The impact of natural resource consumption on carbon emissions: evidence of a symmetric and asymmetric effect from Sub-Saharan Africa

Sub-Saharan African countries are among mineral-rich developing countries strategically competing to guarantee sustainable economic development through resource exploration. The possibility of increasing the level of carbon emission due to using low-cost fuels and high pollutants during mineral resource extraction activities leading to environmental degradation continues to draw the attention of researchers and policy makers. This research aims to analyze the response of carbon emissions in the African continent to symmetric and asymmetric shocks on resource consumption, economic growth, urbanization, and energy consumption. Following the Shin et al. (2014a) linear and nonlinear autoregressive distributed lag (ARDL) methodology in panel form, we construct symmetric and asymmetric panel ARDL-PMG model to evaluate both short- and long-run impacts of resource consumption on carbon dioxide emissions for a panel of 44 African countries over the period 2000-2019. The symmetric results show that the effect is not statistically significant despite natural resource consumption positively impacting carbon emission in the long and short runs. Energy consumption was found to affect environmental quality in the long and short runs adversely. Interestingly, economic growth was found to improve environmental quality in the long run significantly, and no significant impact was reported in the case of urbanization. However, the asymmetric results prove that a positive and negative shock to natural resource consumption contributes significantly to carbon emission, contrary to the insignificant impact established in the linear framework. The gradual growth in the manufacturing sector and an expansion in the transportation sector in Africa led to high demand and consumption of fossil fuels. This possibly accounts for the adverse effect of energy consumption on carbon emissions. Most African countries depend mainly on exploring natural resource endowment and agricultural activities to drive the growth of their economies. Due to the weak environmental regulatory frameworks in most African countries and public corruption, multinational companies (MNCs) in the extractive sector do not adhere to environmentally friendly activities. The majority of African countries are also battling illegal mining activities and illicit felling of trees, which may account for the positive relationship between natural resource rents and environmental quality reported. In terms of policy implications of the study, governments in Africa must preserve natural resources, use environmentally friendly and technologically advanced resource extraction methods, opt for green energy, and strictly apply environmental laws to promote environmental quality on the continent.

Enhancing of pretreatment on high solids enzymatic hydrolysis of food waste: Sugar yield, trimming of substrate structure

The development of high solids enzymatic hydrolysis (HSEH) technology is a promising way to improve the efficiency of bioenergy production from solid waste. Pretreatment methods such as ultrasound (USP), freeze-thaw (FTP), hydrothermal (HTP), and dried (DRD) were carried out to evaluate the effect and mechanism of the pretreatment methods on the HSEH of FW. The reducing sugar of HTP and DRD reached 94.75% and 94.92% of the theoretical value. HTP and DRD could reduce the crystallinity of FW. DRD resulted in lower alignment and the occurrence of fractures of the substrate and exposed the α-1,4 glycosidic bond of starch. The high destructive power of HTP and DRD reduced the obstacles caused by the high solid content. Moreover, DRD consumed only 27.62% of the total energy of HTP. DRD could be a promising pretreatment methods for glucose recovery for its high product yield, significant substrate destruction, and economic feasibility.

Evaluating a pathway for environmental sustainability: the role of energy mix and research and development in European countries

Within the European Union (EU), the majority of countries are considered developed, and the level of economic activity is rising. As a result, carbon dioxide emissions have increased. If the European Union wants to maintain long-term, sustainable growth, it must act quickly to find solutions to pollution. Population, wealth, renewable energy, nuclear energy, and research and development (R&D) are all factored into the STIRPAT model to determine their respective environmental impacts. Slope heterogeneity and cross-sectional dependence are explored in panel data for 30 European nations from 1990 to 2021 using a newly developed Cross Section Autoregressive Distributed Lag (CS-ARDL) method. The study found that population growth and the continued use of fossil fuels are major causes of environmental degradation. Alternately, employing renewable and raising incomes both have the potential to significantly cut pollution over the long run. Likewise, investments in R&D assist lessen the damage done to the environment. The nuclear energy coefficients, however, are insignificant. However, fossil fuels have negative effects on the ecosystem. If the EU wishes to stop the degradation of the environment, the analysis demonstrates that renewable energy is the best way to do it. The time has come for the EU to make a gradual transition away from fossil fuels and toward more environmentally friendly alternatives. Economic growth should be matched by decreased CO2 emissions, and increasing investment in R&D can serve as a catalyst for environmental sustainability. The results were reviewed using three different estimators: the augmented mean group (AMG), the mean group (MG), and the common correlated effects mean group (CCEMG). Important policy recommendations for a sustainable European environment are also suggested by the research.

The impact of health expenditure and economic growth on CO2 in China: a quantile regression model approach

Based on the environmental Kuznets curve (EKC) hypothesis and using Chinese provincial panel data from 2002 to 2019, this study examines how different types of healthcare expenditure and levels of economic development and energy consumption contribute to carbon emissions regionally. Considering the wide regional differences in the development levels of China, this paper uses quantile regressions and draws the following robust conclusions: (1) The EKC hypothesis was validated by all methods in eastern China. (2) The carbon emission reduction of government, private, and social health expenditure is confirmed. Furthermore, the impact of health expenditure on carbon reduction decreases from East to West. (3) Government, private, and social health expenditure all cause reductions in CO2 emissions, with private health expenditure having the largest negative effect on CO2 emissions, followed by government health expenditure and finally social health expenditure. Overall, the limited empirical work available on the impact of different kinds of health expenditure on carbon emission in the existing literature, this study greatly assists policy makers and researchers to understand the importance of health expenditure in improving environmental performance.

GHG emissions and energy consumption of residential buildings-a systematic review and meta-analysis

Residential buildings generate significant greenhouse gas (GHG) emissions and consume energy throughout their life cycle. In recent years, research on GHG emissions and energy consumption of buildings has developed rapidly in response to the growing climate change and energy crisis. Life cycle assessment (LCA) is an important method for evaluating the environmental impacts of the building sector. However, LCA studies of buildings show widely varying outcomes across the world. Besides, environmental impact assessment from a whole life cycle perspective has been undeveloped and slow. Our work presents a systematic review and meta-analysis of LCA studies on GHG emissions and energy consumption in the preuse, use, and demolition stages of residential buildings. We aim to examine the differences among the results of diverse case studies and demonstrate the spectrum of variations under contextual disparities. Results show that residential building emits about 2928 kg GHG emission and consumes about 7430 kWh of energy per m² of gross building area on average throughout the life cycle. Residential buildings have an average GHG emission of 84.81% in the use phase, followed by the preuse phase and demolition phase; the mean energy consumption in the use stage occupied the largest share of 84.52%, followed by preuse stage and demolition stage. GHG emissions and energy use vary significantly in different regions due to different building types, natural conditions, and lifestyles. Our study stresses the compelling requirement to slash GHG emissions and optimize energy consumption from residential buildings by use of low carbon building materials, energy structure adjustment, consumer behavior transformation, etc.

Impact of economic variables on CO2 emissions in belt and road and OECD countries

The rebirth of the Belt and Road Initiative (BRI) programme have necessitated the study as it has a vast potential to promote economic growth, yet, marred with numerous energy use and ecological concerns. The article is the first to comparatively examine the impact of economic variables on consumption-based CO₂ emissions in the BRI and the Organisation for Economic Co-operation and Development (OECD) countries by testing the Environmental Kuznets Curve (EKC) and the Pollution Haven Hypothesis (PHH). The Common Correlated Effects Mean Group (CCEMG) estimates the results. Income (GDP) and GDP² positively and negatively impact CO₂ emissions in the three panels, validating the EKC. Foreign direct investment (FDI) significantly affects CO₂ emissions for the global and BRI panels, supporting the PHH. However, the PHH is refuted for the OECD panel as the impact of FDI on CO₂ emissions is negative and statistically significant. GDP and GDP² decline by 0.029% and 0.0446%, respectively, for BRI countries, compared to OECD countries. It is recommended that BRI countries enact new and stringent environmental laws and use more tidal energy, solar energy, wind power, bioenergy, and hydropower instead of fossil fuels, for the sustainable attainment of higher economic growth, devoid of pollution.

A continental and global assessment of the role of energy consumption, total natural resource rent, and economic growth as determinants of carbon emissions

To limit the effects of carbon emissions and realize the Sustainable Development Goals (SDGs), countries worldwide seek efficient energy usage, economic sustainability, and natural resource blessing. Studies at the continental level mostly neglected the differences between the continents, while this study explores the long-run effect of natural resource rents, economic development, and energy consumption on carbon emissions and their interactions across the global panel of 159 countries divided into six continents from 2000 to 2019. Recently proposed panel estimators, causality tests, variance decomposition, and impulse response techniques were adopted. Findings from the panel estimator revealed that economic development contributed to environmental sustainability. At the same time, energy consumption increases ecological pollution globally and on most continents. The interaction between economic development and energy consumption positively impacted ecological pollution. Natural resources' rent was found to promote environmental pollution in Asia. The causality test results were mixed across continents and globally. However, findings from the impulse response and variance decomposition confirmed that economic development and energy consumption counted higher variations of carbon emissions than natural resource rents within the 10-year forecast. This study provides a valuable baseline for formulating policies related to the economy-energy-resources‑carbon nexus.

A hybrid approach for low-carbon transportation system analysis: integrating CRITIC-DEMATEL and deep learning features

As supply chains, logistics, and transportation activities continue to play a significant role in China's economic and social developments, concerns around energy consumption and carbon emissions are becoming increasingly prevalent. In light of sustainable development goals and the trend toward sustainable or green transportation, there is a need to minimize the environmental impact of these activities. To address this need, the government of China has made efforts to promote low-carbon transportation systems. This study aims to assess the development of low-carbon transportation systems in a case study in China using a hybrid approach based on the Criteria Importance Through Intercriteria Correlation (CRITIC), Decision-Making Trial and Evaluation Laboratory (DEMATEL) and deep learning features. The proposed method provides an accurate quantitative assessment of low-carbon transportation development levels, identifies the key influencing factors, and sorts out the inner connection among the factors. The CRITIC weight matrix is used to obtain the weight ratio, reducing the subjective color of the DEMATEL method. The weighting results are then corrected using an artificial neural network to make the weighting more accurate and objective. To validate our hybrid method, a numerical example in China is applied, and sensitivity analysis is conducted to show the impact of our main parameters and analyze the efficiency of our hybrid method. Overall, the proposed approach offers a novel method for assessing low-carbon transportation development and identifying key factors in China. The results of this study can be used to inform policy and decision-making to promote sustainable transportation systems in China and beyond.

Impact of technology on the relation between disaggregated energy consumption and CO2 emission in populous countries of Asia

All around the world, but particularly in developing nations, carbon dioxide emissions are on the rise, and climate change and global warming are brought on by an increase in CO₂ emissions. This article provides an overview of the technological effect on energy consumption in the residential, transport, and industrial sector and its ultimate effect on the environment. Using the STIRPAT-Kaya-EKC model for the years 1990 to 2020, this study looked at the threshold impact of technological advancements on the link between disaggregated energy use and CO₂ emissions for a panel of 10 Asian countries using the panel threshold regression. Findings demonstrate that the EKC phenomenon is present in the chosen Asian region. Findings also suggest that technology has a threshold influence on the relationship between energy use and carbon emissions; however, this effect varies across sectors.

Towards environmental degradation mitigation: The role of regulatory quality, technological innovation and government effectiveness in the CEMAC countries

The study explores the interaction between regulatory quality, economic growth, technological innovation, energy consumption, government spending on research and development, and environmental degradation (EVD) in the Economic and Monetary Community of Central Africa (CEMAC) region. The study applied the econometric approach CS-ARDL to estimate the short and long-term interaction between the regressors and the explanatory variable. The study period covers from 1990 to 2020. To summarize the findings of this research, (1) the study discovered a positive relationship between energy consumption, government effectiveness, regulatory quality, and environmental degradation. (2) Economic growth, government spending on research and development, and technological innovation, on the other hand, extensively dissipates EVD in the CEMAC economies. (3) The causality analysis espoused a bidirectional connection between energy consumption, technological innovation, and EVD. (4) Lastly, a unidirectional interplay exists between economic growth, government effectiveness, regulatory quality, and EVD. This study also serves as a reference point for policymakers and governmental institutions to invest in cleaner technologies and increase government research and development spending to mitigate environmental degradation in these areas.

Impact of green technological innovations on environmental quality for Turkey: evidence from the novel dynamic ARDL simulation model

The contribution of this research is to provide empirical evidence that investing in green technology innovation (GTI) can reduce the ecological footprint in Turkey, which can lead to sustainable economic growth and environmental quality. The research also highlights the importance of controlling energy consumption, GDP, trade openness, and urbanization, as these variables have a positive or negative effect on ecological footprint. The findings of this research can be useful for the Turkish government, policymakers, and environmentalists to promote the implementation of GTI and eco-friendly resources, which can reduce the impact of climate change and contribute to economic prosperity. Overall, this research provides important information for decision-makers to adopt policies that prioritize green innovation and environmental protection in Turkey.

Application of different Trombe wall solutions on the reduction of energy load and sustainable development in an eco-resort residential building in Binalood region with a cold and dry climate

Trombe wall is a passive strategy that reduces the energy consumption in buildings and helps for sustainable development of the residential sector. Applying these walls is very important in areas that need heating load in winter. This study evaluates a set of Trombe walls for the energy management of a residential building under real conditions in Binalood region with a cold and dry climate. In order to study the potentials of the Trombe wall, four different designs, including cubic Trombe wall with rectangular structure and three-sided glass, Trombe wall with trapezoidal structure and three-sided glass, Trombe wall with trapezoidal structure and four-sided glass, and Trombe wall with thicker storage wall, trapezoidal structure, and three-sided glass, for Trombe wall are considered. Trombe walls of all four suggested designs are exposed to outdoor conditions and installed at 17 places on the southern walls of the residential building. The results show that the most optimal design, i.e., Trombe wall with thicker storage wall, trapezoidal structure, and three-sided glass, leads to the greatest decrease (1637 kWh) in heating load in January. In addition, this design of the Trombe wall has the greatest effect in increasing the indoor air temperature among other Trombe walls investigated in this study. The Trombe wall with thicker storage wall, trapezoidal structure, and three-sided glass with a storage wall thickness of 40 cm is able to reduce the heating load of the building by 5.59 MWh in 5 months. This plan reduces the energy demand of the building by 8% more than the conventional structure of Trombe wall.

Hydrochar synthesis from waste corncob using subcritical water and microwave-assisted carbonization methods and ammonium enrichment of synthesized hydrochars

Corncob (CC) is an industrial biological waste that is generated in significant quantities, and converting such biological wastes into value-added hydrochars through a viable process such as hydrothermal carbonization can provide significant benefits. It is of great importance to ensure eco-friendly and appropriate methods that are suitable for the area where the hydrochar will be used. This study aimed to synthesize hydrochars from a solid food waste, CC, using two different hydrothermal carbonization methods based on microwave-assisted (MHC) and subcritical water (SHC) using them as a biosorbent for NH₄⁺ adsorption from water and characterizing their specific features. Hydrochars were synthesized in 1 h at 180 °C and 240 °C by MHC and SHC methods, respectively. Hydrochars synthesized by MHC and SHC methods were characterized by SEM-EDX, N₂ adsorption-desorption isotherms, and FT-IR analyses. According to the EDX results, the C/O ratio (atomic %) in MHC and SHC was determined to be 0.55 and 0.35, respectively. Nitrogen adsorption-desorption isotherms revealed that hydrochars obtained by both methods have three distinct pore types, namely, micro, meso, and macro. In the energy consumption per unit adsorbent, a lower value was obtained for MHC than SHC. NH₄⁺ adsorption using MHC and SHC was found to be compatible with the Langmuir isotherm model and the NH₄⁺ adsorption capacities were 13.09 and 10.54 mg/g, respectively. pH was the most effective variable on hydrochars in the NH₄⁺ adsorption based on the response surface method (RSM), and the highest adsorption occurred at pH 6.5 and 40 mg/L of initial NH₄⁺ concentration, using 1.5 g/L of adsorbent at 35 °C. The results revealed that MHC is a unique method that can be used for hydrochars derived from CC in NH₄⁺ adsorption, and MHC is more cost-effective than SHC in hydrochar production.

Exploring the nexus link of environmental technology innovation, urbanization, financial development, and energy consumption on environmental pollution: Evidence from 27 emerging economies

The core intent of the present study seeks to probe the connection linking environmental technology innovation (ENVTI), economic growth (ECG), financial development (FID), trade openness (TROP), urbanization (URB) and energy consumption (ENC) on environmental pollution (ENVP) by employing 27 chosen African economies panel data. These variables merit critical attention when implementing decarbonization policies and significantly safeguarding a country's well-being in pursuit of massive industrialization and economic expansion. The fully modified ordinary least squares (FMOLS), the dynamic ordinary least square (DOLS), and the pooled mean group (PMG) estimation techniques were utilized to analyze the series from 2000 through 2020. This research used the FMOLS for long-run connections interaction of the variables, while the DOLS and PMG were used for robustness checks. Further, the Pedroni, Kao, and Westerlund cointegration approaches were employed to determine cointegration in the series. Also, the cross-sectional Im, Pesaran, and Shin (CIPS) and the cross-sectional augmented Dickey-Fuller (CADF) unit root testing approaches were utilized to check the stationarity of the series. Again, the stochastic impact on regression, population, affluence, and technology (STIRPAT) model, and the environmental Kuznets curve (EKC) was used as the theoretical framework supporting this research. The findings of the long-run analysis give credence to the EKC assumption demonstrating that a significant long-term ECG will support the decrease in ENVP when nations experience increases in the level of income. Further, this study found that ENVTI and URB are conducive to reducing ENVP in the long run. The current research finding is sensitive to the respective nations' income levels. This empirical research furnishes prudent policies tailored for the respective countries' pursuit of ECG and reducing ENVP.

Household electricity consumption in Greece: A dataset based on socio-economic features

The electricity consumption of a residence depends on many factors such as the habits and economical status of the occupants, the properties of the household and many more. To shed more light on the subject a data set for households was created. The data were collected in Greece through an anonymous survey that comprises 26 questions, resulting in 188 data points from 104 households from different time periods. Each data point contains attributes that are divided into four categories. In the first category, the information is about the household data such as the type and properties of the residence. Next, occupants' socio-economic features are gathered. In this category information for the number and type of the occupants, the employment status and the total income of the residents is included. The third category of attributes is about the energy-related occupants' behavior. Finally, the location of the household was provided from the users to estimate the weather conditions for the provided time. Data augmentation was performed to discover non-trivial relationships between the data points. Thus, a secondary set of features was computed based on the raw attributes and is also included. The provided data set can be used to extract insights that could be valuable during the imminent energy crisis.

Probing environmental sustainability pathways in G7 economies: the role of energy transition, technological innovation, and demographic mobility

Global warming remains the most devastating environmental issue embattling the global economies, with significant contributions emanating from CO₂ emissions. The continued rise in the level of greenhouse gas (GHG) emissions serves as a compelling force which constitutes the core of discussion at the recent COP26 prompting nations to commit to the net-zero emission target. The current research presents the first empirical investigation on the roles of technological advancement, demographic mobility, and energy transition in G7 pathways to environmental sustainability captured by CO₂ emissions per capita (PCCO2) from 2000 to 2019. The study considers the additional impacts of structural change and resource abundance. The empirical backings are subjected to pre-estimation tests consisting of cross-sectional dependence, second-generation stationarity, and panel cointegration tests. The model estimation is based on cross-sectional augmented autoregressive distributed lag, dynamic common correlated effects mean group, and augmented mean group for the main analysis and robustness checks. The findings reveal the existence of EKC based on the direct and indirect effects of the components of economic growth. The indicators of demographic mobility differ in the direction of influence on PCCO2. For instance, while rural population growth negatively influences PCCO2 in the short-run alone, urban population growth increases PCCO2 in the short-run and long-run periods. Nonrenewable energy, information computer technology (ICT) imports, and mobile cellular subscriptions serve as positive predictors of PCCO2, while ICT exports and renewable energy moderate the surge in PCCO2. Policy implications that enhance environmental sustainability are suggested following the empirical verifications.

Application and planning of an energy-oriented stochastic disassembly line balancing problem

End-of-life (EOL) products are getting more and more attention as a result of the rapid decline in environmental resources and the dramatic rise in population at the moment. Disassembly is a crucial step in the reuse of EOL products. However, the disassembly process for EOL products is highly uncertain, and the disassembly planning method may not produce the anticipated outcomes in actual implementation. Based on the physical nature of the product disassembly process with multiple uncertain variables, certainty disassembly cannot adequately characterize the uncertain variables effectively. Uncertainty disassembly takes into account the changes in parts caused by product use, such as wear and corrosion, which can better coordinate the arrangement of disassembly tasks and better match the actual remanufacturing process. After analysis, it was found that most of studies on uncertain disassembly focus on the economic efficiency perspective and lack of energy consumption considerations. For the gaps in the current study, this paper proposes a stochastic energy consumption disassembly line balance problem (SEDLBP) and constructs a mathematical model of SEDLBP based on the disassembly of spatial interference matrix, In this model, the energy consumption generated by the disassembly operation and workstation standby is not a constant value but is generated stochastically in a uniformly distributed interval. In addition, an improved social engineering optimization algorithm that incorporates stochastic simulation (SSEO) is proposed in this paper to effectively address the issue. The incorporation of swap operators and swap sequences in SSEO makes it possible to solve discrete optimization problems efficiently. A comparison of a case study with some well-tested intelligent algorithms demonstrates the efficacy of the solutions produced by the proposed SSEO.

A new truck-drone routing problem for parcel delivery by considering energy consumption and altitude

The high population density in metropolitan areas, high-rise buildings, and changes in people's lifestyles have completely changed the way postal packages are delivered. People no longer go to the ground floor to receive a postal package. In the meantime, the delivery of postal packages through the balconies and windows of the units on the upper floors of the buildings will gradually become inevitable. Hence, a new Vehicle Routing Problem with Drone mathematical model has been developed with the objective of minimizing total delivery time and with the ability to deliver postal packages in the path of drones at different heights. In addition, the drone's energy consumption is computed by taking into account wind speed, the weight of the postal parcel, the weight of the drone's body, and other factors in the drone's path. A two-phase algorithm based on the nearest neighborhood and local search is presented to solve the developed mathematical model in different instances. Several small-sized test problems are designed and solved, and the performance of the heuristic approach is evaluated compared to the outputs of the CPLEX solver. Finally, the proposed model is implemented on a real-world scale to demonstrate the efficacy and applicability of the proposed model as well as the heuristic approach. The results show that the model successfully finds the optimal planning of the delivery routes, especially when we deal with delivery points at different heights.

Decomposing the decoupling relationship between energy consumption and economic growth in China's agricultural sector

Sustainable food supply is affected by high energy consumption and negative environmental effects. Regarding the national strategy of "carbon peaking and carbon neutrality targets", the decoupling between energy consumption and economic growth in China's agriculture has received significant attention. Therefore, this study first presents a descriptive analysis of the energy consumption in China's agricultural sector from 2000 to 2019, before analyzing the decoupling state between energy consumption and agricultural economic growth at the national and provincial levels using the Tapio decoupling index. Finally, the logarithmic mean divisia index method is used to decompose the decoupling driving factors. The study draws the following conclusions: (1) At the national level, the decoupling of agricultural energy consumption from economic growth fluctuates among expansive negative decoupling, expansive coupling, and weak decoupling, before stabilizing in the last state. (2) The decoupling process also differs by geographic region. Strong negative decoupling is found in North and East China, and strong decoupling lasts longer in Southwest and Northwest China. (3) The factors driving decoupling are similar at both the levels. The economic activity effect promotes the decoupling of energy consumption. The industrial structure and energy intensity effects are the two main suppressive factors, whereas the population and energy structure effects have relatively weaker impacts. Therefore, based on the empirical results, this study provides evidence for regional governments to formulate policies on the relationship between the agricultural economy and energy management from the perspective of effect driven policies.

Removal of COD from real oily wastewater by electrocoagulation using a new configuration of electrodes

In order to bring the chemical oxygen demand (COD) concentration down to safe levels for widespread use, this study plans to use a state-of-the-art electrocoagulation reactor (ECR) to treat real oily wastewater discharged from the Al-Muthanna petroleum refinery. A one-side finned (1SF) cathode tube was positioned between two tubular anodes in the continuous ECR, where the active area of the cathode was much more than its submerged volume. Each of these electrodes was made of aluminum and joined in a monopolar parallel to a DC power supply. On COD elimination efficiency, the impacts of operational parameters such as electrolysis time (4-60 min), current density (0.630-5.000 mA/cm²), and flow rate (50-150 ml/min) were explored. In conclusion, Increasing current density and electrolysis duration increases COD removal efficiency, whereas increasing flow rate reduces it. COD removal efficiencies were 82% at optimal electrolysis times of 60 (min), 5 (mA/cm²) current density, and 50 (ml/min) flow rate, with energy consumption of 4.787 (kWh/kg _COD) and electrode consumption of 0.544 (g). The investigation results demonstrated that the new reactor could treat oily wastewater within the specified operational limits. It might be used before other, more conventional treatments.

Characterization of reciprocation membrane bioreactor on treatment performance, energy consumption and membrane fouling

Two reciprocating membranes (rMBR) with two frequencies of 0.46 Hz (rMBR-0.46) and 0.3 Hz (rMBR-0.3) were operated to compare the treatment performance and gross energy consumption with a conventional MBR. The average organic removal rates of MBR, rMBR-0.46 and rMBR-0.3 were maintained 295 ± 51; 823 ± 296; and 397 ± 129 mgCOD/gVSS.d, respectively. Nitrogen removal was enhanced in rMBR phases compared to conventional MBR phase due to anoxic membrane chamber. Further, fouling rate was found to be highest of 16.5 mbar/day (at conventional MBR phase), which was and much decreased to1.0 mbar/day (at rMBR-0.46 phase) and then 0.2 mbar/day (rMBR-0.3 phase). The reciprocation membrane also showed energy potential by saving 10.6% electricity for each treated cubic meter of wastewater compared to the conventional MBR.

Integration of hydrothermal and pyrolysis for oily sludge treatment: A novel collaborative process

In this study, hydrothermal treatment and in situ pyrolysis were combined to develop a novel collaborative process (HCP treatment method). In a self-designed reactor, the HCP method was used to study the influences of hydrothermal temperature and pyrolysis temperature on the product distribution of OS. The products from the HCP treatment of OS were compared with that from the traditional pyrolysis. In addition, the energy balance in the different processes of treatment was analyzed. The results showed that compared to the traditional pyrolysis method, the gas products obtained after HCP treatment achieve a higher H₂ production. As the hydrothermal temperature raising from 160 to 200 °C, the H₂ production showed an increase from 4.14 to 9.83 ml/g. In addition, GC-MS analysis showed that the content of olefins from the HCP treatment oil was increased from 1.92% to 6.01% compared to traditional pyrolysis. Energy consumption analysis showed that only 55.39% energy consumption of traditional pyrolysis is required for treating 1 kg OS by employing the HCP treatment at 500 °C. All results indicated that the HCP treatment is a clean production process of OS with low energy consumption.

Methodological framework for Life Cycle Assessment of sustainable aviation (SA) systems

A comprehensive framework is proposed for Life Cycle Assessment (LCA) in the field of commercial aviation (passengers and cargo), capable to ensure transparency and comparability when evaluating the overall environmental performances of four emerging aviation systems, i.e., biofuels, electrofuels, electric, and hydrogen. The projected global revenue passenger kilometer (RPK) and is suggested as the functional unit for two timeframes representing near-term (2035) and long-term (2045), and for two segments, namely domestic and international. To solve the difficulty of comparing liquid fuels and electric aviation, the framework proposes a methodology to translate projected RPK into energy requirements for each of the studied sustainable aviation systems. Generic system boundaries are defined with their key activities for all four systems, with the biofuel system being sub-divided into two categories to distinguish whether it stems from residual or land-dependent biomass. The activities are grouped in seven categories: (i) conventional (fossil-based) kerosene activity, (ii) conversion processes from feedstock supply (to fuel or energy production for aircraft operation), (iii) counterfactual uses of constrained resources and displacement effects associated to co-products management, (iv) aircraft manufacture, (v) aircraft operation, (vi) additional infrastructure needed, and (vii) end-of-life management (aircraft and batteries). Considering applying regulations, the framework also includes a methodology to handle: (i) hybridization (the use of more than one source of energy/propulsion system to power an aircraft), (ii) the mass penalty affecting the number of carried passengers in some of the systems, and (iii) impacts stemming from non-CO₂ tailpipe emissions - aspects that are currently neglected in most LCA studies. The proposed framework builds upon the most recent knowledge in the field; however, some choices are dependent on upcoming scientific advances concerning e.g., tailpipe emissions at high altitude and their environmental impacts, new aircraft configuration, etc., and are subject to significant uncertainties. Overall, this framework provides a guideline for LCA practitioners addressing new energy sources for future aviation.

Energy consumption, CO2 emissions, foreign direct investment, and economic growth in Malaysia: an NARDL technique

This study seeks to ascertain whether there is an unbalanced link  between CO₂ emissions, foreign direct investment, and economic growth in Malaysia over a 40-year timeframe between 1980 and 2019. We investigated the asymmetric relationship , using  non-linear autoregressive distributed lag (NARDL) technique. The findings showed a noteworthy asymmetry between FDI, CO₂ emissions, and GDP in Malaysia. The long-term and short-term effects of negative FDI on GDP are both equivalent to 0.028 and 0.021, respectively. This suggests that, compared to short-term fluctuations, long-term negative FDI adjustments have a considerably more negative impact on economic growth. The coefficient of positive (CO₂⁺) and negative (CO₂^-) changes in economic growth is equal to 0.086 and - 0.152, respectively. It indicates that positive changes in CO₂ emissions have stronger effects in the long run than negative shocks. Considering an asymmetric association between these two variables in the short and long term, Malaysian policymakers must comprehend the dynamic relationship between FDI, CO2 emissions, and GDP to plan appropriate economic and environmental policies that will support sustainable economic development and ensure a safer environment.

Development of a novel induction-heated reactor to enhance the performance of waste tires pyrolysis

Waste tire pyrolysis (WTP) is well-known as a promising technique for waste tires (WTs) management. However, the requirements of high cost and intense energy, as well as steel wire stripping remain the major drawbacks for the widespread applications of WTP technologies. In this research, a novel induction-heated pyrolysis (IHP) reactor has been developed to enhance the performance of WTP and the results were compared with a conventional fixed bed pyrolysis (FBP) reactor. The performance of the IHP reactor has been evaluated using three different feedstocks of sidewall (no steel wire), tread section (20% steel wire), and real mode (14% steel wire) at two different sizes of A and B. The results revealed that the presence of steel wire in the IHP reactor not only reduced the effect of WTs particles size, but also improved the average heat and oil production rate up to 36 % and 60 %, respectively through better heat distribution. The minimum REC (13.03 KJ/g) was achieved for the tread section after 12 min of the IHP process. The comparison of the results of the IHP reactor and the FBP reactor proved that using IHP reactor could significantly improve the performance WTP in terms of optimum heating time, heat rate, REC and power consuming cost up to 68 %, 44 %, 56 % and 61 % respectively. The findings of this study suggest IHP reactor which eliminates the need of stripping steel wires as novel and promising approach for sustainable WTs management.