Life Cycle Energy Consumption Research Articles

Embodied Energy Coefficient Quantification and Implementation for an Energy-Conservative House in Thailand

Embodied Energy Coefficient Quantification and Implementation for an Energy-Conservative House in Thailand

Enhancing indoor thermal comfort and sustainability: A solar-driven desiccant cooling and adsorption chiller system with environmental impact assessment

Addressing indoor thermal comfort in buildings located in hot and humid climates is a persistent challenge, demanding innovative cooling solutions that are both efficient and environmentally responsible. This paper introduces a new integration of a Phase Change Material (PCM)-based solar desiccant cooling system with an adsorption chiller, a setup designed to enhance indoor thermal comfort conditions while utilizing renewable energy sources. This research simultaneously leverages the heating and cooling capacities of the adsorption chiller, leading to an efficient system performance. The TRNSYS software is used to evaluate the system's behavior in a typical house with moderate cooling demand and characterized by high relative humidity. Two types of solar collectors, the evacuated tube and Wavy Direct Absorption Solar Collectors (WDASC), are evaluated to supply the required thermal energy, providing a comprehensive assessment of the system’s efficiency under different configurations. Additionally, the study conducts a comprehensive Life Cycle Assessment (LCA) to quantify the Global Warming Potential (GWP) of the systems. The results confirm the proposed system's capability to maintain indoor thermal comfort within acceptable Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) ranges. The evacuated tube collector showed marginally better performance (average PMV: 0.018, average PPD: 6.7 %) compared to the WDASC (average PMV: 0.075, average PPD: 7.3 %). Additionally, the evacuated tube collector demonstrates superior energy (75.68 %) and exergy (10.82 %) efficiencies compared to the WDASC. The system utilizing the evacuated tube collector surpasses the WDASC configuration, achieving a higher Coefficient of Performance (COP) of 0.47 compared to 0.41, and emitting lower GWP values of 0.0194 kg-CO2 per kWh of cooling capacity compared to 0.0201 kg-CO2. An analysis of Embodied Energy reveals that the adsorption chiller is the most significant contributor to lifecycle energy consumption, with a quicker Energy Payback Time (EPBT) for the evacuated tube system (2.75 years) compared to the WDASC system (3.94 years). This research thus contributes a highly efficient, sustainable, and environmentally friendly solution to the challenge of cooling in buildings, setting a new standard for future green building practices.

Evaluation indicators for road traffic energy consumption: a review and prospect.

Indicators for evaluating road traffic energy consumption are critical parameters in the research field of road traffic energy consumption. Improving the applicability of energy consumption indicators can promote the development of green transportation in cities. However, there is currently a lack of systematic analysis of energy consumption indicators in research. Therefore, based on a comprehensive analysis of relevant literature, this study divides the indicators for evaluating road traffic energy consumption into two categories: macro (aimed at traffic systems or traffic flow) and micro (aimed at vehicles). These indicators are subdivided into four categories according to their application characteristics, including general, specific, predictive, and comprehensive. This paper provides a complete summary of various evaluation indicators, including their scope of application, advantages, and limitations, and highlights the relationships between them. Additionally, recommendations are made for the future development of evaluation indicators. Research has found that micro-level general indicators serve as the fundamental components of the mathematical structure for almost all other indicators. Specialized indicators primarily evaluate energy consumption in different driving states of vehicles. Predictive indicators are mainly used for assessing transportation energy consumption in simulation conditions. Comprehensive indicators are mainly applied to evaluate the life cycle energy consumption of vehicles or transportation systems. In future research, the performance of indicators can be improved through the design of standardized indicators, enhancement of energy consumption prediction accuracy, and integration of traffic flow parameters. The research contributes to upgrading energy-saving technologies in road transportation and developing sustainable urban transportation systems.

Research on the whole life cycle energy consumption and pollution emission of new energy vehicles and traditional fuel vehicles based on the perspective of single vehicle currency of the same vehicle model

To construct an evaluation framework based on whole-life energy consumption and pollution emissions, the control variable method is used when selecting vehicles for comparison. By assessing a new energy vehicle (the Audi Q2L e-tron) and a traditional fuel vehicle (the Audi Q2L) of the same model, differences in emission and energy consumption are solely attributed to power forms. Results are monetized to facilitate analysis of the societal benefits of new energy vehicles, reflecting environmental impact in monetary terms. The results of the paper show that although the replacement of traditional fuel vehicles by new energy vehicles can achieve carbon emission reduction and considerable energy savings in the energy cycle, due to the fact that new energy vehicles produce more sulphur dioxide (SO2) and nitrogen oxides (NOx) in the production phase, the full replacement of traditional fuel vehicles by electric vehicles at this stage will not be able to achieve an improvement in the overall welfare of the society. Therefore, under the current conditions, the improvement of new energy vehicles should start with finding cleaner and more environmentally friendly ways in the manufacturing stage of automobiles, as well as modifying the way of producing electricity.

The multi-objective optimization framework: A step towards minimizing life-cycle costs and energy consumption of carbon fibre automotive structures

Design of a sustainable and economical composite structure is challenging due to the often contradicting design drivers such as energy consumption and cost. Therefore, predicting the environmental and economic impact in the early stages of product design results in the significant reduction of energy consumption and cost. Consequently, the impact of contrasting objectives on an optimized carbon fibre reinforced polymer (CFRP) demonstrator is evaluated in this study. This evaluation is performed by integrating a predictive life-cycle assessment and costing framework in a multi-objective optimization methodology. The varying design configurations include designs with and without stiffeners. Furthermore, the impact of end-of-life allocation on the optimized design is also evaluated in this study. The results show a marked difference between the energy consumption of the various optimized designs with energy optimization producing the most efficient solution. However, the mass of the demonstrator increases by 7–9 kg across the different design configurations when the closed loop allocation model is implemented. Consequently, the results show the importance of selecting an appropriate EOL allocation methodology in evaluating the energy consumption of a product. The results also show that the parameters driving the energy consumption (mass and material configuration) and cost (complexity and manufacturability) are varied and often contrasting. The differences in mass, cost, and energy optimized designs further reinforces the importance of coupling cost and energy evaluation in design of sustainable products. Finally, the study demonstrates the need for a holistic life-cycle based assessment in early stage sustainable product design.

Selective thermal recycling for graphene growth on natural substrates: A comparative study on life cycle assessment, energy consumption, and mechanical performance in recompounding

AbstractManufacturing of carbon‐based materials from waste thermoplastics is a keystone to reduce adverse environmental impacts. There are numerous attempts for sustainable graphene manufacturing from various waste sources by thermal treatment but there is no clear distinction on the effective conversion process by addressing reliable CO2 footprints. This study provides a comprehensive benchmarking study on the conversion of waste polypropylene plastics coming from yogurt containers into graphene on the substrate of talc by applying two upcycling techniques of catalytic carbonization (CC) and flash pyrolysis (FP) by comparing energy and speed of the processes and a dimensional stability and physical characteristics of the produced graphene substances by adopting a comparative life cycle assessment. FP led to the sphericalization of graphenes due to fast dehydration, cross‐linking, and carbonization of aromatic structures. On the other hand, gradual heating in CC caused the formation of tubular‐like graphene structures. In addition, FP became advantageous by resulting in 52% of CO2 emission compared with CC process. On the other hand, graphenes separated from talcs exhibited a remarkable 70% reduction in global warming potential compared with conventional graphene production from graphite. In order to complete the value chain and circularity, the mechanical performance of two different hybrid additives produced by selective thermal recycling in recompounding with copolymer polypropylene was examined, and additives from CC enhanced the flexural and tensile properties two times better than the one from FP. With this study, it becomes possible to compare analysis of graphene growth on natural substrates by exploring life cycle assessment, energy consumption, and mechanical performance with selective thermal recycling and recompounding.

Dynamically assessing life cycle energy consumption of buildings at a national scale by 2020: An empirical study in China

Dynamically assessing life cycle energy consumption of buildings at a national scale by 2020: An empirical study in China

Life cycle assessment and life cycle cost analysis of surgical mask from production to recycling into hydrogen process

Global greenhouse gas emissions and medical supply management systems are facing increasing challenges at the social, environmental, and economic levels. This study aims to propose a multi-objective assessment method coupled with life cycle assessment and life cycle cost analysis to evaluate the entire process of medical supply represented by surgical mask from production to recycling into hydrogen from environmental and economic perspectives. Mass and energy flow data are obtained from literature and the hydrogen production process by plasma gasification of surgical mask established using Aspen Plus. The results reveals that the life cycle energy consumption, global warming potential, acidification potential and photochem ozone creation potential in the surgical mask collection, pretreatment, plasma gasification and waste heat recovery stage account for 77.34%, 40.20%, 46.00% and 44.63% of the entire life cycle, respectively. Operating costs have a significant impact and using of fully automatic equipment and improving the energy consumption of plasma torches are critical to reducing system operating costs. A sensitivity analysis of the four modes of hydrogen transport is performed, and the best mode of hydrogen transport is proposed. This study provides basic information reference for the medical product management system.

Life cycle energy consumption prediction based on an extended system boundary with the Bi-LSTM model: An empirical study of China

Global warming and natural disasters have wreaked havoc on Earth these days. Energy conservation has been a priority under social development pressure, especially in the building sector. Energy consumption prediction serves as a vital tool for effective building energy management, guiding energy policy making and services distribution. However, despite the application of advanced technologies, achieving accurate energy consumption prediction still faces challenges due to potential influencing factors. This study aims to explore previously unidentified factors to enhance building energy consumption prediction accuracy. An extended life cycle energy boundary of buildings including embodied, operational, and mobile energies is proposed. To optimize the prediction processes, a hybrid Life Cycle Assessment (LCA) approach and a non-linear Bidirectional Long Short-Term Memory (Bi-LSTM) model are combined. An empirical study was conducted to predict the life cycle energy consumption of urban residential buildings in China by 2035. Results show: (1) life cycle energy consumption increased dramatically from 195.837 (±11.77) Mtce in 2000 to 1151.69 (±80.38) Mtce in 2022, but then achieved a slow decline to 796.998 ((±51.46)) Mtce by 2035; (2) there were four significant development stages in the residential field: rapid growth (2000–2010), sharp growth (2010–2018), slow growth (2018–2022), and stable fall (2022–2035); (3) mobile energy related to building location accounted for up to 28% of total energy consumption, and daily commuting is its largest emitter. However, calculation errors caused by diverse data sources and the fundamental model itself need to be addressed later. This study provides an original pathway of combining LCA with a non-linear model to improve energy consumption prediction and the completed primary historical data to help local governments’ energy decision-making.

Shear behaviors of engineered cementitious composites to seawater sea-sand concrete (ECC-to-SSSC) interfaces cast using 3D-printed pre-grooving formwork: Mechanical properties, characterization, and life-cycle assessment

This paper aims to investigate shear behaviors of engineered cementitious composites to seawater sea-sand concrete (ECC-to-SSSC) interfaces cast using 3D-printed pre-grooving formwork. The investigation involves experimental tests and economy/environmental analysis. The investigated parameter includes concrete types, interface roughness, and ECC compressive strength. A novel and eco-efficient interface treatment method was developed using 3D printing pre-grooving formworks, and an accurate interface roughness quantification method was proposed. The interface shear test was conducted to obtain shear load-slip curves and interfacial shear strengths. The characterization results showed that, ECC-to-SSSC interfaces contained Frieda's salt, which improved hydration rate and generated more hydration products to enhance interface strength. Moreover, economic/environmental analysis showed that the use of SSSC, ECC, and 3D-printed pre-grooving formwork greatly reduced life-cycle cost, carbon footprint, and energy consumption. This study is promising to enhance the understanding of interfacial behaviors of ECC-to-SSSC interface and mitigate material cost and carbon footprint in concrete.

Development and application of life-cycle energy consumption and carbon footprint analysis model for passenger vehicles in China

China has become the global largest electric vehicle (EV) market, making the energy and climate issues of EV industry in terms of life cycle attract widespread attention. Based on the self-designed life-cycle analysis tool and up-to-date database, this study analyzes energy consumption and greenhouse gas (GHG) emissions of a typical passenger internal combustion engine vehicle (ICEV), and battery EV (BEV) and plug-in hybrid EV (PHEV) installed with different lithium-ion battery types, covering both fuel cycle and vehicle cycle. Owing to the battery installation, which shares nearly 30% of the GHG emissions in EV's vehicle cycle, the BEV and PHEV emit 13533–15445 kgCO2,eq/vehicle and 11572–12186 kgCO2,eq/vehicle, 65.6%–89.0% and 41.6%–49.1% higher than that of the ICEV, respectively. EV's fuel-cycle low emissions offset its surplus emissions in vehicle cycle. The EV generates 219.8–230.9 gCO2,eq/km in life cycle, achieving 18.3%–22.6% of reduction compared to the ICEV. Development of non-fossil power will highlight the advantages of EVs in energy conservation and GHG emission reduction, e.g. if the proportion of coal power decreased to 10%, BEV's life-cycle GHG emissions will reduce about 70% than current level. Policies should focus on both EVs development acceleration and the low-carbon automotive and battery industry creation.

Technical and life cycle performance comparison between petroleum coke chemical looping combustion and oxy-combustion combining with advanced steam cycles for power generation processes

Inferior petroleum coke is attractive to be used in power generation industry since it has the advantage of high calorific value. To address the environmental problem of petroleum coke combustion for power generation, this paper establishes a process model of petroleum coke chemical looping combustion (CLC) and compares its performance with that of a petroleum coke oxy-combustion (OCB). The results show that CO2 capture rate of the CLC and OCB both reach about 100%. Under the petroleum coke conversion rate of 70%, the net electrical efficiencies of the petroleum coke CLC and OCB are 28.61% and 24.68%. The life cycle energy consumption and GHG emission of the CLC and OCB are 12.08/12.76 GJ/MWh and 338.03/397.91 kg CO2 eq/MWh, respectively. Compared with the sub-critical steam cycle in the above base case, the net electrical efficiencies of the CLC integrated with supercritical and ultra-supercritical cycles are increased by 0.93 and 1.53 percentages points, while their life cycle energy consumption and GHG emission are decreased by 0.31/0.49 GJ/MWh and 5.85/10.34 kg CO2 eq/MWh. When the conversion rate increases from 70% to 95%, the net electrical efficiencies of the CLC process are increased to 39.71/40.97/41.84%, and their life cycle results are decreased to 9.32/9.09/8.95 GJ/MWh and 300.85/296.20/292.07 kg CO2 eq/MWh. Therefore, improving conversion rate of the CLC and its coupling with advanced steam cycles for power generation are important for clean and efficient utilization of inferior petroleum coke.

Life cycle assessment of steel-glued laminated bamboo (GluBam) hybrid truss in China

Glued Laminated Bamboo (GluBam) has been innovated under the support of modern industrial technology, and this renewable material can drive the development of building structural system in a fashion of low carbon footprint. From the perspective of carbon emission, energy consumption and cost-based economy, this paper presents a comprehensive life cycle assessment (LCA) of steel-GluBam hybrid truss and virtually designed steel truss for a comparison. A steel-GluBam hybrid truss constructed at the Nanjing Tech University is used to carry on this study. The system boundary (i.e., production phase, transportation phase, construction phase, operation phase and disposal phase) of life cycle are fist determined. The mechanical properties of the truss structure are considered as the functional equivalence. The inventory of construction materials and the elements in each phase in the life cycle is compiled from the SimaPro and the available literature/specification. Based on the inventory analysis, the Monte Carlo method is employed to conduct the uncertainty analysis of carbon emission of the truss. The assessment results show that the life cycle carbon emission, energy consumption and cost of the steel-GluBam hybrid truss are equal to 4572.5 kgCO2eq, 71.15 GJ and 15626.6 CNY, respectively. The production phase is the largest contributor to the carbon emission, energy consumption and cost, and the following one is the operation phase. Whereas the transportation phase, the construction phase and the disposal phase together contribute to only the small parts of emissions and cost. GluBam has the function of carbon sequestration leading to the reduction of carbon emission and energy consumption in the production phase, and other phases have no advantage on the emissions and cost of GluBam. The 95% confidence interval of life cycle carbon emission based on the Monte Carlo simulation is estimated as [4290,6370] kgCO2eq for the steel-GluBam hybrid truss. With respect to the whole life cycle, using GluBam to replace the steel pipe in the upper chord pole and the diagonal web pole of the truss has a little larger cost but its environmental impact and energy consumption reduce a lot. The railway transportation of GluBam reduces 36.5 kgCO2eq carbon emission, 0.68 GJ energy consumption and 83.7 CNY cost in the life cycle with reference to the road transportation. The steel-GluBam hybrid truss optimized based on the functional unit occurs in the case of reducing the cross-section of steel pipe from 42 mm × 4 mm to 32 mm × 2.5 mm.

Research on Hierarchical Clustering LEACH Protocol Optimization Algorithm Based on Chebyshev Distance

For the problems of premature death of cluster head nodes, short network life cycle and fast energy consumption in hierarchical clustering LEACH protocol in wireless sensor networks, an improved routing protocol K-means LEACH distance optimization algorithm based on LEACH is proposed in this paper. The improved routing algorithm takes into account the problems such as random selection of cluster heads and tedious calculation of distance formula in LEACH algorithm, so K-means clustering algorithm is introduced. The specific scheme is to first divide the data into K classes, then select the appropriate cluster heads, and introduce the Chebyshev distance formula on the basis of K-means clustering algorithm. From the comparative analysis of the simulation results, the K-means LEACH distance optimization algorithm compared to the original LEACH algorithm wireless network node life cycle by 64%, node energy consumption by 26%, which is conducive to improving the stability of WSN, reducing node energy consumption and extending the network survival time.

ALUMINUM AS A PROMISING MATERIAL IN THE AUTOMOTIVE INDUSTRY

Aluminum alloys are extensively applied in the transport sector and contribute to sustainability, lean production and circular economy as well; their widespread use can be considered as accelerators for transition to Industry 4.0 and Industry 5.0 concepts. One of the features is that at the end of a vehicle`s life cycle almost all aluminum can be recycled for production of new products. The presence of aluminum in all kinds of transport provides an increase of speed, safety, energy savings and decrease of transport emissions. Thus, with a 10 % reduction in the total weight of the car a fuel saving of 5…10 % is achieved in the total spent fuel per kilometer [Tolun, 2019]. Replacement of 1 kg of steel on 1 kg of aluminum / aluminum alloy in automobile construction decreases the overall carbon dioxide emissions by 5…8 kg CO2-eq. for the life cycle (or per 200,000 km of mileage) [Geyer, 2008; Peppas et al., 2021]. There is also a reduction of total life cycle energy consumption up to 20 % [The Aluminum Association]. Aluminum discs ensure a smooth ride and improved heat dissipation from the braking system. In the event of an accident, aluminum absorbs the impact more effectively than steel.

Towards the goal of zero-carbon building retrofitting with variant application degrees of low-carbon technologies: Mitigation potential and cost-benefit analysis for a kindergarten in Beijing

China's building industry urgently needs to accelerate the deployment of zero-carbon building technologies and zero-carbon project practices to facilitate the net-zero target. This study aims to explore the application potential and benefits of applying low-carbon technologies in existing buildings from a life-cycle perspective to drive zero-carbon building retrofits in China. To illustrate the impacts of the application of low-carbon technologies on zero-carbon building retrofitting, the mitigation values and abatement costs were evaluated for 16 typical low-carbon technologies of buildings, and the comprehensive incremental benefits model considering the environmental, economic and social impacts was developed. The incremental cost-effectiveness ratio index with the time value was proposed to explain the feasibility of building zero-carbon retrofit for different levels of technology application. In this study, a public building (kindergarten) in Beijing was taken as a study case, and the initial life-cycle energy consumption and carbon emissions based energy simulation were considered as the benchmark to compare the effect of zero-carbon transformation of the case building with different degrees of technology application. It is found that the economic benefit of implementing zero-carbon retrofitting of the case building through these low-carbon technologies increases from 42% to 66%, while the environmental benefit decreases from 57% to 32%. The analysis of incremental cost-effectiveness ratio indicates that achieving zero-carbon renovation over the lifetime of the kindergarten is economically feasible, and the comprehensive incremental benefits of the application of low-carbon technologies will exceed the incremental cost. The quantitative research for building low-carbon technologies in this study might provide an effective assistance on technology selection at the project level for better zero-carbon renovation strategies.

Is the Transition to Electric Passenger Cars Sustainable? A Life Cycle Perspective

Compared to conventional passenger cars, the hybrid and electric alternatives include electric motors and large batteries; the use of clean energy, reduced operation emissions, and decreasing purchase prices can represent solid reasons for their market adoption. The feasibility of the transition to electric cars is analyzed herein in terms of the costs, main pollutants, and energy consumption of compact to large-sized cars. In this regard, the proposed life cycle assessment methodology evaluates the pollution and energetic impacts of the current passenger car models with a weight varying from 1.6 to 1.8 tons, depending on the car type, for a complete life cycle. The life cycle emissions and energy consumption are also determined through simulation in order to validate the estimated values for the considered powertrains. This study has shown that a transition to current full-electric passenger cars, based on a European and United States energy mix, is not currently sustainable in terms of energy consumption. The complete life cycle values are similar for the tested conventional and full-electric passenger cars, ranging from 5 to 5.2 MJ/km. By comparison, the hybrid alternatives and full-electric cars based solely on renewable energy present lower energy consumption, ranging from 3.32 to 4.62 MJ/km. At the same time, the hybrid alternatives and conventional cars provide relevant benefits in life cycle costs: 20–25% lower than full-electric cars. In terms of life cycle emissions, the tested full-electric cars based on renewables show a noticeable reduction in greenhouse gases and in other relevant pollutants: 37% and 62%, respectively, lower than that of conventional cars.

Multi-Model Assessment for Secondary Smelting Decarbonisation: The Role of Hydrogen in the Clean Energy Transition

Extensive decarbonisation efforts result in major changes in energy demand for the extractive industry. In 2021, the extraction and primary processing of metals and minerals accounted for 4.5 Gt of CO2 eq. per year. The aluminium industry was responsible for 1.1 Gt CO2 eq. direct and indirect emissions. To reach the European milestone of zero emissions by 2050, a reduction of 3% annually is essential. To this end, the industry needs to take a turn towards less impactful production practices, coupling secondary production with green energy sources. The present work aims to comprehensively compare the lifecycle energy consumption and environmental performance of a secondary aluminium smelter employing alternative thermal and electricity sources. In this frame, a comparative analysis of the environmental impact of different thermal energy sources, namely natural gas, light fuel oil, liquified petroleum gas, hydrogen and electricity, for a secondary aluminium smelter is presented. The results show that H2 produced by renewables (green H2) is the most environmentally beneficial option, accounting for −84.156 kg CO2 eq. By producing thermal energy as well as electricity on site, H2 technologies also serve as a decentralized power station for green energy production. These technologies account for a reduction of 118% compared to conventionally used natural gas. The results offer a comprehensive overview to aid decision-makers in comparing environmental impacts caused by different energy sources.

Second Skin of Facade Impact on Office Building Life Cycle Energy Consumption: A Comparative Study

Second Skin of Facade Impact on Office Building Life Cycle Energy Consumption: A Comparative Study

Analysis and assessment of life-cycle carbon emissions of space frame structures

The construction industry takes up a significant part of global energy consumption and carbon emissions, and thus accurate calculation and evaluation of full life-cycle energy consumption and carbon emissions of different types of building structures are important for low carbon-oriented structural design. Large-span structures usually consume more materials, need more complex construction processes, and thus have a larger environmental impact. In this study, the life cycle assessment of the carbon emission of space frame structures which is a classical type of large-span structure is conducted. Space frame structures with bolted spherical joints and space frame structures with welded hollow spherical joints are considered. The life cycle of a space frame structure is divided into four phases including component production, construction, maintenance, and demolition. The tiered hybrid method that combines process-based calculation and input-output analysis is adopted to evaluate the carbon emission of space frame structures. Parametrical studies on the height-span ratio and grid number are carried out using the proposed assessment scheme. The carbon emissions of the space frame structures with different types of joints are investigated and compared. It is found that lower material consumption does not always result in lower carbon emission, and thus it is necessary to evaluate the life-cycle carbon emission during lower carbon-oriented design of space frame structures. An equation for approximately and quickly estimating the carbon emission of space frame structures is fitted from the material consumption to carbon emission datum obtained from the parametrical studies. This study provides a useful reference for the carbon emission assessment and low-carbon oriented design of space frame structures.