Significant Emission Reductions Research Articles

Numerical simulation of ammonia combustion with coal in a 135 MW tangentially fired boiler

This study conducted a simulation of coal and ammonia co-combustion in a 135 MW tangentially fired utility boiler using Fluent. The combustion process was modeled using a gas-phase non-premixed approach based on finite-rate/turbulent dissipation. Additionally, NO generation and conversion were simulated through multi-step chemical reactions. Upon verifying the accuracy of the proposed model, the effects of ammonia co-firing ratios and injection modes on boiler combustion characteristics and NO emissions were investigated. The results indicate that as the co-combustion ratio increases, the boiler temperature decreases. Concurrently, NO emissions from the furnace exhibit a trend of initial decrease followed by an increase, reaching a minimum of 136.21 ppm at a mixing ratio of 15 %. With a co-firing ratio of 30 %, a significant reduction in NO emissions can be achieved by decreasing the proportion of primary and secondary air. As the excess air factor of ammonia decreases from 0.3 to 0.1, NO emissions initially decrease, followed by a subsequent increase. Overall, optimizing the ammonia injection mode and air distribution ratio can reduce NO emissions to below 220 ppm when the ammonia co-combustion ratio is below 30 %. This study serves as a valuable reference for retrofitting utility boilers for coal-ammonia co-combustion.

A meta-analysis of probiotic interventions to mitigate ruminal methane emissions in cattle: implications for sustainable livestock farming

In recent years, the significant impact of ruminants on methane emissions has garnered international attention. While dietary strategies have been implemented to solve this issue, probiotics gained the attention of researchers due to their sustainability. However, it is challenging to ascertain their effectiveness as an extensive range of strains and doses have been reported in the literature. Hence, the objective of this experiment was to perform a meta-analysis of probiotic interventions aiming to reduce ruminal methane emissions from cattle. From 362 articles retrieved from scientific databases, 85 articles were assessed independently by two reviewers, and 20 articles representing 49 comparisons were found eligible for meta-analysis. In each study, data such as mean, SD, and sample sizes of both the control and probiotic intervention groups were extracted. The outcomes of interest were methane emission, methane yield, and methane intensity. For the meta-analysis, effect sizes were pooled using a fixed effect or a random effect model depending on the heterogeneity. Afterward, sensitivity analyses were conducted to confirm the robustness of the findings. Overall pooled standardized mean differences (SMDs) with their confidence intervals (CIs) did not detect significant differences in methane emission (SMD = −0.04; 95% CI = −0.18–0.11; P = 0.632), methane yield (SMD = −0.08; 95% CI = −0.24–0.07; P = 0.291), and methane intensity (SMD = −0.22; 95% CI = −0.50–0.07; P = 0.129) between cattle supplemented with probiotics and the control group. However, subgroup analyses revealed that multiple-strain bacterial probiotics (SMD = −0.36; 95% CI = −0.62 to −0.11; P = 0.005), specifically the combination of bacteria involved in reductive acetogenesis and propionate production (SMD = −0.71; 95% CI = −1.04 to −0.36; P = 0.001), emerged as better interventions. Likewise, crossbreeds (SMD = −0.48; 95% CI = −0.78 to −0.18; P = 0.001) exhibited a more favorable response to the treatments. Furthermore, meta-regression demonstrated that longer periods of supplementation led to significant reductions in methane emissions (P = 0.001), yield (P = 0.032), and intensity (P = 0.012) effect sizes. Overall, the results of the current study suggest that cattle responses to probiotic interventions are highly dependent on the probiotic category. Therefore, extended trials performed with probiotics containing multiple bacterial strains are showing the most promising results. Ideally, further trials focusing on the use of probiotics to reduce ruminal methane in cattle should be conducted to complete the available literature.

The Carbon Emission Reduction Effects of the Quality and Quantity of R&D Activities: Evidence from Chinese Provinces

Research and Development (R&D) have significant impacts on carbon emissions, yet the specific data on R&D capital stock and carbon emissions have not been released by Chinese officials, hindering in-depth analysis. In light of this, this study calculates the R&D capital stock of Chinese provinces based on the SNA2008 framework and the BEA method, and estimates the carbon emissions from energy consumption and cement production using the carbon emission factor method. It then examines the carbon emission reduction effects of the quality and quantity of R&D activities at the provincial level. We find that the quality of R&D activities has a significant carbon emission reduction effect, which is stronger in regions with high levels of economic growth and marketization, and this effect strengthens over time. Moreover, mechanism analysis shows that both the quality and quantity of R&D activities reduce carbon emissions by promoting industrial structure upgrading. This paper expands the analytical approach and framework for the carbon reduction effects of R&D activities and offers significant policy and practical implications.

The Impact of Green Finance, and Eco-Innovation on CO2 Emissions: The Pool Mean Group Evidence from ASEAN Countries in the Context of SDGs

This study investigates the influence of green finance, green technology, and eco-innovation on CO2 emissions within ASEAN countries, framed within the context of the Sustainable Development Goals (SDGs), particularly SDG 7 (Affordable and Clean Energy), SDG 9 (Industry, Innovation and Infrastructure), and SDG 13 (Climate Action). Utilizing data from 2002 to 2019 and adopting the Pool Mean Group (PMG) methodology, our analysis sheds light on the critical dynamics between sustainable financial practices, technological advancement in green technologies, and eco-innovative approaches towards achieving significant CO2 emissions reduction. Our findings reveal that green finance significantly empowers the deployment of green technologies and eco-innovations, leading to a notable decrease in CO2 emissions across the studied nations. The study highlights the importance of country-specific policy interventions that cater to the unique economic and technological contexts of ASEAN countries to optimize the contribution of green finance and technology to climate action. These insights offer a valuable guide for policymakers, financial institutions, and other stakeholders in harnessing green finance and technology for environmental sustainability, in alignment with the SDGs. This research contributes to the discourse on sustainable development, emphasizing the pivotal role of finance and innovation in environmental stewardship and carbon reduction efforts across ASEAN countries.

Household-scale digesters in Rwanda: Performance analysis and net-greenhouse gas effect

In view of climate change mitigation, the production of biogas through anaerobic digestion has emerged as a prominent renewable fuel source, also in developing countries. The implementation of household-scale digesters in these regions is instrumental in achieving the Sustainable Development Goal 7 of ensuring clean and affordable energy. However, a rigorous quantification of the biogas production and net-greenhouse gas effect of these household digesters, taking into account fuel use, biogas leakage and fertiliser types, is lacking. This study quantified both biogas production and net-greenhouse gas emissions, utilizing Rwanda as a reference region. Through a field survey, biogas measurements, and model simulations, the study revealed that a reference case featuring a fixed dome digester of 4 m3, fed with manure of on average 2 cows produces 0.38 m3 biogas.d−1 which meets 65% of the cooking need of an average family of 4 adults and 2 children. The addition of a toilet to the household-scale digester increased the daily biogas production by 16%. Conversely, the use of a bare soil floor in the cow shed results in a 28% reduction in biogas production, emphasizing the recommendation for a concrete floor. Net-greenhouse gas emissions from a household-scale digester, including an estimated 9% leak percentage, result in a reduction of 2.4 tCO2,eq.year−1 per household compared to wood-only cooking. Besides, using the digestate as a fertiliser further enhances the reduction to a total of 2.5 tCO2,eq.year−1. The main opportunities for minimizing emissions include optimizing temperature, manure flow and reducing leakages, which needs to be considered during design, operation, and policy formulation. In summary, household-scale digesters provide sustainable waste management, renewable energy, and significant greenhouse gas emission reduction, making them a promising technology for decentralized energy solutions in developing regions.

Research on carbon dioxide capture materials used for carbon dioxide capture, utilization, and storage technology: a review.

In recent years, climate change has increasingly become one of the major challenges facing mankind today, seriously threatening the survival and sustainable development of mankind. Dramatically increasing carbon dioxide concentrations are thought to cause a severe greenhouse effect, leading to severe and sustained global warming, associated climate instability and unwelcome natural disasters, melting glaciers and extreme weather patterns. The treatment of flue gas from thermal power plants uses carbon capture, utilization, and storage (CCUS) technology, one of the most promising current methods to accomplish significant CO2 emission reduction. In order to implement the technological and financial system of CO2 capture, which is the key technology of CCUS technology and accounts for 70-80% of the overall cost of CCUS technology, it is crucial to create more effective adsorbents. Nowadays, with the development and application of various carbon dioxide capture materials, it is necessary to review and summarize carbon dioxide capture materials in time. In this paper, the main technologies of CO2 capture are reviewed, with emphasis on the latest research status of CO2 capture materials, such as amines, zeolites, alkali metals, as well as emerging MOFs and carbon nanomaterials. More and more research on CO2 capture materials has used a variety of improved methods, which have achieved high CO2 capture performance. For example, doping of layered double hydroxides (LDH) with metal atoms significantly increases the active site on the surface of the material, which has a significant impact on improving the CO2 capture capacity and performance stability of LDH. Although many carbon capture materials have been developed, high cost and low technology scale remain major obstacles to CO2 capture. Future research should focus on designing low-cost, high-availability carbon capture materials.

Bridging chance-constrained and stochastic optimization for risk estimation of virtual energy hubs dominated by hybrid vehicles under diverse uncertainties: To improve economic sustainability

Virtual energy hubs (VRHBs) combine dispersed energy resources to enhance the efficient use of various energy sources, grid flexibility, and renewable energy adoption. This paper investigates the adoption of VRHBs with power-to-gas (P2G) facilities and hybrid electric-compressed natural gas vehicles (HNGEVs) in the presence of renewable resources to effectively tackle carbon emissions and increase the flexibility of VRHBs. The proposed P2G facility is constructed from carbon capture to collect carbon pollution from fossil fuel resources and HNGEVs to recycle into synthesis gas in a methanation plant. Furthermore, due to severe uncertainties due to renewable resources and energy consumption intensity, the proposed framework utilizes stochastic-driven chance-constrained optimization, which enables decision-makers in VRHBs to account for the probabilistic nature of uncertainties. Chance-constrained optimization explicitly considers uncertainty through probabilistic constraints, providing a more robust and reliable solution compared to deterministic methods. By modeling uncertainties using chance-constrained programming, VRHBs can manage the economic risks under unexpected worst realizations in uncertainties. Based on the results, the P2G facility leads to a significant reduction in the daily emissions by 63.06 % and 42.77 % observed under no-risk and full-risk conditions, respectively. In addition, the suggested chance-constrained method resulted in a major decrease of 69 % in overall operational costs.

Consideration of various configurations of SG6043-based rotor applied in small capacity horizontal axis wind turbine

The SG6043 airfoil model is well known for its high aerodynamic efficiency and it is suitable for designing small wind turbine blades. This paper determined the optimal blade configurations using only the SG6043 airfoil model with ten different lengths from 1 m to 10 m. Then, it proposed the most suitable model for a rated wind speed of 5 m/s in Vietnam. The chord and twist values of each blade’s part were optimized by using the Betz optimization method (BOM) in the Qblade open software. Several important characteristic quantities such as lift coefficient (Cl), drag coefficient (Cd), power factor (Cp) and power (P) of the different blade configurations are determined by using a combination of both XFLR5 code and Qblade software. After that, parameters related to operation such as pitch angle and rotation speed of the rotor were also investigated to find the operating conditions for the best efficiency of wind energy exploitation. The obtained results show that the Cp of the blades has a maximum value of about 0.476 and the P has a value of up to 95.319 kW in operating conditions with a wind speed range between 1 m/s and 10 m/s. In addition, the ratios of power to blade surface area (P/S) and the ratios of power to blade volume (P/V) at the wind speed of 5 m/s were also investigated. The results show that rotors with blades ranging from 3 m to 5 m will give much higher P/S and P/V values than other blade configurations under these operating conditions. This emphasizes that these blade configurations will bring more economic benefit because they will consume less material and reduce production time while still ensuring the required capacity value. Finally, the 5 m blade rotor with a capacity of 2.750 kW at a rated wind speed of 5 m/s was proposed as the rotor suitable for individual household use. This design can help millions of Vietnamese households be proactive in their power source, thereby contributing to the significant reduction of CO2 emissions from coal-fired power plants.

Influence of baffle height on the in-cylinder mixing and performance characteristics of a gasoline direct injection engine - a CFD investigation

In modern GDI engines, in-cylinder flows play a crucial role in the performance and emission characteristics. Adding baffles to the cylinder head is one way to enhance these flows, as baffle effectiveness is linked to its height. This study aims to investigate the influence of baffle height on the in-cylinder flows and its impact on the performance and emission characteristics of a four-stroke, four-valve, spray-guided GDI engine using computational fluid dynamics (CFD) analysis. The maximum baffle height is determined based on the geometry of the engine. Throughout the analysis, the engine operates at a constant speed of 1000 rev/min., under part-load conditions. From the results, the baffle heights of 2 mm and 3 mm significantly improve mixture stratification compared to the base engine. Furthermore, the indicated mean effective pressure (IMEP) for the engine with 2 mm and 3 mm baffle height improves by about 3% and 4%, respectively, compared to the base engine. In addition, with the increase in the baffle height, there is a significant reduction in the HC emissions with a marginal increase in NOX emissions.

Enhanced efficiency nitrogen fertilizers (EENFs) can reduce nitrous oxide emissions and maintain high grain yields in a rain-fed spring maize cropping system

ContextEnhanced efficiency nitrogen fertilizers (EENFs) have provided opportunities for the simultaneous mitigation of nitrous oxide (N2O) emissions and increases in crop productions. However, the practice of combining EENFs with optimal fertilization under conditions of misaligned water and fertilizer inputs in rain-fed spring maize systems remains inadequately understood. ObjectiveThis study aims to determine the factors controlling N2O emissions under the soil climatic conditions in rain-fed plastic mulching cropping systems treated with different nitrogen (N) fertilization rates and EENFs, and to determine the most effective N fertilization measure to reduce N2O emissions while maintaining crop yields. MethodsA 3-year field experiment was conducted in a spring maize system located in the semiarid rain-fed region of the Loess Plateau, applying two types of EENFs: a nitrification inhibitor dicyandiamide (DCD) and a slow-release fertilizer (SRF). It comprised five fertilization treatments: unfertilized (CK), conventional N rate (CON, 200 kg N ha−1), optimal N rate (OPT, 160 kg N ha−1), OPT with the addition of DCD (OPT+DCD), and OPT using SRF (OPT-SRF). ResultsThe average annual cumulative N2O emissions over the 3-year experimental period ranged from 0.74 to 1.87 kg N2O-N ha–1. Fertilizer N contributed 26−60% to annual N2O emissions. The highest N2O fluxes (50–161 μg N2O-N m–2 h–1) typically occurred within the initial 10 days following fertilization, likely induced by strong nitrification processes, constituting 12–19% of the annual N2O emissions during this brief period. In comparison to the CON treatment, the OPT, OPT+DCD, and OPT-SRF treatments resulted in significant reductions in annual N2O emissions of 24%, 46%, and 34%, respectively, without causing any significant decrease in maize grain yields. The application of DCD led to increased ammonium (NH4+-N) concentrations while reducing nitrate (NO3–-N). Conversely, using SRF resulted in a decrease in both NH4+-N and NO3–-N concentrations. ConclusionsUsing EENFs at the ideal fertilization rate significantly curtailed yearly N2O emissions without adversely affecting maize yields in a rain-fed plastic mulching spring maize system prevalent in the Loess Plateau. Most N2O emissions occurred post-fertilization, with rainfall events further influencing these emissions. ImplicationsOur findings recommend the incorporation of nitrification inhibitors, such as DCD, as the most effective fertilizer measure for reducing N2O emissions in the rain-fed region of the Loess Plateau.

Experimental evaluation of the significance of scheduled turbocharger reconditioning on marine diesel engine efficiency and exhaust gas emissions

Poor clearances, misalignments, and carbon deposits in a turbocharger due to high running hours can decrease engine efficiency. This study analyzes the effects of turbocharger reconditioning on the performance and emissions formation of a marine diesel generator engine. The engine test experiments were performed on a university training ship's auxiliary diesel engine with 4309 running hours before and after the TC overhaul. As a result, cylinder peak pressure was increased by a maximum of 3.57 % while fuel saving of 5–8 g/kWh was realized. Lower exhaust gas temperatures and improved charge air pressure by up to 7.7 % were recorded. A significant CO emission reduction of 21.6 % was recorded at idle load whereas NOx and CO2 emissions were reduced to a maximum of 4.86 % and 7.30 % at 50 % engine load. The results indicate that scheduled TC overhaul and maintenance are very useful to improve the engine’s fuel economy, and performance and reduce exhaust emissions.

The Role of Natural Gas in the Socio-Technical Transition to a Carbon-Neutral Society and a Review of the European Union’s Framework

The urgent need for a significant reduction in global greenhouse gas emissions indicates that the change in the world’s energy mix is inevitable. In the power production sector, this would be achieved through decarbonization with renewables, and within the transport sector, this would be achieved by switching to alternative fuels and electric vehicles. However, this transition is neither fast nor cheap, and it will be gradual. The main goal of this article is to propose a feasible change in the present energy mix and to compare natural gas with other fuels used in power production and transport. The strengths, weaknesses, opportunities, and threats of the current system (traditional fossil fuels) and the potential future system (higher share of natural gas) in energy generation and transport were identified, and the influence of recent global trends was analyzed. Natural gas seems to be a viable solution that can help in the transition to a zero-carbon-emissions society.

Accelerating the transition to zero-emissions ferries

This study investigates how the authorities in Norway have managed to reduce greenhouse gas (GHG) emissions from the ferry sector by implementing a strategic tendering process for domestic ferry services. The study was conducted using interviews and document analysis. The authorities used competitive dialogue to implement zero-emissions technology in the procurement process, rendering the tender process and contract period longer than traditional tenders. The authorities’ first competitive environmental bid process was announced in 2011, and all new ferry tenders are now based on hybrid or zero-emissions technology. The authorities employed push and pull strategies to advance a successful green transition in ferry operations. These measures have led to a significant reduction in GHG emissions from this transport sector but an increase in investment costs compared with traditional diesel ferries. How the authorities used the tender system to make ferry transport more environmentally friendly is useful knowledge for others with similar objectives.

Exploring the green and low-carbon development pathway for an energy-intensive industrial park in China

Energy-intensive industrial parks (IPs) with the distinct characteristics of high energy consumption, substantial greenhouse gas (GHG) emissions, and huge pollution, are facing enormous pressure to realize the synergistic mitigation of GHG and air pollutants. Exploring the green and low-carbon transformation of energy-intensive IPs is urgently required to achieve the dual strategies of “carbon peaking and carbon neutrality” and “Beautiful China”. Taking a typical energy-intensive industrial park (IP) in Henan Province—the Red Flag Cannel Industrial Park (RFCP) as the research object, an integrated evaluation framework including multi-objective optimization model alongside the synergistic mitigation potential of carbon and air pollutant emissions, was established in the energy-intensive IPs. Five scenarios were designed to quantify the GHG and air pollutant mitigation potential, while synergistic emission reduction control effects were evaluated under four measures of industrial structure adjustment, energy structure adjustment, energy efficiency improvement, and industrial symbiosis. The scenario analysis indicates that the integrated scenario (S4) shows the most significant emission reduction potential by 2030. Compared to the baseline scenario (S0), the GHG emission reduction is 11.66 Mt CO2eq (53% reduction rate), and the emission reduction rate of air pollutants ranges from 38% to 69% in S4. The findings indicate that industrial structure adjustment and energy structure adjustment are the primary measures for reducing GHG and air pollutants of IPs. Additionally, the evaluation of synergistic effect demonstrates that industrial structure adjustment shows the most significant synergistic effect on GHG and air pollutant by 2030. Finally, some policy recommendations regarding the transformation direction of energy-intensive IPs were proposed. This study will provide valuable references for the green and low-carbon development of energy-intensive IPs.

Sustainable energy transition in Bangladeshi academic buildings: A techno-economic analysis of photovoltaic-based net zero energy systems

Bangladesh faces challenges with global carbon emissions and energy security due to its heavy reliance on imported fossil fuels. This paper investigates the techno-economic viability of photovoltaic (PV) systems for achieving net-zero energy in academic buildings as a sustainable alternative. The study evaluates the performance of PV systems based on factors including annual energy production, capacity factor, net-zero energy potential, self-consumption/sufficiency ratio, renewable fraction, levelized cost of energy (LCOE), net present value (NPV), payback period, profitability index (PI), and carbon emission reduction. The results indicate that optimally sized PV systems can generate net positive energy: 6.18 MWh for universities, 4.04 MWh for high schools, and 3.62 MWh for primary schools. Economic viability was assessed under two billing methods (net metering and all energy buy/sell), and all cases showed positive NPV and PI values greater than 1. Decarbonization analysis revealed significant reductions in CO2 emissions: 2026.5 tons for universities, 18.9 tons for high schools, and 9.7 tons for primary schools. Finally, a sensitivity analysis assessed the optimal PV system size for seven other regions in Bangladesh. These findings suggest that the widespread adoption of PV systems in academic buildings can play a crucial role in achieving net-zero energy, contributing significantly to the government and policymakers' pursuit of sustainable development goals.

Towards informed decision-making: A comprehensive statistical study of economic and financing models for sustainable energy transition in urban environments

This paper presents a comprehensive approach to optimizing renewable energy allocation in urban environments. Our methodology integrates statistical economic modeling and decision-making techniques to address the complex challenges associated with renewable energy management. By employing stochastic programming and robust optimization, we optimize renewable energy allocation to minimize operational costs, reduce emissions, and enhance system reliability. Our analysis demonstrates significant reductions in operational costs (15.2%) and emissions (20.5% for NOx and 18.9% for CO2) compared to baseline scenarios. Moreover, our approach improves system reliability by reducing load shedding (25.1%) and enhancing overall system reliability (12.3%). These findings underscore the effectiveness of our proposed strategy in fostering economic, environmental, and operational sustainability in urban energy environments.

The Effects of Local Food on Carbon Emissions: The Case of the Republic of Korea

This study addresses the urgent environmental issue of climate change, focusing specifically on the role of local food, which is produced and consumed locally, in helping to reduce carbon emissions by eliminating the need for long-distance transportation. Through quantitative analysis, this study elucidates the potential benefits of environmental impact achieved through the consumption of local food, i.e., the significant reduction in carbon emissions. Specifically, the consumption of local food has been found to yield an annual decrease of 2,421,296 tCO2 emissions, representing 2.5% of the Republic of Korea’s total greenhouse gas emissions from the transportation sector. This reduction further translates into an estimated economic value of USD 54.23 million (KRW 70.5 billion). These findings underscore the potential of local food consumption as a tangible strategy to overcome environmental problems. Moreover, the academic contribution of this study lies in its comprehensive analysis of the economic and empirical impacts of local food consumption on the environment. Moving forward, we propose policies such as supporting local food distribution networks, providing public education on local food, fostering local food industries, and implementing incentives to revitalize local food consumption.

Towards a defossilized building sector with field tests in the lab: Review, development, and evaluation

The transformation process in the building sector towards future city concepts requires changes in our society that aim for significant emission reduction until 2045. Currently, buildings in Germany are constructed and operated in such a way that no changes need to be made to them for decades. Therefore, any upcoming changes that do not achieve the climate goals must be avoided immediately. However, making the optimal decision for a change is complex due to (a) multi-domain (e.g., design and control), (b) multi-scale (e.g., single-family building and urban energy system), (c) multi-stakeholder (e.g., users and practice), and (d) long-term implications (up to decades). Conventional testing facilities and methods do not account for the integration of (a)-(d). Therefore, their technology readiness level is limited by 6. This paper introduces an approach that aims at (1) a multi-domain and multi-scale approach by applying process systems engineering to the building sector and that aims at (2) stakeholder integration already in the research process by applying the living lab approach. We combine the two methods, yielding a field test in the lab infrastructure pushing the technology readiness level to 7–8. In all, it consists of five test benches (Refrigerant Cycle Lab, FlexFass, RT-Lab, Raumklimalabor, and InFis). This work focuses on the Refrigerant Cycle Lab. Its concept is based on two further Hardware-in-the-Loop test benches which are extended by a safety system that ensures automated operation dedicated to heat pumps with flammable refrigerants. In two case studies, we show that field tests in the lab allow multi-domain and multi-scale testing. Both aspects support accelerating the transformation process towards a defossilized building sector. In the next step, the combination of test benches at different locations is promising to reduce the need to set up identical experiments at different locations. In the long term, the laboratory is designed to include external stakeholders to avoid time-consuming iterations and can, therefore, save resources, time, and money for our complex transformation process.

Performance and cost potential for direct-fired supercritical CO2 natural gas power plants

Direct-fired supercritical CO2 (sCO2) power cycles are being explored as an attractive alternative to natural gas combined cycle (NGCC) plants with carbon capture and storage (CCS). Therefore, understanding their performance and cost potential is important for the commercialization of the technology. This study presents detailed techno-economic optimization results of natural gas-fired, utility-scale power plants based on the direct sCO2 power cycle, which is lacking in public literature. The study considered multiple plant configurations with varying levels of thermal integration with the plant air separation unit (ASU) to shows the systematic impact of thermal integration on plant performance and economics. Several design variables for each power cycle configuration were identified and optimized to minimize the levelized cost of electricity (LCOE). The optimized direct sCO2 power plants achieved ∼48 % plant efficiency (HHV basis) which is similar or slightly higher plant efficiencies than state-of-the-art NGCC plants based on the F-class gas turbine with carbon capture and storage (CCS). The LCOE of the optimized direct sCO2 plants is 13–17 % higher than the reference NGCC plants with CCS due to high capital costs associated with the ASU and sCO2 power block, though there is significant room for improvement due to high uncertainty in component capital costs for these new plants. Based on the results, direct sCO2 power cycles have the potential to achieve >50 % efficiency (HHV basis) with >98 % CO2 capture rate which can lead to significant efficiency improvement and CO2 emissions reductions compared to NGCC plants with CCS.

Research on Provincial Distribution of Total Carbon Emissions in the Power Generation Industry under Carbon Neutrality Constraints

The power generation industry in China is at the forefront of implementing carbon trading market policies, playing a crucial role in carbon emission reduction. Carbon allocation in each province is pivotal for future economic development and achieving a gradual and orderly carbon peak. By analyzing total carbon emissions from 2012 to 2021 and examining emission responsibilities from a producer perspective, this study extends the STIRPAT model to evaluate factors influencing carbon emissions in the national and provincial power generation sectors. Key findings highlight the urgent need for industrial structure changes in provinces like Xinjiang, Tibet, Guangdong, Shandong, and Jiangsu, which bear significant emission reduction responsibilities. The spatial and temporal distribution of carbon emissions is shifting from the southeast coast to central and western regions. Factors such as energy consumption, electric power intensity, urbanization rate, power structure, economic development level, and industrial composition significantly impact carbon emissions. To achieve carbon peak goals, a multifaceted approach is essential for reducing emissions in China's power generation sector, emphasizing the need for strategic interventions across various perspectives.