash pyrolysis offers a renewable and eco-friendly alternative. It is easy to synthesize and has a high surface area, porous structure, reasonable conductivity, and chemical stability which make it a suitable material for bioelectrochemical processes and energy storage devices. It has shown promise in MFCs, supercapacitors, and batteries, enhancing electricity production, charge storage capacity, and stability. However, challenges persist in optimizing biochar preparation and scaling up production. To fully realize its benefits, further research is needed to understand underlying electrochemical processes and develop effective large-scale implementation strategies, leading to a greener and more sustainable energy landscape. [Display omitted] • Growing industrialization amplifies energy needs. • Biomass can be converted into biochar using pyrolysis and gasification. • Renewables tackle rising energy demand and necessitate efficient storage. • Batteries and supercapacitors are vital for high-density energy storage in electronics. • Biochar is an affordable eco-friendly electrode promoting sustainability. [ABSTRACT FROM AUTHOR]

The industrial sector accounts for more than one-third of global energy consumption and greenhouse gas (GHG) emissions. In the sector, the chemical industry makes up nearly 30% of global industrial energy consumption. In this study, a framework is developed to apply bottom-up energy modelling for analyzing energy efficiency improvement and GHG mitigation potential in the chemical sector. Also, techno-economic and policy analyses are used to analyze the applicability and economic performance of different mid- to long-term energy efficiency measures. The comprehensive, data-intensive, and technology-rich model is flexible and can be used to study the GHG mitigation potential in different regions. A case study was conducted for Alberta, one of the biggest industrial hubs in Canada, using the Long-range Energy Alternative Planning model. Twenty-eight GHG mitigation scenarios in the petrochemical and fertilizer industries (the two major chemical industry sub-sectors) were developed. The costs of implementing each mitigation measure were calculated and used to develop cost curves. The results suggest that cumulative mitigation potential from the chemical industry would be 7.1 and 29.7 megatonnes CO 2 equivalent in the periods ending 2030 and 2050, respectively. We also found that more than 75% of the emissions reductions are achievable with negative cost. [ABSTRACT FROM AUTHOR]

The development of a cost structure for energy storage systems (ESS) has received limited attention. In this study, we developed data-intensive techno-economic models to assess the economic feasibility of ESS. The ESS here includes pump hydro storage (PHS) and compressed air energy storage (CAES). The costs were developed using data-intensive bottom-up models. Scale factors were developed for each component of the storage systems. The life cycle costs of energy storage were estimated for capacity ranges of 98–491 MW, 81–404 MW, and 60–298 MW for PHS, conventional CAES (C-CAES), and adiabatic CAES (A-CAES), respectively, to ensure a market-driven price can be achieved. For CAES systems, costs were developed for storage in salt caverns hard rock caverns, and porous formations. The results show that the annual life cycle storage cost is $220–400 for PHS, $215–265 for C-CAES, and $375–480 per kW-year for A-CAES. The levelised cost of electricity is $69–121 for PHS, $58–70 for C-CAES, and $96–121 per MWh for A-CAES. C-CAES is economically attractive at all capacities, PHS is economically attractive at higher capacities, and A-CAES is not attractive at all. The developed information is helpful in making investment decision related to large energy storage systems. [ABSTRACT FROM AUTHOR]

The life cycle energy consumption and greenhouse gas (GHG) emission performances of forest biomass-derived oxymethylene ether (OME) synthesis used as a diesel additive are analyzed in this study. OME, a new alternative liquid fuel, has great miscibility with conventional fuels like diesel. OME can reduce combustion emissions significantly when used as a diesel additive without any modification to the engine. A data-intensive spreadsheet-based life cycle assessment (LCA) model was developed for OME synthesis from woodchips derived from two different kinds of forest biomass, whole tree and forest residue. Woodchip harvesting, chip transportation, chemical synthesis of OME from biomass-derived syngas, OME transportation to blending, and vehicle combustion of this transportation fuel were considered in the system boundary. The results show that the whole tree pathway produces 27 g CO 2 eq/MJ of OME, whereas the forest residue pathway produces 18 g CO 2 eq/MJ of OME over 20 years of plant life. The difference is mainly due to some emissions-intensive operations involved in biomass harvesting and biomass transportation such as skidding, road construction, etc., in the whole tree pathway. Also, vehicle combustion was found to be the most GHG-intensive unit for both pathways. OME combustion in a vehicle accounts for about 77% and 83% of the total life cycle GHG emissions for the whole tree and forest residue pathways, respectively. This study also compares the diesel life cycle emission numbers with the life cycle emissions of OME derived from forest biomass, and it was observed that GHG emissions can be reduced by 20–21% and soot (black carbon) emissions can be reduced by 30% using a 10% OME blended diesel as a transportation fuel compared with conventional diesel. [ABSTRACT FROM AUTHOR]

The worldwide energy demand is steadily increasing and estimated to be doubled by the year 2050 due to a continuous hike in economies and population. A large part of the global energy requirement procures using traditional energy sources such as fossil fuels, which are non-renewable. Also, their excessive consumption imparts negative impacts on the environment by CO 2 , and CO emissions, which constantly increase the average global temperature. Therefore, the need for a more reliable, sustainable, inexpensive, renewable and environmentally-friendly form of energy is imperative. From these perspectives, hydrogen energy is emerging as one of the most promising alternatives to overcome rising energy demand with a zero-carbon footprint. Herein, various layered double hydroxides (LDH) nanocomposite owing to their attractive physicochemical properties and synergistic effect with other materials in the field of hydrogen production are reviewed. Why the class of LDHs materials is critical and their ideographic properties which make them promising materials in the field of water splitting via photocatalysis and electrocatalysis are also discussed. The synthetic methods of LDHs based nanocomposites fabrication are summarized. Various challenges and strategies from the viewpoint of a different method of hydrogen production through LDHs are reported. Additionally, multiple techniques like surface plasmon resonance (SPR), heterojunction formation, and doping with co-catalyst to increase the efficiency for photocatalytic hydrogen production are also presented. Hopefully, this review will help the readers explore highly efficient, inexpensive and stable LDH catalysts toward photocatalytic water splitting. • Current issues related with energy requirements and green energy sources. • Recent advancements in LDH based electrocatalysts and photocatalysts for water splitting. • Challenges in conventional photocatalysts based water splitting. • Strategies to enhance photocatalytic hydrogen evolution and oxygen evolution reactions. [ABSTRACT FROM AUTHOR]

Bioenergy derived from biomass provides a promising energy alternative and can reduce the greenhouse gas (GHG) emissions generated from fossil fuels. Biomass-based thermochemical conversion technologies have been acknowledged as apt options to convert bioresources into bioenergy; this bioenergy includes electricity, heat, and fuels/chemicals in solid, liquid, and gaseous phases. In this review, the techno-economic and life cycle assessment of these technologies (combustion, gasification, pyrolysis, liquefaction, carbonization, and co-firing) are summarized. Specific indicators (production costs in a techno-economic analysis, functional units and environmental impacts in a life cycle analysis) for different technologies were compared. Finally, gaps in research and future trends in biomass thermochemical conversion were identified. This review could be used to guide future research related to economic and environmental benefits of bioenergy. [ABSTRACT FROM AUTHOR]

A life cycle assessment (LCA) is an extremely useful tool to assess the greenhouse gas (GHG) emissions associated with all the stages of a crude oil’s life from well-to-wheel (WTW). All of the WTW life cycle stages of crude oil consume energy and produce significant amounts of GHG emissions. The present study attempts to quantify the WTW life cycle GHG emissions for transportation fuels derived from five North American conventional crudes through the development of an LCA model called FUNNEL-GHG-CCO ( FUN damental E n gineering Principl E s-based Mode L for Estimation of G reen H ouse G ases in C onventional C rude O ils). This model estimates GHG emissions from all the life cycle stages from recovery of crude to the combustion of transportation fuels in vehicle engines. The contribution of recovery emissions in the total WTW GHG emissions ranges from 3.12% for Mars crude to 24.25% for California’s Kern County heavy oil. The transportation of crude oil and refined fuel contributes only 0.44–1.73% of the total WTW life cycle GHG emissions, depending on the transportation methods and total distance transported. The GHG emissions for refining were calculated from the amount of energy use in the refining of crude oil to produce transportation fuels. All the upstream GHG emissions were allocated to gasoline, diesel, and jet fuel. Refining GHG emissions vary from 13.66–18.70 g-CO 2 eq/MJ-gasoline, 9.71–15.33 g-CO 2 eq/MJ-diesel, and 6.38–9.92 g-CO 2 eq/MJ-jet fuel derived from Alaska North Slope and California’s Kern County heavy oil, respectively. The total WTW life cycle GHG emissions range from 97.55 g-CO 2 eq/MJ-gasoline derived from Mars crude to 127.74 g-CO 2 eq/MJ-gasoline derived from California’s Kern County heavy oil. [ABSTRACT FROM AUTHOR]

A comprehensive LCA (life cycle assessment) for transportation fuels (gasoline, diesel, and jet fuel) derived from Canada's oil sands was conducted, and all the current possible pathways from bitumen extraction to use in vehicles were explored. Authors, in earlier studies, have presented the energy consumption and GHG (greenhouse gas) emission results for individual unit operations-recovery, extraction, upgrading and refining. The LC (life cycle) inventory data for the current LCA study were obtained from theoretical model named FUNNEL-GHG-OS ( FUN damental E N gineering Principl E s- based Mode L for Estimation of G reen H ouse G ases in the O il S ands), developed from fundamental engineering principles. The impact of the cogeneration of electricity in oil sands recovery, extraction, and upgrading on the LC GHG emissions of gasoline was explored. LC WTW (well-to-wheel) GHG emissions range from 106.8 to 116 g-CO 2 equivalent/MJ of gasoline, 100.5 to 115.2 g-CO 2 equivalent/MJ of diesel, and 96.4 to 109.2 g-CO 2 equivalent/MJ of jet fuel, depending on the pathway. Combustion emissions (64.7%–70.3%) are the largest constituent of WTW emissions for gasoline production; recovery (through surface mining and steam assisted gravity drainage) forms 7.2%–16% depending on the LC production process of gasoline. [ABSTRACT FROM AUTHOR]

A model – FUNNEL-GHG-OS ( FUN damental E N gineering Principl E s-based Mode L for Estimation of G reen H ouse G ases in the O il S ands) was developed to estimate project-specific energy consumption and greenhouse gas emissions (GHGs) in major recovery and extraction processes in the oil sands, namely surface mining and in␣situ production. This model estimates consumption of diesel (4.4–7.1 MJ/GJ of bitumen), natural gas (52.7–86.4 MJ/GJ of bitumen) and electricity (1.8–2.1 kW h/GJ of bitumen) as fuels in surface mining. The model also estimates the consumption of natural gas (123–462.7 MJ/GJ of bitumen) and electricity (1.2–3.5 kW h/GJ of bitumen) in steam assisted gravity drainage (SAGD), based on fundamental engineering principles. Cogeneration in the oil sands, with excess electricity exported to Alberta’s grid, was also explored. Natural gas consumption forms a major portion of the total energy consumption in surface mining and SAGD and thus is a main contributor to GHG emissions. Emissions in surface mining and SAGD range from 4.4 to 7.4 gCO 2 eq/MJ of bitumen and 8.0 to 34.0 gCO 2 eq/MJ of bitumen, respectively, representing a wide range of variability in oil sands projects. Depending upon the cogeneration technology and the efficiency of the process, emissions in oil sands recovery and extraction can be reduced by 16–25% in surface mining and 33–48% in SAGD. Further, a sensitivity analysis was performed to determine the effects of key parameters on the GHG emissions in surface mining and SAGD. Temperature and the consumption of warm water in surface mining and the steam-to-oil ratio (SOR) in SAGD are major parameters affecting GHG emissions. The developed model can predict the energy consumption and emissions for surface mining and SAGD for oil sands. [ABSTRACT FROM AUTHOR]

A model-FUNNEL-GHG-OS ( FUN damental E N gineering Principl E s- based Mode L for Estimation of G reen H ouse G ases in the O il S ands) based on fundamental engineering principles was developed to estimate the specific energy consumption and GHGs (greenhouse gas emissions) for upgrading bitumen to produce SCO (synthetic crude oil). The model estimates quantity of SCO produced, the consumption of hydrogen, steam, natural gas and power in two different upgrading operations, namely delayed coking and hydroconversion. Hydroconversion upgrading is more energy and GHG (433.4 kgCO 2 eq/m 3 of bitumen) intensive than delayed coker upgrading (240.3 kgCO 2 eq/m 3 of bitumen) but obtains a higher yield of SCO. This research explores bitumen pathways in oil sands – upgrading bitumen to SCO, followed by transporting and refining SCO as compared to transporting and refining dilbit. The energy consumption, GHG emissions and volume of transportation fuels obtained from refining of different oil sands feeds has been investigated. Refining of oil sands products produce 7.9 to 15.72 gCO 2 eq per MJ of refined product. Refining of SCO to transportation fuels produces 41% and 49% less emissions than dilbit and bitumen respectively. [ABSTRACT FROM AUTHOR]

The energy sector is the largest contributor to gross domestic product (GDP), income, employment, and government revenue in both developing and developed nations. But the energy sector has a significant environmental footprint due to greenhouse gas (GHG) emissions. Efficient production, conversion, and use of energy resources are key factors for reducing the environmental footprint. Hence it is necessary to understand energy flows from both the supply and the demand sides. Most energy analyses focus on improving energy efficiency broadly without considering the aggregate energy flow. We developed Sankey diagrams that map energy flow for both the demand and supply sides for the province of Alberta, Canada. The diagrams will help policy/decision makers, researchers, and others to understand energy flow from reserves through to final energy end uses for primary and secondary fuels in the five main energy demand sectors in Alberta: residential, commercial, industrial, agricultural, and transportation. The Sankey diagrams created for this study show total energy consumption, useful energy, and energy intensities of various end-use devices. The Long-range Energy Alternatives Planning System (LEAP) model is used in this study. The model showed that Alberta’s total input energy in the five demand sectors was 189 PJ, 186 PJ, 828.5PJ, 398 PJ, and 50.83 PJ, respectively. On the supply side, the total energy input and output were found to be 644.84 PJ and 239 PJ, respectively. These results, along with the associated energy flows were depicted pictorially using Sankey diagrams. The Sankey diagrams reveal the current efficiencies within various end-use sectors and could help identify options for improving energy efficiency in order to reduce GHG emissions. [ABSTRACT FROM AUTHOR]

A method for determining the minimum practical energy for comminution was developed and is presented in this paper. An objective of the method was to determine experimentally the energy-breakage relationship for a wide size range in order to evaluate the energy performance of both crushing and grinding processes using one energy benchmarking value. Single-particle compression breakage, referred to in the field of comminution as one of the more efficient forms of mechanical comminution, was the basis for a test regimen to characterize the energy-breakage properties of ores. Existing models for impact breakage were found to be valid for single-particle compression breakage when used in a modified form. A key parameter of the adopted model, the threshold energy, was also investigated for three ore types and a range of particle sizes. The energy performance of comminution processes at a Canadian mining operation was determined by comparing the determined minimum practical energy, using the new method, with actual site specific energy requirements. In order to evaluate the energy performance of different crushing and grinding technologies, the proposed energy benchmarking method was used to compare the energy performance of alternative comminution flowsheets. [ABSTRACT FROM AUTHOR]

Highlights: [•] This paper evaluated the energy use and GHG emissions for forest harvest residues. [•] Two chipping scenarios were compared for power plant sizes from 10 to 300MW. [•] Feedstock transportation to power plant highest energy use and GHG emissions. [•] Chipping at landing used less energy and GHG emissions than chipping at power plant. [•] Results were most sensitive to biomass moisture content and power plant lifetime. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel method to estimate total technical potential for improving energy efficiency. • Bottom-up sector energy model used to characterize energy demands and opportunities. • Technology-explicit analysis framework used to estimate integrated energy savings. • Application to Canada's pulp & paper sector indicates major savings are possible. • Technical potential to reduce natural gas use by 95% and net electricity by 54% Industrial energy efficiency has long been recognized as a critical tool for energy management and emissions reduction and is increasingly considered to be an energy resource in its own right. However, the complexity of most industrial sectors creates barriers for modellers, companies, and policymakers in understanding and achieving the overall potential for efficiency-driven energy savings. To address this gap, we have developed a novel method that combines disaggregated bottom-up sector energy modelling with analysis of a comprehensive set of technology-explicit energy efficiency measures. This approach overcomes the deficiencies of top-down analyses and better represents the complexities of multi-measure efficiency investments compared to piecewise studies of individual measures. In this study, we demonstrated application of our method to the case of the Canadian pulp and paper sector. Our analysis shows that the sector can reduce its natural gas and electricity use by 95% and 41%, respectively, by adopting economical efficiency measures. This equates to 71 PJ of natural gas and 44 PJ of electricity saved annually and would result in cost savings of $81 per tonne of output sector-wide. Notably, we find that efficiency and fuel switching have the technical potential to reduce natural gas consumption by 98% across the sector. Taken together, the results provide quantitative evidence that energy efficiency is an underestimated resource for cost-effective energy savings in the Canadian pulp and paper sector. Our analysis framework can be applied to any industrial sector in any region to provide insights regarding energy conservation strategies and policy design. [ABSTRACT FROM AUTHOR]

[Display omitted] • Renewable energy seems a promising approach to fulfill the future energy demand. • Biochar is an economic, and efficient material for energy production. • It can be utilized for electrode preparation used in MFC. • Biochar is also used as a catalyst for biodiesel and hydrogen production. • Need to work on technology for biochar synthesis with desired properties. Tremendous population growth and industrialization have increased energy consumption unprecedentedly. The depletion of fossil-based energy supplies necessitates the exploration of solar, geothermal, wind, hydrogen, biodiesel, etc. as a clean and renewable energy source. Most of these energy sources are intermittent, while bioelectricity, biodiesel, and biohydrogen can be produced using abundantly available organic wastes regularly. The production of various energy resources requires materials that are costly and affect the applicability at a large scale. Biomass-derived materials (biochar) are getting attention in the field of bioenergy due to their simple method of synthesis, high surface area, porosity, and availability of functional groups for easy modification. Biochar synthesis using various techniques is discussed and their use as an electrode (anodic/cathodic) in a microbial fuel cell (MFC), catalysts in transesterification, and anaerobic digestion for energy production are reviewed. Renewable energy production using biochar would be a sustainable approach to create an energy secure world. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization, and storage (CCUS) has been identified as the only option for substantially reducing greenhouse gas (GHG) emissions from fossil fuel-based processes. There has been limited research into the long-term GHG reduction potential of integrating CCUS into unconventional oil extraction processes. We developed a CCUS-oil sands market penetration model and integrated it with a bottom-up energy model (LEAP-Canada) to conduct a cost-benefit case study for the Canadian oil sands. Scenarios were developed considering currently available CCUS technologies and were investigated under different carbon pricing policies. Cumulative GHG emission mitigation potential from the CCUS applications ranged from 3 to 232 million tonnes (Mt) with marginal costs of $-28–42/tCO 2 e. Carbon pricing led to an average 3% increase in 2050 market shares of the technologies, resulting in additional GHG abatement of 4.9% (172 Mt). CCUS was found to be the costliest GHG emission mitigation option compared to increased integration of cogeneration and energy efficiency measures. The maximum cumulative oil sands GHG emission mitigation achieved in this study was 7%. This research ultimately provides insights into applications of CCUS technologies into the oil sands industry that might be useful to industry planners and policymakers and support the sustainable development of oil sands resources. • A novel bottom-up energy modeling framework for carbon capture in the oil sands. • 7% of industry GHG emissions from 2020 to 2050 could be mitigated at -$16.15/tCO 2 e. • Oxyfuel boilers powered by bituminous fuels provide 90% of mitigation potential. • Carbon pricing policies increased GHG abatement potential by 66 Mt. • Opportunities to utilize captured carbon increased GHG abatement potential by 94 Mt. [ABSTRACT FROM AUTHOR]

Abstract The cement industry is responsible for between 5% and 9% of global greenhouse gas (GHG) emissions. The increasing trend of GHG emissions from cement sector highlights the importance of GHG mitigation in this industry. In the current study, bottom-up energy modelling and scenario analyses were used to assess long-term GHG mitigation potential in the cement industry. The developed comprehensive, data-intensive, and technology-rich model is flexible and can be used to study the GHG mitigation potential in different regions. For the case study of Canada, a reference scenario along with 20 GHG emissions' reduction scenarios were developed in the Long-range Energy Alternative Planning (LEAP) model. For each scenario, cumulative energy saving and GHG reduction potential were analyzed. Furthermore, the net present value, cost of saved energy, and carbon were calculated to assess the economic performance of different scenarios. Carbon abatement cost curves were also developed using the GHG mitigation potential and the cost of implementing different energy efficiency options. Overall, compared to the reference scenario, the cumulative GHG mitigation potentials in the Canadian cement sector are 27 and 59 million tonnes CO 2 eq. by the years 2030 and 2050, respectively. More than 70% of the emissions' reduction is achievable with negative cost. Highlights • A bottom-up and technology-rich model is developed for the cement industry. • Energy consumption demand tree is used to analyze the energy intense sub-processes. • 20 scenarios are developed to assess the long-term energy saving and GHG mitigation. • Carbon abatement cost curves are developed to rank energy saving options. [ABSTRACT FROM AUTHOR]

• Techno-economic and life cycle assessments of energy storage systems were reviewed. • The levelized cost of electricity decreases with increase in storage duration. • Efficiency, lifetime, and duration of discharge influence the final costs and emissions. • A consistent system boundary is crucial for conducting life cycle assessment. • An integrated techno-economic and life cycle assessment model is recommended. Incorporating renewables in the power grid has challenges in terms of the stability, reliability, and acceptable operation of the power system network. One possible solution is to integrate an energy storage system with the power network to manage unpredictable loads. The implementation of an energy storage system depends on the site, the source of electrical energy, and its associated costs and the environmental impacts. Moreover, an up-to-date database with cost numbers, energy use, and resulting emissions is required for decision-making purposes. This paper reviews the techno-economic and environmental assessments of mechanical, electro-chemical, chemical, and thermal to give an update on recent developments and generate a relevant database for costs and emissions. We reviewed 91 publications, 58 on techno-economic assessment and 33 on life cycle assessment. We found that, because of economies of scale, the levelized cost of energy decreases with an increase in storage duration. In addition, performance parameters such as round-trip efficiency, cycle life, and cycle length highly influence the final costs and environmental footprints of various storage technologies. However, further research is required to build a bottom-up model that can handle all the technical parameters to quantify the levelized cost of energy and environmental footprints of the storage systems simultaneously. [ABSTRACT FROM AUTHOR]

Process-level energy efficiency improvement is regarded as an effective technique for emissions reduction from the petroleum refining industry. Assessing the systems-level impacts of these energy efficiency improvements is crucial for effective long-term climate change policy- and decision-making. In this study, we developed a framework that integrates process simulation with integrated resource planning and techno-economic assessment techniques to evaluate long-term GHG mitigation potential in the refining sector. Detailed process simulations were done for eleven energy efficiency improvement measures in the refining sector. A case study was conducted for Alberta's (a province in western Canada) refining sector to assess GHG emissions reduction potential and their implications for long-term climate change policy-making. The GHG mitigation scenarios considered time horizons to the years 2030 and 2050. The results show that compared to the reference scenario, integrating the energy efficiency options in the refining sector will result in cumulative emissions reduction of 5%. About 60% of the anticipated emissions reductions are economically attractive. The proposed framework is an effective tool for the evaluation of long-term refining sector GHG mitigation potential and can be used for decision-making and policy formulation at various levels. • A framework is developed to assess GHG mitigation potential in the refining sector. • Process simulation, economic analysis, and energy planning models are integrated. • 22 mitigation scenarios are developed in time horizons ending in 2030 and 2050. • GHG mitigation potential is calculated and GHG abatement cost curves are developed. • 60% of the GHG emissions reductions are found to be economically attractive. [ABSTRACT FROM AUTHOR]