Megajoule Research Articles

Reduction of CO2 emissions through the co-combustion of lignite with biomass residues: Renewable and non-renewable CO2 per produced megajoule and fuel characterization

Accumulation of unmanaged agricultural wastes is related to increased environmental concern, as they usually are left unexploited and/or burned uncontrolled in the fields. The reduction/utilization of these wastes by turning them into solid biofuels for energy production is a viable solution for addressing the related environmental issues. In this study, twelve alternative solid biofuels of biomass residues and lignite (sunflower husk - BSH, stem, disk florets and seeds biodiesel sunflower wastes -BSW, corn husk -HKC, corn stalk and husk -SHC) were mixed with lignite in several proportions and assessed by using energy content analysis, proximate analysis, and ultimate analysis. Empirical chemical formulas were also determined. Furthermore, it introduces a novel concept to separate and quantify the renewable CO2 emissions, from the non-renewable emissions resulting from biomass co-combustion with lignite (alternative solid composite biofuels). The renewable and non-renewable CO2 emissions were expressed per produced megajoule (MJ) and per kilogram (Kg). The non-renewable CO2 emissions per produced MJ of the blends were compared to lignite emissions. The results showed that blends with 70 wt%, 50 wt% and 30 wt% biomass in blend could reduce about 75 %, 57 % and 34 % the non-renewable CO2 emissions per produced MJ, respectively. The present work suggests that blends of agricultural residues with lignite not only could be used as alternative solid biofuels (with better combustion characteristics than lignite sample, e.g. better energy content, less ash content, less Sulphur content, and similar Nitrogen content), but also could help to reduce carbon emissions via the co-combustion process.

Effect of different feeding strategies and dietary fiber levels on energy and protein retention in gestating sows.

The aim of the study was to investigate whether increased inclusion of sugar beet pulp (SBP) alters retention of fat, protein, and energy when backfat (BF) is restored in early- and mid-gestation. In total, 46 sows were fed one of four dietary treatments with increasing inclusion of SBP providing dietary fiber (DF) levels of 119, 152, 185, and 217g/kg; sows were assigned to one of three feeding strategies (FS; high, medium, and low) depending on BF thickness at mating and again at day 30 for the following month. On days 0, 30, 60, and 108, body weight (BW) and BF thickness were measured and body pools of protein and fat were estimated using the deuterium oxidetechnique. On days 30 and 60, urine, feces, and blood samples were collected to quantify metabolites, energy, and nitrogen (N) balances. On days 15 and 45, heart rate was recorded to estimate heat energy. At farrowing, total born and weight of the litter were recorded. In early gestation, BW gain (P < 0.01) and body protein retention increased (P < 0.05) with increasing fiber inclusion, while body fat retention increased numerically by 59%. The increase in BF was greatest for sows fed the high FS, intermediate when fed the medium strategy, and negligible for sows fed the lowest FS (P < 0.001). Nitrogen intake, N loss in feces, and N balance increased linearly, whereas N loss in urine tended to decrease with increasing inclusion of fibers in early gestation. Concomitantly, fecal energy output and energy lost as methane increased linearly (P < 0.001), while energy output in urine declined linearly. Total metabolizable energy (ME) intake therefore increased from 36.5 MJ ME/d in the low fiber group to 38.5 MJ ME/d in the high fiber group (P < 0.01). Changing the ME towards more ketogenic energy was expected to favor fat retention rather than protein retention. However, due to increased intake of ME and increased N efficiency with increasing fiber inclusion, the sows gained more weight and protein with increasing fiber inclusion. In conclusion, increased feed intake improved both fat and protein retention, whereas increased DF intake increased protein retention.

Bireysel Derin Kuyu Sulama İşletmesinde Enerji Kullanımı ve Sera Gazı Emisyonunun Belirlenmesi

This study was conducted to determine the annual energy use and related greenhouse gas (GHG) emissions of individual deep well irrigation enterprise. That study was conducted at deep well farm belonging to one farmer with volunteer preforming farming activities in Konya-Meram-Çarıklar location for the growing season of 2021. In that regard, the activities using alfalfa and dry bean production, and total production inputs with their amounts as well as crop yields were determined separately. By considering unit energy equivalent values and GHG emission factors of each input, annual energy consumption and GHG emission values were calculated. Similarly, by examining energy content and crop yield in accordance of crop production unit (kg), annual produced energy amount was calculated. The evaluation was made using energy used and energy produced as well as GHG emission values indicators at individual deep well irrigation farm. According to the results obtained, annual energy use and energy production were calculated 253035 mega-joule (MJ), and 487960 MJ, respectively for individual well irrigation farm. The electricity used during the irrigation processes resulted around 71% of annual energy consumption. The annual GHG emission amount as an equivalent to the carbon dioxide (CO2eqv) for research farm with GWI was determined as 18575 kg (18575 kgCO2eqv year-1). Almost 52% of annual GHG emission was resulted from electricity used in irrigation.

Life Cycle GHG Perspective on U.S. Natural Gas Delivery Pathways.

Recent emission measurement campaigns have improved our understanding of the total greenhouse gas (GHG) emissions across the natural gas supply chain, the individual components that contribute to these emissions, and how these emissions vary geographically. However, our current understanding of natural gas supply chain emissions does not account for the linkages between specific production basins and consumers. This work provides a detailed life cycle perspective on how GHG emissions vary according to where natural gas is produced and where it is delivered. This is accomplished by disaggregating transmission and distribution infrastructure into six regions, balancing natural gas supply and demand locations to infer the likely pathways between production and delivery, and incorporating new data on distribution meters. The average transmission distance for U.S. natural gas is 815 km but ranges from 45 to 3000 km across estimated production-to-delivery pairings. In terms of 100-year global warming potentials, the delivery of one megajoule (MJ) of natural gas to the Pacific region has the highest mean life cycle GHG emissions (13.0 g CO2e/MJ) and the delivery of natural gas to the Northeast U.S. has the lowest mean life cycle GHG emissions (8.1 g CO2e/MJ). The cradle-to-delivery scenarios developed in this work show that a national average does not adequately represent the upstream GHG emission intensity for natural gas from a specific basin or delivered to a specific consumer.

Microalgae biomass production from cultivation in availability and limitation of nutrients: The technical, environmental and economic performance

Microalgae cultivation offers the potential to produce different biomass compositions while preventing pollution, treating waste and recovering resources. However, the energy, environmental and economic performance of the production of microalgae biomass should be advantageous compared to that of conventional biomass sources. The goal of this research was to quantify the performance of energy demand, carbon footprint and financial cost of microalgae biomass production in cultivation with availability and limitation of nutrients. The product system is composed of microalgae cultivation in open raceway ponds with carbon dioxide injection and harvesting with settling, filtration and centrifugation. The average annual biomass productivity in the cultivation was 18 g (m2 day)−1 in the base scenarios with availability (S1) and limitation (S2) of nitrogen and phosphorus, which was changed to 8.5 g (m2 day)−1 in S1LOWER and S2 LOWER and 25 g (m2 day)−1 in S1HIGHER and S2HIGHER. The methods used in this study were attributional life cycle assessment (LCA) for energy demand (Cumulative Energy Demand – CED) in Megajoule (MJ) and carbon footprint (IPCC-2021, Global Warming Potential 100 years) in kilogram of carbon dioxide equivalent (kg CO2eq) and techno-economic analysis (TEA) for financial cost in United States dollar (USD). The energy demand, carbon footprint and financial cost, respectively, in S1 were 10 MJ kg−1, 0.48 kg CO2eq kg−1 and 0.59 USD kg−1 for a dewatered biomass in total solids, while those varied by: +30%, +24% and +72% in S1LOWER; −11%, −8.9% and −19% in S1HIGHER; −38%, −46% and −15% in S2; −6.1%, −20% and +62% in S2LOWER; and −50%, −56% and −36% in S2HIGHER compared to S1. The largest contribution of energy demand and carbon footprint, respectively, in S1 was the fertilizer supply (52% and 61%), while in S2 it was the electricity supply (51% and 48%). The use of residual N and P and photovoltaic electricity supply were considered in the sensitivity analysis, which showed a potential to reduce up to 61% in energy demand, 84% in carbon footprint and 37% in financial cost compared to S1. Therefore, limiting nutrients and using nutrients from residual sources in cultivation along with providing electricity from a cleaner and affordable source are strategies for commodity production from microalgae biomass.

Environmental, Energy, and Water Footprints of Marble Tile Production Chain in a Life Cycle Perspective

The marble industry is growing in Pakistan, and Khyber Pakhtunkhwa province is the largest producer of marble tiles in Pakistan. Marble production consumes a considerable amount of water during its life cycle stages and impacts various environmental compartments, such as air, water, and soil; therefore, this study aimed to quantify the environmental impacts, water footprint, and cumulative energy demand of one-tonne marble tile manufactured in a small industrial estate Mardan (SIEM), Pakistan, and provide recommendations to improve its environmental impact profile. The study covers water consumption, energy use, and associated environmental impacts of raw materials and processes through different stages of the marble life-cycle during 2017–2018. The cradle-to-gate (extraction to factory gate or store house) life cycle assessment approach was followed in this study. The functional unit for the current study was one tonne of finished marble tile produced. Primary data from the field surveys and secondary data were modeled using the water scarcity index (WSI), CML 2000 v.2.05 methodology, and the cumulative energy demand indicator present by default in SimaPro v.8.3 software. The total water footprint required for one tonne of finished marble tile was 3.62 cubic meters per tonne (m3/t), with electricity consumed at processing units contributing to environmental burdens the most. Similarly, electricity consumed (at processing units and during polishing) and transportation of finished marble tile to the local market were responsible for global warming potential (388 kg CO2 eq/tonne tile), human toxicity (84.34 kg 1,4-DB-eq/tonne), freshwater aquatic ecotoxicity (94.97kg 1,4-DB eq/tonne) and abiotic depletion (7.1 × 10−5 kg Sb eq/tonne). The results of our study follow other marble tile LCA studies conducted globally (such as in Turkey and Italy), which also reported a high contribution to GWP, AP, EP, and HT due to electricity and fossil fuels consumption. The total cumulative energy demand (CED) was calculated as 5863.40 MJ (Mega Joule), with most energy usage associated with non-renewable fossil fuel sources. The results indicated that reducing electricity (using standard automatic machinery) and waste materials, especially paper and plastic wastes, can reduce environmental impacts. Most of the surveyed industrial units did not have wastewater treatment and recycling plants, and wastewater directly flows to nearby freshwater bodies and terrestrial ecosystems. These wastewaters should be adequately treated before being discharged into freshwater aquatic bodies. Environmental impacts must be improved by using the latest automatic machinery, reducing waste materials generation, reducing the distance between processing units and the market, and installing wastewater recycling plants.

Increased feed supply and dietary fiber from sugar beet pulp improved energy retention in gestating sows.

The aim of the study was to investigate whether increased inclusion of sugar beet pulp (SBP) alters retention of fat, protein, and energy when backfat (BF) is restored in early- and mid-gestation. In total, 46 sows were fed one of four treatments with increasing inclusion of SBP with dietary fiber (DF) levels of 119, 152, 185, and 217g/kg; sows were assigned to one of three feeding strategies (FS; high, medium, and low) depending on BF thickness at mating and again at day 30 for the following month. On days 0, 30, 60, and 108, body weight (BW) and BF thickness were measured, and body pools of protein and fat were estimated using the deuterium technique. On days 30 and 60, urine, feces, and blood samples were collected to quantify metabolites, energy, and N balances. On days 15 and 45, heart rates were recorded to estimate the heat production. At farrowing, total born and weight of the litter were recorded. In early gestation, BW gain (P < 0.01) and body protein retention increased (P < 0.05) with increasing fiber inclusion, while body fat retention increased numerically by 59%. Increase in BF was the greatest for sows fed the high FS, intermediate when fed the medium strategy, and negligible for sows fed the lowest FS. N intake, N loss in feces, and N balance increased linearly, whereas N loss in urine tended to decrease with increasing inclusion of fibers in early gestation. Concomitantly, fecal energy output and energy lost as methane increased linearly (P < 0.001), while energy output in urine declined linearly, and total metabolizable energy intake, therefore, increased from 40.5 MJ ME/d in the low-fiber group to 43.5 mega joule (MJ) metabolizable energy (ME)/d in the high-fiber group (P < 0.001). Changing the metabolizable energy toward more ketogenic energy was expected to favor fat retention rather than protein retention. However, due to increased intake of metabolizable energy and increased N efficiency with increasing fiber inclusion, the sows gained more weight and protein with increasing fiber inclusion. In conclusion, increased feed intake improved both fat and protein retention, whereas increased DF concentration increased protein retention.

Waste management planning toward zero waste in Hotel XYZ Bandung with circular economy principles (case study: room service facility’s solid waste)

Hotel XYZ is a commercial area in the city of Bandung which still applies the traditional linear economic cycle. The 61.61% of ±9000 m2 building area is used for room service facilities. The hotel has not paid attention to its waste management so all the waste generated from this hotel end up at the landfill area. This study aims at improving the waste management in Hotel XYZ to meet the principle of circular economy. Using SNI 19-3964-1994 approach to measure the generation of waste composition, the amount of waste generated from room service facilities is 0.03 kg/m2/day or 0.41 liter/m2/day. The zero waste index (ZWI) calculation was used for the evaluation of waste management in the hotel. The waste generated at Hotel XYZ has the potential to achieve substitute material savings by 63.16 kg, substitution of energy by 775.79 MegaJoule (MJ), greenhouse gas (GHG) reduction by 49.36 kg/CO2e, -164.06 L/kg of water saving. The most waste generated by hotel room service facilities is recyclable waste consisting of single-use packaging from hotel equipments. Waste reduction plan for the room service facilities is carried out by replacing single-use packaging with refillable packaging so the hotel is able to save their shopping expenditure costs up to Rp. 844,691.00 per day.

Substitution strategies for cooking energy: To use gas or electricity?

The Chinese government has called for clean and effective energy substitution for cooking in rural areas. This paper assesses the environmental and economic impacts of various types of cooking fuels and stoves. According to the assessment results, the environmental impacts are highly influenced by the types of fuels and the efficiency of stoves used for cooking. Using biogas, liquefied petroleum gas (LPG), and natural gas for cooking instead of solid fuels can significantly reduce environmental emissions. To provide 1 megajoule (MJ) of useful cooking heat, the environmental costs of lump coal, honeycomb briquettes, and straw are the largest, estimated to be 80.4 yuan/MJ, 73.1 yuan/MJ, and 71.4 yuan/MJ, respectively. In addition, the economic assessment results show that the most expensive source of cooking fuel is LPG, with an average annual cost of 1700 yuan, while the cost of straw and firewood is the cheapest, at less than 100 yuan. The average annual cost of electricity is higher than that of natural gas. Regarding the substitution effects, using natural gas for cooking is better than using electricity. The environmental benefit of electricity substitution is only 10%–20% of natural gas substitution, and the corresponding increasing cost for residents is 1.5 times that of natural gas substitution.

Flywheel energy storage systems: A critical review on technologies, applications, and future prospects

Energy storage systems (ESSs) are the technologies that have driven our society to an extent where the management of the electrical network is easily feasible. The balance in supply-demand, stability, voltage and frequency lag control, and improvement in power quality are the significant attributes that fascinate the world toward the ESS technology. However, being one of the oldest ESS, the flywheel ESS (FESS) has acquired the tendency to raise itself among others being eco-friendly and storing energy up to megajoule (MJ). Along with these, FESS also surpasses the quality of high power density, longer life cycle, higher rate of charge and discharge cycle, and greater efficiency. In this article, an overview of the FESS has been discussed concerning its background theory, structure with its associated components, characteristics, applications, cost model, control approach, stability enhancement, maintenance, and future trends. The FESS structure is described in detail, along with its major components and their different types. Further, its characteristics that help in improving the electrical network are explained. The applications of the FESS have also been illustrated through their economically available prototypes. The economics associated with FESS technology has been projected. A thorough survey of various control strategies of FESS highlighting the merits and demerits of each has been discussed in depth. The stability enhancement and maintenance of the FESS unit have also been enumerated. Further, the article also recommends numerous future work that plays a vital role in the hassle-free operation of FESS for the efficient functioning of the electrical power system.

Energy efficiency in maize crops in different regions of Brazil

Assessment of energy efficiency (EE) enables the evaluation of the sustainability of agrosystems, as well as decision-making regarding reduction in production costs and environmental pollution and even to increase production in a sustainable way. In this context, the objective of this study was to assess energy efficiency in maize in different regions of Brazil. For this purpose, 32 areas of maize crop distributed across the major producing states and regions were assessed. Energy inputs and outputs of agricultural operations and/or agricultural inputs were calculated by multiplying the amount used by their calorific value or energy coefficient at each stage of production. Energy efficiency was calculated as the ratio between the total output energy and the total input energy during the production process. For every megajoule (MJ) of energy consumed in the production of second-crop maize and first-crop maize seasons, 9.9 and 8.7 MJ respectively of renewable energy were produced in the form of grain. In both maize cropping seasons, most of the energy use was attributed to fertilizers, herbicides and fuel. To be representative the evaluation of energy efficiency of the maize crop should be performed in different Brazilian cultivation regions, as it will represent different edaphoclimatic and management conditions spread over the national territory within an agricultural year.

Environmental impact assessment for ornamental plant greenhouse: Life cycle assessment approach for primrose production

Improving the environmental impact is a critical factor in achieving sustainable development in agricultural systems. To achieve this goal, the environmental assessment of agricultural products to identify environmental hot-spots and provide strategies for reducing them is essential. In line with that, the current study is performed to assess the environmental impacts of Primrose greenhouse production in Savojbolagh County, Iran. More specifically, the environmental impacts of Primrose greenhouse production based on the cradle to gate analysis using the life cycle assessment approach are evaluated. According to results, production and combustion of diesel fuel are introduced as the environmental hotspot in non-carcinogens, respiratory inorganics, respiratory organics, terrestrial acid/nutri, aquatic acidification, global warming, and non-renewable energy impact categories. The application of pesticides and fertilizers in the greenhouse has the highest contribution in aquatic ecotoxicity as well as terrestrial ecotoxicity impact categories. Moreover, electricity consumption has the highest impact on carcinogens, and ozone layer depletion impact categories. Based on the outcomes of the life cycle assessment approach, the production of a piece of Primrose leads to damages of 1.48 × 10−7 DALY (disability-adjusted life year) and 3.41 × 10−1 PDF.m−2.yr−1 (potentially disappeared fraction in square-meters per year) to human health and ecosystem quality, respectively. In addition, the production of each Primrose plant results in primary damages of 2.06 × 10−1 kg CO2eq. (equivalent carbon dioxide) and 2.94 MJ (Megajoule) to climate change and resources, respectively. Finally, the weighing of environmental impacts based on IMPACT 2002+ methods shows that the ecosystem quality damage category has a share of 30% in total environmental impacts of one piece of Primrose production. Damages to ecosystem quality are mostly caused by pesticide and fertilizer applications in Primrose greenhouse. Accordingly, it could be concluded that correct management of pesticides and fertilizers can potentially mitigate environmental impacts of Primrose production in a greenhouse.

Intake of whole grain and associations with lifestyle and demographics: a cross-sectional study based on the Danish Diet, Cancer and Health-Next Generations cohort.

The aim was to analyze the intake of whole grain (WG) and associations with lifestyle and demographics in a newly established cohort of Danish adults. Between 2015 and 2019, Danes were enrolled into The Diet, Cancer and Health-Next Generations cohort. A total of 38,553 persons were included in the current cross-sectional study, where all completed a 376-item food frequency questionnaire, a lifestyle questionnaire, and a physical examination in a study center where physical measurements and biological samples were collected. The median intake of WG was 79g/10 mega joule (MJ) and 54% of the participants consumed the amount of WG recommended in Denmark, which is 75g/10MJ. The probability of consuming the recommended amount of WG was highest among men, persons < 30years, students, persons with body mass index (BMI) < 25kg/m2, persons participating in sports, who did not exceed the recommended maximum intake of alcohol and did not smoke. The probability of having a low intake of WG defined as < 25g/10MJ was highest among persons with short education, BMI ≥ 25kg/m2, persons not participating in sports, persons having an alcohol intake above the recommended maximum level and persons being active smokers. The median intake of WG was 79g/10MJ. The probability of consuming at least 75g WG/10MJ was highest among persons who also adhered to healthy lifestyle measured by other factors. Only 6% of the cohort participants consumed < 25g WG/10MJ, these persons were more likely to have a general less healthy lifestyle.

Hydrogen enhanced biofuels for transport via fast pyrolysis of biomass: A conceptual assessment

The potential to increase biofuel output from a fast pyrolysis-based biorefinery through hydrogen enhancement is assessed for thermal fast pyrolysis (TFP) and catalytic pyrolysis (CAT) processes featuring bio-oil upgrade into gasoline, diesel and heavy hydrocarbon fractions. Results show that utilizing pyrolysis process off-gases to produce synthetic natural gas with an external hydrogen source could provide up to 48.2% (TFP) and 61.2% (CAT) reductions in biomass resource utilization. These savings are enabled by significantly improved carbon efficiency of the hydrogen enhanced designs, with efficiencies increasing from 40.5% to 66.3% for TFP and from 28.9% to 58.6% for CAT. Although the CAT process has a lower biofuel yield than the TFP process, it has a higher potential for hydrogen enhancement and achieves a higher biofuel output than TFP when fully enhanced with external hydrogen. The trade-off to the improved biofuel yield (higher carbon efficiency) is the substantial need for electricity to produce hydrogen via electrolysis, as for every megajoule (MJ) of biomass feedstock, 0.65–0.66 MJ of electricity is needed for the electrolyser.

Comprehensive Environmental Impacts and Optimization of Onshore Shale Gas Development and Delivery

The environmental impact of shale gas hydraulic fracturing is not completely understood. Therefore, the objective of this paper is to estimate the lifecycle environmental impact of shale gas production per mega joule (MJ) of energy extracted and delivered. The analysis is based on using CML 2001‐Apr 2015 methods in GaBi software on a case study of a shale gas well. The global warming potential (GWP100) ranges from 54 to 99 g CO2e /MJ with a central estimate of 72 g CO2e /MJ. The GWP 100, including land use change, is 230 g CO2e /MJ. The best‐case scenario, with no venting of the gas, has the minimum GWP 100 impact. Shale gas has a high marine ecotoxicity potential, among other environmental impacts. Bentonite contributes the most to the abiotic depletion potential elements impact. The frac water contributes the most to the freshwater aquatic ecotoxicity potential (FAETP) impact. Mercury (Hg) and radioactive elements (e.g., radon) are the major pollutants contributing to the terrestrial ecotoxicity potential impacts. The findings of this study can be used for optimization of the processes used by mining and exploration companies.

Life-cycle green-house gas emissions of onshore and offshore wind turbines

Onshore and offshore wind turbines may have different environmental sustainability due to their own characteristics, and this information is important for future growth of wind power. The paper uses life cycle assessment (LCA) to estimate the life-cycle greenhouse gas (GHG) emissions of onshore and offshore wind turbines with the nominal capacity of 2 MW, to advance our understanding of onshore and offshore wind energy and to inform policy, planning, and investment decisions for future growth of wind power. Results show that the life-cycle GHG emission intensity is 0.082 kg CO2-equivalent (eq)/Megajoule (MJ) for onshore wind turbine and is 0.130 kg CO2-eq/MJ for offshore wind turbine, respectively. Offshore wind turbine has larger life-cycle GHG emissions than onshore wind turbine, owing to the floating platform fixed in sea. Onshore and offshore wind turbines have much smaller life-cycle GHG emission intensity than coal power plants. If the installed wind turbines in 2014 displace coal, the saved GHG emissions can roughly reach 5.08 × 107 t CO2-eq, accounting for 0.09% of global GHG emissions in 2012. The sensitive analysis shows that the lifetime and energy production of wind turbine have large influences on the GHG emission intensity of both onshore and offshore wind turbines, implying that it is an effective way to prolong the lifetime of wind turbine and increase the energy production of wind turbine to reduce the GHG emission intensity of wind turbine. The sensitivity analysis further shows that the distance from wind turbine factory to wind farm site has more significant influence on the life-cycle GHG emission intensities of both onshore and offshore wind turbines than that from wind farm site to the recycling and landfill locations, suggesting that the wind farm site and the wind turbine factory should be as close as possible.

Carbon footprint and embodied energy assessment of roof-covering materials

The residential building sector regularly satisfies a diverse range of housing needs whilst addressing respective capital-cost considerations. Designers and builders must also be aware of the environmental implications of their design specifications; the work here adds to a body of knowledge concerned with carbon footprint and embodied energy demand, specifically through an examination of alternative roof-covering materials. A life cycle assessment (LCA) has been carried out, within a West Australian context, to compare impacts for the roof specification options of: clay tile; concrete tile; and sheet metal. In locations where recycling facilities are unavailable and thus disregarded, it is found that clay tiles have the lowest carbon footprint of 4.4 t of CO2 equivalent (CO2e-) and embodied energy demand of 52.7 Mega Joule (MJ) per 100 m2, while sheet-metal roofing has the highest carbon footprint (9.85 t of CO2e-), with concrete roof tiles having the highest embodied energy demand (83 MJ). Findings confirm that a sheet-metal roof can obtain significant carbon and embodied energy saving benefits (i.e. 71–73%) compared to clay tile or concrete roof covers through ongoing encouragement of recycling strategies and increased local recycling facilities able to embrace residual cradle-to-cradle material reuse.

The Decreasing Trend in Dietary Glycaemic Index and Glycaemic Load in Australian Children and Adolescents between 1995 and 2012.

This study aims to examine whether there were changes between 1995–2012 in the dietary glycaemic index (dGI) and glycaemic load (dGL) in Australian children (<16 years) according to three national surveys in 1995 (1995NS), 2007 (2007NS), and 2011–2012 (2012NS). Glycaemic index (GI) values of foods were assigned using published methodology. Plausible 24-h recall data from the 1995NS, 2007NS and 2012NS (weighted n = 2475, 4373 and 1691 respectively) were compared for differences in dGI and dGL, and the contribution to dGL from different foods using one-way ANOVA with Bonferroni post hoc comparisons and linear regression. Decreasing trends across surveys were found in dGI and dGL (p < 0.001). Between 1995 and 2012, dGI and dGL per Megajoule (MJ) dropped by 2% and 6% respectively. The per capita dGL contribution from breads and bread rolls, fruit and vegetable juices, sweetened beverages and potatoes showed strong decreasing trends (R2 > 0.7). Our findings suggest that dGI and dGL of Australian youths declined between 1995 to 2012, which may be due to increased awareness of the GI concept and healthy diet, widened food choices and immigrants with diverse dietary habits. This may lower the future risks of chronic degenerative diseases in Australian youths.

Biofuel and Biochemical Analysis of Amphora coffeaeformis RR03, a Novel Marine Diatom, Cultivated in an Open Raceway Pond

(1) Background: To increase the biochemical productivity and to reduce the production cost of microalgal biodiesel, this study aimed to investigate the effects of CO2 on biomass, fatty acids, carbon-hydrogen, and biochemical accumulation of the marine diatom, Amphora coffeaeformis RR03 (A. coffeaeformis) RR03. (2) Methods: Fatty acid composition of the dry biomass of A. coffeaeformis RR03 was analysed using Gas chromatography-mass spectrometry (GC-MS). (3) Results: The results showed that A. coffeaeformis RR03 contained high biomass productivity and biochemical composition in different cultivation conditions. A. coffeaeformis RR03 showed maximum growth of 5.2 × 106/mL on 21st day cultivation under CO2 supply. The bio-crude oil production from A. coffeaeformis RR03 was 36.19 megajoule (MJ). GC-MS analysis found that the dry biomass of A. coffeaeformis RR03 contained maximum of 47.72% fatty acids of 16-octadecanoic acid methyl ester (10:12) and 19.58% pentadecanoic acid, 13-methyl-, and methyl ester (9.24). (4) Conclusion: The results of this study may suggest that a novel diatom of A. coffeaeformis RR03 could be a suitable candidate for biocrude production in order to meet the future demand of energy.

Greenhouse gas emissions of electricity and biomethane produced using the Biogasdoneright™ system: four case studies from Italy

AbstractWe reported previously on the Biogasdoneright™ system for on‐farm biogas production. This innovative system employs sequential (year‐round) cropping to produce both food and energy from agricultural biomass, primarily cellulosic materials. This paper uses a marginal analysis approach to estimate the life cycle greenhouse gas emissions (GHGs) of electricity and biomethane produced by four currently operating Italian biogas plants that process various agricultural feedstocks, residues, and by‐products. The biogas is burned on‐farm to generate electricity that is then exported to the grid. The marginal lifecycle GHGs of this farm‐produced electricity range from ‐335 to 25 grams CO2 per kilowatt hour (kWh). By comparison, the marginal GHGs of electricity generated by fossil fuels in the European Union (EU) is 752 grams CO2 per kWh. The biogas might also be upgraded to produce pipeline‐quality biomethane, a direct substitute for natural gas. The marginal lifecycle GHGs of biomethane potentially produced from the Biogasdoneright™ plants range from 10 to ‐36 grams CO2 per megajoule (MJ) while the corresponding figure for a conventional biogas plant is 27 grams CO2 per MJ. Natural gas in the EU produces 72 grams CO2 per MJ and marginal fossil fuel in the EU generates 115 grams CO2 per MJ. Negative GHG emissions arise largely from avoided emissions of agricultural effluents and residues. © 2017 Society of Chemical Industry and John Wiley &amp; Sons, Ltd