Greenhouse Gas Emissions Research Articles

Comprehensive study on waste heat recovery from gas turbine exhaust using combined steam rankine and organic rankine cycles

Waste heat recovery technology has proven to be an effective approach for enhancing energy efficiency, reducing greenhouse gas emissions, and lowering energy costs. This study assesses the performance of different waste heat recovery systems from thermodynamic, exergy destruction, economic, and environmental perspectives. Using the DWSIM software, the study simulated a waste heat recovery cycle powered by a high-temperature heat source (508.99 °C) to maximize recovery power and determine the optimal system configuration, including standalone Organic Rankine Cycle (ORC), standalone Steam Rankine Cycle (SRC), and combined systems like SRC with series ORC (SRC + S-ORC), cascade ORC (SRC + C-ORC), and a combination of both (SRC + S-ORC + C-ORC). Among these configurations, the SRC + S-ORC + C-ORC configuration delivered the best performance, achieving a net power output of 3,532.14 kW and a thermal efficiency of 17.09 %. Economically, it demonstrated strong results with a net present value of €1.478 million, a payback period of 8.01 years, and a benefit-cost ratio of 1.32. This configuration also had the highest environmental impact, reducing CO2 emissions by 12,452.48 metric tons per year, equivalent to annual earnings of approximately €999,933.85 through carbon credits trading. The study also found that the evaporator experienced the most significant exergy destruction, suggesting opportunities for improving the highest exergy destruction area, leading to an increase in overall system efficiency. In conclusion, the SRC + S-ORC + C-ORC configuration offers the most promising combination of thermodynamic, economic, and environmental benefits for waste heat recovery systems.

Optimum carbon tax rate for emission targets of electricity generation system by life cycle techno-economic-environmental optimization model

Reduction of greenhouse gas emissions from the electricity sector is of special interest for decarbonization of energy systems. Optimum carbon tax as a powerful policy tool is here studied by integrated techno-economic-environmental life cycle analysis in a unit commitment problem. The present model is formulated as a bi-level optimization problem to reach the optimum carbon tax rates for different emission targets. The total life cycle CO2 emissions are estimated to be 20333.90 tons/hr in a real case study of Iran's electricity sector for the peak demand hour. The carbon tax rate for a 2% and a 3% emissions reduction is equal to 15.87 and 24.65 $/ton, respectively. In the business-as-usual scenario, higher carbon taxes will be required each year to meet the same emission target. However, developing the electricity sector with cleaner technologies and strategic plans may decrease the carbon tax rate. The extent of this reduction depends on the type of development program implemented in the green revolution scenario. Therefore, policy makers play a direct role in ensuring the sustainable development of the electricity sector. The present model provides a robust framework to analyze the real carbon tax rates for the whole life cycle of electricity generation dispatch.

Clustering Analysis of Food Security, Waste and Loss: Malaysia Agricultural Insights

As the world population grows rapidly nowadays, the demand for food has come to rise. The escalating demand for food has caused substantial wastage and loss, which not only hampers food security efforts but also aggravates greenhouse gas (GHG) emissions, intensifying the environmental crisis. Among numerous countries, Malaysia, with its diverse agricultural profile, emerges as a good fit for our case study. This study chooses the clustering technique to examine food sector data in Malaysia and investigate the link between the clustering results on food data and the data on GHG emissions. This case study aims to find crops depending on their production efficiency, underline those that match major waste, and estimate their contribution to greenhouse gas emissions. Three clustering techniques, Gaussian Mixture Modelling (GMM), Birch, and Density Peak clustering, are applied in the Production and Supply Utilisation Accounts (SUA) datasets, help to identify and cluster crops based on their similar traits to acquire uncovered patterns between the food sector and environmental issues. Using cutting-edge clustering algorithms and visualization tools, this study investigated in-depth the complex interactions among food production, waste, and greenhouse gas emissions in Malaysia. By addressing food production efficiency and waste reduction, the outcome will be a cascade of benefits that not only improve food security but also help to lessen negative environmental effects. This study illuminates the multifaceted dynamics of food production, waste, and environmental impact, offering valuable insights and pathways toward a more sustainable future for Malaysia and potentially other nations.

Evaluating the effectiveness of environmental taxes: A Case study of carbon pricing in the UK as a tool to reducing Greenhouse Gases Emissions

This paper evaluated the effectiveness of environmental taxes and adopted a case study approach which used carbon pricing in the UK as a tool to reducing Greenhouse Gases Emissions. The objectives of the research are to determine the effect of carbon pricing on greenhouse gases emissions in the United Kingdom, evaluate how fossil energy depletion affect greenhouse gases emissions in the United Kingdom and ascertain the effect of total energy consumption from different energy mix on greenhouse gases emissions in the United Kingdom. The paper used an ex post facto research design and the estimated model was estimated using the ordinary least squares regression technique. The data were sourced from different sources and covered the period between 2010 and 2023. The findings of the study revealed that carbon pricing is an effective tool for reducing greenhouse gases emissions in the UK while renewable energy is also a significant tool for reducing greenhouse gases emissions. Based on these findings, the study recommends that the government should consider increasing the carbon price incrementally over time to ensure that it continues to effectively discourage high-emission activities.

A Study on the Development of Destruction or Removal Efficiency (DRE) Considering the Characteristics of Greenhouse Gas Abatement Technology Used in the Semiconductor and Display Industries in South Korea

In this study, the Destruction or Removal Efficiency (DRE) of 10 types of F-gases used in the semiconductor and display industries in South Korea was measured. These industries use a large volume of F-gases with high Global Warming Potential (GWP), significantly contributing to national greenhouse gas emissions. Therefore, accurately calculating the greenhouse gas emissions from these industries and establishing appropriate mitigation plans is crucial. The current IPCC guidelines provide parameters for estimating greenhouse gas emissions for each gas, including DRE values. However, they present only a single coefficient for each gas, without considering the diverse abatement technologies that are commercially applied in practice. As a result, there is a potential for overestimating South Korea’s national greenhouse gas emissions, as these guidelines do not reflect the advanced abatement technologies used in each country’s semiconductor and display industries. To address this, the DREs of Combustion-type and Plasma-type abatement technologies, which are widely used in South Korea, were measured based on the Korean KS guidelines, developed from the U.S. EPA’s reduction efficiency measurement guidelines. The results showed that Plasma-type technologies, which are generally known to have better reduction efficiency, achieved higher DRE values compared with Combustion-type technologies. Furthermore, statistical analysis was conducted using SPSS 26 to assess whether it is significant to develop separate DRE values for different technologies. The analysis confirmed that developing distinct DREs for each technology is statistically significant. The findings of this study provide practical guidance for selecting optimal abatement technologies in South Korea’s semiconductor and display industries and serve as fundamental data for contributing to the achievement of sustainable carbon neutrality goals through more accurate greenhouse gas inventories in countries involved in semiconductor and display production.

Towards Supporting Satellite Design Through the Top-Down Approach: A General Model for Assessing the Ability of Future Satellite Missions to Quantify Point Source Emissions

Monitoring and accurately quantifying greenhouse gas (GHG) emissions from point sources via satellite measurements is crucial for validating emission inventories. Numerous studies have applied varied methods to estimate emission intensities from both natural and anthropogenic point sources, highlighting the potential of satellites for point source quantification. To promote the development of the space-based GHG monitoring system, it is pivotal to assess the satellite’s capacity to quantify emissions from distinct sources before its design and launch. However, no universal method currently exists for quantitatively assessing the ability of satellites to quantify point source emissions. This paper presents a parametric conceptual model and database for efficiently evaluating the quantification capabilities of satellites and optimizing their technical characteristics for particular detection missions. Using the model and database, we evaluated how well various satellites can detect and quantify GHG emissions. Our findings indicate that accurate estimation of point source emissions requires both high spatial resolution and measurement precision. The requirement for satellite spatial resolution and measurement precision to achieve unbiased emission estimation gradually decreases with increasing emission intensity. The model and database developed in this study can serve as a reference for harmonious satellite configuration that balances measurement precision and spatial resolution. Furthermore, to progress the evaluation model of satellites for low-intensity emission point sources, it is imperative to implement a more precise simulation model and estimate method with a refined mask-building approach.

Insight into the production factors influencing the physicochemical properties of densified briquettes comprising wood shavings and rice husk

The present work aims at elucidating the impact of various densification parameters on the physicochemical and combustion properties of fuel briquettes issued from the co-processing of wood shavings (W) and rice husks (RH) using a mechanical piston press machine. To that end, a design of experiments integrating three feeding speeds (15.76, 18.56, and 21.73 mm·s−1), two wood particle sizes (< 7 mm and between 7 and 10 mm) and six different RH contents ranging from 0 to 100 wt% was built. The obtained results showed that all the above operating factors influence the apparent density of the produced briquettes. Values ranging from 1143 to 1247 kg·m−3 were notably measured, with the highest one determined when considering a low feeding speed, small wood particles and an RH proportion of 80 wt%. While increasing the RH content led to an increase in the briquette density, the obtained results also showed that the higher the RH content, the lower the water resistance index. Measured values indeed went from 94 % on average for pure wood to ⁓85 % for pure RH, attesting to the potential challenge associated with the storage of briquettes containing high RH contents. As for the net calorific value, it was shown to rise from ⁓11 to ⁓ 16 MJ·kg−1 when varying the proportion of wood between 0 and 100 wt%. This trend was especially traced to an increase of the wt% of volatile matters in the produced briquettes accompanied by a decrease of their ash content. Combustion tests performed with different briquette samples then allowed inferring burning rates between 10.9 and 13.4 g·min−1, specific fuel consumptions ranging from 115.8 to 138.4 g·l−1 and combustion efficiencies of around 12 %. As highlights, these tests demonstrated that the higher the wood content, the higher the burning rate, the lower the specific fuel consumption and the higher the combustion efficiency. Finally, two tested briquette formulations containing 80 and 100 wt% of wood were shown to have better combustion properties than a commercial firewood used for comparison. Total greenhouse gas (CO2 and CH4) emissions were even found to be reduced by 9.4 % when burning the RH-containing sample instead of firewood, while providing the same amount of sensible heat to a 3-l volume of water. These findings thus highlight the potential interest of beneficiating biomass wastes into briquettes for heat generation, further noting that the development of this type of alternative energy carrier offers multiple advantages in terms of waste management, reduction of the deforestation induced by the intensive use of firewood and mitigation of climate change through a potential reduction greenhouse gas emissions.

Are healthy diets also sustainable? Experimental study using a Fake Food Buffet

Interventions to promote healthy and sustainable diets are urgently needed to curb growing obesity rates and greenhouse gas emissions. To date, little is known about consumers' awareness of the co-benefits of healthy and sustainable diets. Studies furthermore lack a global perspective. This study therefore aimed (1) to compare the composition of sustainable, healthy, and typical meals using an experimental Fake Food Buffet (FFB) study and (2) to compare sustainable diet knowledge and perceptions between individuals who grow up in Global North and Global South countries. The experiment used a 3 Meal Type x 2 Region mixed design. Participants (N = 74), of which half grew up in the Global North and South, respectively, were asked to self-serve three meals (typical, healthy, sustainable) from the FFB and to complete the Food Sustainability Knowledge Questionnaire (FSKQ). Sustainable meals contained more vegetables, grains, legumes, and plant-based protein (Fs[2, 144] ≥ 4.26, ps ≤ .016), and less red meat, animal-based protein, and sugar than healthy or typical meals (Fs[2, 144] ≥ 11.77 ps ≤ .001). FSKQ scores did not differ between regions (W[71.82] = 0.58, p = .564). However, participants from the Global North self-served more vegetables, grains, and plant-based protein from the FFB compared to participants from the Global South (Fs[2, 72] ≥ 4.89 ps ≤ .003). Many people are not fully aware of the substantial overlap of healthy and sustainable diets. Furthermore, culture influences food choices and thus needs to be considered when designing and implementing dietary interventions on a global scale.

Feasibility Study of Wind Farm Using RETScreen Model: A Case Study of Al-Razaza Site, Iraq

In recent years, interest in renewable energies has increased due to their clean, renewable, and inexhaustible characteristics. Iraq faces a significant challenge in the shortage of electric power. The green economy, especially in renewable energy, has become one of the world's main pillars, especially after the remarkable rise in greenhouse gas emissions (GHG) from fossil fuel combustion for electricity production. This study evaluates wind farm feasibility, assessing costs, revenue, and financial viability. It identifies potential hazards and difficulties, enabling developers to develop strategies to mitigate risks during project creation and operation. This paper aims to undertake a feasibility study to assess the viability of constructing a wind farm with a capacity of 340 megawatts at the Al-Razaza location in Karbala province. The study site utilized authentic data from the meteorological tower installed on the premises. The data employed spanned three years, encompassing a comprehensive and integrated dataset for the study. RETScreen, a powerful model renowned for its energy efficiency analysis and sustainable decision-making capabilities, was employed. Through the application of RETScreen, a meticulous assessment and analysis of the intricate project components were facilitated. A study of risk analysis was conducted to ascertain the impact of various parameters on the payback period of the project. The findings showed that the capacity factor of the wind farm is 22.3%, which is relatively low, the simple payback period is 10.3 years, and the energy production cost is 0.059$/KWh.

Utilization of Waste Glass in Cement Clinker Production: Impacts on Quality, Process Efficiency and Environmental Benefits

The incorporation of waste glass as a component in clinker production presents a sustainable approach to addressing critical challenges in the cement industry, including the reduction of CO2 emissions and effective waste management. Waste glass, characterized by its high silica content and alkali properties, can serve as an alternative alkali source in clinker manufacturing, replacing traditional raw materials and regulating the alkali-sulphur ratio. This dual functionality not only optimizes the chemical balance in the kiln process but also enhances clinker quality by controlling phase formation. The utilization of waste materials in industrial processes is increasingly significant in promoting circular economy principles. Integrating waste glass reduces the dependence on natural raw materials such as limestone and clay, which are associated with high energy and CO2 emission intensities during production. Furthermore, waste glass contributes to a reduction in the carbon footprint of cement production by facilitating lower-temperature clinkering, thus cutting energy consumption and greenhouse gas emissions. This study highlights the potential of waste glass as a viable alternative in clinker production, emphasizing its importance in achieving sustainability goals. Beyond the environmental benefits, adopting waste materials in industrial applications contributes to waste diversion from landfills, resource conservation, and cost efficiencies, aligning with global efforts to mitigate climate change and promote sustainable development.

Economic and Environmental Assessment of Ammonia as a Sustainable Fuel for Tugboat Operations at the Port of Texas

This study assesses the feasibility of ammonia as a sustainable alternative fuel for tugboat operations in the Port of Texas, a major U.S. maritime, oil and gas hub. Tugboats, while critical to port logistics, contribute significantly to localized air pollution and greenhouse gas emissions, impacting both environmental quality and public health in surrounding communities. Given the International Maritime Organization’s (IMO) goals to reduce carbon emissions by 40% by 2030 and 70% by 2050, exploring alternative fuels has become imperative. Ammonia, a carbon-free fuel, presents both opportunities and challenges. While ammonia combustion produces no direct CO₂ emissions, making it attractive from a decarbonization standpoint, its lower energy density results in higher fuel volumes and increased operational costs compared to marine fuel oil (MFO). This paper presents a comparative analysis based on real-world data, mathematical modeling, and emission trade-offs, examining the economic implications, environmental impact, and safety concerns of adopting ammonia as a tugboat fuel. Results indicate that while ammonia could enable significant CO₂ reductions, challenges related to fuel storage, cost, and infrastructure must be addressed. The findings suggest that with appropriate policy support and investment in handling infrastructure, ammonia can become a viable fuel option for sustainable maritime operations.

Snow and nitrogen manipulation do not alter the dominant role of fungi in the N2O production of biocrusts in a temperate desert

The impact of global climate change and human-induced nitrogen (N) deposition on winter weather patterns will have consequences for soil N cycling and greenhouse gas emissions in temperate deserts. Biological soil crusts (referred to as biocrusts) are crucial communities in soil and significant sources of nitrous oxide (N2O) emission in desert ecosystems and are sensitive to environmental changes. The contribution of bacteria and fungi to N2O production in drylands has been acknowledged. However, the effect of changes in snow cover and N deposition on the N2O production of different microbial groups of microorganisms is not yet clear. In this study, we examine the responses of fungi and bacteria mediated pathways involved in soil N2O production from biocrusts to long-term snow cover manipulation and N addition experiments in the Gurbantunggut Desert. These soils were incubated and subjected to biocide treatments (such as cycloheximide and streptomycin, and fungal and bacterial inhibitors), after which rates of potential nitrification and N2O production were measured. Compared with controls, snow removal treatments from bare sand, lichen crust and moss crust reduced background rates of N2O production by 29.41 %, 26.21 % and 20.49 %, respectively; N2O production rates were 1.53-fold higher in bare sand, 1.38-fold higher in lichen crust, and 1.56-fold higher in moss crust after N addition. The addition of streptomycin significantly reduced the potential nitrification rates of bare sand and biocrusts, indicating that bacteria may be important sources of NO3− production in biocrusts rather than fungi. Conversely, fungi were main sources of N2O production in biocrusts. Additionally, fungi also played a major role in N2O production in biocrusts after snow cover manipulation and N addition. Both snow cover manipulation and N addition treatment indirectly affected the N2O production in biocrusts by considerably affecting the content of substrate N and the abundance of microbial groups. Our research suggests that fungi are main contributors for denitrification in biocrusts, and that snow cover changes (removal snow and double snow) and N addition alter the contribution of biotic pathways responsible for N cycling.

Integrating fiber with new cement trends to create a greener future for sustainable concrete

The need for innovation in the construction sector is increasingly pressing, propelled by rising environmental issues and the ongoing quest for structural efficiency. This study investigates the transformational potential of fiber-reinforced concrete (FRC), analyzing its ability to improve mechanical performance and promote environmental sustainability. By using diverse fibers, including natural, synthetic, and industrial waste fibers, FRC enhances qualities like as tensile strength, fracture resistance, and durability while promoting more sustainable building techniques. This research carefully explores current improvements in the processing and handling of various fibers and assesses their effects when integrated into concrete. Particular emphasis is placed on the use of recovered industrial by-products, including slag, fly ash, and recycled plastics, in conjunction with natural fibers such as bamboo, kenaf, and flax. These materials are recognized for both augmenting the structural integrity of concrete and substantially decreasing the carbon footprint of construction by lowering dependence on virgin resources and encouraging the recycling of industrial waste. Experimental investigations and life cycle evaluations were performed to measure the improvements in performance and sustainability provided by FRC. The study results indicate that FRC has enhanced durability and performance attributes, making it a suitable choice for both structural and non-structural applications. Moreover, the incorporation of sustainable fibers has shown a decrease in greenhouse gas emissions, consistent with international sustainability objectives. Nonetheless, the implementation of FRC encounters obstacles pertaining to the inconsistency of fiber characteristics, economic viability, and industrial scalability. Confronting these obstacles via continuous research and interdisciplinary cooperation is essential for the widespread adoption and use of FRC in the construction sector. This study emphasizes the significance of new materials, such as fiber-reinforced concrete, in promoting sustainable building methods, illustrating its potential to profoundly influence the future of construction regarding environmental responsibility and structural efficacy.

Sustainable supply chain management in U.S. healthcare: Strategies for reducing environmental impact without compromising access

The U.S. healthcare sector’s supply chain operations are responsible for about 8.5% of all national greenhouse gas (GHG) emissions. In healthcare, traditional supply chain management has focused on cost efficiency to the detriment of environmental considerations leading to higher emissions, waste, and resource depletion. The focus of this study is to investigate strategies for making sustainable supply chain management (SSCM) in the U.S. healthcare system, while reducing environmental impact at minimal cost to patient care quality. The objectives of the study are to evaluate the current state of healthcare supply chains, explore sustainable practices, evaluate emerging technologies, propose an SSCM implementation framework, and explore policy implications. Sustainable supply chain management can be achieved by forming the key strategies: comprehensive waste reduction and recycling programs, adoption of energy efficient transportation and storage solutions, green energy sourcing, and use of data driven inventory management that would help optimize inventory, along with other technologies like blockchain, IoT and artificial intelligence that could achieve transparency and efficiency. The research wouldn't go into specific case studies but would likely look at institutions that have already been able to implement these practices. The findings indicate that considerable environmental footprint reduction of the U.S. healthcare sector is possible without sacrificing access to high quality care through adoption of SSCM practices. But it requires joint efforts from policymakers, healthcare providers and industry partners. The long-term goal is a sustainable, resilient healthcare system that will integrate environmental stewardship with high quality care, that will help mitigate climate change and acknowledge the interdependence of environmental and human health.

Fundamentals of a healthy and sustainable diet

BackgroundA healthy and sustainable diet is a prerequisite for population and planetary health. The evidence of associations between dietary patterns and health outcomes has now been synthesised to inform more than 100 national dietary guidelines. Yet, people select foods, not whole dietary patterns, even in the context of following specific diets such as a Mediterranean diet, presenting challenges to researchers, policymakers and practitioners wanting to translate dietary guideline recommendations into food-level selection guidance for citizens. Understanding the fundamentals that underpin healthy and sustainable diets provides a scientific basis for helping navigate these challenges. This paper’s aim is to describe the fundamentals of a healthy and sustainable diet.ResultsThe scientific rationale underpinning what is a healthy and sustainable diet is universal. Everyone shares a physiological need for energy and adequate amounts, types and combinations of nutrients. People source their energy and nutrient needs from foods that are themselves sourced from food systems. The physiological need and food systems’ sustainability have been shaped through evolutionary and ecological processes, respectively. This physiological need can be met, and food systems’ sustainability protected, by following three interlinked dietary principles: (i) Variety – to help achieve a nutritionally adequate diet and help protect the biodiversity of food systems. (ii) Balance – to help reduce risk of diet-related non-communicable diseases and excessive use of finite environmental resources and production of greenhouse gas emissions. (iii) Moderation – to help achieve a healthy body weight and avoid wasting finite environmental resources used in providing food surplus to nutritional requirements.ConclusionThe fundamentals of a healthy and sustainable diet are grounded in evolutionary and ecological processes. They are represented by the dietary principles of variety, balance and moderation and can be applied to inform food-level selection guidance for citizens.

Climate action and social equity: Mitigation strategies and carbon credits

Carbon taxes are a critical tool in global efforts to reduce greenhouse gas emissions, but they often have regressive effects, disproportionately burdening low-income households. This study examines the economic impact of carbon taxes on different income groups, with a focus on the regressive nature of these policies. Low-income households, which typically spend a higher percentage of their income on energy and carbon-intensive goods, are more adversely affected by carbon taxes. This analysis explores potential mitigation strategies, such as rebates, targeted subsidies, and income-based tax adjustments, to offset these regressive effects. Additionally, the study investigates the role of carbon credits in income distribution, analyzing how the allocation and trading of credits can influence social equity. The research also considers the broader implications of carbon taxes and credits on income distribution, highlighting the need for policies that balance environmental objectives with social equity. By examining the intersection of carbon pricing mechanisms and income inequality, this study provides insights into how policymakers can design carbon taxes and credits that minimize regressive impacts while promoting fair and equitable climate action. The findings underscore the importance of integrating social equity considerations into carbon pricing strategies to ensure that climate policies contribute to sustainable and inclusive economic growth.

Biofuel: A sustainable and clean alternative to fossil fuel

Increasing fuel consumption has threatened energy supply stability, raising significant environmental and economic concerns for many countries. As global energy demand rises, reliance on fossil fuels poses serious challenges, including greenhouse gas emissions and resource depletion. In response, substantial efforts are made to develop and adopt clean renewable fuel alternatives. Replacing fossil fuels with biofuels can significantly reduce emissions of carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), and tropospheric ozone (O3). Recent advances in the development of biofuels via genetic engineering have larger prospects for commercial-scale production. However, large-scale production remains challenging; therefore, to address this issue, it is vital to convert biomass into biofuels by developing revolutionary technology to improve biofuel production to meet present and future energy demands. The study aims to analyze alternative renewable energy sources and recent trends in the production of biofuel that are required to meet the demands of the global energy sector and economy while also considering future demand and utilization.

Techno-economic analysis of a biogas power plant: Moving to sustainable energy supply and green environment through waste management

The feasibility of establishing an anaerobic digestion power plant for producing electricity, heat, and bio-fertilizer using a combined heat and power system using municipal solid waste in Sanandaj has been designed and simulated. The optimal condition for biogas production will be identified using an experimental design, and subsequently, modeling under optimal conditions was performed using Aspen Plus. The anaerobic digestion process was simulated under thermophilic conditions at a temperature of 55 °C, pressure of 1 atm, and retention time of 15 days. The daily biogas production amounted to 32,174 m3 from 380 tonnes of municipal solid waste. The daily production of electricity and heat was 2.9 MW and 3.3 MW, respectively. The daily production of bio-fertilizer was 48 tonnes. The electricity produced can meet approximately 3 % of Sanandaj's total demand. In addition to energy production from waste, the economic evaluation indicated that the project's net present value over a 20-year operational period was approximately 6333,333 €, demonstrating the project's economic viability. Furthermore, establishing this power plant will prevent 85,023 tonnes of CO2 annually. The results indicated the effectiveness of the designed plant in replacing power generation with fossil fuel and reducing greenhouse gas emissions.

Green hydrogen blending in natural gas: A global review and a local analysis on Türkiye based on greenhouse gas emission reduction targets

In this study, Türkiye's natural gas consumption till 2030 is forecasted based on the greenhouse gas emissions reduction targets announced by the Turkish President. Two novel semi-empirical per capita based models are generated for forecasting. It is estimated that Türkiye's natural gas consumption in 2030 could reach 65.5 billion m3, and at this level nearly 650 million m3 of green hydrogen could be needed for 1.0% (v/v) blending. Root mean squared error (RMSE) and mean absolute percentage error (MAPE) values of forecast generated by Model 2 are estimated as 3.6 and 5.5%, respectively. These RMSE and MAPE values indicate high accuracy. The forecasting results of Model 2 are also compared with highly cited forecasts from the literature. The accuracy of fit with these forecasts changed between 90.7%–99.9%, which might be considered as an indication of model success. Finally, it is believed that this study could further be adapted by other researchers for estimating local or national natural gas consumption and potential green hydrogen requirements for blending conditional that historic geographical per capita data is available and associated addition/availability factors are calculated based on current circumstances.

Study of the Combustion Characteristics of a Compression Ignition Engine Fueled with a Biogas–Hydrogen Mixture and Biodiesel

Increasing the use of renewable energy sources is essential to reduce the use of fossil fuels in internal combustion engines and to reduce greenhouse gas emissions. An experimental and numerical simulation study of the combustion process of a compression ignition engine was carried out by replacing fossil diesel with a dual fuel produced from renewable energy sources. In conventional dual-fuel applications, fossil diesel is used to initiate the combustion of natural gas or petroleum gas. In the present study, fossil diesel was replaced with advanced biodiesel – hydrotreated vegetable oil, and natural gas was replaced with biogas. In the experimental study, a gas mixture of 60% natural gas (by volume) and 40% carbon dioxide (by volume) was used to replicate the biogas while maintaining a 40%, 60%, and 80% gas energy share in the fuel. It was observed that using fossil diesel and biogas in the dual-fuel engine significantly slowed down the combustion process, which normally resulted in poorer energy performance. One way to compensate for the lack of energy (due to the presence of carbon dioxide) in the cylinder is to use a gas such as hydrogen, which has a high energy content. To analyze the effect of hydrogen on the dual-fuel combustion process, hydrogen gas was added to the replicated biogas at 10%, 20%, and 30% of the natural gas volume, maintaining the biogas at a (natural gas + hydrogen)-to-carbon dioxide volume ratio of 60%/40% and the expected gas energy share. The combustion process analysis, which was conducted using the AVL BOOST software (Austria), determined the heat release rate, temperature, and cylinder pressure rise in the dual-fuel operation with different renewable fuels and compared the results with those of fossil diesel. It was found that when the engine was operated at medium load and with the flammability of the biogas approaching the limit, the addition of hydrogen significantly improved the combustion characteristics of the dual-fuel engine.