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Decoupling of production activities and greenhouse gas (GHG) emissions, or a decline in GHG intensity, is a key metric for gauging GHG mitigation performances. In this study, we explore the determinants of GHG intensity in Canadian industries to understand its key drivers. This study is relevant, because Canada is a developed country characterized by high energy and GHG intensities. Canada has also introduced a series of policy measures to mitigate GHG emissions, including a carbon tax and investments in renewable electricity. The most significant factor for GHG intensity is energy intensity. However, fuel mix, policy trends, and sectoral shifts are essential. After conducting stationarity and cointegration tests, we estimated the relationship between GHG intensity and these determinants using panel error correction, dynamic fixed effects, and dynamic OLS methods to determine the long-run relationships. Besides the strong effect of energy intensity, we found that industrial production mix that indicates sectoral shifts, fuel mix, and the time-fixed effects that capture factors such as the introduction of a carbon tax and technology standards have statistically significant impacts on GHG intensity. We found that industries that rely more on fuel sources other than electricity are characterized by higher GHG intensity. The policy implication is that energy efficiency and fuel switching are essential for reducing GHG intensity, but the role of factors such as sectoral shifts should not be ignored. [ABSTRACT FROM AUTHOR]

Firefighters' or instructors' exposure to airborne chemicals during live-fire training may depend on fuels being burned, fuel orientation and participants' location within the structure. This study was designed to evaluate the impact of different control measures on exposure risk to combustion byproducts during fire dynamics training where fuel packages are mounted at or near the ceiling. These measures included substitution of training fuels (low density wood fiberboard, oriented strand board (OSB), pallets, particle board, plywood) and adoption of engineering controls such as changing the location of the instructor and students using the structure. Experiments were conducted for two different training durations: the typical six ventilation cycle (six-cycle) and a shorter three ventilation cycle (three-cycle) with a subset of training fuels. In Part A of this series, we characterized the fire dynamics within the structure, including the ability of each fuel to provide an environment that achieves the training objectives. Here, in Part B, airborne chemical concentrations are reported at the location where fire instructors would typically be operating. We hypothesized that utilizing a training fuel package with solid wood pallets would result in lower concentrations of airborne contaminants at the rear instructor location than wood-based sheet products containing additional resins and/or waxes. In the six-cycle experiments (at the rear instructor location), OSB-fueled fires produced the highest median concentrations of benzene and 1,3 butadiene, plywood-fueled fires produced the highest total polycyclic aromatic hydrocarbon (PAH) concentrations, particle board-fueled fires produced the highest methyl isocyanate concentrations, and pallet-fueled fires produced the highest hydrogen chloride concentrations. All fuels other than particle board produced similarly high levels of formaldehyde at the rear instructor location. The OSB fuel package created the most consistent fire dynamics over six-cycles, while fiberboard resulted in consistent fire dynamics only for the first three cycles. In the follow-on three-cycle experiment, PAH, benzene, and aldehyde concentrations were similar for the OSB and fiberboard-fueled fires. Air sampling did not identify any clear differences between training fires from burning solid wood pallets and those that incorporate wood-based sheet products for this commonly employed fuel arrangement with fuels mounted high in the compartment. However, it was found that exposure can be reduced by moving firefighters and instructors lower in the compartment and/or by moving the instructor in charge of ventilation from the rear of the structure (where highest concentrations were consistently measured) to an outside position. [ABSTRACT FROM AUTHOR]

The use of hydrogen can be a potential solution to reduce high CO and unburnt HC emissions, which is one of the most critical challenges, from Reactivity Controlled Compression Ignition (RCCI) engines at low loads as it is a very clean and carbon-free fuel candidate for internal combustion engines. Therefore, the aim of this study is designed to investigate numerically the effect of the hydrogen share on combustion characteristics in a diesel research engine operated in RCCI mode. The engine is fueled with conventional diesel and iso-octane enriched with hydrogen and is operated at 20% of the maximum torque (low load) and 2400 rpm. A 40% of conventional diesel (in the case of conventional diesel mode (CDM), its share was 100%) is injected per cycle into cylinder of the engine, while varying proportions of iso-octane (60% to 12%) and hydrogen (0% to 48%) are sprayed into the air from the intake manifold. Both CDM and RCCI combustion models built by 3D scanning of the existing engine using reverse engineering to computational fluid dynamic (CFD) was simulated through ANSYS-Forte coupled with a chemical kinetics solver (Chemkin-Pro). The simulation results showed that by adding hydrogen to iso-octane in RCCI mode, the proportion of hydrogen could be increased up to 48% while improving thermal efficiency by 33.3% in comparison with 24.9% with RCCI without hydrogen addition. Therefore, the overall hydrocarbon fuel consumption per cycle was reduced by up to 47.52%. Hydrogen addition resulted in a higher concentration of OH species in the flame front, and higher pressure and temperature in the cylinder, in turn, contributed to an increase in NOx emissions considerably but led to decrease in CO/HC emissions of RCCI operation. The decrease in the emissions of CO, HC, and C2H2 of up to 64.6, 81.8, and 76.6%, respectively, was observed by using 48% of H2 in RCCI mode compared to RCCI mode without hydrogen addition. It was concluded that high CO and unburned HC emissions from RCCI combustion. This research provides promising contributions to the literature for using hydrogen in substitution of hydrocarbon fuels and reducing emissions from RCCI engines. [ABSTRACT FROM AUTHOR]

This study estimates agricultural residue biomass available for biogas generation in smallholder farming systems in the rural Vakinankaratra region of Madagascar, during 2017–2018. Estimations of biomass were done using a combination of agricultural household surveys, literature models, and publicly available data. Manure from four types of farm animals and 17 residue types from ten crops were assessed. In the studied period, gross biomass produced from animal manure and crop residue were 19.4 ± 7.41 and 7.3 ± 1.08 tonnes fresh weight per year per agricultural household, respectively, of which up to 54% and 83% are estimated as recoverable for the production of bioenergy in the studied area, respectively. Estimations indicate that available animal manure and crop residue have the potential to generate 291 ± 92 and 745 ± 122 Nm3 of methane per year per agricultural household respectively, equivalent to 10.5 ± 3.34 and 26.8 ± 4.28 GJ of heat energy from manure and residues, respectively. Theoretically, the average estimated energy potential can result in the complete substitution of domestic fuels in agricultural households. Approximately 0.12 tonnes of nitrogen per household per year can be recovered from the estimated digestate (using all residue types) after energy recovery, which can be employed for crop fertilization. The recovered nitrogen corresponds to 0.26 tonnes urea fertilizer per household per year. The investigation shows that anaerobic digestion based on crop residue and manure has the potential to meet a significant portion of energy needs of smallholder farmers in the Vakinankaratra region of Madagascar and can make an important contribution to providing fertilizer for on-farm use. [ABSTRACT FROM AUTHOR]

The electrical power of a thermionic reactor-converter is determined by various parameters of the thermionic fuel element and reactor core, as well as by the formation of the electrical branch that connects thermionic fuel elements according to various criteria. The formation of electric branches is possible in various ways. The number of branches is determined by the specified characteristics of the thermionic fuel element and the required electrical power. In this case, the thermionic fuel elements are connected electrically in series to the branches, and the branches themselves are connected in parallel. The selection of the electrical branch in the core of the reactor is based on the characteristics of each thermionic fuel element. In this article, we evaluate the characteristics of the thermionic reactor-converter with various options for switching thermionic fuel elements. [ABSTRACT FROM AUTHOR]

Cumulative emissions budgets are increasingly being used by decision-makers and analysts to understand emissions reductions and associated transitions in the context of long-term goals such as limiting global mean temperature increase over the century to 1.5 or 2 °C. While previous studies have explored the implications of such budgets for the global economy, few studies have conducted regional- and national-level analyses. This paper explores budgets through 2050 consistent with the 1.5 and 2 °C long-term temperature goals in the context of the USA. We employ a state-level model of the USA embedded within a global human-Earth system model (GCAM-USA) to study the implications of such budgets for the US energy system. Our results show that achieving the stringent budgets entails accelerated deployment of energy conserving technology, almost complete decarbonization of the power sector, increased electrification of buildings and industrial end-use sectors, and decarbonization of transport employing a combination of electrification and the substitution of fossil fuels for bioenergy. We also find substantial state-level differences in the relative roles of these decarbonization strategies. Furthermore, our results highlight that increased ambition in the near term will be valuable in setting the stage for smoother transformations in the future to achieve stringent budgets. [ABSTRACT FROM AUTHOR]

The effect of natural gas compositions on the thermodynamic performance characteristics of the single-shaft gas turbine cycle is analyzed in this study. The fuel characteristics are signified by H/C ratio and heating value, then the system are analyzed, and the full off-design analysis is performed by using TIT, TET, and power control. As the heating value of natural gas decreases, power output increases due to the increased mass flow passing through the turbine for all control methods. Additionally, regardless of the control method, the compressor surge margin is reduced and the turbine blade temperature is raised, making the gas turbine operation extremely vulnerable. Most parameters are sensitively affected by the HC ratio of fuel with TIT control. When the power control is used, gas turbine efficiency is reduced due to the increased operation of the compressor. The results are expressed by polynomial equations relative to each design value. In terms of the performance curves of the gas turbine cycle, the trends of most parameters accord with high H/C ratio and low heating value. [ABSTRACT FROM AUTHOR]

The aim of the present work to investigate the performance of oil derived from the waste plastic on diesel engine. Waste plastic fuel (WPF) is derived from the waste plastics by catalytic pyrolysis. Test were employed to completely characterize the Fuel by determining the physical, chemical and spectroscopic like FTIR, GC-MS properties of WPF and WPF-diesel blends in different proportions and to evaluate the performance and emission characteristics of these fuel and their blends on a single cylinder diesel engine and finally the results were compared with reference test fuel diesel. It is observed that the engine can operate with neat WPF and their blends without any modification and can be used as an alternative fuel for diesel engine. However, it is found that WPF10D90 (10% waste plastic oil and 90% diesel fuel) shows similar results as compare to diesel. [ABSTRACT FROM AUTHOR]

Due to the shortage of petroleum products and its increasing cost, efforts are on to develop alternate fuels, especially diesel oil, for partial or full replacement. Also, internal combustion engines generate undesirable emissions during combustion process. The emissions exhausted in to the surroundings pollute the atmosphere and causes several problems. The emissions of concern are: unburnt hydrocarbons, oxides of carbon, and oxides of nitrogen (NO X). Advanced diesel fuel formulations offer significant emission reductions to new and older in-use engines every time the fuel tank is filled. The addition of water to diesel fuel lowers particulate emissions by serving as diluents to the key combustion intermediates that lead to particulate formation. The incorporation of water also reduces NO X emissions by lowering the peak combustion temperatures through high heat of vaporization. When using water blend diesel, the engine fuel system recognizes the liquid as diesel fuel because the water droplet is encapsulated within a diesel fuel. In this experiment, we have used single cylinder four-stroke engine and the water-blend diesel emulsion is used and the diesel emission test, emulsion emission test, and various gases has been analyzed; smoke meter test is also conducted for various rate of loads. The test results from the engine fuelled with water-blend diesel showed reduction in emissions as compared to that of engine fuelled with conventional diesel. The better emissions in the CI engine using water-blend diesel is due to the incorporation of water which reduces NO X emissions by lowering the peak combustion temperatures. Water-blend fuel enhances fuel atomization by micro-explosion. The addition of water to diesel fuel lowers particulate emissions by serving as diluents to the key combustion intermediates that lead to particulate formation [ABSTRACT FROM AUTHOR]

Abstract  Biomass has gained prominence in the last few years as one of the most important renewable energy sources. In Brazil, a sugarcane ethanol program called ProAlcohol was designed to supply the liquid gasoline substitution and has been running for the last 30 yr. The federal government’s establishment of ProAlcohol in 1975 created the grounds for the development of a sugarcane industry that currently is one of the most efficient systems for the conversion of photosynthate into different forms of energy. Improvement of industrial processes along with strong sugarcane breeding programs brought technologies that currently support a cropland of 7 million hectares of sugarcane with an average yield of 75 tons/ha. From the beginning of ProAlcohol to the present time, ethanol yield has grown from 2,500 to around 7,000 l/ha. New technologies for energy production from crushed sugarcane stalk are currently supplying 15% of the electricity needs of the country. Projections show that sugarcane could supply over 30% of Brazil’s energy needs by 2020. In this review, we briefly describe some historic facts of the ethanol industry, the role of sugarcane breeding, and the prospects of sugarcane biotechnology [ABSTRACT FROM AUTHOR]

Activities to reduce net greenhouse gas emissions by biological soil or forest carbon sequestration predominantly utilize currently known, readily implementable technologies. Many other greenhouse gas emission reduction options require future technological development or must wait for turnover of capital stock. Carbon sequestration options in soils and forests, while ready to go now, generally have a finite life, allowing use until other strategies are developed. This paper reports on an investigation of the competitiveness of biological carbon sequestration from a dynamic and multiple strategy viewpoint. Key factors affecting the competitiveness of terrestrial mitigation options are land availability and cost effectiveness relative to other options including CO2 capture and storage, energy efficiency improvements, fuel switching, and non-CO2 greenhouse gas emission reductions. The analysis results show that, at lower CO2 prices and in the near term, soil carbon and other agricultural/forestry options can be important bridges to the future, initially providing a substantial portion of attainable reductions in net greenhouse gas emissions, but with a limited role in later years. At higher CO2 prices, afforestation and biofuels are more dominant among terrestrial options to offset greenhouse gas emissions. But in the longer run, allowing for capital stock turnover, options to reduce greenhouse gas emissions from the energy system and biofuels provide an increasing share of potential reductions in total US greenhouse gas emissions. [ABSTRACT FROM AUTHOR]