Comprehensive Environmental Evaluation Research Articles

Evaluation of energy performance and environmental benefits for transcritical CO2 thermal system in high-speed trains

The conventional air conditioning system used in high-speed railways has limitations in heating performance and environmental impact, necessitating the exploration of alternative refrigerants. The transcritical CO2 system has gained popularity due to its exceptional heating efficiency and environmental benefits. This study aims to evaluate the energy and environmental potentials for transcritical CO2 systems in high-speed trains based on four-vertical-and-four-horizontal railway lines within different climatic regions of China. A high-fidelity transcritical CO2 system model was first developed and validated through experiments. Then, a comprehensive energy and environmental evaluation method was proposed and applied to the four-vertical-and-four-horizontal railway lines. The results indicated that the transcritical CO2 system had a superior heating performance and competitive cooling performance based on daily and annual operations. Furthermore, the transcritical CO2 system exhibited significant environmental advantages with lower total life cycle climate performance for all lines, with an average emissions reduction ratio of 17.6% and a maximum emissions reduction ratio of 26.98%. These findings highlight the competitive energy performance and outstanding environmental benefits offered by transcritical CO2 systems as promising alternatives to air conditioning systems in railway transportation.

Research on waste gas treatment technology and comprehensive environmental performance evaluation for collaborative management of pollution and carbon in China's pharmaceutical industry based on life cycle assessment (LCA)

China is the largest industrial and pharmaceutical country in the world. The pharmaceutical industry, being a highly polluting sector, is the primary target of environmental regulation in the industry. The rapid development of pharmaceutical industry has posed a severe challenge to the environmental protection strategy of “carbon reduction and carbon neutrality” and the goal of “synergizing the reduction of pollution and carbon emissions” in China's “14th Five-Year Plan”. Therefore, this paper starts from the whole industry, takes the life cycle of the whole production process of the pharmaceutical industry as the guidance, and selects a pharmaceutical company in Tianjin as the research object. Then using Life Cycle Assessment (LCA) to Characterization, Standardization, and Weighting the environmental impact of the waste gas treatment process before and after improvement based on waste gas emission characteristics from the pharmaceutical factory. LCA results show that GWP and AP are the most important environmental impact types, which account for >85 % of the total characterization value. I and II - Chemical Pharmaceutical Stage is the critical life cycle stage, accounting for over 80 % of the total characteristic values. This research proposes emission reduction countermeasures based on LCA results and simulates Emission reduction scenarios and economic evolution. If effectively implementing emission reduction countermeasures, reducing the environmental characterization value by 80 to 90 %, and generating economic benefit of 2.66 × 108 RMB/year. This research could guide improvement plans and emission reduction countermeasures of waste gas treatment in the pharmaceutical industry, which realizes collaborative management about efficient reduction of pollution and carbon and generates significant environmental, technological, economic, and social benefits.

Comprehensive performance assessment and multi-objective optimization of high-power proton exchange membrane fuel cell system under variable load

Due to the advantages of zero emission, high efficiency and low noise, Proton Exchange Membrane Fuel Cell (PEMFC) has grown to be the spotlight in the field of new energy in recent years. In this work, a high-power PEMFC system model is designed, which consists of the fuel feed Subsystem, the air feed subsystem, the thermal management subsystem and the stack. Among them, the material diffusion in the catalyst layer of the stack is intensively studied and derived. For the comprehensive system performance assessment, the thermodynamic, economic and environmental evaluation models have been developed. The mapping relationships between the operating parameters, the structural parameters and the system comprehensive performance under variable load conditions are obtained. The results of the study prove that increasing the operating temperature and decreasing the membrane thickness under high load current conditions are conducive to increase the system net power output, but at the same time increase the levelized cost of energy and the carbon mass specific emission. In addition, a multi-objective optimization strategy based on the NSGA-Ⅱ is designed to obtain the optimal performance of the system under different operating conditions. The optimized net power, the levelized cost of energy and the carbon mass ratio emission of the system for the final optimal operating point are increased by 40.5 %, 10.3 % and 33.3 % respectively. The aforementioned evidence substantiates the effectiveness of the proposed multi-objective optimization strategy in enhancing the overall performance of the PEMFC system.

A novel method to evaluate phase change materials' impact on buildings' energy, economic, and environmental performance via controlled natural ventilation

The construction industry consumes a significant portion of global energy, with space conditioning in buildings accounting for a substantial 34% of energy usage. Notably, the energy consumption of a building is significantly influenced by its envelope. Researchers widely acknowledge that incorporating phase change materials (PCM) into the building envelope is a promising way to enhance energy efficiency and mitigate CO2 emissions in the building sector, owing to their high latent heat capacity. However, PCM must be completely charged after each cycle to exploit its full potential. Natural ventilation is a viable technique to facilitate the charging and discharging cycle of PCM within a 24-h period. To this end, the present study utilized EnergyPlus simulations to optimize the cooling energy savings of a residential building incorporating PCM into its envelope for PCM melting temperatures, considering various ventilation strategies across 45 cities in 15 climate zones worldwide. In order to evaluate the latent heat utilization of PCM and its improvement facilitated by natural ventilation, two novel indicators, namely HS and HR, were formulated to represent the heat stored and released by PCM during a 24-h cycle, respectively. In addition, following an economic analysis of PCM integration, a comprehensive environmental evaluation was carried out, which included the carbon intensities (CI) of all fuel sources contributing to power generation. The study's findings reveal substantial energy savings across all climate zones when controlled natural ventilation is coupled with PCM, and the newly proposed indicators precisely quantify the performance of PCM in all scenarios evaluated. In the arid climate zone (A), combining PCM and natural ventilation enhances energy savings, albeit to a similar extent as using ventilation alone. However, the integration of PCM with temperature-controlled ventilation yields striking energy reductions of up to 72.8%, 85.3%, and 61% in arid (B), warm temperate (C), and snow (D) climate zones, respectively. The cost-benefit analysis reveals a minimal return period of as short as five years in climate zone C. In the same climate zone C, the in-depth environmental analysis reveals a maximal reduction of 42,004 CO2-e kg/year in carbon emissions. In conclusion, this research study demonstrated that integrating PCM with controlled natural ventilation offers a practical, sustainable, and cost-effective solution with eco-friendly and energy-efficient outcomes.

A Comprehensive Technoeconomic and Environmental Evaluation of a Hybrid Renewable Energy System for a Smart Farm in South Korea

The farming sector like any other industry needs to be decarbonized. Hence, it is essential to meet the energy demands of the farms by adopting energy systems with a low-carbon footprint. Depending on the weather conditions, heating or cooling is needed. Within this context, this study presents a new hybrid renewable decentralized energy system that is designed to satisfy the requirements for heating, cooling, and electricity of a smart farm in South Korea. The under-investigation energy system comprises solar PV arrays, heat pumps, thermal energy storage tanks, and a wood pellet boiler. This study is the first to conduct an inclusive techno-enviroeconomic assessment of such a hybrid energy system by utilizing actual meteorological data on an hourly basis. This enables the model to be dynamic and facilitate accurate and reliable assessments. The modelling efforts have been performed in Aspen Plus and MATLAB to investigate the thermodynamic behaviour of the system. The investigation shows that the proposed system has achieved a daily average temperature of around 23.9°C inside the farm throughout the year with a standard deviation of 2.16°C. For the economic assessment, the levelized cost of energy has been selected as the main economic indicator, and this has been estimated at $0.218/kWh. It is found that the PV panels and the biomass boiler dominate the capital expenditures, and the biomass feedstock is the major contributor to the operating expenditures. Further, the proposed energy system reduces CO2 emissions, by up to 88.94%, when compared to conventional fossil-based energy systems. The outcomes of this study represent a holistic evaluation for such a low-carbon hybrid energy system when applied to greenhouses in Korea and in similar locations.

Effects of indoor air quality and home environmental characteristics on allergic diseases among preschool children in the Greater Taipei Area

Indoor air quality and home environmental characteristics are potential factors associated with the onset and exacerbation of allergic diseases. Our study examined the effects of these factors on allergic diseases (i.e., asthma, allergic rhinitis, allergic conjunctivitis, and atopic dermatitis) among preschool children. We recruited a total of 120 preschool children from an ongoing birth cohort study in the Greater Taipei Area. A comprehensive environmental evaluation was conducted at each participant's residence and included measurements of indoor and outdoor air pollutants, fungal spores, endotoxins, and house dust mite allergens. A structured questionnaire was used to collect information on the allergic diseases and home environments of participants. Land-use characteristics and points of interest in the surrounding area of each home were analyzed. Other covariates were obtained from the cohort data. Multiple logistic regressions were used to examine the relationships between allergic diseases and covariates. We observed that all mean indoor air pollutant levels were below Taiwan's indoor air quality standards. After adjustment for covariates, the total number of fungal spores and the ozone, Der f 1, and endotoxin levels were significantly associated with increased risks of allergic diseases. Biological contaminants more significantly affected allergic diseases than other pollutants. Moreover, home environmental characteristics (e.g., living near power facilities and gas stations) were associated with an increased risk of allergic diseases. Regular and proper home sanitation is recommended to prevent the accumulation of indoor pollutants, especially biological contaminants. Living away from potential sources of pollution is also crucial for protecting the health of children.

How far does the Copper/Nickle recovery from the practical application in the electroplating wastewater?

Metal recovery from electroplating wastewater presents a promising alternative approach for Cu/Ni resource procurement, alleviating traditional mineral mining shortages. This article reviews diverse metal recovery technologies, including adsorption, electrocoagulation, chemical precipitation, resin adsorption, extraction, membrane separation, and electrodeposition. Most studies successfully transfer Cu2+ or Ni2+ from electroplating wastewater to intended metal carriers in lab-scale technologies, thus purifying the wastewater and concurrently enriching desired metals. However, these studies primarily focus on lab-scale heavy metal enrichment and purification, often yielding a mixture of metals with impurities or concentrated salt solution. The importance of reutilization of the recovered metal mixture or metal salt solution, largely unexplored in existing research, is pivotal for sustainability. We propose that future works prioritize pilot-scale experiments, emphasizing reutilization strategies for recovered materials. Consequently, a comprehensive environmental impact evaluation of metal recovery from electroplating wastewater could be made via life cycle assessment, underscoring the importance of reuse in this process.

A comprehensive technical, economic, and environmental evaluation for optimal planning of renewable energy resources to supply water desalination units: Kuwait case study

A comprehensive technical, economic, and environmental evaluation for optimal planning of renewable energy resources to supply water desalination units: Kuwait case study

Extending effectiveness to efficiency: Comparing energy and environmental assessment methods for a wet cooling tower

AbstractImproving the environmental performance and energy efficiency of cooling towers requires systematic evaluation. However, methodological challenges emerge when applying typical environmental assessment methods to cooling towers. Hence, this paper compares the methods, analyzes their strengths and weaknesses, and proposes adaptions for evaluating cooling towers. As a case study, we applied five methods for assessing the wet cooling system of the high‐performance data center in Stuttgart. These are material flow analysis (MFA), life cycle inventory, life cycle assessment (LCA), exergy analysis, and life cycle exergy analysis (LCEA). The comparison highlights that the LCA provides the most comprehensive environmental evaluation of cooling systems by considering several environmental impact dimensions. In the case of the wet cooling tower, however, electricity and water consumption cause more than 97% of the environmental impacts in all considered impact categories. Therefore, MFA containing energy flows suffices in many cases. Using exergy efficiency is controversially debated because exergy destruction is part of the technical principle applied in cooling towers and, therefore, difficult to interpret. The LCEA appears inappropriate because construction and disposal barely affect the exergy balance and are associated with transiting exergy. The method comparison demonstrates the need for further methodological development, such as dynamic extensions or the efficiency definition of cooling towers. The paper highlights that the methodological needs depend on the specific application.

Life-cycle greenhouse gas emission assessment for bike-sharing systems based on a rebalancing emission estimation model

Bike sharing is regarded as a green transportation mode, while the existing studies on its greenhouse gas (GHG) emission assessment seldom consider bike-rebalancing process. In this research, a Bike Sharing System-Rebalancing Emission Estimation Model (BSS-REEM) was proposed to conservatively quantify historical GHG emitted by rebalancing vehicles. Taking the largest bike sharing system (BSS) in North America as a case, we comprehensively assessed its life cycle GHG footprint considering the system's infrastructures, rebalancing process and cycling activities and analyzed the GHG reduction benefits of using pedal and electric trikes to assist trucks in dispatching bikes. Results showed that the bike rebalancing activity level fluctuated throughout 2020 and 56.1% of bikes were dispatched by vehicles and the rest driven by customers' incentive mechanisms. The annual conservative GHG emission of bike rebalancing was 92.1 tCO2-eq when merely diesel trucks were used. Such emissions would be reduced with trikes to assist rebalancing. The emission reduction driven by riding in 2020 reached 14,333.6 tCO2-eq, representing 1.8 times of the entire system's GHG emissions over its service life. Quantifying GHG emissions of the bike-rebalancing process promotes a systematic and comprehensive environmental evaluation of BSSs, providing a basic for their sustainable management.

Energy pellets from whole-wheat straw processed with a deep eutectic solvent: A comprehensive thermal, molecular and environmental evaluation

Storage and transportation are main considerations for seasonal crop residues to become competitive alternatives to non-sustainable fossil fuels and chemicals. Hence, pelletization and briquetting are highly relevant to mass and energy densification and associated supply chains. Here, we propose a green treatment based on recyclable, deep eutectic solvent (DES) to achieve partial swelling and dissolution of residual agricultural biomass (wheat straw), leading to improved structuring and cohesion of energy pellets. The mild DES-based process enhances access to lignin, which migrates and regenerates at interphases for effective binding, enabling improved pellet durability (increased by 90–97% compared to pellets produced from the untreated biomass). The role of lignin was studied by molecular dynamics simulation, which revealed non-bonding interactions with cellulose, impacting the strength of the pellet structure. The DES treatment enhanced the heating value of the pellets (from 16.1 to 19.5 MJ/kg), partially a result of a higher acidy ratio, and simultaneously led to better devolatilization, lignin accessibility and release of volatile matter during pyrolysis. The potential environmental benefit of DES-treated pellets over wood-based counterparts is revealed by a life cycle assessment. Our study further indicates the reduced environmental impact of DES-treated pellets, which can be furthered by recycling of the solvent.

Criticality assessment of metal resources for light-emitting diode (LED) production – A case study in China

Understanding the importance of raw materials is crucial for ensuring high material efficiency in industrial production processes. A common criticality assessment of resources is usually a top view on their supply risk and economic importance. This cannot directly be integrated in a specific process for material manufacturing, which is in high demand to identify the importance of a resource for the process and implement process optimization. In this study, a parameter named resource recirculation factor is introduced, and the criticality assessment model is reformed to facilitate the evaluation of the LED production process from substrate preparation to lamp manufacture. 22 types of materials were selected for evaluation with material flow analysis. The criticalities of gallium and indium, with values of 159.33 and 24.18, were found to be the largest owning to their high supply risk and environmental risk values, which were significantly higher than those of the other materials, such as copper (0.01) and iron (0.27). The high criticality of gallium resulting in trimethyl gallium being the most important material, while trimethyl indium and indium tin oxide (ITO) etchant ranked second and third, respectively. Based on the comparison of the production sections, the epitaxial growth and chip fabrication compressed the two most important sections, which were closely related to the critical metals. Under comprehensive environmental evaluation, the environmental impact of LED production sections was in the order of chip fabrication > substrate preparation > lamp manufacture. The proposed criticality assessment method can provide a basis for the material evaluation and cleaner production of industrial production processes, where comprehensive environmental evaluation can also contribute to the criticality evaluation. • Resource recirculation factor is introduced to criticality assessment model. • Light-emitting diode (LED) production processes were evaluated. • Comprehensive environmental assessment analyzed environmental impact of the waste.

Research on environmental cost control of manufacturing enterprises under double carbon target——Take the "public benefit snack box" product as an example

Environmental cost control is an important part of enterprise cost management, which is based on the premise of enterprise environmental cost management objectives, environmental cost prediction, and the adoption of appropriate models and policies to control the whole process of environmental cost formation. This paper focuses on manufacturing enterprises and takes "charity snack box" as an example to establish a comprehensive environmental cost control system and performance evaluation system for charity snack box. It adopts specific methods to assist analysis, promote the development of environmental cost control for charity snack box enterprises and maximize the comprehensive benefits of economic and environmental benefits.

Study on Environmental Performance Evaluation Model of Coal Mine Using Balanced Scorecard and Ubiquitous Computing

Based on the analysis of the current situation of environmental performance evaluation of coal enterprises in China, this paper uses the Balanced Scorecard as the basic framework to comprehensively evaluate environmental performance from the dimensions of environmental finance, internal environmental management, stakeholders and learning and growth. Set up a number of indicators in each dimension, use AHP to determine the weights of indicators at all levels, and test the rationality of index weights through consistency, and establish a comprehensive environmental performance evaluation system.

Development and performance examination of an integrated plant with desalination process for multigeneration purposes

Increasing environmental problems are of great importance in the development of efficient energy utilization. This article proposed an innovative design gas turbine-based multi-generation plant that integrating a desalination unit for advanced energy management and utilization. Furthermore, this modeled plant comprises a Brayton cycle, a reheat Rankine cycle, an organic Rankine Cycle which does with ammonia, a greenhouse, a Proton Exchange Membrane electrolyzer, and a desalination component. The main purpose of this study is also to provide beneficial commodities such as energy, hydrogen, heating, freshwater, in addition to this to reduce the emission rate by integrating different subsystems, and also to increase system performance. On the other hand, comprehensive thermodynamic assessment and environmental impact evaluation are made that are energy efficiency, exergy efficiency, carbon dioxide emission rate, and sustainability index evaluations, for the overall model and sub-systems. The conclusions of the analysis demonstrated that the whole plant's energy and exergy effectiveness are determined as 0.6076 and 0.5671, respectively, while the carbon dioxide emission rate of the planned model is 0.31 t/MWh. The whole irreversibility of the advised model is 2679.09 kW, and also the maximum exergy destruction rate is found in the combustion chamber with 1216 kW. Moreover, the proposed configuration system has a hydrogen production amount of 0.001742 kgs−1 and a clean water production amount of 0.7647 kgs−1.

Spatial features of the chemical composition of Thala Hills surface snow, East Antarctica

Despite the great interest in the study of the chemical composition of the surface snow cover in Antarctica, the knowledge of the Enderby Land area remains extremely limited. In the Vecherny Oasis, where the construction of the Belarusian Antarctic Research Station has been carried out since 2015, the study of the chemical composition of the surface snow began in 2012 in preparation for the Comprehensive Environmental Evaluation. Its continuation is due to the need to assess the consequences of the construction and operation of the station in accordance with the requirements of the Antarctic Treaty Protocol on Environmental Protection.Snow samples were taken from 2012 to 2019 during the seasonal Belarusian Antarctic expeditions. Sampling was carried out from the surface horizons, which characterize the annual snow fallout. Chemical analytical studies were performed using standard methods. A total of 144 samples of snow water were analyzed.The aim of the study is to characterize the chemical composition of the surface snow of the Vecherny Oasis (and of the Thala Hills as a whole) to identify the areas of anthropogenic impact and trends in its change.The data on the main ions content in the surface snow, the value of pH and electrical conductivity, as well as the variabilities of the main indicators are presented. It is shown that the snow water of the Vecherny Oasis is very low-mineralized, with the sum of ions in the range of 1,04–57,3 mg/l (average — 7,4 mg/l), the values of electrical conductivity — 2,7–85,1 µS/cm (10,7 µS/cm). The snow water in most cases is characterized as slightly acidic. The chemical composition of the snow water and its mineralization is determined mainly by the content of chlorides and sodium ions. The high variability of the indicators of snow water hydrochemical composition within the areas of former and current human activities, as well as the increased content of sulfate ions, is considered to be indicative of anthropogenic impact.

Comprehensive environmental impact evaluation for concrete mixing station (CMS) based on improved TOPSIS method

This study presents an approach based on the improved technique for order preference by similarity to an ideal solution (TOPSIS) to perform comprehensive environmental impact evaluation for concrete mixing station (CMS) and to determine the optimal location of CMS. An evaluation framework consisting of four indicators and 12 sub-indicators from the environmental and sustainable aspects is established. Entropy method is adopted to determine the weights of indicators and sub-indicators. The improved TOPSIS method is employed to rank candidate locations according to the values of closeness coefficient index (CCI). A case study regarding on CMS location selection of a tunnel project is demonstrated the performance of developed approach. Results show that factors, i.e. environmental impact and pollution reduction management, are top two indicators which should be paid more attention. Moreover, the ranking order of candidate location is presented. Sensitivity and comparison analysis indicate that ranking results considering only profitability indicators is opposite that the results in only consumption indicators. The developed approach provides a guideline in MCS management to increase the sustainability of city.

Small-scale biochar production on Swedish farms: A model for estimating potential, variability, and environmental performance

Several small-scale pyrolysis plants have been installed on Swedish farms and uptake is increasing in the Nordic countries. Pyrolysis plants convert biomass to biochar for agricultural applications and syngas for heating applications. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts, and improving farm finances and resilience. Before policy support for on-farm pyrolysis projects is implemented, a comprehensive environmental evaluation of these systems is needed. Here, a model was developed to jointly: (i) simulate operation of on-farm energy systems equipped with pyrolysis units; (ii) estimate biochar production potential and its variability under different energy demand situations and designs; and (iii) calculate life cycle environmental impacts. The model was applied to a case study farm in Sweden. The farm’s heating system achieved net carbon dioxide removal through biochar carbon sequestration, but increased its impact in several other environmental categories, mainly due to increased biomass throughput. Proper dimensioning of heat-constrained systems is key to ensure optimal biochar production, as biochar production potential of the case farm was reduced under expected climate change in Sweden. To improve the environmental footprint of future biochar systems, it is crucial that expected co-benefits from biochar use in agriculture are realised. The model developed here is available for application to other cases.

Environmental Evaluation of Coal Mines Based on Generalized Linear Model and Nonlinear Fuzzy Analytic Hierarchy

To create a good working environment for workers in coal mines and ensure that they can work safely and comfortably, environmental assessments of coal mines represent an important method used to achieve this goal. In this paper, a comprehensive environmental evaluation model of coal mines was established based on generalized linear theory and fuzzy analytic hierarchy processes. First, the importance degree of each index factor was obtained by analyzing the statistical source data of air, water, soil, ecological compensation, and other indexes that affect the ecological environmental safety of coal mines using generalized linear theory. Based on the importance degree of each index factor, a pairwise comparison matrix was constructed by the logarithmic fuzzy preference programming method, and the influence weight value of each index factor was accurately obtained through MATLAB software. The results indicated that the model can effectively reduce the impact of expert subjectivity on the evaluation results, which is consistent with the reality of coal mines. In addition, in the process of environmental assessment of coal mines, the model is proven to be convenient, precise, and easy to operate.

Hepatic oxidative stress and neurotoxicity in Pelophylax kl. esculentus frogs: Influence of long-term exposure to a cyanobacterial bloom

Although the long-term exposure of aquatic organisms to cyanobacterial blooms is a regular occurrence in the environment, the prooxidant and neurotoxic effects of such conditions are still insufficiently investigated in situ. We examined the temporal dynamics of the biochemical parameters in the liver of Pelophylax kl. esculentus frogs that inhabit the northern (N) side of Lake Ludaš (Serbia) with microcystins (MCs) produced in a cyanobacterial bloom over three summer months. The obtained data were compared with data on frogs that live on the southern (S), MC-free side of the same lake. Our results showed that the MC-producing bloom induced oxidative damage to proteins and lipids, observed as a decrease in the concentration of protein –SH groups and increased lipid peroxidation (LPO) in the liver of N frogs in comparison to S frogs. Glutathione (GSH) played a key role in the transient defense against the MC-induced development of LPO. The low glutathione peroxidase (GPx) activity detected in all groups of frogs from the N site was crucial for the observed prooxidant consequences. The bloom impaired cholinergic homeostasis as a result of a decrease in ChE activity. A delayed neurotoxic effect in relation to the prooxidant outcomes was observed. Our results also showed that even though the integrated biomarker response (IBR) of the antioxidant biomarkers increased during exposure, the individual biochemical parameters did not exhibit a well-defined time-dependent pattern because of specific adaptation dynamics and/or additional effects of the physicochemical parameters of the water. This comprehensive environmental ecotoxicological evaluation of the cyanobacterial bloom-induced biochemical alterations in the liver of frogs provides a new basis for further investigations of the prolonged, real-life ecotoxicity of the blooms.