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Management of natural resources is pivotal for sustained economic growth—the increasing ecological footprints causing biocapacity deficit threaten the resource conversation agenda. The study identified the potential causes and consequences of natural resource depletion in a broad cross-section of 138 countries. Ecological footprints, international migrant stocks, industrial value-added, and population growth influenced natural resource capital across countries. The results show that ecological footprints, industrial value-added, and population growth are the detrimental factors of resource capital. In contrast, continued economic growth is helpful to conserve natural resources for future generations. The rise and fall in the natural resource degradation are evident in the wake of international migrants’ stocks to support an inverted U-shaped relationship between them. The Granger causality inferences confirmed the one-way linkages, running from international migrant stocks, economic growth, and population growth to natural resource degradation. It verifies migrants-led, affluence-led, and population-led resource degradation. Ecological footprints Granger causes industrial value-added across countries. The forecasting estimates suggested that economic growth would likely to influenced greater in magnitude to resource degradation by its innovation shocks of 4.791%, followed by international migrant stocks, population growth, ecological footprints, and industrial value added by their innovation shocks of 4.709%, 1.829%, 1.247%, and 0.700%, respectively. The study concludes that international migrant stocks should manage smartly, causing more resource degradation via a channel of increasing biocapacity deficit across countries.

Abstract The idea of producing water-containing slurries and emulsions based on Diesel fuel, oil, coal, and coal processing waste has spread around the world. One of the ways to make the combustion of such fuels more efficient is through the micro-explosive droplet breakup, that is, the secondary atomization directly in the car combustion chambers and furnaces of boiler units. Here we study experimentally how micro-explosion affects the energy-related and environmental parameters of the combustion of slurry fuel droplets based on coal and its processing wastes. We present the results of experiments determining the threshold temperatures and ignition delay times, dimensions of the flame cloud of the dispersing particles, and anthropogenic emissions. The results obtained indicate that the micro-explosive atomization of fuel droplets can improve the environmental performance by up to 40%. The comprehensive analysis of the prospects of using coal-water slurries containing petrochemicals instead of coal has shown that the relative performance indicator of slurry fuel is 1.7–3.3 times higher than that of coal. With varying values of weight coefficients (environment, energy, and cost), the dimensionless slurry fuel performance coefficient may increase by 3–30% as compared to the case of equal values for these coefficients.

Biomass is a promising resource for the production of renewable energy, liquid fuels, and chemicals. Microwave pyrolysis is one of the directions of multifunctional conversion of raw materials. In the present work, the effect of microwave power on the characteristics of sawdust pyrolysis is studied. With an increase in power, the maximum yield of combustible gases increased, and a large proportion of the total pyrolysis time included the useful time for the release of gases. An increase in power affected the yield of individual gases non-linearly and on a different scale. The average yield of CO and CO2 remained practically unchanged when the microwave power was increased from 840 to 1760 W. However, with a further increase in power to 2200 W, there was a significant increase in the average yield of CO and CO2 (2.5 and 1.4 times, respectively). An increase in power by 2.6 times contributed to an increase in the average yield of CH4 by 5 times and H2 by 3.8 times. The increased power of microwaves contributed to the degassing of wood and intensification of secondary pyrolysis reactions, which resulted in a decrease in the mass of the solid residue by 5.3 times and a decrease in the liquid product yield by 2.7 times. A comprehensive analysis using MCDA showed that an increase in energy costs with an increase in microwave power is integrally compensated by an improvement in pyrolysis performance. So, when the power was varied from 840 W to 2200 W, the pyrolysis efficiency indicator increased by 1.3–2.2 times, considering the growth in energy consumption.

Abstract The growing concerns of global warming and depleting oil/gas reserves have made it inevitable to seek energy from renewable energy resources. Many nations are embarking on introduction of clean/renewable solar energy for displacement of oil-produced energy. Moreover, solar photovoltaic (PV)–diesel hybrid power generation system technology is an emerging energy option since it promises great deal of challenges and opportunities for developed and developing countries. The Kingdom of Saudi Arabia (K.S.A) being enriched with higher level of solar radiation, is a prospective candidate for deployment of solar PV systems. Literature indicates that commercial/residential buildings in K.S.A. consume about 10–45% of the total electric energy generated. The aim of this study is to analyze long-term solar radiation data of Dhahran (East-Coast, K.S.A.) to assess the techno-economic feasibility of utilizing hybrid PV–diesel–battery power systems to meet the load of a typical residential building (with annual electrical energy demand of 35,120 kWh). The monthly average daily solar global radiation ranges from 3.61 to 7.96 kwh/m 2 . National Renewable Energy Laboratory's (NREL) Hybrid Optimization Model for Electric Renewable (HOMER) software has been employed to carry out the present study. The simulation results indicate that for a hybrid system composed of 4 kWp PV system together with 10 kW diesel system and a battery storage of 3 h of autonomy (equivalent to 3 h of average load), the PV penetration is 22%. The cost of generating energy (COE, US$/kWh) from the above hybrid system has been found to be 0.179 $/kWh (assuming diesel fuel price of 0.1$/l). The study exhibits that for a given hybrid configuration, the operational hours of diesel generators decrease with increase in PV capacity. The investigation also examines the effect of PV/battery penetration on COE, operational hours of diesel gensets for a given hybrid system. Concurrently, attention is focussed on un-met load, excess electricity generation, fuel savings and reduction in carbon emissions (for different scenarios such as PV–diesel without storage, PV–diesel with storage, as compared to diesel-only situation), COE of different hybrid systems, cost of PV–diesel–battery systems, etc.

Recent years a worldwide interest in the use of alternative sources of protein, in particular, protein from insects, has increased. Edible insects for thousands of years have been a part of the human diet in Asian-Pacific region and South America, while in the European Union, the USA and Canada the use of insects for food purposes is a modern trend that is determined by the care of the environment, global warming combating, etc. Thus, the legal rules governing the food use of insects have significant differences among countries. In the Eurasian Economic Union requirements to food are regulated by the Customs Union Technical Regulations. Since none of the Technical Regulations contains the name of such food as "products obtained with the use of insects", these products may be classified as "food products of novel type" which are subjected to state registration. Fundamental and applied research should be conducted as a part of this novel food safety assessment system, that include the determination of nutritional and biological value of food raw materials derived from insects, and toxicological, reprotoxicological, allergological experiments in vivo on several generations of laboratory animals. The aim of the research was studying and comparing the nutritional and biological values of Hermetia illucens larvae dry biomass and basic foodstuffs of animal and plant origin. Material and methods. Nutritional and biological value analysis of H. illucens minced dry larvae biomass, dried at 110-120 °C, was carried out on 83 indicators, which included determination of protein content and amino acid composition, determination of fat level and fatty acid composition, determination of the content of carbohydrates, vitamins, minerals and trace elements, ash and moisture. Results. A study of the nutritional value of dry larvae biomass showed high levels of protein and fat (39 and 38%, respectively), while ash, dietary fiber and carbohydrate accounted for less than 20%. The amino acid profile had a balanced content of essential amino acids and was comparable to the protein of a hen's egg, as well as other animal products. The fatty acid composition of the biomass was characterized by a relatively high content of lauric acid (39.9% of the total fatty acid content), also found in some fruits and seeds of tropical plants; the ratio of other acids was more consistent with the fatty acid profile of fish oil. The dry larvae biomass contained carotenoids (0.23 mg/100 g), tocopherol (3.1 mg/100 g) and thiamine (53 μg/100 g) in amounts significantly lower to those of foods, which traditionally are sources of these vitamins. Based on the analysis of the mineral composition, the H. illucens biomass can be attributed to the sources of calcium, iron, copper and chromium. In terms of the content of the above elements, as well as magnesium and zinc, dry biomass significantly exceed the main food products of animal origin (beef, eggs, fish and seafood), and in terms of the content of potassium and phosphorus, it was comparable to them. Conclusion. The results of dry larvae biomass comparative evaluation with the basic foodstuffs of animal and plant origin evidence to its high nutritional and biological value, allowing to consider H. illucens as a promising source of complete protein, lauric acid, minerals and trace elements.

Oil and gas is a key sector for greenhouse gas inventory of the Russian Federation represented by non-CO2 greenhouse gases methane (CH4) and nitrous oxide (N2O). The CH4 and N2O emission estimates are mainly performed with the use of default method (IPCC 2000). As a result of continuous inventory improvement, the national parameters for oil and gas sector were derived and IPCC methodology was adjusted. The parameters were developed on the basis of specific features of producing industry and the properties of oil and gas produced. These developments enabled a shift to tier 2 estimation approach (IPCC 2006). The aim of the study was to highlight the differences between both estimation methods. For this purpose, the CH4 and N2O emissions were estimated from 1990 to 2009 with the use of default (tier 1) and a combination of tier 1 and tier 2 methods. The results of the estimates were compared and their uncertainty assessed. The results of comparison showed insignificant differences in the emission profile. Th...

Agricultural waste-based heterogeneous catalysts are emerging as efficient and green catalysts. The present study explored the agricultural waste-based heterogeneous catalyst utilized in the production of biodiesel. The plant waste is composed of organic compounds and various metals which, on combustion, produces ashes that mainly consist of various metal carbonates and oxides. The most commonly employed approach for the solid catalyst preparation from plant materials is the calcination process, and it is performed at temperatures ranging from 300 to 1200°C. It is known that the temperature employed for calcination plays a vital role in the composition and development of the morphology of the catalyst. The variation in alkalinity, porosity, and, accordingly, the catalytic activity of the catalyst is significantly influenced by the calcination temperature. It was found that the potassium present in the form of oxide and carbonate as the main constituent in such catalysts played a significant role in delivering catalytic efficacy. Therefore, a number of agricultural waste-based catalysts were reported as efficient catalysts. The selection of the catalyst may be one of the important issues for application in large-scale biodiesel production. Thus, the present study was undertaken for the preparation of a rank list among the reported catalysts by following the VIKOR (Višekriterijumsko Kompromisno Rangiranje) multicriterion decision-making approach. In this work, the ranking study was performed considering the reported optimum reaction conditions (ORCs) of biodiesel synthesis reactions. The study was conducted strictly on the basis of the parameters, viz., catalyst concentration ( C 1 ), MTOR ( C 2 ), reaction temperature ( C 3 ), reaction time ( C 4 ), and biodiesel yield ( C 5 ). The parameters are considered good if C 1 , C 2 , C 3 , and C 4 are low or minimum and if C 5 is high or maximum. The catalyst prepared from plantain peel showed the best performance and ranked as the first one followed by Musa paradisiaca peel and cocoa pod husk catalysts which are ranked second. Thus, the VIKOR method can be useful for comparison and ranking purposes if there are a large number of data, and this may be expanded for thorough study by considering more criteria which may give more fruitful results.

Anthropogenic activities in search of livelihood come with its environmental implications. This is in line with the current crusade of the United Nations sustainable development goals (SDGs) target 7 and 13 for effective clean energy access and mitigating the adverse effect of climate change issues. Since the seminal study of Kraft and Kraft (1978) on the nexus between energy and gross national product, there has been no consensus in the extant literature in the last four decades. To this end, the current study applies recent data for the case of Nigeria from 1970 to 2017 on an annual frequency. Modified Wald causality test of Toda-Yamamoto is in conjunction with the recent gradual shift causality test with Fourier approximation for robustness and precision of analysis. Empirical results show the pollutant driven economy as one-way causality is seen running from pollutant emission to economic growth. This suggests that economic growth is driven by dirty energy sources that are from non-renewable energy sources. This is further validated in the pollution haven hypothesis (PHH) confirmed in the study by the causality seen running from foreign direct investment and carbon dioxide emissions. Additionally, the exploration of natural resources also engenders economic expansion in Nigeria. Based on the current study findings, a couple of submissions are made such as the need for a paradigm shift to cleaner energy sources. More so, the need for the adoption of cleaner, eco-system friendlier innovations, and technologies will aid in the attainment of the SDGs of mitigating climate and pollution issues.