Substantial Emission Reductions Research Articles

Mitigating Risk and Emissions in Power Systems: A Two-Stage Robust Dispatch Model with Carbon Trading

The large-scale integration of renewable energy sources is crucial for reducing carbon emissions. Integrating carbon trading mechanisms into electricity markets can further maximize this potential. However, the inherent uncertainty in renewable power generation poses significant challenges to effective decarbonization, renewable energy accommodation, and the security and cost efficiency of power system operations. In response to these challenges, this paper proposes a two-stage robust power dispatch model that incorporates carbon trading. This model is designed to minimize system operating costs, risk costs, and carbon trading costs while fully accounting for uncertainties in renewable energy output and the effects of carbon trading mechanisms. This model is solved using the column-and-constraint generation algorithm. Validation of an improved IEEE 39-bus system demonstrates its effectiveness, ensuring that dispatch decisions are both robust and cost-efficient. Compared to traditional dispatch models, the proposed model significantly reduces system risk costs, enhances the utilization of renewable energy, and, through the introduction of a ladder carbon trading mechanism, achieves substantial reductions in carbon emissions during system operation.

Hybrid and Electric Vehicle (EV) integration in public transport: Challenges and opportunities

As cities worldwide grapple with the dual challenges of increasing urbanization and climate change, the integration of hybrid and electric vehicles (EVs) into public transport systems emerges as a critical solution. This article examines the multifaceted challenges and opportunities associated with adopting hybrid and EV technologies for buses and coaches. Key challenges include the high initial costs, the need for robust infrastructure, and concerns regarding vehicle reliability. Conversely, the transition offers significant benefits, such as substantial emissions reductions, improved operational efficiency, and enhanced public perception of sustainable practices. Through an evaluation of successful case studies from cities like London, Amsterdam, and Shenzhen, this article highlights effective strategies and outcomes achieved in the realm of public transport electrification. Ultimately, the findings underscore the necessity for collaborative efforts among stakeholders to drive the successful integration of hybrid and EV technologies, paving the way for a more sustainable urban mobility future.

Progress in Corrosion Protection Research for Supercritical CO2 Transportation Pipelines

Carbon Capture, Utilization, and Storage (CCUS) technology is an emergent field with the potential for substantial CO2 emissions reduction, enabling low-carbon utilization of fossil fuels. It is widely regarded as a critical technology for combating global climate change and controlling greenhouse gas emissions. According to recent studies, China has identified CCUS as a key emissions reduction technology in climate change response and carbon neutrality objectives. Within this framework, supercritical CO2 (SC-CO2) transport pipelines are an essential means for efficient and safe transportation of CO2. Corrosion protection of pipelines enhances the efficiency and safety of CCUS technology and supports broader implementation and application. This paper reviews the current research on corrosion protection for SC-CO2 transport pipelines, discusses effect factors, compares various corrosion protection strategies, and analyzes the challenges in corrosion protection of SC-CO2 transport pipelines. It concludes with a perspective on future research and development directions in this field. This paper is dedicated to providing new research strategies for pipeline corrosion protection in CCUS technology in the future, and providing technical support for pipeline corrosion protection in CCUS industrial applications.

The impact of calcined mud on the rheological properties of eco-friendly concretes using the equivalent mortar method (CEM)

In order to harmonise technical and environmental aspects, people today focus not only on concrete's technical characteristics but also on environmental imperatives. Thus, the emphasis is on the development of concrete and cements that offer ecological and sustainable advantages. Commonly, people use various natural materials as cement additives, demonstrating their effectiveness by replacing a significant portion of the cement in the hardened state of concrete. This substitution leads to a substantial and remarkable reduction in carbon dioxide emissions. However, when it comes to the physical properties of the material in its fresh state, challenges may arise. Indeed, the rheological changes induced by these additives may hinder the on-site use of this eco-concrete. The main purpose of this study is to find out how adding minerals to environmentally friendly concrete changes its rheological parameters (yield stress, plastic viscosity) and fresh properties (slump, flow time). We will approach this using the concept of mortar equivalent to concrete (CEM). We developed five formulations of CEM’s by substituting cement with calcined mud (CM) in binary mixing systems at a temperature of 20 °C. The results showed that adding binary cements with calcined mud had a negative effect on the fresh properties and rheological parameters. However, when substitution happens at a low rate, it behaves almost like control mortar (OPC).

Study on properties and CO2 emission of self-pulverizing calcium sulfoaluminate (SPCSA) after carbonization curing

The extensive use of Portland cement (OPC) has resulted in a steady rise in CO2 emissions from the construction industry, posing a significant climate threat. While adopting low-carbon cement enriched with belite minerals holds promise for substantial CO2 emission reduction in the cement industry, the limited early hydration activity of C2S constrains its engineering applications. Carbon capture, storage, and utilization (CCUS) technology, capable of rapidly developing the strength of C2S, opens up a new avenue for utilizing low-carbon cement. This study evaluated the properties of self-powdering calcium sulfoaluminate (SPCSA) cements with different C2S contents, and the carbon emissions during production and application were analyzed. The samples' carbonation area, compressive strength, and capillary water absorption properties were tested. The carbonation products and pore structures were also characterized using XRD, TGA, SEM, and Low-NMR. The results show that when the molar ratio of C4A3S̅ to C2S is 1:12 (S̅12), the compressive strength and CO2 sequestration of SPCSA are 69.78 MPa and 0.15 g/g, respectively. When CCUS technology is adopted, the CO2 emission during the production and application of SPCSA is 585.78 kg/t, much lower than that of OPC of 878.28 kg/t. This is significant as a reference for realizing carbon neutrality in the cement industry.

Carbon Emission Reduction Associated With Utilisation Of Telehealth In Outpatient Clinics In An Australian Quaternary Health Service

Objective: To assess the impact of implementing telehealth in outpatient clinics on the carbon emissions associated with the delivery of health care. Design & Setting: Retrospective cohort study in large metropolitan quaternary referral health service from January 2021- December 2022. Participants: All patients who attended an outpatient clinic appointment during the study period, either in-person, via telehealth or via telephone. Main outcome measures: The estimation of carbon emissions in tonnes (t) of CO2-equivalent (CO2-e) associated with in-person and telehealth appointments based on emissions associated with travel, telehealth platform usage and N95 mask usage. Results: There were 571,121 outpatient clinic appointments during the study period. Of the appointments, 251,458 (44%) were conducted remotely, resulting in an estimated reduction in 3,629t of CO2-e emissions in the two-year period. Telehealth consultations in this time contributed 4.5t of CO2-equivalent emissions. The total emission usage of telehealth clinic was only 0.12% of emissions generated from face-to-face clinic appointments. Conclusion: Telehealth offers the opportunity of substantial carbon emissions reduction within the healthcare sector, while also providing cost and time-saving benefits for healthcare services and patients. Limitations include generalisation of transportation modes and the retrospective nature of the data collection.

A System Dynamics Supply Chain Analysis for the Sustainability Transition of European Rolled Aluminum Products

This research presents a system dynamics model to study the interaction among demand and supply evolutions, government regulations, sustainable adoption trends, investments in different decarbonization technologies, and environmental requirements for the European Aluminum Rolled Product Supply Chain (ARPSC). It allows stakeholders to assess the quantitative impact of investing in decarbonization technologies on supply chain sustainability. Investing in decarbonization technologies reduces greenhouse gas (GHG) emissions. The most substantial GHG emission reductions can be achieved if upstream ARPSC actors invest according to an aggressive investment strategy between 2031 and 2040. However, even with an aggressive investment strategy, investing in decarbonization technologies alone is likely to be insufficient to achieve the European Green Deal goals. Furthermore, barriers to investment in decarbonization technologies and a low rate of progress in doubling the European Union’s circularity rate may put extra stress on achieving the European Green Deal goals for the European ARPSC. Instead, ARPSC actors will additionally need to optimize the recycling of aluminum rolled products and adopt strategies for resource sufficiency, e.g., by sharing cars and using packaging multiple times.

Coarse bubble mixing in anoxic zone greatly stimulates nitrous oxide emissions from biological nitrogen removal process

The biological nitrogen removal process in wastewater treatment inevitably produces nitrous oxide (N2O), a potent greenhouse gas. Coarse bubble mixing is widely employed in wastewater treatment processes to mix anoxic tanks; however, its impacts on N2O emissions are rarely reported. This study investigates the effects of coarse bubble mixing on N2O emissions in a pilot-scale mainstream nitrite shunt reactor over a 50-day steady-state period. Online and offline N2O monitoring campaigns show that coarse bubble mixing in the anoxic zones significantly elevates N2O emissions, yielding an extremely high emission factor of 15.5 ± 3.5 %. Intensive sampling and isotopic analyses suggest that the elevated emissions are primarily due to the inhibition of the N2O denitrification process by oxygen in the anoxic phase introduced by coarse bubbling. Substituting coarse bubble mixing with submersible pump mixing resulted in a substantial reduction of N2O emissions, decreasing the emission factor by an order of magnitude to 1.2 ± 0.8 %. The findings reveal that a previously overlooked factor, coarse bubble mixing, can significantly stimulate N2O emissions. The use of coarse bubble mixing in anoxic tanks of biological nitrogen removal warrants caution.

A-124 Sustainable Transport: Assessing Environmental Impact in Medical Sample Transit via Drones and Vehicles

Abstract Background This research explores the ecological implications associated with different methods of transporting medical samples, specifically focusing on drones, combustion cars, and electric cars within two laboratories in central European countries. With the primary goal of assessing and comparing CO2 consumption, delivery time, and overall environmental impact, the study aims to provide a basis for adopting sustainable practices in healthcare logistics. Methods The transportation of medical samples occurred between two laboratories in the Principality of Liechtenstein and Switzerland, utilizing authorized aerial and road routes. Various weather conditions and distances were considered for sample transports using different vehicles (8 combustion cars, two electric cars, and one drone model). Energy consumption was documented, and the CO2 footprint was calculated based on data from the Swiss Federal Office for the Environment (FOEN) for both imported and renewable electricity. Comparative analyses were conducted to quantify the environmental impact of each transportation method. Results In terms of CO2 footprint, combustion cars exhibited a CO2 release of 159.5 g/km, while electric cars showed 3.43g (2.15 to 4.08% of combustion cars). Drones demonstrated a minimal 0.09g CO2 emission per kilometer (0.066% of combustion car CO2 emission; 2.6% of electric car CO2 emission). The distance traveled by drones was significantly shorter (16.7% to 50%). Additionally, the efficiency of drone transport was emphasized by its ability to avoid traffic jams and associated detours, resulting in time savings ranging from 31.25 to 50% per delivery when comparing transport times during rush hour and regular hours in the selected setting. Conclusions The integration of drone technology emerges as a crucial strategy for establishing a “green laboratory.” The substantial reduction in CO2 emissions and enhanced delivery efficiency position drone transport as a sustainable and operationally effective solution for medical sample logistics, offering shorter delivery times. These findings highlight the potential for transformative change in healthcare logistics, aligning with the global shift towards sustainability and green practices.

An Immersive VR Training Scenario for Safe Methanol Bunkering in the Maritime Industry

Abstract The maritime industry, pivotal in global commerce, faces critical challenges in mitigating environmental impacts, especially greenhouse gas emissions. The International Maritime Organization (IMO) targets a substantial reduction in emissions by 2050, necessitating innovative approaches to fuel usage. Methanol, recognized for its lower carbon intensity, emerges as a viable alternative fuel. However, its flammability and toxicity introduce complex safety and operational demands. To address these challenges, we have developed a state-of-the-art Virtual Reality (VR) training program specifically for methanol bunkering operations. This training, utilizing Unity 3D and Meta Quest 2, offers a highly interactive and realistic experience. Trainees engage in a comprehensive simulation that covers the entire bunkering process, including safety checks, equipment handling, and emergency response protocols. The VR environment allows for dynamic adjustments by trainers, enhancing the realism and educational value of the scenario. Our program also includes an assessment component that evaluates the trainee’s performance across various metrics such as safety protocol adherence, decision-making, and situational awareness. The anticipated outcome of this VR training initiative is to significantly improve the preparedness of maritime personnel in handling alternative fuels, thereby supporting the industry’s transition towards sustainable practices and contributing to broader environmental protection goals.

DESIGN and be SMART: Eleven engineering challenges to achieve sustainable air transportation under safety assurance in the year 2050

The aviation industry faces various challenges in meeting long-term sustainability goals amidst surging demand for air travel and growing environmental concerns of the general public. The year 2050 is set as an ambitious goal for net zero emissions, a substantial reduction in carbon dioxide emissions per passenger kilometer flown, major improvements in aircraft energy efficiency, and a development towards autonomous, intelligent operations. This review explores the pivotal role of advancements in engineering for achieving sustainability in aviation. Through a comprehensive review of existing literature and case studies, our work highlights how innovations in all aspects of aircraft engineering coupled with operations-related technologies, offer promising solutions to mitigate environmental impact, enhance efficiency, and ensure long-term sustainability in aviation operations. To discuss the necessary advances, we promote the so-called ‘DESIGN and be SMART’ framework, consisting of eleven complementary engineering challenges towards reaching sustainability. To address the high safety levels reached in air transportation, our DESIGN and be SMART framework also addresses the safety assurance challenge that is overarching each of the eleven engineering challenges. We believe that through an orchestrated integration of hardware advancements with innovative software solutions, and novel safety assurance methods, the aviation industry can realize synergistic benefits that drive sustainable growth of air transportation. Our review contributes to such an orchestration by describing the status quo and research challenges ahead.

Energy Transition Analysis and Climate Action Strategy in the Power Sector: A Case Study of the Java-Bali System

Abstract The transformation of societies over time has led to a marked shift in energy consumption patterns. In the face of rapid industrial growth and a burgeoning population, Indonesia confronts the multifaceted challenge of achieving a balance among energy trilemma: energy security, economic affordability, and environmental sustainability. This study assesses the feasibility of low-carbon energy systems in Indonesia, evaluating current policies and proposing a roadmap for net-zero emissions. Utilizing the Low Emissions Analysis Platform (LEAP) and the Next Energy Modeling System for Optimization (NEMO), the study explores multiple scenarios—namely, Business-as-Usual (BAU), Carbon Capture and Storage Mitigation (CCSM), and New and Renewable Energy Mitigation (NREM). Of these, the NREM scenario, emphasizing the integration of innovative and renewable energy sources, achieves the most substantial reduction in greenhouse gas emissions while maintaining economic viability. This strategy advocates for the comprehensive adoption of new and renewable energy, aiming to approximate zero emissions by 2060. The peak direct cost of production for this scenario is estimated at $270.8 billion. However, each scenario presents its own set of technological, economic, and policy-related challenges, necessitating strategic solutions for a successful transition to sustainable energy systems.

Exploring the long-term variations and high concentration episodes of peroxyacetyl nitrate in Megacity Seoul

Over the past few years, peroxyacetyl nitrate (PAN) has drawn significant attention as a key indicator of photochemical pollution owing to its intimate relationship with ozone and associated health effects. This study presents measurements conducted at the Korea University campus in Seoul during the high-ozone seasons from 2018 to 2021. PAN concentration was measured using fast gas chromatography with luminol chemiluminescence detection (GC-LCD), alongside measurements of O3, volatile organic compounds (VOCs), NO, NO2, and meteorological variables, including boundary layer height (BLH).The mean concentrations of PAN and O3 over the years were 0.56 ppbv and 35 ppbv in 2018, 1.29 ppbv and 58 ppbv in 2019, 0.21 ppbv and 50 ppbv 2020, and 0.53 ppbv and 46 ppbv in 2021, respectively. The annual variation observed in Seoul is consistent with trends seen in major cities worldwide during the COVID19 pandemic, reflecting a substantial reduction in urban emissions. Notably, the mean concentration of NOx and VOCs decreased significantly by more than 50 % and 25%, respectively, from 2019 to 2021.At temperatures above 30 °C, PAN decomposition was accelerated, decoupling a consistent positive relationship between PAN and O3 in 2020 and 2021. The results of a 0-D photochemical model (F0AM) calculation demonstrated that PAN formation primarily stems from anthropogenic VOCs, particularly > C2 alkenes. Elevated PAN concentrations during nighttime were attributed to boundary layer expansion and upper-air entrainment. Instances where PAN concentrations surged to at least 3 ppbv or higher in 2019 were attributed to biomass burning impacted air, as evidenced by concurrent elevations in K+ and OC in PM2.5, and O3.This study underscores the complex interplay of factors influencing PAN and ozone enhancements under decreased precursor levels, with an emphasis on dynamic change in the boundary layer, and long-distance transport of non-fossil sources during agricultural burning seasons.

Are farmers willing to pay for low-carbon agriculture? Evidence from China

PurposeReducing carbon emissions in agriculture is vital for fostering sustainable agricultural growth and promoting ecological well-being in rural areas. The adoption of Low-Carbon Agriculture (LCA) by farmers holds great potential to accomplish substantial reductions in carbon emissions. The purpose of this study is to explore the farmers' preference and willingness to engage in LCA.Design/methodology/approachThis study employs the Choice Experiment (CE) method to examine farmers' preferences and willingness to adopt LCA, using field survey data of 544 rural farmers in the Weihe River Basin between June and July 2023. We further investigate differences in willingness to pay (WTP) and personal characteristics among different farmer categories.FindingsThe empirical results reveal that farmers prioritize government-led initiatives providing pertinent technical training as a key aspect of the LCA program. Farmers' decisions to participate in LCA are influenced by factors including age, gender, education and the proportion of farm income in household income, with their evaluations further shaped by subjective attitudes and habits. Notably, we discovered that nearly half of the farmers exhibit indifference towards LCA attributes.Originality/valueTo the best of the authors' knowledge, this study is the first to investigate farmers' attitudes toward LCA from their own perspectives and to analyze the factors influencing them from both subjective and objective standpoints. This study presents a fresh perspective for advocating LCA, bolstering rural ecology and nurturing sustainable development in developing nations.

Reducing the carbon footprint for a 30-bed haemodialysis unit by changing the delivery of acid concentrate supplied by individual 5 L containers to a central delivery system

BackgroundHaemodialysis treatments generate greenhouse gas (GHG) emissions mainly as a result of the equipment, consumables and pharmaceuticals required. An internal audit demonstrated a 33% wastage of acid concentrate when using individual 5.0 L containers at a 1:44 dilution ratio. We therefore investigated whether changing the delivery system for acid concentrate would reduce wastage and any associated greenhouse gas emissions.MethodsWe calculated the difference for a 30-bed dialysis unit between receiving acid concentrate in single-use 5.0 L plastic containers versus bulk delivery for a central acid delivery system connected to the dialysis machines. Estimates of carbon dioxide equivalent (CO2e) emissions were made using the United Kingdom government database and other sources.ResultsA 30-station dialysis unit functioning at maximum capacity (3 shifts and 6 days/week), switching to bulk delivery and central acid delivery could realise an approximate total reduction of 33,841 kgCO2e/year; in reduced product wastage, saving 6192 kgCO2e, 5205 kgCO2e from fewer deliveries, and 22,444 kgCO2e saving from a reduction in packaging and waste generated, which equates approximately to a one tonne reduction in CO2e emissions per dialysis station/year.ConclusionsSwitching from delivering acid concentrate in individual 5.0 L containers to a central acid delivery system can result in substantial reductions in CO2e emissions within a dialysis clinic. The emission savings from reducing the single-use plastic packaging greatly outweigh any gains from eliminating wastage of acid concentrate. Dialysis companies and clinicians should consider reviewing the design of current and future dialysis facilities and policies to determine whether reductions in CO2e emissions can be made.Graphical

Low-NOx thermal plasma torches: A renewable heat source for the electrified process industry

Industrial thermal plasma torches can heat a gas up to 5000–20,000 K, i.e., well above the temperature needed to replace the heat generated from the combustion of traditional fossil fuels (e.g., coal, oil, and natural gas) in large-scale process industry furnaces producing construction materials (e.g., iron, steel, lime, and cement). However, there is a risk for significant NOx emissions when air or N2 are used as plasma-forming gas since the temperature somewhere in the furnace always will be higher compared to the threshold NOx formation temperature of ∼1800 K. Torch NOx forms inside the high temperature region of the plasma torch (>5000 K) when air is used as gas. Process NOx forms instead when the hot gas (when air or nitrogen is used as plasma forming gas) from the plasma torch mixes with process air downstream the torch. By analysing the complex chemistry of both the torch- and process NOx formation with thermodynamic equilibrium and one-dimensional chemical kinetic calculations it was shown that adding H2 to the plasma-forming N2 gas significantly reduces the NOx emissions with more than 90 %. Verifying experiments with air, pure N2, and mixtures of H2 and N2 as plasma-forming gas were performed in a laboratory scale insulated laboratory furnace with different pre-heating temperatures of process air (293, 673, and 1073 K) which the plasma gas mixes with downstream the torch. Depending on the pre-heating temperature the NOx emissions were between 12,000–14,000 mg NO2/MJfuel when air was used as plasma forming gas. Substantial NOx emission reduction occurs both when N2 replaces air, where the NOx emissions was in the span of 8000–11,500 mg NO2/MJfuel and furthermore when H2 was mixed into the N2 gas stream. For the highest degree of H2 mixing (28.6 vol-%), the NOx emissions were between 450–1700 mg NO2/MJfuel depending on the pre-heat temperature of the process air, i.e., a reduction of 88–96 % and 85–94 %, respectively when air or N2 was used as plasma forming gas. The measured NOx emissions are then of the same order of magnitude as would be expected from the combustion of traditional fuels (coal, oil, biomass and pure H2). Finally, by analysing the aerodynamics in an axisymmetric furnace with an experimentally validated computational fluid dynamics (CFD) model using reduced chemistry for the NOx formation (19 species and 70 reactions), further guidelines into the process of NOx reduction from thermal plasma torches are given.

Rewetting on agricultural peatlands can offer cost effective greenhouse gas reduction at the national level

To reach EU’s carbon neutrality target by 2050, emission reductions in the land-use sector are needed. Agricultural peatlands attribute for half of the greenhouse gas emissions of cropland in both in EU and Finland. High greenhouse gas emissions from agricultural peatlands are primarily caused by CO2 emissions following aerobic peat decomposition due to deep drainage, and studies have shown that raising water-table has potential to slow down the decomposition process. Here we studied the emission reduction potential and cost of implementing controlled drainage, paludiculture, peatland restoration and afforestation to current land use on agricultural peatlands in Finland. We created three scenarios with increasing amount of wet field use on cultivated organic soils and estimated their effects on national greenhouse gas emissions and farmers’ income. The yearly emission reduction ranged from 0.3 to 5.0 Mt CO2 equivalents in the different scenarios compared to the current state in Finland. Emission reductive land use had a negative impact on the farmers income, which should be compensated. Assuming the government compensates the lost income for the farmers, the cost of emission reduction ranged from −4 to 45 € per ton of CO2 equivalents. Rewetting provided the most emission reduction per area and was the most cost effective. We conclude that substantial emission reduction is attainable by rewetting agricultural peatlands. The cost of emission reduction is inexpensive compared to average carbon price in European Union emission trading system, or to the costs of technical carbon capture and storage in Finland.

The future of single-use plastics in life science: Sterile printing of PLA reduces greenhouse gas emissions by 80% and enables carbon neutrality

The European Union’s Green Deal emphasizes life science and biotechnology as key drivers for achieving a circular economy. However, the prevalent use of non-sustainable single-use plastics derived from petrochemical sources in life science research and development contradicts this ecological goal. This study presents a viable alternative through on-site sterile 3D printing of single-use plastics using poly(lactic acid) (PLA). The sterile printing of PLA demonstrates a substantial reduction in CO2eq emissions per shake flask, decreasing from 260 g CO2eq to 145 g CO2eq. Suitability for cell culture was demonstrated for sterile printed PLA, autoclaved high-temperature PLA and for suspension cell cultures in shake flasks using CHO and insect cells as well as adherent Vero cell cultures in cell culture wells. Further optimization of sustainable shake flasks is achieved by utilizing recycled PLA, resulting in a remarkable reduction to 73 g CO2eq, constituting a 72% decrease in CO2eq emissions compared to conventional single-use plastics. Moreover, by employing geometric optimization to minimize material usage, emissions can be further reduced to 44 g CO2eq, representing an 83% reduction in CO2eq emissions. Anticipated advancements in PLA production suggest future carbon net negative PLA production, potentially achieving zero carbon emissions for single-use plastics using PLA. The exceptionally cost-effective nature of 3D printed single-use plastics, coupled with negligible capital costs for implementation, positions sterile 3D printing as a practical solution aligned with the 2030 Green Deal goals. Moreover, ongoing improvements in bioplastic production underscore the feasibility of meeting the 2050 targets of carbon neutrality for single-use plastics in life science research and development.

Comparative assessment of waste-to-energy scenarios to mitigate GHG emission from MSW in a developing mega city

The search for sustainable municipal solid waste management in urban areas has become a dire need as the generated unprecedented volumes of waste eventually end up in landfills and emits greenhouse gas (GHG). To offer sustainable waste management in Dhaka, Bangladesh, the performance of incineration, anaerobic digestion, and hydrothermal carbonization (HTC) based Waste to Energy (WtE) processes were assessed and compared. The population and the GDP of Dhaka North City Corporation from 2015 to 2023 were used to estimate the MSW generation rate with an empirical multivariable linear regression model. In 2023 around 3600 tons/day of MSW was generated which was 35 % higher than in 2015. The IPCC decay models, ZODM, FODM, and modified triangular model (MTM) yielded 87.3, 41.3, and 38-k tonnes of CH4 generation, respectively. The power generation from incineration-based plants can fall from 30 MW to 3 MW if the moisture content of MSW increases from 70 % to 90 %. Anaerobic digestion produces 34 MW of power. The Optimization of the HTC operating parameters was done and it demonstrates substantial energy potential (up to 65 MW with co-feeding of 420 tons/day of hydrochar with 426 tons/day of plastic from MSW) and GHG emission reduction (221.5 %) compared to landfilling. Additionally, HTC-derived wastewater presents an opportunity for nutrient recovery with 8.16 and 2.66, 0.3 tons/day of K, Na, and P reclamation potential, respectively. A comparison of different scenarios in plastic recycling in incineration and sensitivity analysis for three WtE schemes were conducted. Thus, the study provides a rigorous assessment of different pathways to offer a comprehensive framework for sustainable MSW management that contributes to a cleaner urban environment.

Measuring and reducing the carbon footprint of fMRI preprocessing in fMRIPrep.

Computationally expensive data processing in neuroimaging research places demands on energy consumption-and the resulting carbon emissions contribute to the climate crisis. We measured the carbon footprint of the functional magnetic resonance imaging (fMRI) preprocessing tool fMRIPrep, testing the effect of varying parameters on estimated carbon emissions and preprocessing performance. Performance was quantified using (a) statistical individual-level task activation in regions of interest and (b) mean smoothness of preprocessed data. Eight variants of fMRIPrep were run with 257 participants who had completed an fMRI stop signal task (the same data also used in the original validation of fMRIPrep). Some variants led to substantial reductions in carbon emissions without sacrificing data quality: for instance, disabling FreeSurfer surface reconstruction reduced carbon emissions by 48%. We provide six recommendations for minimising emissions without compromising performance. By varying parameters and computational resources, neuroimagers can substantially reduce the carbon footprint of their preprocessing. This is one aspect of our research carbon footprint over which neuroimagers have control and agency to act upon.