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This study investigates the impact of incorporating lime mud (LM) as a filler material to develop sustainable, cementless ultra-high performance concrete (UHPC) by replacing silica powder (SP) and silica sand (SS) at varying percentages. Flowability analysis reveals that LM, with its distinctive particle size, influences flow characteristics differently at different replacement levels. Compressive strength was improved by 5.4% with 30% SP replacement, showcasing the role of LM in nucleation, as well as its particle size advantage. The heat of hydration analysis indicates that LM likely influences the early curing stages, enhancing reactivity and nucleation. TGA analysis also confirms that LM plays a role in hydration reaction, influencing weight loss and hydration peaks. The mercury intrusion porosimeter results show the impact of LM on pore distribution, with 30% for SP and 50% for SS replacements, favoring denser matrices. Life cycle assessment (LCA) demonstrates reduced CO 2 emissions and favorable environmental performance, highlighting the sustainability potential of LM replacements. Overall, the incorporation of LM in UHPC shows promise in terms of enhancing its mechanical properties and environmental sustainability. [Display omitted] • Lime mud (LM) in UHPC boosts material strength, leading to denser, more effective concrete. • LM enhances hydration, flowability, and refines pore structure. • High LM ratios in UHPC increase sustainability and reduce CO 2 emissions. • LM's use in UHPC significantly advances its mechanical properties and eco-friendliness. [ABSTRACT FROM AUTHOR]

China is the top emitter of greenhouse gases in the world. Pulp and paper industry is one of eight the strictly regulated industries about carbon emission in China. However, estimates of carbon emissions from China's pulp and paper industry have been suffered from remarkable uncertainty. It is summarized that is aroused by the inaccuracy of factors evaluating energy consumption, and the huge gap between the calculation standards for assessing energy consumption in the production process and the actual level recorded in the factories. This paper re-evaluated the carbon emission of China's pulp and paper industry from the perspective of life cycle assessment, and applied more accurate emission factors, taking account of the actual energy consumption of the production process in factories, to estimate the actual carbon emissions in maximum. It is found that the national standards about the energy consumption quota of China's pulp and paper industry is no longer applicable, and the actual energy consumption regulated in the production process is far better than the advanced level given by the national standards. The greenhouse gas emission have been seriously overestimated approximately 12.00%–56.17% by international organizations. • Life Cycle Analysis of the China's pulp and paper Industry is conducted thoroughly. • The pulp flow of China's pulp and paper Industry is analyzed. • Energy regulated in factory is far better than the national standards' required. • Carbon emissions of China's pulp and paper Industry are overestimated. [ABSTRACT FROM AUTHOR]

Numerical simulations based on Computational Fluid Dynamic techniques are performed to analyze the possibility of feeding a biomass-derived syngas into the combustion chamber upstream of the hoods for tissue-paper drying, to replace fossil fuels and thus decarbonize the plant. It was observed that, in the context of Favre-Averaged Navier–Stokes equations simulation, syngas requires detailed kinetics and finite-rate approaches, as the fast-chemistry ones, largely employed in the industrial practice for conventional fuels, lead to unreliable results. The actual chamber, originally designed to be fed with liquid petroleum gas, does not operate properly when fueled with syngas, with incomplete oxidation of carbon monoxide. Numerical simulations have proven how very few modifications of the chamber can be devised to permit feeding efficiently the syngas, obtaining low pollutant emissions and meeting the desired requirements in terms of flow and thermal uniformity for the drying process. The solution proposed in the present study, with the effective use of a biomass-derived syngas to feed the drying section of a tissue paper plant, will allow saving approximately 8500 ton/y of CO 2 emissions in comparison with today's fossil fuel carbon footprint. [Display omitted] • Use of syngas from biomass gasification to decarbonize a tissue paper plant. • CFD simulations to comprehend the behavior of chamber and hood fed with bio-syngas. • Need for detailed kinetics to model with CFD the bio-syngas combustion. • Modification of the combustion system needed to limit CO with the bio-syngas. • Reduction of 8500 ton/y of CO 2 emissions in comparison to today's LPG. [ABSTRACT FROM AUTHOR]

Abstract Although paper production demonstrates high energy and water sensitivity in their life cycles, only a few systematic analyses have focused on these issues. Therefore, an energy and carbon coupled water footprint analysis of five types of Kraft wood pulp-based paper (i.e., specialty-, art-, household-, light coated-, and tissue paper) is conducted in this study to help improve the environmental performance of the paper industry. All investigations are conducted with an impact-oriented approach based on ISO standards. Results show that elemental-chlorine-free bleaching is more environmentally friendly than chlorination-alkaline extraction-hypochlorite bleaching, specifically for global warming, aquatic eutrophication, and human health (i.e., carcinogens and non-carcinogens). Gray water footprint along whole life cycles of each product is approximately twice of blue water footprint. Direct processes contribute approximately 50% to water scarcity, while their impact on aquatic eutrophication ranges from 0.002% to 50.72%. For other midpoints, indirect processes dominate the influences. Meanwhile, COD, BOD 5 , CO 2 , TP, Cr (Ⅵ), Ti, Hg, and As are key contributors. Finally, reusing sludge by direct burning in the recovery furnace, reclaiming organic compounds in black liquor before alkali recycling, and integrating black liquor gasification technology are expected to provide substantial environmental benefits. Amelioration of wastewater treatment, optimization of the national energy structure, and improvement of the efficiency of chemicals and freshwater are recommended. Highlights • Energy and carbon coupled water footprint analysis of Kraft pulp paper is applied. • The environmental benefit of black liquor recovery is dominated by reused alkali. • Direct processes contribute a lot to water scarcity and aquatic eutrophication. • COD, BOD, TP, and heavy metals are key substances. • Optimizing waste reuse and availability efficiency of chemicals is recommended. [ABSTRACT FROM AUTHOR]

Paper has shaped society for centuries and is considered one of humanity's most important inventions. However, pulp and paper products can be damaging to social and natural systems along their lifecycle of material extraction, processing, transportation, and waste handling. The pulp and paper industry is among the top five most energy-intensive industries globally and is the fourth largest industrial energy user. This industry accounts for approximately 6% of global industrial energy use and 2% of direct industrial CO 2 emissions. The pulp and paper industry is also the largest user of original or virgin wood, with deleterious impacts on both human health and local flora and fauna, including aquatic ecosystems. This critical and systematic review seeks to identify alternatives for mitigating the climate impacts of pulp and paper processes and products, thus making the pulp and paper industry more environmentally sustainable. This study reviews 466 studies to answer the following questions: what are the main determinants of energy and carbon emissions emerging from the pulp and paper industry? What are the benefits of this industry adopting low-carbon manufacturing processes, and what barriers will need to be tackled to enable such adoption? Using a sociotechnical lens, we answer these questions, identify barriers for the pulp and paper industry's decarbonization, and present promising avenues for future research. •This review identifies carbon-intensive processes in the pulp and paper industry. •Presents decarbonizing practices, potential transformations and innovations. •Presents promising avenues for future research. •No agreed consensus on the most promising technologies to achieve net-zero in the pulp and paper industry. •Pulp and paper products are associated with other sociotechnical systems that create compelling interdependencies among industries. [ABSTRACT FROM AUTHOR]

• RCF wastes brick achieves 24% lower thermal properties than the control brick. • RCF wastes brick requires 10% lower firing temperature than the control brick. • Utilizing as-received waste materials requires zero grinding energy, benefiting manufacturers and cutting emissions. • Lower firing temperature saved $158,460 by cutting 417 tonnes of CO 2. Building materials drive the global economy, yet face severe environmental hurdles: resource depletion, greenhouse gas emissions, and waste generation. In order to mitigate the impact from these challenges, authorities seek sustainable and eco-friendly alternatives as an urgent need. This study focuses on the utilization of as-received rejected contaminated fines (RCF) obtained from the yellow bins' waste (paper) recycling process, in brick production. Diverse tests assessed the brick performance, including compressive strength, absorption rate, thermal conductivity, 3D CT scanning for morphological analysis, and durability analysis. Additionally, a leachate analysis was performed to evaluate the environmental implications. Economic benefits, particularly the reduction of CO 2 emissions, were also evaluated. The findings confirmed that as-received waste can be utilized for fired clay brick production without the need for pulverization. The novel brick product made with as-received RCF waste exhibited superior thermal characteristics (up to a 31.25 % reduction compared to control bricks) while meeting the essential compliance requirements outlined by national standards. Moreover, each firing cycle led to a potential value of up to USD 158,460 through a reduction of 417 tonnes of CO 2 , resulting from a 9.5 % reduction in firing temperature (1000 °C). The results from this study offer valuable insights into the potential of using RCF waste as a sustainable alternative in the brick manufacturing industry. This alternative could address the soaring demand in the current market, resolve the escalating solid waste crisis, and mitigate clay shortages, while providing a sustainable solution for the brick industry. [ABSTRACT FROM AUTHOR]

The pulp and paper industry is a high energy consuming and polluting sector, and carbon emissions emitted from this sector are worthy of attention. This article, based upon an analysis of China’s Pulp and Paper Industry (CPPI), provides estimates of each of the following: carbon emissions from energy consumption, pre-treatment sector, combustion of condensed black liquor, and methane emitted from incomplete aerobic digestion during sewage treatment of CPPI. During the study period (2005–2012), total CO 2 emissions ranged from 126.0 Mt to 155.4 Mt. Energy consumption was estimated to be the largest source of carbon emissions, however, due to the application of the local emission inventory rather than the IPCC inventory, energy consumption decreased by 4.7%, a lower percentage than was calculated in a previous study. According to this study’s estimation, the emissions caused by the recovery of biomass energy contributed 26–29% of the total CO 2 emissions. CH 4 generated from sewage treatment accounted for 9–11% of the total carbon emissions. The CO 2 intensity dropped during the study period, which reflected the improvement of energy efficiency in the pulp and paper industry. The outcome of this study provides not only detailed information about CPPI’s carbon emissions, but also a calculation framework for studying carbon emissions from pulp and paper sector in the other regions. It suggests that the local carbon emissions inventory should be used for estimating carbon emissions and to reduce the fossil fuel energy, increase energy recovery from biomass, and that promoting cleaner production is essential to achieve a low carbon development of the pulp and paper industry. [ABSTRACT FROM AUTHOR]

Ex-situ mineral carbonation, a CCU process, is one possible approach for the decarbonisation of emission-intensive industry with hard-to-abate process emissions like the cement industry. The chemical reaction ensures long-term binding of carbon dioxide in minerals with the effect of storing otherwise emitted CO 2 long term. As a major hurdle for CCU processes is often their economic viability, to create incentives for the usage of this process, these carbonated mineral products must become marketable. A separation approach for the reaction products of this process and possible utilization paths are presented. The separation results in three different fractions, each enriched in either the reaction products amorphous silica or magnesium/calcium silicate or unreacted peridotite. The fractions enriched with reaction products are tested as supplementary cementitious material in cement or as a filler in rubber and paper. The application tests show promising results, comparable or even better than the conventional product. Additionally, based on the laboratory explorations, we present initial economic and environmental investigations showing potential carbon footprint reductions of up to 27% for blended cement with a total global reduction potential of 681 Mt CO2e /a. Also, potential carbon footprint reductions of 52% can be achieved by using carbonation products as fillers in rubber and 197% in paper, respectively. While the costs for the utilization of carbonated minerals have been calculated to be higher than for the conventional products, CO 2 emission certificates could ensure the same price for cement and even lower costs for the substitution of fillers in paper and rubber. [Display omitted] • The technical feasibility of the separation of the carbonation products by centrifugal classification has been proven. • Yield of the separation process can be optimized by better liberation of the particles. • Application tests for cement, paper or rubber show the potential of the carbonated and separated products as a (partial) substitute. • The modeled industrial process – in this case a cement plant with carbonation products as clinker substitute – is ecological and economical feasible. [ABSTRACT FROM AUTHOR]

Low-quality materials contained in separately collected (SC) packaging waste generate environmental and economic burdens associated to both sorting operations of Material Recovery Facilities (MRFs) and landfilling of non-recyclable materials. In this study, based on quantification of both impurities and recyclable fractions, the quality of SC municipal packaging waste streams was determined by compositional analysis of the waste entering a MRF throughout a year. Foreign materials (% w/w) found in the monitored SC glass, paper plus cardboard and lightweight packaging waste, were on average 5.0, 14.7 and 23.0, respectively, while landfilled materials (% w/w) after MRF sorting operations were on average 4.3, 10.3 and 22.0, respectively. A Life Cycle Assessment study was conducted to determine the environmental impact of SC packaging waste streams quality of three different scenarios: current situation (CS), better (BS) and ideal (IS) scenario with reduced presence and absence, respectively, of improper materials in the three examined SC packaging waste streams. Emission of 32.1 kg CO 2 eq/t waste was calculated for the current situation with a reduction by 66.1% and 98.0% in CO 2 eq emission for BS and IS scenario, respectively. Similar emission reductions were calculated for ozone depletion, ionizing radiations, particle matter formation, fossil fuel depletion and primary energy demand impact categories. The environmental life cycle costing study demonstrated that total savings of € 35.2 and € 66.6 for each ton of SC packaging waste stream entering the MRF could be obtained for BS and IS scenario, respectively. [Display omitted] • Impurities in packaging waste streams generate environmental and economic burdens. • 23.0% of impurities were found in separately collected lightweight packaging waste. • Plant sorting operations generate 32.1 kg CO 2 eq for each ton of packaging waste. • € 35.2/ton of sorted packaging waste could be saved by reducing impurities content. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile one-step solvothermal synthesis of FA-CDs using folic acid as raw materials. • FA-CDs and corresponding paper sensor can detect Hg2+ with LOD of 1.29 nM. • Both FA-CDs and paper sensor can be recovered by EDTA for detection of Hg2+. • FA-CDs exhibit excellent cellular imaging performance due to low cytotoxicity. In this work, the blue emission carbon dots (FA-CDs) are synthesized by one-pot solvothermal method by using folic acid as precursor. The FA-CDs emitted bright emission at 445 nm when excited at 360 nm with the QY of 31.2 %. The FA-CDs exhibit sensitive quenching response to Hg2+ with variable concentrations systematically, which determined FA-CDs can be employed as fluorescent probe, with a reliable linear relationship between fluorescence intensity and Hg2+ concentration, and a limit of detection (LOD) of 1.29 nM. Notably, the quenched FA-CDs can be recovered by using EDTA saturated solution with the emission comparable to initial in succession. The FA-CDs based paper sensor can be explored with similar detection performance, and it can also be restored by EDTA saturated solution. Both the restored CDs and paper sensor can be reused in the next turn for detecting Hg2+, which allowed the FA-CDs and their paper sensor can be serviced as sustainable probe for Hg2+ detection. The visual LOD of paper sensor can be determined at 0.1 μM, notably, the paper sensor can be reused at least 3 times with good performance, which is beneficial to environmental protection and saving resources. Possess excellent water solubility and non-toxic properties, the cellular imaging of FA-CDs was evaluated with excellent quality fluorescent image results. The FA-CDs provide a promising convenient fluorescent probe for multi-application in detection and imaging. [ABSTRACT FROM AUTHOR]

• Offering a novel fuzzy robust approach for closed-loop supply chain network design. • Examining the hybrid uncertainties and flexibility of constraints in the problem. • Considering economic, responsibility, and environmental subjects in modeling. • Using the interactive fuzzy programming approach to solve the multi-objective model. • Introducing a new application for stone paper closed-loop supply chain network design. Nowadays, the production of stone paper, in addition to its widespread utilization in various fields, does not require water consumption, cutting down trees, and stone paper products are easily recyclable and recoverable. Due to the importance of developing and using stone paper and paying attention to environmental matters, Closed-Loop Supply Chain Network Design (CLSCND) is very important for stone paper products. Moreover, due to epistemic, randomness uncertainties, the uncertainties in Objective Function (OF), and the flexible constraints for CLSCND in the real world, this paper introduces a novel Mixed Robust Stochastic, Possibilistic, and Flexible Programming (MRSPFP) approach based on credibility theory. The different attitudes of the Decision-Makers (DMs) are addressed by a more flexible measurement of the optimistic and pessimistic parameters using the criterion of credibility. In the study, a comprehensive procedure is proposed for stone paper CLSCND, to minimize costs, increase responsiveness by minimizing transit time between different facilities, and regarding environmental concerns into account through minimizing carbon emissions. The model is solved utilizing an interactive fuzzy programming solution procedure and the Best-Worst Method (BWM). The results of sensitivity analysis, the effect of changing the problem parameters, and the performance of the proposed model are investigated and compared. The results show that the MRSPFP model has a better performance compared to other previous models. The MRSPFP model performs better in strategic decisions that require high investment costs due to the minimization of the absolute deviation of OF from its mean. Also, the applied results of the study show that CLSCND has a good capability and potential for sustainable development in the field of stone paper. [ABSTRACT FROM AUTHOR]

Partly inspired by the concept of masterbatch in plastics manufacturing, we developed a strategy to improve the technical viability, the economic feasibility, and the environmental performance of lignocellulosic micro-/nanofibers. Instead of investing strenuous efforts in dewatering and/or drying nanocellulose suspensions to maximize their consistency without significantly hampering redispersion, which still stands as an unresolved challenge, we used them in high proportions (up to 50 wt%) to reinforce a high-yield pulp. The suspension can be dewatered-pressed (0.70–1.75 MPa) to obtain wet laps of never-dried reinforced pulps, or dried to consistencies over 90% to produce dry boards, but at the cost of lower strengthening capability. In any case, both wet and dry reinforced boards succeeded in enhancing the breaking length of a recycled pulp by up to 62% and 56%, respectively. In light of these results, we proposed a tentative upscaling and subsequent assessment of the process, evaluating different scenarios. From the technical point of view, reinforced pulp boards are much easier to handle and to deliver than dilute aqueous suspensions. In economic terms, savings in transportation costs are worth remarking. Last but not least, this strategy fulfills at least three goals associated with the concept of cleaner production: water recovery (internal recycling), lower CO 2 emissions (especially if transportation takes place by road), and avoiding hazardous chemicals such as hypochlorite. [Display omitted] • The masterbatch strategy in plastics manufacturing is applied in papermaking. • Micro-/nanocellulose-enriched pulp boards were produced by dewatering-pressing and/or heating. • Reinforced pulp boards were used as an effective strengthening agent for packaging paper. • This novel approach to distribute lignocellulosic micro-/nanofibers minimizes volume and cost of transportation. • Water recycling is enhanced and CO 2 emissions in transport/delivery are lowered. [ABSTRACT FROM AUTHOR]

Hydrogen is emerging as a critical player in transitioning to sustainable and renewable energy systems, serving roles in energy storage, grid balancing, and decarbonization. This paper explores various aspects of hydrogen, including its production through renewable-electricity-driven electrolysis, advanced storage techniques, and incorporation into current energy systems. It highlights primary electrolysis methods like PEM and alkaline, noting their improved efficiency and cost-effectiveness. Various hydrogen storage methods, such as physical, chemical, and advanced porous materials, are examined for their benefits and limitations. The review further explores hydrogen's integration into grid storage systems and microgrids to enhance energy reliability. It discusses hydrogen's application in fuel cells for electricity generation, focusing on technological advancements that improve efficiency and reduce costs. Additionally, the paper underscores hydrogen's crucial role in reducing CO 2 emissions in industrial processes like steel production and its use in residential and commercial energy supply through combined heat and power systems. Economic aspects and supportive policies from regions are analyzed, highlighting the global efforts and policies supporting the potential hydrogen in renewable energy systems. This analysis emphasizes hydrogen's comprehensive role in enhancing renewable energy systems and achieving global sustainability objectives, providing a thorough review of recent progress and challenges. • Identifies PEM and alkaline as efficient electrolysis methods. • Analyzes varied H 2 storage options for mobility and stationarity. • Highlights advancements in H 2 fuel cells for vehicles. • Discusses global policies supporting H 2 integration. • Reviews economic impacts of scaling H 2 infrastructure. [ABSTRACT FROM AUTHOR]

• The North-South gap of China has widened in recent decades. • This paper focused on the North-South industrial transfer and its impact on emissions. • The North-South transfer aggravated the imbalance of carbon emissions across regions in China. • The spillover effect is the dominant path behind the impact of the transfer. In recent years, the gap between the north and the south of China has been expanding, showing a decreasing proportion of value-added and an increasing proportion of carbon emissions in the north of China, and vice versa in the south of China. Based on the most recent inter-provincial input-output table of China in 2012 and 2017, this paper focused on the North-South industrial transfer of manufacturing, quantified its impact on regional carbon emissions, and decomposed the path of impacts. The results suggest that the North-South industrial transfers of China during 2012-2017 indeed aggravated the imbalance of carbon emissions in the north and the south of China. Further explorations of path decompositions show that the spillover effect through production linkages is the major path where industrial transfer influences regional carbon emissions, particularly in the north of China. The results provide insightful policy implications for the achievement of carbon emissions reduction targets in China as well as the globe. [ABSTRACT FROM AUTHOR]

Hydrogen as a clean energy to deal with carbon emissions has been favored by many scholars, while the problems of low efficiency and high energy consumption in the process of liquefaction storage and transportation have become one of the important factors restricting the development of it. The combination of heat exchanger and ortho-para (O–P) hydrogen converter has attracted considerable attention as a high efficiency and low energy consumption technology. In this paper, based on the catalyst-filled spiral wound heat exchanger (CSWHE) and coupled with ortho-para hydrogen conversion, the flow and heat transfer characteristics of gaseous hydrogen are studied. Firstly, low-temperature O–P hydrogen catalytic conversion experiments and flow characteristics experiments were carried out by filling catalyst in the heat exchange tube. and an equation for calculating pressure drop in the section filled catalyst was proposed. Secondly, a new numerical model was established validated by the experiments. The influence of catalyst on heat transfer and the effects of velocity on the heat transfer performance and O–P hydrogen conversion efficiency were studied by numerical simulation. Finally, this paper analyzed the significant factor affecting the para hydrogen content at outlet: reaction time. And an equation for calculating para hydrogen content at outlet with reaction time was proposed. This study is expected to provide a reference for the design of CSWHE. • An isothermal reactor is designed and employed to low-temperature ortho and para hydrogen catalytic conversion experiments. • A new pressure drop calculation equation for porous region is proposed by modifying Ergun equation. • A new numerical model is established to study the coupling mechanism of flow and heat transfer. • The key factor affecting the catalytic conversion of ortho and para hydrogen is pointed out: reaction time. [ABSTRACT FROM AUTHOR]

With the development of energy technology, hydrogen is gradually becoming widely used. China is also rapidly developing its own hydrogen energy industry in an effort to accomplish the "dual carbon target'. Hydrogen from methane is one of the mainstream sources, of which hydrogen from methane cracking is the decomposition of methane into hydrogen and solid carbon, with the solid carbon also having a high economic value. In particular, this technology does not emit carbon dioxide, which is very friendly to the environment, but it cannot avoid larger energy consumption. In contrast, hydrogen production from methane cracking driven by solar energy not only combines the characteristics of no CO 2 emission, but also greatly reduces the consumption of primary energy, which is the future development trend of hydrogen production from methane. This paper provides a brief overview of the various technological pathways for methane to hydrogen production in the context of China's actual development, focusing on the current status of the development and application of solar methane cracking to hydrogen production technologies at home and abroad. Among them, this paper mainly discusses the characteristics of solar reactors of different sizes and structures, and summarizes the results of related optimization studies. Meanwhile, the application of catalysts in solar reactors and the problem of carbon deposition are analyzed, and the practical application of solar methane cracking hydrogen production system is outlined. Finally, the future development of solar methane cracking hydrogen production technology is prospected from the national situation of China. [Display omitted] • Solar methane cracking for hydrogen can reduce emissions and energy consumption. • The current state of research on solar reactors is summarized. • Solar methane cracking requires higher performing catalysts. • Providing insights into the future development of solar methane cracking in China. [ABSTRACT FROM AUTHOR]

Urbanization and the release of carbon emission are two significant features of contemporary economic and social progress in China. However, there are few studies that consider how urbanization policy goals affect carbon emission. This paper aims to study the nonlinear effects of urbanization policy goals on carbon emission in 13 cities of the Beijing-Tianjin-Hebei region. In this paper, a multi-dimensional spatial disturbance grey model is proposed. Based on matrix perturbation theory, this paper explores the spatial perturbation bounds of the novel model and verifies that the spatial property of the model is consistent with the viewpoint of the First Law of Geography. Then, the novel model is used to predict the urban carbon emission under different urbanization policy goal scenarios. The results showed that the novel model has spatial regional correlation in spatial region prediction. With the development of urbanization level, carbon emissions show a downward trend in more than 50% of cities from 2022 to 2025. In addition, the improvement of urbanization policy goals will promote the carbon peak time of most cities. The carbon emission intensity will exhibit an inverted U-shaped trend distribution in space. The research results are conducive to providing scientific guidance for the formulation of new-type urbanization policies and helping to achieve the dual carbon goals. • A multi-dimensional spatial disturbance grey model is proposed. • The novel grey model is consistent with the viewpoint of the First Law of Geography. • The spatial distribution of carbon intensity showed an inverted U-shaped pattern. [ABSTRACT FROM AUTHOR]

The environmental issues within the transport industry need to be given priority attention. Optimizing the transport structure and promoting low-carbon transport are essential measures for achieving carbon emission reduction. However, the rail-water multimodal transport scale is currently limited. The government has to intervene in the market through incentive policies, so how to expand the revenue of carriers and enhance the volume has become a major dilemma. Our paper constructs a transport system that includes road, water, and railway, and examines the impact of incentive policies on separate stakeholders. It is discovered that incentive policies can increase the revenue of carriers and simultaneously attract more shippers to elect rail-water multimodal transport. Subsidy policy can hasten the structural transformation of inland transport, making railway transport volume rise. Unfortunately, although the dry port policy may enhance the revenue of railway carriers, it leads to an apparent decline in the revenue of road-water multimodal transport participants. However, the subsidy policy can create a win-win scenario for multiple carriers while achieving carbon emission reduction, but to the detriment of social welfare. Additionally, the paper compares the interactions between diverse incentive policies and pivotal factors such as transport time. The conclusions of our research serve strategic recommendations for maximizing carriers revenues and provide support for government decision-making. • The impact of incentive policies on the rail-water multimodal transport is inspected. • Subsidy policy can make carriers better off, but may have adverse effects on social welfare. • Subsidy policy expands carrier volume and stimulates transport structure transformation. • Although dry port is conducive to social welfare, it hurts the revenue of carriers. • The dry port is beneficial for achieving long-distance carbon emissions reduction. [ABSTRACT FROM AUTHOR]

COVID-19 has represented a watershed in people's lifestyle. One important consequence has been the change in how people buy groceries online/offline that represent the most frequent shopping-related trip any household performs. Since this has substantially different transport and environmental implications, it is crucial to investigate what are the COVID-19-induced variations. This paper estimates both travel and environmental impacts grocery channel choice implies by comparing, in a diachronic fashion, the pre and during COVID-19 situation in Norway, considering alternative scenarios describing different service configurations for each channel considered. Stated preferences are used to estimate market shares for grocery purchase distinguishing between different channels: in-store, home delivery and click&pick. The robust comparative analysis between the two time periods is guaranteed by the use of the same methodological approach in the same geographical context. Results show that total emissions are lower during the pandemic and adopting a free delivery strategy not only increases home delivery market shares but also produces the lowest level of CO2 emissions regardless of COVID-19. The results obtained are particularly relevant in the "new normal" the world is experiencing both from a public policymaking perspective, when promoting transport-related interventions to curb emissions, and from a private standpoint, when customising market strategies to increase sales and profits. • COVID-19 has represented a watershed in people's lifestyle. • Investigating changes in how people buy groceries online/offline is important. • Stated preferences are used to estimate grocery market shares for different channels. • The paper estimates travel and environmental impacts pre and during COVID-19 via scenario analysis. • Results are particularly relevant for both the public and private sector in the "new normal" conditions. [ABSTRACT FROM AUTHOR]

Hydrogen is considered as a promising fuel in the 21st century due to zero tailpipe CO 2 emissions from hydrogen-powered vehicles. The use of hydrogen as fuel in vehicles can play an important role in decarbonising the transport sector and achieving net-zero emissions targets. However, there exist several issues related to hydrogen production, efficient hydrogen storage system and transport and refuelling infrastructure, where the current research is focussing on. This study critically reviews and analyses the recent technological advancements of hydrogen production, storage and distribution technologies along with their cost and associated greenhouse gas emissions. This paper also comprehensively discusses the hydrogen refuelling methods, identifies issues associated with fast refuelling and explores the control strategies. Additionally, it explains various standard protocols in relation to safe and efficient refuelling, analyses economic aspects and presents the recent technological advancements related to refuelling infrastructure. This study suggests that the production cost of hydrogen significantly varies from one technology to others. The current hydrogen production cost from fossil sources using the most established technologies were estimated at about $0.8–$3.5/kg H 2 , depending on the country of production. The underground storage technology exhibited the lowest storage cost, followed by compressed hydrogen and liquid hydrogen storage. The levelised cost of the refuelling station was reported to be about $1.5–$8/kg H 2 , depending on the station's capacity and country. Using portable refuelling stations were identified as a promising option in many countries for small fleet size low-to-medium duty vehicles. Following the current research progresses, this paper in the end identifies knowledge gaps and thereby presents future research directions. • Technological advancements of hydrogen production, storage and transport are reviewed. • Emissions and economic aspects of production, storage, transport and fuelling are analysed. • Refuelling protocols, temperature rise issue and its control strategies are discussed. • Recent progress of mobile hydrogen refueller is explored. • Challenges of hydrogen production to fuelling and future research directions are presented. [ABSTRACT FROM AUTHOR]

Recently, ammonia is getting more attractive as a potential alternative fuel for future power generation and transportation purposes due to its ability to reduce consumption of fossil fuels, soot, CO 2 emissions, and hydrocarbon pollutants. In the recent past, several studies aimed to the development of ammonia combustion systems have been conducted. However, ammonia combustion systems face several challenges, such as poor ignition timings, lower burning velocity, low energy density, shorter flammability limits than hydrocarbons. These issues are compounded by the significant increase in NOx emissions, which makes practical application of ammonia challenging. Various conventional methods, such as blending ammonia with other hydrocarbons and hydrogen, have been employed to improve combustion performance and reduce NO x emission. Meanwhile, it increased the engine complexities and at the same time, it raised CO 2 and NO x emissions. Recently, plasma-assisted combustion (PAC) has emerged as a promising technology to boost the ammonia combustion process by improving ignition delay timings, increasing flame speed, extending flammability limits, and reducing NO x emissions. In recent years, plasma-assisted combustion (PAC) has emerged as a promising technology to enhance the ammonia combustion process by improving ignition delay timings, increasing flame speed, extending flammability limits, and reducing NOx emissions. Nevertheless, only a few studies on plasma-assisted ammonia combustion (PAAC) are available in the literature. This review paper aims to summarize the latest advancements in the field of PAAC during the last years, including progress in the development of numerical models and experimental studies. The paper highlights the detailed procedure of PAAC numerical modeling and the limitations of numerical models. Finally, the latest numerical and experimental developments of PAAC have been discussed. • Ammonia is getting more attraction as an alternative fuel for future power and transportation sectors. • A comprehensive outlook of non-thermal plasma for ammonia combustion is provided. • The in-depth mechanisms of plasma assisted combustion are highlighted. • The latest numerical and experimental studies of Plasma assisted combustion were analyzed. [ABSTRACT FROM AUTHOR]

Using past episodes of climate change as a source of evidence to inform our projections about contemporary climate change requires establishing the extent to which episodes in the deep past are analogous to the current crisis. However, many scientists claim that contemporary rates of climate change (e.g., rates of carbon emissions or temperature change) are unprecedented, including compared to episodes in the deep past. If so, this would limit the utility of paleoclimate analogues. In this paper, I show how a data adjustment procedure called "temporal scaling," which must be applied to both contemporary and past rate data, complicates the claim that contemporary rates are truly unprecedented. On top of giving actionable recommendations to scientists, this paper advances the philosophical literature concerning the use of models that are known to be somewhat disanalogous to their target systems. [ABSTRACT FROM AUTHOR]

Policy synergy is a unique way for the government to establish a policy network and a crucial way for cities to expand their carbon reduction channels. Using urban data from China, this paper empirically investigates how environmental governance policy synergy (EGPS) affects carbon emissions. In comparison to non-pilot cities, the environmental information disclosure (EID) policy and low-carbon city (LC) policy play an inhibitory role in carbon emissions. Furthermore, EGPS has a stronger effect and is heterogeneous by region. Through the use of technical advancement and industrial structure optimisation, EGPS lowers carbon emissions, and this effect of EGPS grows over time in tandem with the level of environmental pollution in the cities. Our paper proposes policy implications in order to improve the overall effect of environmental governance policy and help achieve the dual carbon targets. [ABSTRACT FROM AUTHOR]

This paper proposes a novel aviation CO 2 emissions reduction method by introducing a market-based incentive mechanism. An aviation carbon emissions prediction model is proposed to characterize both the microscopic flight dynamics and the macroscopic air traffic demand trend. Based on emissions prediction, a linear climate response model is applied to evaluate the environmental impact of the aviation carbon emissions. Finally, a market-based framework for aviation CO 2 emissions reduction is established based on a two-phase carbon trading model, which provides a piecewise charge method through emission taxation and cap-and-trade. A case study is carried out to demonstrate the effectiveness of the proposed framework using a real-world dataset from the Hefei Air Traffic Control Zone in China. Three scenarios are defined to describe the possible development speed of sustainable aviation fuel application in the future: not applied, medium-speed development, and high-speed development. The results show that the carbon peak will be reached in 2025 in the high-speed development scenario, when the emission amount and associated environmental impact will be reduced by 23.7% and 22.3%, respectively. Thus, the market-based framework proposed in this paper can effectively reduce aviation CO 2 emissions and mitigate the effects of global warming. • An aviation CO 2 emissions prediction model is proposed considering both microscopic flight dynamics and macroscopic traffic demand. • A more efficient market-based CO 2 emission reduction framework is developed based on a two-phase carbon trading model by means of taxation and cap-and-trade. • Case study shows that the proposed method has a more optimal incentive for CO 2 emission reduction. [ABSTRACT FROM AUTHOR]

The conversion of renewable energy into chemical energy carriers, such as ammonia, enhances the accommodation of renewable energy for power distribution networks (PDN) and supports the decarbonization for ammonia production systems (APS). This paper addresses the integration of PDN with APS through a collaborative planning considering a carbon emission flow (CEF) model. A collaborative planning model with carbon emissions constraints is designed, and a sensitivity analysis is performed to evaluate the impact of varying renewable energy costs on the system. To further reduce carbon emissions from green ammonia production and stabilize renewable energy volatility, a nodal CEF model that incorporates energy storage systems (ESS), wind turbines (WT), and photovoltaics (PV) is proposed. The economic feasibility of the proposed model is verified via comprehensive experiments. Numerical results show that collaborative scheduling reduces both costs and carbon emissions in PDN and APS. Implementing a carbon tax encourages the transition from grey to blue ammonia production, while a decrease in renewable energy costs further promotes the shift from blue to green ammonia. Besides this, the analysis indicates that integrating long-term operation of WT and PV, together with low-cost renewable electricity and ESS, boosts the economic efficiency of the green ammonia production system. • An integration of PDN with APS through a collaborative planning considering CEF model is proposed. • Employing the CEF model to calculate carbon emissions from grey, blue, and green ammonia production. • Carbon tax is used as a tool to encourage the low carbon transition of ammonia production. • A CEF model that incorporates ESS, WT, and PV is designed and the economic feasibility of the proposed model is verified. [ABSTRACT FROM AUTHOR]

Although renewable energy-based technologies such as water electrolysis and biomass gasification for hydrogen production are cleaner than fossil energy-based routes, there are still prevailing challenges associated with the high cost and operational challenges in the scale-up of those technologies in the short term. Considering the abundance of coal as a current primary source of energy in Australia, the use of coal to produce hydrogen is not only in line with Australia's resource endowment but is also expected to become a supplement to the other hydrogen production pathways during the global energy transition period. This paper presents a comprehensive techno-economic assessment of low-emission hydrogen production from Australian coal gasification integrated with carbon capture and storage (CCS). The study explores four cases of hydrogen production, comparing Australian brown coal (Victorian brown coal) and black coal (Queensland black coal) gasification. Variations in gasifiers, gasification agents, and associated operating conditions contribute to differences in energy efficiency, costs, and CO 2 emissions among the cases. The findings reveal a levelized cost of hydrogen from coal gasification ranging between A$4.12–4.90 per kg of hydrogen. Notably, entrained flow gasification of Victorian brown coal in a mixture of oxygen and steam environment demonstrates advantages under the current market conditions. However, less mature technologies like dual fluidized bed gasifiers could emerge as viable alternatives if deployed on a commercial scale. The study also addresses direct carbon emissions from the process, indicating a CO 2 emission intensity range of 16.3–20.9 kg CO 2 /kg H 2 without CCS and 0.1–1.1 kg CO 2 /kg H 2 with CCS for the four cases. These insights contribute valuable information for decision-making in the pursuit of sustainable and economically feasible hydrogen production methods during the ongoing energy transition. • Coal is the primary source of energy in Australia and could still play a role in the transition to a low-carbon future. • Coal gasification integrated with CCS is a viable option for low-emission hydrogen production. • The Levelized cost of Hydrogen from Australian coal gasification is A$4.12–4.90/kg H 2. • EFR gasification of VBC in an O 2 /steam environment is the most economically viable option for hydrogen production. • The Direct CO 2 emission from coal-to-H 2 with CCS is 0.1–1.1 kgCO 2 /kgH 2. [ABSTRACT FROM AUTHOR]

In September 2020, the European Parliament decided to include the CO2 emitted on the all intra-European and 50% of extra-European voyages in the European Union Emission Trading System (EU-ETS) starting from 2022, in order to reduce the CO2 emission. With the implementation of EU-ETS, the maritime supply chain will inevitably be significantly affected. Different carbon quota allocations in ETS have different impact on the CO2 emission reduction, which motivates us to investigate the effect of different carbon quota allocations on maritime CO2 emission reduction. Therefore, this paper considers two carbon quota allocations: the historical total quantity method and the historical intensity method, and develops a game model for each method. Then, the equilibrium solutions of each game model are analyzed. With the help of the system dynamics and the software Vensim, numerical experiments are conducted to verify the properties obtained in the analysis of the equilibrium solutions. The experimental results indicate that 1) Green technology (GT) can effectively reduce carbon emissions. Based on long-term simulation results, the GT investments will be gradually offset by profiting from carbon quota trading. 2) Profits may vary with price, but the Historical Intensity method consistently achieves better carbon reduction effects or relatively higher profits. 3) The marginal profits of companies with similar historical intensity baselines are almost the same. This gives an advantage to companies who implement green technologies earlier, as they can quickly gain returns from GT. • Comparing the effect of different carbon allocation methods on the maritime supply chain. • The historical intensity method reduces carbon emissions effectively, especially for companies with high unit emissions. • Using system dynamics to investigate the interaction of maritime supply chain. [ABSTRACT FROM AUTHOR]

The integrated energy system (IES) with hydrogen storage has become one of the most important developments in multi-energy coupling field, where the severe conflict of interests between different entities leads to great challenges to the economy and low-carbon operation. A multi-objective robust dynamic pricing and operation strategy optimization method based on the Stackelberg game is proposed for the hydrogen-containing energy storage (HES) IES. Firstly, the HES-IES trading framework is established based on the introduction of an integrated energy operator (IEO) and a load aggregator (LA). Secondly, a multi-objective robust Stackelberg game model is developed with the IEO as the leader and the LA as the follower, considering the minimization of operating costs and carbon emissions of the IEO and the minimization of integrated energy costs of the LA as the objectives. Finally, the compromise planning and the max-min fuzzy are addressed to solve the multi-objective model, which adopts the adaptive differential evolution (ADE) algorithm. In addition, the robust optimization (RO) with adjustable coefficients is employed to tackle uncertainties of source and load. The results show that this method can effectively balance the operating costs and carbon emissions of the system, improve the benefit of the IEO, reduce the costs of the LA, and avoid the uncertainty risk. Compared with traditional algorithms, the ADE algorithm has significant advantages in the number of iterations and solving time. In summary, the multi-objective robust dynamic pricing and operation strategy optimization proposed in this paper could effectively achieve the benefit balance between the IEO and the LA, also further improve the economy and robustness of the system and reduce carbon emissions. [Display omitted] • A multi-objective robust dynamic pricing and operation strategy optimization method based on Stackelberg game is proposed. • The compromise planning, max-min fuzzy method and adaptive differential evolution algorithm are adopted to solve the model. • The robust optimization with adjustable coefficients is employed to deal with the source-load uncertainty. • The economy and robustness of the system are improved, and carbon emissions are reduced. [ABSTRACT FROM AUTHOR]

Hydrogen is characterized by zero carbon emissions and high energy density, which can effectively support the consumption of a high proportion of intermittent new energy. Considering the seasonal nature of renewable energy sources, a seasonal hydrogen storage model is incorporated in an electric-hydrogen integrated energy system (EH-IES). In this paper, a two-layer optimization method is proposed for EH-IES with seasonal hydrogen storage. The problem of co-optimizing the equipment capacity and configuration in the proposed system is coordinated by establishing a two-layer optimization framework. Specifically, the system is optimized to minimize cost and carbon emissions at the upper layer using the multi-objective stochastic paint optimizer (MOSPO) algorithm, with the capacity configuration results being transmitted to the lower layer. The lower layer, aiming to reduce the total system cost, utilizes a commercial solver to obtain the optimal economic scheduling results for a typical day. The final analysis of the four scenarios shows that the increase in renewable energy reduces the purchasing cost of electricity by 1.89%, while in contrast, the total cost increases by 4.4% in the system with a lower proportion of renewable energy. In the case of higher heating and cooling loads, the increase in renewables reduces the purchase cost of natural gas by 9.10%. The results demonstrate that the proposed method can leverage the seasonal complementary benefits to drive new energy consumption, enhance system operation efficiency, and effectively reduce EH-IES's total operation cost and carbon emission. [Display omitted] • Seasonal hydrogen storage is introduced into the electric-hydrogen integrated energy system model. • A two-layer optimization model is developed in the electric-hydrogen integrated energy system. • A Multi-objective Stochastic Paint Optimizer (MOSPO) method is employed to solve the planning problem. [ABSTRACT FROM AUTHOR]

Hydrogen hubs are emerging as strategic solutions to meet governmental emission reduction targets. A critical aspect of hydrogen hub design involves diversifying end uses, encompassing mobility, backup/storage, heating and cooling provision, onsite electricity generation, and grid energy supply. This paper introduces a comprehensive hydrogen hub model catering to these varied applications. Additionally, a novel multi-stage planning framework is proposed to assist hub operators in making informed decisions regarding the integration of diverse renewable energy sources and infrastructure. This framework addresses varying demands efficiently and economically. Moreover, to align with governmental emission reduction policies leading to net-zero targets, a proactive strategy is suggested. Through zoning for commercial, residential, educational, and healthcare sectors, the Sydney hydrogen hub is envisioned under two scenarios: business-as-usual and towards-net-zero design. Notably, CO 2 emissions are projected to decrease from 18.3 ktonnes in the former to 4.7 ktonnes in the latter scenario. [Display omitted] • Introduces a comprehensive hydrogen hub model catering to varied applications. • Multi-stage planning framework to assist hub operators in making informed decisions. • A proactive strategy aligning with governmental emission reduction/net-zero policy. • Determines optimal sizing, scheduling, and timing for a mix of technologies. • Designing Sydney H 2 hub zoned for commercial, residential, and educational tenants. [ABSTRACT FROM AUTHOR]

Maritime propulsion is recognized as a hard-to-abate sector and its decarbonization will therefore require transversal efforts, including the introduction of alternative fuels to reduce CO 2 emissions. Both ammonia and hydrogen could provide clean power; however, forecasts hint that ammonia will be especially useful for longer routes, while hydrogen suffers from low volumetric energy density. This paper evaluates the feasibility of a cargo ship with a SOFC powertrain equipped with LOHC-based hydrogen storage and compares the sizing and heat management requirements of four LOHC systems, namely N-ethylcarbazole (NEC), dibenzyltoluene (DBT), methylcyclohexane (MCH), decaline (DEC), with an ammonia-based one. The size of the 8.4 MW SOFC system is similar for the five carriers as expected. The dynamic performance of the LOHC system shows that the hydrogen flow rate can be effectively controlled by acting on the LOHC flow rate, reactor temperature, and pressure. However, LOHC systems are heavier (by a factor of 1.6 to 2.1) and larger (by 1.6 to 2.3 times) than ammonia systems. The decalin system results in the lowest mass and volume, while NEC is the heavier, and MCH is the least dense of the evaluated LOHCs. Similarly, the utilization of SOFC waste heat to cover dehydrogenation heat ranges from 45.6 % (NEC) to 27.9 % (ammonia). Overall, even considering the lower reaction temperature, LOHCs do not appear to be competitive with ammonia as hydrogen storage systems in the maritime sector. • Liquid organic hydrogen carrier (LOHC) systems discussed for maritime applications. • Different LOHC systems are sized, and the heat demand is evaluated. • Control strategies are devised to meet instantaneous hydrogen demand. • The dynamic response of LOHC-based systems is more than satisfactory. • Comparison with ammonia is unfavorable in terms of mass, volume and heat demand. [ABSTRACT FROM AUTHOR]

• We examine the role of circular economy and inclusive green growth in promoting energy transition and carbon neutrality in Europe. • We used three-pronged empirical strategy framed in advanced dynamic econometrics. • The results reveal that lagged of CO 2 emissions is a positive predictor of CO 2 emissions. • We show that embracing circular economy and inclusive green growth will be highly beneficial towards the attainment of carbon neutrality. • We recommend policy measures that considers both current and past emissions to promote environmental quality. This paper examines the role of the circular economy and inclusive green growth in promoting energy transition and carbon neutrality for several European countries during 2009–2021, using an advanced econometric strategy. To achieve this objective, we employed a three-pronged empirical strategy. The first strategy involved standard panel specifications, such as pooled ordinary least squares, Fixed Effects, Roger panel regression, white panel regression, and Driscoll–Kraay standard errors. The second strategy explored the long- and short-term dynamics of the relationships using the dynamic specifications of the Generalised Method of Moments, comprising the augmented Arellano–Bond, Ahn–Schmidt, Arellano–Bond, and Arellano–Bover/Blundell–Bond estimators. It further controls for endoegeneity using the Two stages Lease Square (2SLS and Lewbel 2SLS). The third strategy employed the Machado and Silva quantiles via moments to re-evaluate the heterogeneity drivers of carbon neutrality. Furthermore, an alternative and complementary strategy based on the statistical procedures of Hausman–Taylor and Feasible Generalized Least Squares was employed to verify robustness. The findings suggest that prior carbon emissions positively predict future emissions. Also, our results reveal that the adoption of a circular economy, including green growth and renewable energy, can significantly contribute to reducing carbon emissions. In contrast, domestic economic drivers, and eco-innovation increase carbon emissions. We propose that policymakers mandate producers to oversee the entirety of their product life cycles as a means to mitigate carbon emissions. Furthermore, endorsing training programs and educational initiatives aimed at cultivating the requisite skills for the energy transition and the adoption of circular economy practices is imperative for ensuring the realization of a successful low-carbon economy. [ABSTRACT FROM AUTHOR]

• E-waste has become a major environmental concern due to its increasing volume. • Socioeconomic and institutional factors are used to analyse the recycling of EEE. • Annual data from 2010 to 2018 were analysed in 20 EU countries by using a GMM. • GDP per capita, research & development and CO2 emissions decrease EEE recycling. • Education, environmental taxes, and waste collected drive the recycling rate of EEE. Moving from a linear to a circular economy is crucial to reduce environmental pressure. This transition is particularly relevant in the Electrical and Electronic Equipment (EEE) industry, given that EEE has one of the fastest-growing waste streams. Recycling is one solution for dealing with the growing amounts of this e-waste. Therefore, this paper analyses the drivers and barriers to e-waste recycling, taking into account the role of economic, social, institutional, and behavioural factors. Yearly data from 2010 to 2018 for 20 European Union countries were analysed employing an Arellano-Bond Generalised Method of Moments. The main findings were that, while environmental taxes and education boost the rate of e-recycling, economic growth and R&D appear to reduce it, and certain age groups are less likely to recycle e-waste. Recycling policies should prioritize education, environmental taxes, and addressing reluctance among the young and elderly to recycle. [ABSTRACT FROM AUTHOR]

Environmental governance approaches are critical for carbon reduction and energy security. Using the data from government work reports and public search, this paper investigates the impact of government policies and public awareness on carbon emissions. The 'top-down' administrative regulation is found to have more effective in promoting carbon reduction in cities than 'bottom-up' public awareness, and this carbon reduction effect is more pronounced in central, western and lower levels of economic development cities. The findings suggest that regions with higher economic development tend to exhibit greater dependency on carbon, posing challenges in achieving prompt reductions in carbon emissions through governmental policies and public awareness. Additional discoveries indicate that 'top-down' administrative regulation exhibits a certain sustainability, mainly through industrial structure adjustments. This aspect proves beneficial for enhancing the city's developmental path and quality in the long term. [ABSTRACT FROM AUTHOR]

Climate change engendered by carbon emissions has become a major threat to human life and the world economy. Many of early studies corroborate that carbon tax and subsidy are effective policy tools to alleviate climate change. Most of them, however, use closed-economy models with a single firm to analyze the effects of these two policies. This paper explores the effects of carbon tax, subsidy and foreign carbon emissions on economic activities in an open macroeconomic model that features low- and high-carbon firms. The main findings suggest that carbon tax, subsidy and foreign carbon emissions all deliver heterogeneous outcomes by largely affecting high-carbon firms. The shortage of national income due to weak economic activities leads the economy to issue more international bonds. The takeaway from all the analyses is that government should introduce various carbon taxes that are geared towards target firms with different carbon emissions and adopt optimal means to manage national debt. [ABSTRACT FROM AUTHOR]

The urgent development of economically practical and sustainable electrocatalysts to accelerate the hydrogen evolution reaction (HER) is critical for solving the pressing issues related to carbon dioxide emissions. Because of their platinum-like catalytic efficiency, excellent stability, and multidimensional structure of their crystal phases, molybdenum phosphides have emerged as extremely promising HER electrocatalysts. In this account, we begin with a meticulous explication of the hydrogen-generating process by water electrolysis, followed by an examination of the criteria used to assess HER catalytic activity. Also, the role of the phosphorus component and synthetic routes of molybdenum phosphides is presented in HER applications. Moreover, in recent years, various strategies designed to enhance the HER performance of molybdenum phosphides have been introduced, encompassing state-of-the-art techniques such as the fabrication of heterostructures, hetero-atom doping, hybrid structures involving carbon materials, and defect engineering. Furthermore, the theoretical studies based on density functional theory (DFT) are mentioned for HER. The paper concludes by emphasizing the current challenges and auspicious prospects in advancing electrocatalysts for hydrogen production, with a dedicated focus on catalysts based on molybdenum phosphides. • Outstanding features of molybdenum phosphides were presented. • Various methods were introduced in the fabrication of molybdenum phosphides. • Enhancement strategies in HER efficiency of molybdenum phosphides were discussed. • Current challenges and possible solutions on molybdenum phosphides-based HER electrocatalyst were provided. • DFT works of molybdenum phosphides on HER were presented. [ABSTRACT FROM AUTHOR]

The blending of hydrogen into natural gas can utilize existing natural gas pipeline infrastructure to achieve long-distance, large-scale, and cost-effective hydrogen transportation. However, the introduction of hydrogen poses a series of new technical and safety challenges to the operation of natural gas pipelines. Addressing these issues, this paper focuses on minimizing compressor station energy consumption and carbon emissions as objective functions, conducting a comprehensive analysis of station operation modes. Incorporating the characteristics of the model, the soft frost search strategy, the hard frost penetration mechanism, and the positive greedy selection mechanism are introduced to propose the IRIME algorithm. Comparisons are made with well-performing optimization algorithms using classical test functions to evaluate algorithm performance. To further validate the algorithm's accuracy, the West-East Gas Pipeline (Line 1) is considered, comparing the convergence speed and precision of the IRIME algorithm, leading to its selection for solving the model. Furthermore, consider analyzing the impact of different hydrogen blending ratios on the performance curves and operating points of compressors. Results indicate that compared to conditions without hydrogen blending, the compressor outlet temperature and pressure drop increase for hydrogen blending ratios of 5%, 10%, 15%, and 20%; as the hydrogen blending ratio increases, the efficiency of fuel-driven compressors, efficiency of electrically driven compressors, and average efficiency of compressor units decrease; with an increase in hydrogen blending ratio, carbon emissions from fuel-driven compressors and electric-driven compressors both decrease. In conclusion, with an increasing hydrogen blending ratio, total energy consumption increases by 3.14%, 5.69%, 8.68%, and 10.90%, while total carbon emissions decrease by 2.99%, 5.36%, 8.32%, and 10.68%. These findings provide valuable insights for operational guidance in the field. • Establish an optimization model for energy consumption and carbon emissions in hydrogen-blended natural gas pipelines. • Analyze the effects of varying hydrogen blending ratios on compressor performance curves and operational points. • Introduce the RIME algorithm, validate its speed and precision, test it on the West-East Gas Pipeline (Line 1). [ABSTRACT FROM AUTHOR]

As a promising strategy to mitigate carbon emissions, hydrogen enrichment of conventional fuels is gaining increasing interest, but can lead to increased propensity to damaging thermoacoustic instability. This paper demonstrates the ability of machine learning algorithms to reliably predict a key flame behavior relevant to thermoacoustic stability prediction – the flame's nonlinear response to upstream acoustic forcing. Using computational simulations of a laminar premixed flame under difference hydrogen enrichment and equivalence ratio conditions, training data for machine learning are generated. The machine learning models are then used to predict the flame response under new test conditions, including extrapolating into new hydrogen enrichment regimes. The effect of algorithm choice, data structure, data size, and extrapolation distance on the performance of different machine learning models is investigated with particular attention to performance with sparse training data. It is found that a type of neural network known as the multi-layer perceptron (MLP) model outperforms the Gaussian process and random forest models in both interpolation and extrapolation tasks. A physics-informed preprocessing strategy, involving extracting the time delay of the flame response (which can be deduced from geometry and flow parameters) prior to applying machine learning, is found to remarkably improve the accuracy of machine learning models, especially in extrapolation tasks. When the extrapolation into new hydrogen content levels is strong enough, the MLP model no longer performs well. However, for small and intermediate extrapolation, the MLP model shows a commendable level of prediction, even with small data sets, fulfilling needs relevant to thermoacoustic stability prediction. Extending the MLP model to experimental data from turbulent flames, the gain fall-off frequency and phase lag are accurately predicted but not the secondary periodic fluctuations in gain. • AI-assisted prediction of flame response in new hydrogen enrichment regimes. • A physics-informed strategy extracting the time delay improves model performance. • The effects of algorithm choice, data structure and data size are studied. • MLP model shows good predictions in small extrapolation tasks with sparse data. • Extending to turbulent flames, the MLP model captures fall-off frequency in gain. [ABSTRACT FROM AUTHOR]

In order to guide the operation of the actual cascade system, this paper takes the cascade system as the research object and compares the use of six refrigerant pairs. Unlike the previous single-objective optimization of refrigeration system carbon emissions and other indicators, this research uses a multi-objective optimization algorithm, that is, we consider the cascade system's exergy efficiency and carbon emissions at the same time. We reduce carbon emissions while improving the system's exergy efficiency, and finally find out the specific operating conditions under which the system can realize low-carbon and high-efficiency operation, which further promotes the process of achieving energy saving and emission reduction in factories. The optimization results show that among the six refrigerant pairs, the use of R744-R134a and R744-R290 refrigerant pairs can make the system operate better, but considering the high global warming potential (GWP) of R134a refrigerant, the use of R744-R290 combination is more recommended. [Display omitted] [ABSTRACT FROM AUTHOR]

Solar energy absorption and storage of integrated ceramic materials is both the absorption of sunlight and storage of sunlight into thermal energy functional materials. In this paper, the effect of Fe 2 O 3 on the solar absorptivity, thermal storage properties, sintering temperature, and physical properties of mullite-based thermal storage ceramics was investigated. The results show that the absorptivity and thermal storage density of the sample AF4 (Bauxite:50 wt%, Clay:50 wt%, Fe 2 O 3 :11 wt%) after sintering at 1420 °C are 87.2% and 1116.5 kJ kg−1, respectively; and the unit volume of the AF4 sample can provide the power grid with 918.01 kW h of electricity, save 112.91 kg of coal, and reduce 361.33 kg of CO 2 emission. This study systematically elucidated the mechanism of the enhancement of sample absorption caused by Fe3+ doping-induced changes in substrate color, reduction in material forbidden bandwidth, and lattice anharmonic vibration effect, in addition to comprehensively evaluating the feasibility of the optimal AF4 sample for use in solar energy absorbing and storing integrated ceramic materials. [ABSTRACT FROM AUTHOR]

The ever-increasing challenges related to water security and climate mitigation underscore the pressing need for forward-thinking systems planning tools to drive urban sustainability transitions. In this study, we propose a novel city-level multi-objective planning framework that explores the nexus between carbon trading and water management, with the aim of facilitating water-efficient urban industrial restructuring. The framework integrates cap-and-trade mechanisms into a two-layered optimization model, creating an integrated approach to optimizing carbon emissions and generating economic opportunities for improving water efficiency. To illustrate the potential application of this framework, we conducted a case study focusing on Dongguan City, a water-stressed industrial metropolis in southern China. The results illustrate potential synergies between water planning strategies and carbon trading schemes, which could be harnessed to enable targeted reductions in water usage and carbon emissions. Furthermore, our findings identify the textile, apparel, and paper products manufacturing industries as primary candidates for strategic production scale reduction, emphasizing the importance of sustained support for the development of the computer and electronic manufacturing sector as a catalyst for urban sustainability transitions. By pioneering this new nexus-based perspective, our study offers valuable insights into long-term strategic planning for a low-carbon and resource-efficient urban economy. • Synergizing carbon trading and water management within a novel integrated planning framework. • Implementing resource-efficiency-driven optimization for water- and carbon-intensive manufacturing sectors. • Gaining insights into the specific roles of key manufacturing sectors in water management and carbon trading. • Introducing carbon trading systems may help in promoting water-efficient industrial restructuring. [Display omitted] [ABSTRACT FROM AUTHOR]

• We study the relationship between GVC embedding and carbon emission density. • A mediation effect model was established to test the mechanism. • There is a U-shaped relationship between urban GVC embedding and carbon emission density. To achieve its carbon peak and neutrality plan, whether China's global value chain (GVC) embedding has a carbon emission reduction effect is a question worthy of attention. This paper measures the GVC embedding degree of 218 Chinese cities from 2000 to 2016, and constructs a panel data model to investigate the impact and its mechanism of GVC embedding on carbon emission intensity. This study finds that there is a significant U-shaped relationship between GVC embedding and carbon emission intensity, and a series of robustness test results support this conclusion. Export scale, energy consumption structure and technological innovation play a mediation role in the impact path of GVC embedding on carbon emission intensity. Based on this, this paper proposes that while participating in GVC, China needs to actively utilize the emission reduction effect of GVC, promote the transformation of export mode to high quality, reduce the use and dependence on high-carbon resources such as coal, and encourage companies to innovate. [ABSTRACT FROM AUTHOR]

A new method of recycling cooking with pulping wastewater was developed to save energy and reduce carbon dioxide emissions in a pulp mill, which used bio-fuel of eucalyptus instead of coal and oil, and reduced the steps of black liquor combustion and lime regeneration in the traditional pulp mill to reduce carbon dioxide emission. As results, the bio-fuel consumption and CO 2 emission are 2.04 × 104 MJ (1.2 tons of eucalyptus) and 2.2 tons for per ton of pulp. It reduces 28.23% of fuel energy consumption and 14.06% of CO 2 emission comparison with that by the traditional pulp mill. In addition, while using the generated lignin as part of bio-fuel, the product value-added is 765.88 RMB for per ton of pulp, being 23.72% lower than that of 1004.08 RMB by the traditional pulp mill. Therefore, this study demonstrates the advance and feasibility of using only bio-fuel for a new pulp mill with a new method of recycling cooking, and will promote the technological revolution of cleaner production in the pulp and paper industry. [ABSTRACT FROM AUTHOR]

[Display omitted] • TGA analysis was performed for MSW components (food waste, paper, and plastics). • Solid residues of paper were 2 and 10 times higher than plastic and food. • Air/CO 2 reduced the burnout temperature by 300 ℃ for food waste than CO 2. • Combustion index (S) of MSW under Air/CO 2 was 4 times more than CO 2. • MSW reduced H f by 2.5 times than food waste, promising better combustion. This study examines the gasification kinetics of Brazilian municipal solid waste (MSW) and its components under air, CO 2, and air/CO 2 (70/30 vol%) atmospheres. The ignition indices of paper and plastic are 6 and 3 times that of food waste, which are 38.6 × 10−3 %/min3 and 19.6 × 10−3 %/min3, respectively, implying a faster separation of volatile compounds from the paper and plastic. The minimum E α values of 132 kJ/mol and 140 kJ/mol have been obtained for paper waste under air and air/CO 2 , respectively. On CO 2 condition, MSW has an average E a value of 96 kJ/mol. Under an air/CO 2 atmosphere, a high synergistic ΔW of −4.7 wt% has been identified between individual components. The presence of air and CO 2 improves the oxidation and char gasification process, thus resulting in better combustion. Hence, the gasification of MSW under an air/CO 2 atmosphere would improve the waste-to-energy plant's performance and minimize the CO 2 emission. [ABSTRACT FROM AUTHOR]

The current study examines a novel multigeneration plant that uses geothermal energy to produce clean and sustainable products. The process includes a re-compression supercritical Brayton power plant (re-sBC), an ejector cooling unit (EJCS), a humidifier dehumidifier desalination (HDH) unit, a Proton-Exchange Membrane (PEM) process, and a hot water preparation unit. The designed plant is able to generate hot water, cooling, power, hydrogen, and freshwater using the geothermal source. In the current paper, the thermodynamic analysis, CO 2 emission assessment, and exergoenvironmental index evaluation are executed to determine the system efficiency and the association between the system and the environment. A thorough parametric examination is fulfilled, to show how the system indicators impact efficiency and generated products. According to analysis data, the proposed multigeneration plant is able to generate 1278 kW of heating load, 229.6 kW of refrigeration capacity, and 109.5 kW of net power rate. Additionally, the capacity of the freshwater is 0.1188 kgs − 1 and the hydrogen is 0.001317 kgs − 1 . This developed system emits a total of 117 tonnes of CO 2 emissions per year for these useful outputs. In conclusion, the energetic and exergetic performance of the suggested MG plant are 14.09 % and 23.35 %, respectively. • A sustainable geothermal energy-based MG is proposed. • The thermodynamic, emission, and environmental analysis is conducted. • Design and evaluation of the Green hydrogen production and storage. • Re-compressed sBC integrated into geothermal driven MG plant. • Total energy and exergy efficiency is computed as 14.09 % and 23.35 %, respectively. [ABSTRACT FROM AUTHOR]

Ports are essential and strategic nodes of international trade and economic activities. The integration of port resources helps enhance the optimal division of port functions to further promote economic development. This paper explores the evolutionary trends of port integration policy from 2011 to 2021 in China through a text-mining approach. We first used the Latent Dirichlet Allocation (LDA) topic analysis method to analyze the port integration policies and summarize the evolutionary trends of port policies. In addition, an association analysis was conducted to explore port integration policies' impacts by examining their relationships among the environmental protection, digitalization level, and port development scale. Our findings suggested that China's port integration policy has evolved from specific and simple to abstract and complicated at the managerial level. Port development has enriched from infrastructure construction to the ideology of economic development. Our findings show that China's port integration is gradually improving the port operation. The findings of the study contribute to the extant literature by analyzing the port integration policy evolution in China and can be referred to by other countries. • Text mining method was used to explore the port integration policy evolution. • Port integration policy evolved from specific and simple to abstract and complicated. • Port development enriched from basic infrastructure to the governance model. • The evolution of port integration policy was related to reducing carbon emissions in the port sector. • The evolution of port integration policy made the ports intelligent in association with digital technology such as big data and AI. [ABSTRACT FROM AUTHOR]

Hydrogen is crucial in the forthcoming low-carbon energy systems offering the potential to reduce CO 2 emissions and its versatility to be utilized across diverse energy sectors. Precise assessment of hydrogen thermo-physical characteristics is vital for the effective design and execution of numerous processes encompassing hydrogen production, transportation, storage, and utilization. In this paper, various distinct machine learning (ML) approaches, namely extreme gradient boosting (XGBoost), Random Forest (RF), Adaptive boosting (AdaBoost), and Light gradient boosting machine (LightGBM) were implemented to estimate thermo-physical properties, namely thermal conductivity, density, viscosity, and diffusivity in water based on pressure and temperature variables. For this purpose, comprehensive experimental data points covering a broad range of pressures and temperatures were acquired from the literature. The results demonstrated a strong agreement between the predictions generated by all proposed techniques and the experimental data. Furthermore, XGBoost yielded a root mean square error (RMSE) of 0.0085, 2.1548, 0.3343, and 1.5308 for the estimation of thermal conductivity, density, viscosity, and diffusivity, respectively, demonstrating superior accuracy in predicting all outcomes. In the sensitivity evaluation, it was observed that temperature, with absolute relevancy factor 0.88, 0.54, 0.246, and 0.92 had the most significant influence on the hydrogen thermo-physical properties in the order mentioned above. Furthermore, the trend analysis of the model indicated that all thermo-physical properties of hydrogen experience positive effects from temperature and pressure, except for density, which decreases as temperature increases. The leverage technique confirmed the statistical validity of both the experimental dataset used for modeling and the model's development. This study's results provide the efficient design and secure operation of hydrogen storage, refueling stations, transportation infrastructure, and production facilities. [Display omitted] • Hydrogen holds great importance in the forthcoming low-carbon energy. • XGBoost, RF, AdaBoost, and LightGBM are utilized for modeling the thermo-physical properties of hydrogen. • XGBoost demonstrates its superior accuracy in predicting thermal conductivity, density, viscosity, and diffusivity. • Temperature has the most significant influence on the hydrogen thermo-physical properties. [ABSTRACT FROM AUTHOR]

Excessive NO x and CO 2 emissions pose a significant challenge in the clean combustion of natural gas, which is expected to be solved through the combination of exhaust gas recirculation and hydrogen enrichment. In this study, the pollutant emission and temperature distribution of a laminar diffusion flame during the combustion of CH 4 mixed with CO 2 /N 2 /H 2 are experimentally investigated. The NO emission reduction effect of CO 2 dilution on hydrogen-enriched methane is evaluated as well. The experimental results show that CO 2 dilution has a deeper NO emission reduction and flame temperature attenuation than N 2 dilution. At a given blending ratio of 50%, CO 2 dilution effectively reduces NO emissions by approximately 50%, whereas N 2 dilution decreases NO emissions by about 10%. Compared with N 2 dilution, the peak flame temperatures of CO 2 dilution cases are reduced by 15.3 K, 45.1 K, 31.7 K, 32.6 K, and 44.3 K, respectively, when the blending ratios increase from 10% to 50% with an interval of 10%. The difference caused by the CO 2 /N 2 dilutions between the inhibition effect from the inherent attributes and the enhanced mixing effect on the flame temperature, results in a significant peak temperature gap of 45.1 K at a 20% blending ratio. H 2 enrichment enhances the flame temperature and promotes the combustion reaction process, resulting in a more compact flame structure. NO emission factors for H 2 blending ratio of 0% and 50% are 1953 mg·(kg Fuel)−1 to 2544 mg (kg Fuel)−1, respectively, which is due to the excessive NO generation because of the temperature rise in the combustion zone. CO 2 dilution demonstrates an excellent NO emission reduction effect on hydrogen-enriched methane gas. This paper may provide some references for the development and application of exhaust gas recirculation and hydrogen enrichment. • The combustion characteristics of CH 4 mixed with CO 2 /N 2 /H 2 are investigated. • CO 2 is better than N 2 in NO emissions reduction and flame temperature attenuation. • H 2 enrichment increases the NO emissions and decreases the CO emissions. • H 2 enrichment increases the flame temperature and promotes combustion reaction. • CO 2 shows an excellent NO emissions reduction for hydrogen-enriched methane. [ABSTRACT FROM AUTHOR]

[Display omitted] • Glass fiber wind turbine blades (WTBs) can provide raw material to produce cement. • Glass fiber WTBs can serve as fuel and replace coal to produce cement. • High boron in some glass fiber WTBs might limit replacement rates. • Combustion of fossil-fuel polymer in WTBs can slightly reduce plant CO 2 emissions. • Glass fiber wind turbine blades are compatible with the cement production process. The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO 2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process. [ABSTRACT FROM AUTHOR]