Energy Carbon Emissions Research Articles

Enhancing domestic hot water energy efficiency in High-Rise residential buildings through interconnected and sharing mode

Residential buildings in China are consuming over 20 % of their operating energy on domestic hot water (DHW), a percentage that has been increasing in recent years. The use of energy-efficient water heaters is a direct solution to reduce DHW energy consumption, but high costs and installation requirements often deter households from adopting them. This issue is particularly prevalent in high-rise residential buildings, resulting in a low adoption rate of energy-efficient water heaters in China's high-rise residential sector. To address this challenge, this study proposes a DHW interconnected and sharing mode as a novel approach to enhance DHW energy efficiency in high-rise residential buildings. A dynamic performance calculation model based on the China Energy Efficiency Label (CEEL) for various types of water heaters was developed to evaluate the energy efficiency of this mode. The total energy consumption, carbon emissions, and energy costs of the building were assessed under both decentralized mode and interconnected and sharing mode. The findings indicate that implementing the interconnected and sharing mode can significantly decrease the annual total energy consumption, carbon emissions, and energy costs of DHW. Among the two operational strategies examined (economic optimal and environmental optimal), the economic optimal strategy is more suitable for China's current energy landscape. Under the economic optimal strategy, the annual total energy consumption, carbon emissions, and energy costs of DHW in the target building are reduced by 41.58 %, 27.97 %, and 34.87%, respectively.

Removal mechanism of adhering heavy oil from pipeline wall in low-temperature flow

With the global emphasis on heavy oil development and increasing water content in Chinese oilfields, the low-temperature flow of heavy oil has been widely concerned. Integrating experiments and theoretical modeling, a hydrodynamic balance model for removing adhering heavy oil from pipeline wall was proposed to determine the temperature threshold for heavy oil transportation (adhesion temperature, AT). Two forms of heavy oil removal from pipeline wall were identified in the study: slide and lift-off. At low temperatures, the abrupt increase in wall-adhesion mass is primarily due to the inability of oil droplets to be removed through lift-off, but rather only through slide. Therefore, the temperature marking the transition from lift-off to slide is suggested as the AT criterion. Predicted AT values were in effective concordance with experimental values, with a maximum deviation of 3.78 °C. ATs for oilfields were predicted, and field cooling transportation tests showed no significant pressure drop increase, indicating the model's practical applicability. Additionally, the influence factors of the model were analyzed based on considerations of adhesion force and hydrodynamic removal force. This study aims to reduce heating energy consumption and carbon emissions during transportation under the premise of ensuring safe flow of high water-content heavy oil.

Asymmetric nexus between nuclear energy technology budgets and carbon emissions in European economies: Evidence from quantile-on-quantile estimation

Our research seeks to assess the influence of nuclear energy technology on carbon emissions in the top 10 European economies comprising the topmost nuclear energy R&D budget (France, Germany, Russia, the Netherlands, the UK, Finland, Spain, Sweden, Italy, and Switzerland). Unlike prior investigations predominantly relying on panel data methodologies without considering the distinctive characteristics of each economy, our study employs the advanced 'Quantile-on-Quantile' approach. This novel methodology enables us to investigate the interactions between variables within each unique nation, thereby improving the precision of our analysis. As a result, the study provides a thorough global perspective, revealing nuanced findings pertinent to each economy's specific attributes. Our outcomes demonSstrate a positive interconnection between nuclear energy technology and carbon emissions across various quantiles in our analyzed nations. Additionally, the study highlights diverse patterns in these associations within individual economies. These findings emphasize the significance of policymakers performing comprehensive measurements and devising effective strategies to monitor fluctuations in nuclear energy technology and carbon emissions.

System development and thermodynamic performance analysis of a system integrating supercritical water gasification of black liquor with direct-reduced iron process

Hydrogen metallurgy is an effective way to decarbonize the steel industry. In this study, a new system integrating biomass supercritical water gasification (SCWG) with hydrogen generation-shaft furnace-electric arc furnace (HSE) was proposed. The thermodynamic performance of SCWG-HSE system were analyzed and optimized. The results show that the gasification and energy efficiency of SCWG system increase with an increase in the gasification temperature. The carbon emission of the SCWG-HSE system are effectively reduced, and the product yield and energy efficiency of the system are improved by increasing gasification temperature and recovering furnace top gas. The energy and exergy efficiency of the SCWG-HSE system are 46.66% and 40.17%, respectively. The exergy destruction of SCWG gasifier and electric arc furnace are the major exergy damage sources of the SCWG-HSE system. The exergy efficiency of the ironmaking system reaches 51.60%, and the energy consumption and carbon emission per unit product are 18.49 GJ/t and 902.40 kg/t, respectively. Compared with the traditional Coking-Blast furnace ironmaking process, the energy consumption and carbon emission of this system are reduced by 7.32% and 40.84% respectively. This work is expected to open a new way for the application of biomass in the low-carbon steel industry.

Assessment of energy consumption and environmental safety measures in a plasma pyrolysis plant for eco-friendly waste treatment

A plasma pyrolysis plant with a 50 kg/h installed capacity is investigated for its performance in terms of energy consumption, carbon emission, and environmental safety. Municipal Solid Waste (MSW), precisely the combustible fraction, is processed at approximately 1000 °C. A temperature shoot study is conducted to reduce the energy required for waste processing, revealing a total energy consumption of 0.586 kWh per kg of waste, leading to a reduction of ∼15%. A mass and energy balance has been done to get a clear understanding of different products, by-product generation, and heat losses during waste treatment. The gas analysis identified CO and H2 as dominant components, comprising around 30% of the produced gases, with a lower heating value (LHV) of 4.7 MJ/Nm3. The cold gas efficiency ranges from 44 to 53%. The Energy Dispersive X-ray (EDX) and Inductively Coupled Plasma Mass Spectrometer (ICP-MS) techniques characterize the ash generated during the process and are found carbonless and non-toxic in nature. The wastewater produced during gas cleaning exhibited a neutral acidic nature, with total dissolved solids (TDS) ranging from 1200 to 1500 mg/l. These findings contribute to the plant's promising role in sustainable waste management practices, highlighting its potential as an environmentally sound solution for processing waste.

Multi-Objective Optimization with Active–Passive Technology Synergy for Rural Residences in Northern China

Due to the serious problems with energy efficiency, carbon emissions, and thermal comfort of rural residences in northern China, an optimization of active and passive heating technologies for rural residences is necessary. In this paper, an optimization for rural residences in northern China is conducted with four objectives: the whole life cycle carbon emission; the annual energy consumption through heating, ventilation, and air conditioning systems; the annual cost; and thermal comfort. In addition, the optimization model with active–passive heating technology synergy is resolved by NSGA-II genetic algorithm. The active and passive design variables, including the type of air source heat pump, orientation, the type and thickness of envelope insulation, the layer of window glass, the window-to-wall area ratio, as well as sunspace parameters are preferred to obtain the optimal solution. The results indicate that the optimal solution obtained by the ideal point method gives the most outstanding performance. Compared with the prototype, the optimized carbon emissions in severe cold and cold regions decreased by 56.1% and 54.6%, respectively. The annual energy consumption decreased by 59.7% and 62.2%. Finally, the roof insulation thickness is the most sensitive design variable in Pareto-optimal solution sets. This paper offers significant guidance in the application of the optimization method of active–passive technology synergy to the energy-saving design of buildings.

The role of renewable energy in the energy–growth–emission nexus in the ASEAN region

BackgroundThe Association of Southeast Asian Nations (ASEAN) relies mainly on fossil fuels in their energy supply, leading to higher CO2 emissions, pollution, and further environmental degradation. This paper uses the panel vector autoregressive and the Granger non-causality test in the heterogeneous panels, together with long-run estimation techniques, to examine the dynamic link among energy consumption, economic growth, and carbon emissions with the focus on renewable energy for the ASEAN countries in the past three decades.ResultsThe findings from this paper indicate that carbon emissions are associated with energy consumption. In contrast, renewable energy usage reduces CO2 emissions, improving environmental quality. Economic growth is associated with increased energy consumption and carbon emissions in the ASEAN countries. The findings also indicate that the effects of energy consumption on economic growth are more significant than those of renewable energy in ASEAN. When considered together, these findings form a vicious circle regarding the energy–growth–emission nexus for the ASEAN economies. In addition, a bidirectional Granger causality among energy consumption, economic growth, CO2 emissions and renewable energy usage is confirmed.ConclusionsRenewable energy has emerged as an important viable option for the ASEAN nations to achieve their dual objectives of enhanced economic growth, reduced CO2 emission, leading to improved environmental quality.

Sustainable utilization of alkali-activated steel slag material: Effects of silicate modulus and GBFS on fresh, mechanical and pore structure properties

To improve the sustainable utilization of alkali-activated steel slag material, experiments were conducted to systematically investigate effects of sodium silicate modulus and GBFS content on the setting time, workability, mechanical properties and pore structure of alkali-activated steel slag cementitious material. Results show that the setting time is prolonged and workability is reduced as silicate modulus increases. The setting time is first shortened and then prolonged and workability is slightly reduced as GBFS content increases. Increasing silicate modulus and adding GBFS have positive effects on the development of elastic modulus, compressive and splitting tensile strength of alkali-activated steel slag material due to more refined pore structure. The highest compressive strength at 28 d can reach C35 strength level. Manufacturing alkali-activated steel slag material can achieve low energy consumption and carbon emission. If chemical activators can be replaced by some industrial wastes, cost, energy consumption and carbon footprint will be further decreased.

Evaluation of energy consumption and carbon emission in EDM

Evaluation of energy consumption and carbon emission in EDM

Interventional Imaging Systems in Radiology, Cardiology, and Urology: Energy Consumption, Carbon Emissions, and Electricity Costs.

BACKGROUND. The energy demand of interventional imaging systems has historically been estimated using manufacturer-provided specifications rather than directly measured. OBJECTIVE. The purpose of this study was to investigate the energy consumption of interventional imaging systems and estimate potential savings in the carbon emissions and electricity costs of such systems through hypothetical operational adjustments. METHODS. An interventional radiology suite, neurointerventional suite, radiology fluoroscopy unit, two cardiology laboratories, and two urology fluoroscopy units were equipped with power sensors. Power measurement logs were extracted for a single 4-week period for each radiology and cardiology system (all between June 1, 2022, and November 28, 2022) and for the 2-week period from July 31, 2023, to August 13, 2023, for each urology system. Power statuses, procedure time stamps, and fluoroscopy times were extracted from various sources. System activity was divided into off, idle (no patient in room), active (patient in room for procedure), and net-imaging (active fluoroscopic image acquisition) states. Projected annual energy consumption was calculated. Potential annual savings in carbon emissions and electricity costs through hypothetical operational adjustments were estimated using published values for Switzerland. RESULTS. Across the seven systems, the mean power draw was 0.3-1.1, 0.7-7.4, 0.9-7.6, and 1.9-12.5 kW in the off, idle, active, and net-imaging states, respectively. Across systems, the off state, in comparison with the idle state, showed a decrease in the mean power draw of 0.2-6.9 kW (relative decrease, 22.2-93.2%). The systems had a combined projected annual energy consumption of 115,684 kWh (range, 3646-26,576 kWh per system). The systems' combined projected energy consumption occurring outside the net-imaging state accounted for 93.3% (107,978/115,684 kWh) of projected total energy consumption (range, 89.2-99.4% per system). A hypothetical operational adjustment whereby all systems would be switched from the idle state to the off state overnight and on weekends (versus being operated in idle mode 24 hours a day, 7 days a week) would yield the following potential annual savings: for energy consumption, 144,640 kWh; for carbon emissions, 18.6 metric tons of CO2 equivalent; and for electricity costs, US$37,896. CONCLUSION. Interventional imaging systems are energy intensive, having high consumption outside of image acquisition periods. CLINICAL IMPACT. Strategic operational adjustments (e.g., powering down idle systems) can substantially decrease the carbon emissions and electricity costs of interventional imaging systems.

Short-Term Load Forecasting Method for Industrial Buildings Based on Signal Decomposition and Composite Prediction Model

Accurately predicting the cold load of industrial buildings is a crucial step in establishing an energy consumption management system for industrial constructions, which plays a significant role in advancing sustainable development. However, due to diverse influencing factors and the complex nonlinear patterns exhibited by cold load data in industrial buildings, predicting these loads poses significant challenges. This study proposes a hybrid prediction approach combining the Improved Snake Optimization Algorithm (ISOA), Variational Mode Decomposition (VMD), random forest (RF), and BiLSTM-attention. Initially, the ISOA optimizes the parameters of the VMD method, obtaining the best decomposition results for cold load data. Subsequently, RF is employed to predict components with higher frequencies, while BiLSTM-attention is utilized for components with lower frequencies. The final cold load prediction results are obtained by combining these predictions. The proposed method is validated using actual cold load data from an industrial building, and experimental results demonstrate its excellent predictive performance, making it more suitable for cold load prediction in industrial constructions compared to traditional methods. By enhancing the accuracy of cold load predictions. This approach not only improves the energy efficiency of industrial buildings but also promotes the reduction in energy consumption and carbon emissions, thus contributing to the sustainable development of the industrial sector.

The power of technology innovation: can smart transportation technology innovation accelerate green transportation efficiency?

Purpose The purpose of this study is to explore the causal relationship between smart transportation technology innovation and green transportation efficiency. Design/methodology/approach A comprehensive framework is used in this paper to assess the level of green transportation efficiency in China based on the instrumental variable – generalized method of moments model, followed by an examination of the impact of innovation in smart transportation technology on green transportation efficiency. Additionally, their non-linear relationship is explored, as are their important moderating and mediating effects. Findings The findings indicate that, first, the efficiency of green transportation is significantly enhanced by innovation in smart transportation technology, which means that investing in such technologies contributes to improving green transportation efficiency. Second, in areas where green transportation efficiency is initially low, smart transportation technology innovation exerts a particularly potent influence in driving green transportation efficiency, which underscores the pivotal role of such innovation in bolstering efficiency when it is lacking. Third, the relationship between smart transportation technology innovation and green transportation efficiency is moderated by information and communication technology, and the influence of smart transportation technology innovation on green transportation efficiency is realized through an increase in energy efficiency and carbon emissions efficiency. Originality/value Advancing green transportation is essential in establishing a low-carbon trajectory within the transportation sector.

Carbon emissions in the logistics industry: driving factors and decoupling effects.

The explosive growth of the logistics industry has led to an increase in energy consumption and carbon emissions. To reduce emissions and increase the efficiency of the logistics industry, we studied the driving factors and decoupling effects of carbon emissions of logistics industry (LICE). First, an energy coefficient method is used to calculate the LICE. Second, the Logarithmic Mean Divisia Index (LMDI) decomposition method is used to decompose the driving factors of LICE into five types. Third, the decoupling model is used to explore the decoupling relationship between economic growth and LICE. Considering Anhui Province as an example, this study describes the method's implementation process based on a comparison of the four Yangtze River Delta provinces and cities. The results indicate that the growth rate of LICE in Anhui Province has decreased during the research period, from 9.7% in 2013 to 2.1% in 2021; however, the Tapio decoupling elasticity has been approximately 0.4 for the last 2 years, remaining in a weak decoupling stage from economic development. The LMDI decomposition results indicate that the average contribution of economic level to carbon emissions is 1.763. This study proposes some solutions and recommendations for the logistics industry's low-carbon development to offer methodological and theoretical support for LICE research.

Preliminary thermal performance characterization of a flexible separate heat pipe used for the tracking-type photovoltaic/thermal system

In the solar heating field, the separate heat pipe-based photovoltaic/thermal technology can improve the comprehensive utilization efficiency of solar energy and reduce the maintenance difficulty in long-term outdoor operation by preventing freezing and scaling problems. Its promotion and application are of great significance for reducing fossil energy consumption and carbon emissions, and thus have attracted much attention. However, the performance of conventional photovoltaic/thermal modules is limited by their frame shadow due to the insulation demand, which leaves plenty of room for overall efficiency gains. To solve this problem, a novel separate heat pipe-based photovoltaic/thermal system is proposed by introducing a dual-axis tracking method through a flexible separate heat pipe and side-altitude inclination. To preliminarily characterize the thermal performance of the flexible separate heat pipe in dual-axis tracking conditions, an indoor experimental platform of the flexible separate heat pipe using the solar collector and finned-tube heat exchanger in the water tank as the evaporator and condenser was set up. The effects of side inclination angle, altitude angle of the solar collector and solar irradiance on the thermal efficiency, mass flow rate, and thermal resistance of the system are investigated in detail. The experimental results show the system can generally maintain effective heat transfer in side inclination states, with thermal efficiency mostly ranging from 44.68% to 86.12%. The proposed flexible separate heat pipe is qualified for the dual-axis tracking of photovoltaic/thermal system and shows great potential in improving the utilization of solar energy.

Household size and transport carbon emissions in China: Direct, heterogeneity and mediating effects

Shrinking household sizes presents a significant sustainable challenge by reducing the sharing of means of transportation and increasing individual resource consumption and carbon emissions. Research from the historical literature reveals that larger households generally exhibit lower per capita energy consumption and carbon emissions. However, it remains uncertain how widely these trends extend and their implications for carbon emissions within the expanding transportation industry. This paper employs inter-provincial data from China spanning 2003–2021 to investigate the effects, regional heterogeneity, and mechanisms by which household size influences carbon emissions from the transport sector. The findings show that the expansion of household size in China significantly reduces carbon emissions from transport by 0.2805 %. Households with 2 to 4 members are more effective in achieving transport carbon emission reductions, with an average reduction level of 0.1853 %. Moreover, in terms of geographic factors, reducing transport carbon emissions is more effective in low-density areas than in high-density areas. At the income and carbon emissions level, household size significantly reduces transport carbon emissions in high-income and low-emission regions, and to a lesser extent in low-income and high-emission regions. Additionally, the study revealed that transport consumption expenditure and energy consumption indirectly strengthen the effect of household size on reducing transport carbon emissions. Future sustainable development strategies should focus on regulating household size and promoting moderate household size to decrease personal resource consumption and transportation carbon emissions, and to achieve the objective of sustainable development.

Achieving carbon neutrality in Africa is possible: the impact of education, employment, and renewable energy consumption on carbon emissions

This paper analysed the causal link between education, employment, renewable energy consumption and carbon emissions in Africa, where there is scant evidence. Relying on panel data obtained from the World Development Indicators for thirty-two African countries covering a period of 19 years, and five panel rigorous regression models, we found that renewable energy, investment in education, school enrolment, net national income per capita, and employment had negative and significant effects on carbon emission, thus increasing these predictors would result in significant reduction in carbon emission in Africa. We identified a bidirectional causality between carbon emissions and net national income per capita, education expenditure and renewable energy consumption, and carbon emissions and employment. Our findings suggest that investment in education, renewable energy, and employment are relevant in mitigating carbon emissions in Africa. We recommend African governments to invest heavily in education, improve school enrolment, environmental education, renewable energy and employment provision to mitigate carbon emissions.Graphical

Choosing to Pay More for Electricity: An Experiment on the Level of Residential Consumer Cooperation

Reducing energy consumption and carbon emissions is necessary in the fight against climate change. We are interested in the situation of Quebec (Canada), where low-cost hydropower sold below market value, akin to a consumption subsidy, leads to high residential consumption. We conducted an experiment to test whether individuals would be willing to pay more for electricity. Increasing regulated prices closer to their market value would result in a direct welfare gain and free some green energy, reducing greenhouse gases (GHGs) in other sectors. Giving clear and transparent information on the consequences of the price increase induces a majority of people to choose to pay more. In addition to the economic benefit of the public good, the presence of the environmental benefit increases contributions. Participants with a more-severe budget constraint tend to contribute less. These results are encouraging for the development of efficient energy policies reducing GHG emissions.

A Composite Index for Tracking the Evolution towards Energy Transition at Urban Scale: The Turin Case Study

Cities play a pivotal role in achieving worldwide carbon neutrality due to their significant contribution to global energy consumption and carbon emissions. Therefore, planning effective strategies and guiding evidence-based policymaking at the city scale becomes even more crucial. Composite indices serve as a valuable tool for monitoring urban energy transition trends. This paper aims to present a novel approach, robust and flexible even under conditions of data scarcity, for tracking the energy transition trend of a city by means of a composite index (UETI). The Turin case study is introduced to test the applicability of the proposed approach. Additionally, to demonstrate the robustness of the composite index framework, the paper includes the findings of correlation and sensitivity analyses. This study reveals a significant improvement in Turin’s environmental and energy domains, while the socio-economic domain shows more modest improvement. Furthermore, the study highlights the need to address the shortage of urban data to enhance the accuracy and reliability of metric-based frameworks and to extend the assessment to a larger sample of cities.

The dynamic nexus between agricultural productivity and renewable energy consumption in BRICS: the role of financial inclusion and foreign direct investment

Purpose This study aims to examine the impact of renewable energy consumption on agricultural productivity while accounting for the effect of financial inclusion and foreign direct investment in Brazil, Russia, India, China and South Africa (BRICS) countries during 2000–2020. Design/methodology/approach The study has used the latest data from World Bank and International Monetary Fund databases. The dependent variable in the study is agricultural productivity. Renewable energy consumption, carbon emissions, financial inclusion and foreign direct investment are independent variables. Autoregressive distributed lag (ARDL) approach was used to examine the short-run and long-run impact of renewable energy consumption, carbon emissions, foreign direct investment and financial inclusion on agricultural productivity. Findings The findings imply that consumption of renewable energy, carbon emissions and foreign direct investment have a positive impact on agricultural productivity while financial inclusion in terms of access does not seem to have any significant impact on agricultural productivity. Providing farmers, access to financial services can be beneficial, but its usage holds more importance in impacting rural outcomes. The problem lies in the fact that there is still a gap between access and usage of financial services. Research limitations/implications Policymakers should encourage the increase in the usage of renewable energy and become less reliant on non-renewable energy sources which will eventually help in tackling the problems associated with climate change as well as enhance agricultural productivity. Originality/value Most of the earlier studies were based on tabular analysis without any empirical base to establish the causal relationship between determinants of agricultural productivity and renewable energy consumption. These studies were also limited to a few regions. The study is one of its kind in exploring the severity of various factors that determine agricultural productivity in the context of emerging economies like BRICS while accounting for the effect of financial inclusion and foreign direct investment.

Upcycling use of red mud-based solid waste in engineered cementitious composites: Properties, activation mechanism, and life-cycle assessment

In this study, a low-carbon engineered cementitious composite (ECC) was produced by combining alkali-activated red mud (RM)/ground granulated blast-furnace slag (GGBS) with polyvinyl alcohol (PVA) fibers as the reinforcement. Both calcium aluminosilicate hydrate (C-A-S-H) and sodium aluminosilicate hydrate (N-A-S-H) gels are detected in the reaction products. A higher modulus of sodium silicate in the activator results in a higher degree of reaction of silicates in the samples, but not promising a higher mechanical property. The potential mechanism of iron activation in the alkali-activation RM-based ECC system was revealed. The four-point bending test results indicate a large deflection ability and multiple cracking characteristics of the composite. Life cycle assessment of this system is also presented by calculating energy consumption and carbon emissions. This study not only sheds light on the feasibility of using RM in the preparation of high-toughness alkali-activated ECC but also provides a promising method to upcycle industrial solid wastes in a highly effective way.