Reduce CO2 Emissions Research Articles

An Empirical Study of the Economic Net-Zero Energy Mix in Industrial Complexes

This study examines the optimal energy mix for industrial complexes by incorporating renewable energy systems, decarbonization strategies, and sector coupling technologies. Using data from the Balan Industrial Complex in Korea, five energy scenarios were evaluated, ranging from conventional systems (Scenario 1) to advanced renewable configurations (Scenario 5). The results show that Scenario 5, which integrates sector coupling systems and decarbonization technologies, is the most cost-effective and environmentally sustainable. Scenario 5 achieves the lowest Net Present Cost (NPC), and significantly reduces CO2 emissions. Furthermore, an analysis of electricity prices and CO2 costs from Korea, the United States, and Germany highlights the critical role of regional electricity tariffs and carbon pricing in determining the economic feasibility of energy systems. While renewable setups require higher initial investments, Scenario 5 proves to be the most economically viable over time, offering both cost savings and environmental benefits. These findings provide valuable insights for policymakers and industry leaders, emphasizing the importance of customized strategies to optimize energy systems in industrial applications.

Advancing urban mobility in developing countries: A mobile RSU approach for sustainable transportation

AbstractThe rapid and uncontrolled urbanization of cities in developing countries has engendered a plethora of urban mobility issues, including traffic congestion, accidents, and air pollution. To address these challenges, contemporary urban mobility trends are incorporating innovative technologies and sustainable governance practices. This article investigates how urban managers can leverage the opportunities presented by cost‐effective technologies and the management of urban data to enhance urban mobility in developing countries. Within this discourse, an RSU‐based approach is proposed that employs motorbike taxis for inter‐vehicular communication, given their status as the most widely used form of public transportation. This approach substantially diminishes investment costs and reinforces the sustainability of urban mobility. Through the implementation of this solution, a noteworthy reduction is anticipated in the emission of gases such as CO2, and NOx, known contributors to climate change and various respiratory diseases. To validate the efficacy of the proposed solution, four distinct scenarios are scrutinized in a case study centered on the city of Douala in Cameroon, utilizing tools such as OMNET++, SUMO, Veins, and INET. The proposed framework offers significant benefits in terms of environmental sustainability and operational efficiency. It enables a 10% reduction in CO2 emissions, a 15% reduction in NOx emissions, an 11% drop in fuel consumption, and a 15% reduction in waiting time in traffic jams. The envisaged solution aims to aid urban managers in their decision‐making processes, specifically in advancing sustainable urban mobility. Through the adoption of this approach, cities in developing countries can mitigate challenges associated with urban mobility and enhance the overall well‐being of their residents.

Study on Impact Resistance of Alkali-Activated Slag Cementitious Material with Steel Fiber

Alkali-activated slag cementitious materials (AASCMs) use alkaline activators to activate blast furnace slag and waste slag to replace traditional Portland cement, which can reduce CO2 emissions. An impact resistance test and scanning electron microscopy (SEM) microscopic performance analysis of alkali-activated slag cementitious material specimens with four different steel-fiber contents are performed. The effects of steel-fiber volume content and strain rate on the dynamic elastic modulus Ed, dynamic compressive strength σd, dynamic peak compressive strain εc, and energy absorption of the AASCM-SS are studied. The results indicate that the dynamic elastic modulus Ed, dynamic compressive strength σd, and energy absorption of the AASCM-SS increase with the increase of strain rate, and the dynamic peak compressive strain εc decreases with the increase of strain rate. The dynamic elastic modulus Ed, dynamic compressive strength σd, and dynamic peak compressive strain εc of the SS-AASCM increase first and then decrease with the increase of steel-fiber content. When the steel-fiber content is 0.5%, the σd and εc of the AASCM-SS are the highest, increased by 9.9% and 19.3%. The energy absorption of AASCM-SS increases with the increase of steel-fiber content. A dynamic constitutive model of the FR-AASCM considering the influence of damage, strain rate, and steel-fiber volume fraction is established. The proposed constitutive model is in acceptable agreement with the experimental AASCM-SS dynamic stress–strain curve, and the correlation coefficient is 0.91.

Carbon dynamics: A holistic analysis of FDI, trade liberalization, urbanization, economic growth, and effects on CO2 emissions in South Asia

In recent years, South Asian nations have experienced robust economic growth, prompting concerns among policymakers about the sustainability of this growth due to rising pollution emissions. This study conducts an objective assessment of the impact of key variables, such as trade liberalization, economic growth, foreign direct investment inflows, and urbanization, on environmental outcomes across selected economies of South Asia from 1990 to 2022. To describe cross-sectional dependencies in the dataset, panel cointegration techniques are employed alongside cross-sectionally augmented autoregressive distributed lag (CS-ARDL) models. For added robustness, dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS) techniques are utilized to investigate the long-term coalition among the variables. The study integrates first- and second-generation panel methods to improve the depth and reliability of the analysis by addressing methodological limitations. The pragmatic results reveal that trade liberalization, FDI inflows, economic growth, and urbanization increase CO2 emissions by 0.392%, 0.354%, 0.275%, and 0.429%, respectively. Dumitrescu and Hurlin (D–H) causality tests show a unidirectional causal link from trade liberalization to environmental degradation. Additionally, a bidirectional causal link is observed between environmental deterioration and both FDI inflows and urbanization in South Asian countries. To mitigate environmental impact, these nations should evaluate foreign investment conditions and enhance technology transfer from foreign enterprises. Furthermore, implementing trade-related policies to reduce CO2 emissions is imperative.

Hospital design and planning in the line of foresight of health needs

Abstract The health needs of the population are increasingly difficult to plan and predict. Technological progress, artificial intelligence, new medicines, but also ecological disasters, humanitarian crises, energy crisis and other challenges (as a Covid 19 pandemic) represent the image of our time. New design of hospitals should be able to respond to the challenges of the future: comprehensive provision of health services taking into account the patient’s needs, working conditions taking into account the hospital staff, energy efficiency and construction in accordance with high standards and reduction of CO2 emissions (green hospitals), to ensure alternative sources of electricity and water supply bearing in mind potential emergencies. The big challenge of long-term construction in which advanced technologies and new procedures cannot simply fit into a rigid building structure that is several decades old (example Serbia), so it is necessary to apply precise planning and efficient and high-quality construction in the next generation hospitals, taking into account current modern equipment and that which will appear in the future. Designing hospitals involves anticipating future healthcare challenges, technological advancements, demographic shifts, and changes in patient expectations. Hospitals emphasis on patient-centered design principles, creating environments that prioritize comfort, privacy, and dignity for patients and their families, accessibility and inclusivity, infection control and prevention, sustainability and resilience. Modern hospitals should create collaborative spaces for interdisciplinary teamwork and communication among healthcare providers, research and innovation units, but also community engagement and health promotion activities. Future hospital design requires strong multidisciplinary and cross-sectional cooperation, in which priority is given to architects dedicated to this field and their cooperation with public health and health management experts.

Optimizing urban bus network based on spatial matching patterns for sustainable transportation: A case study in Harbin, China.

The rapid economic development and accelerating urbanization have led to a significant mismatch between the urban bus network allocation and the population flow. Therefore, this paper investigates this challenge by exploring the intricate relationship between the population flow dynamics, traffic congestion conditions, and the efficient allocation of bus resources. In response, two key indexes were introduced based on spatial matching patterns to assess the urban bus network: the Population-Bus Match Index evaluates the matching degree between supply and demand, and the Population-Congestion Match Index evaluates the matching degree between utilization and saturation. Additionally, two distinct optimization strategies have been proposed to enhance the urban bus network. The first optimization strategy considers the bus network's current status, while the second aspires to an idealized scenario. Subsequently, the potential contributions of each bus station in reducing CO2 emission reduction after implementing the two optimization strategies are quantified. Utilizing a case study focused on Harbin, the proposed methods are validated. The findings unveil a substantial misalignment between supply and demand within the bus network during peak periods, with nearly half of the bus stations experiencing a disparity between utilization and saturation. Comparative experiments across different optimization strategies reveal that the second optimization strategy significantly outperforms the first, but the first optimization strategy has a higher degree of CO2 emission reduction contribution. The results of this study provide decision-makers with an environmentally oriented vantage point for the discerning selection of optimization strategies and leave valuable insights for urban areas confronting transportation challenges.

Energy Consumption, Emission, Transportation Sector in Malaysia: Review on Malaysia’s Road Transport

Transportation is a major challenge for energy conservation, with road transport in Malaysia being a significant contributor to greenhouse gas (GHG) emissions. In Malaysia, traditional fossil fuels such as gasoline and diesel dominate the transportation sector, which has become the second-largest source of GHG emissions, accounting for 20% in 2014. This increase in CO2 emissions, driven by rising vehicle ownership and economic growth, underscores the urgent need for effective emission reduction strategies. The rapid growth in road transportation in Malaysia is linked to socioeconomic factors, including rising incomes and urbanization, leading to higher energy consumption and pollution. Data indicates a significant increase in vehicle registrations from 1990 to 2018, with motorcars and motorcycles being the most common. This growth, fueled by subsidies and decentralization, has exacerbated the sector’s environmental impact. The Green Technology Master Plan Malaysia 2017–2040 aims to address these issues by setting ambitious targets to enhance renewable energy, improve energy efficiency, and promote eco-friendly fuels. Key strategies include expanding public transportation, increasing the adoption of electric vehicles (EVs), and introducing alternative fuels like hydrogen. Malaysia has substantial potential to reduce CO2 emissions through initiatives such as expanding EV infrastructure, promoting natural gas vehicles, and improving public transit. Effective implementation of these strategies can significantly lower the transportation sector’s carbon footprint, contributing to a more sustainable future.

Ultrawhite and ultrablack asymmetric coatings for radiative cooling and solar heating

Passive daytime radiative cooling, a zero-energy and zero‑carbon cooling technology, has significant potential to substantially reduce reliance on compression-based cooling systems, combat the urban heat island effect, and mitigate global warming. However, current radiative cooling materials either exhibit low efficiency or are susceptible to overcooling, resulting in cooling penalties on winter days. In this work, we designed and fabricated the ultrawhite and ultrablack asymmetric coatings. The top-layer, designed for efficient radiative cooling, consists of a porous polymethyl methacrylate and hollow silica microspheres composite. The underlayer, tailored for solar heating, is composed of a carbon nanotubes and carbon black composite. The cooling side with an exceptional solar reflectivity of 0.98 and a mid-infrared emissivity of 0.97 achieves a comparable daytime subambient cooling of 7.6 °C, with a theoretical net cooling power of 98.8 W/m2. Conversely, the heating side with a solar absorptivity of 0.96, a ultra-high visible light absorptivity of 0.985, and a mid-infrared emissivity of 0.97, results in a daytime above-ambient heating of 12.8 °C, corresponding to a theoretical net heating power of 745 W/m2. Promisingly, our ultrawhite and ultrablack asymmetric coatings hold the promise of addressing the long-standing challenge of all-season temperature regulation, offering significant potential for electricity savings and CO2 emission reduction.

Routes to a Carbon-Free World

Humans need to cut CO2 emissions rapidly to limit global warming and prevent dangerous climate change. Policies adopted so far in countries worldwide are not enough. The good news is that there are many things we can do. First, we can save energy by using the most energy-efficient technologies and by changing our lifestyles. Second, we can use CO2-free energy sources, such as solar, wind, or hydropower. Third, we can invest in technologies that can remove CO2 from the atmosphere. Finally, we can regrow forests all over the planet. Scientists imagine alternative future “scenarios” including different combinations of technology, energy, and lifestyle solutions. We know it is possible, but we need to act now to reduce CO2 emissions, even if it means making hard choices.

Net‐Zero Transition Pathways in Belt and Road Economies: Insights From Threshold Effects and Heterogeneous Analysis

ABSTRACTGiven the pressing need for economies to mitigate climate change and champion carbon neutrality, this study investigates the threshold effects of financial development and foreign direct investment (FDI) on carbon dioxide (CO₂) emissions in Sub‐Saharan Africa (SSA) within the Belt and Road Initiative (BRI) bloc, taking into account the moderating role of the regulatory environment. Drawing on the environmental Kuznets curve and the pollution haven hypothesis, the study utilizes the dynamic generalized method of moments (GMM) modeling, proposed by Arellano and Bover, to analyze panel data from 37 SSA countries spanning 1990–2022. The findings reveal that financial development in the banking, financial, and private sectors, along with FDI outflows, is associated with a reduction in CO₂ emissions. Conversely, FDI inflows are linked to increased CO₂ emissions. A curvilinear relationship is observed, where initial increases in financial development and FDI correlate with higher emissions, which decline beyond a certain threshold. Stronger regulations enhance the positive impact of financial development on reducing CO₂ emissions. Finally, the findings show a significant heterogeneous effect across the SSA regional blocs. These findings underscore the critical need for implementing stringent environmental regulations and promoting sustainable financial practices to mitigate negative environmental impact. This research provides both theoretical and practical insights into fostering a carbon neutrality agenda and advancing Sustainable Development Goal 13.

Natural resource rent, green finance, and CO2 emissions from the industrial sector

This study investigates the effect of natural resource rents and green finance on industrial sustainability in 20 OECD countries from 2010 to 2020, using the CCEMG-ARDL approach. Findings reveal that a 1% increase in green finance reduces CO2 emissions by 0.43% in the short term and 0.27% in the long term, highlighting its role in supporting environmentally friendly investments. In contrast, a 1% rise in fossil fuel rents increases CO2 emissions by 0.29% short-term and 0.05% long-term, showing the pollutive impact of fossil fuel profits. Additionally, a 1% increase in electricity usage raises CO2 emissions by 0.41% short-term and 0.16% long-term, stressing the need for cleaner energy. Industry-specific patents show limited alignment with sustainability goals. Policy measures should target resource rent management, boost green finance, and encourage sustainable practices to promote industrial greening.

A Study of Heat Recovery and Hydrogen Generation Systems for Methanol Engines

Biofuels are the most essential types of alternative fuels, which currently have significant potential to reduce CO2 emissions compared to fossil fuels. Methanol is a more efficient fuel than petrol due to its physicochemical properties, such as a higher latent heat of vaporization, research octane number, and heat of combustion of the fuel–air mixture. Also, biomethanol is cheaper than traditional petrol and diesel fuel for agricultural countries. The authors have proposed a new approach to improve the characteristics and efficiency of methanol diesel engines by using biomethanol mixed with hydrogen instead of pure biomethanol. Using a hydrogen–biomethanol mixture in modern engines is an effective method because hydrogen is a carbon-free, low-ignition, highest-flame-rate, high-octane fuel. A small quantity of hydrogen added to biomethanol and its combustion in an engine with a heat exchanger increases the combustion temperature and heat release, increases engine power, and reduces fuel consumption. This article presents experimental results of methanol combustion and a hydrogen-in-methanol mixture if hydrogen was retained due to the utilization of the heat of the exhaust gases. The tests were carried on a single-cylinder experimental engine with an injection of liquid methanol and gaseous hydrogen mixtures. The experiments showed that green hydrogen generated onboard the car due to the utilization of heat significantly reduced fuel costs of engines of vehicles and technological installations. It was established a hydrogen gaseous mixture addition of up to 5% by mass to methanol requires a corresponding change in the coefficient of excess air to λ = 1.25. Also, using an additional hydrogen mixture requires adjustment at the ignition moment in the direction of its decrease by 4–5 degrees of the engine crankshaft. Hydrogen gas mixture addition reduced methanol consumption, reaching a maximum reduction of 24%. The maximum increase in power was 30.5% based on experimental data. The reduction in the specified fuel consumption, obtained after experimental tests of the methanol research engine on the stand, can be implemented on the vehicle engines and technological installations equipped with an onboard heat recovery system. Such a system, due to the utilization of heat and the supply of additional hydrogen, can be implemented for engines that work on any alternative or traditional fuels.

Deciphering the complex interplay: Heterogeneous, threshold, and mediation effects of trade openness on CO2 emissions in Africa.

Despite having barely anything to do with the issue of CO2 emissions, Africa has been experiencing more severe climate change and its adverse effects than most other regions of the globe. However, the issue of CO2 emissions and its adverse effects has received relatively little attention in the African research arena. To this end, the present research assesses the effect of trade openness on the CO2 emissions utilizing panel data from 46 African countries spanning 2000 through 2022. To account for the possible heterogeneity and nonlinearity, the panel quantile regression and threshold methods were employed. Moreover, this study investigates the key mediating effects of the channel. The empirical findings show that greater trade openness is associated with significantly higher CO2 emission, additionally; it demonstrates that the influence is heterogeneous across different CO2 emission quantiles in African countries. Besides the result from the double threshold model reveals a complex, nonlinear relationship between trade openness and CO2 emissions in Africa. Moreover, the findings divulge that openness to trade indirectly reduces CO2 emissions through the substitution and technology channels whereas it indirectly increases carbon dioxide production via the economic track. Therefore, it is vital to promote the use of renewable energy, effectively leverage the knowledge spillover effects of trade to decrease energy intensity and formulate pertinent policies aimed at curbing carbon emissions and addressing the imminent threat of climate change in Africa. Besides, the nonlinear and heterogeneous effects of trade openness on CO2 emissions suggest that policies and interventions related to the impact of trade openness on CO2 emissions should consider the current level of carbon dioxide emissions.

City Logistics Solutions for CO2 Emission Reduction and Energy Efficiency: A Comparative Study of Vitoria-Gasteiz, Tartu, and Sønderborg

Modern cities face the challenge of reconciling dynamic development with environmental protection, as well as ensuring a high quality of life for their residents. In a time of continuous urbanization, with more than half of the world’s population living in cities, city logistics plays a crucial role in managing complex urban environments. As part of the concept of sustainable development, city logistics aims to minimize the negative impact of transport on the environment, while increasing operational efficiency and improving the comfort of life of residents in urban agglomerations. This article presents the results of a comparative analysis of the intensity of sustainable urban logistics development in selected cities of the European Union. It examines various strategies that reduce CO2 emissions, improve air quality, and increase building energy efficiency. The analysis demonstrates that cities investing in sustainable urban logistics not only improve their environmental performance but also increase their attractiveness and competitiveness as desirable places to live and work.

Synthesis of highly transparent and fast-responding photochromic coating by template method with space-limited domains

The persistent global high-temperature weather warns us that improving energy efficiency and reducing CO2 emissions are urgent. Controlling the solar energy input in buildings using photochromic smart coating can effectively reduce the energy consumption required for cooling. However, it remains a challenge to achieve high transparency and fast photoresponse in organic–inorganic hybrid photochromic smart coating. Herein, we utilize space-limited domains to design a template polymer that facilitates the formation of amorphous WO3 nanodots, thereby enhancing the polymer network structure through hydrogen bonding and dipole–dipole interactions, which endow the smart coating with excellent adhesion strength up to 13 MPa. Notably, the photochromic smart coating with amorphous WO3 nanodots exhibits higher transparency (96.8 %) than conventional glass (91 %), and a wide visible light modulation range of 96.8 %-4.8 %. Based on this, the cooling efficacy of the smart photochromic coating was assessed within a model residence under actual environmental conditions. The inner temperature of the model house was reduced by up to 13 °C, which decreased indoor heat absorption by 25.8 %, significantly improving energy efficiency. This work provides an important and attractive strategy for achieving energy-efficient building materials and addressing global climate warming.

Dopamine‐modified Highly Dispersed ZIF‐8 to Promote CO2 Absorption

AbstractCO2 capture technology has been widely used to reduce CO2 emissions, resulting in a variety of capture methods and materials. Among them, the more widely used is the chemical absorption method. However, the chemical absorption method has problems such as high energy consumption and slow absorption rate. In order to solve the above problems, we prepared an effective catalyst to improve the CO2 absorption rate. ZIF‐8 and hydrophilic ZIF‐8‐DA were prepared by in situ synthesis under ambient conditions. The catalytic effect of the hydration reaction of ZIF‐8 and ZIF‐8‐DA was tested using CO2 absorption regeneration experiments under aqueous and alkaline conditions, respectively. The results showed that the synthesized catalysts could significantly enhance the CO2 absorption in water and alkaline solution. The addition of 0.1 wt % of ZIF‐8 in alkaline solution increased the average CO2 absorption by 1.80–15.84 %, respectively, while the addition of 0.1 wt % of ZIF‐8‐DA increased the CO2 absorption by 7.01–25.36 %. In addition, both catalysts had excellent reusability and maintained high performance even after five absorption and regeneration cycles. Polymer dispersibility index (PDI) results showed that ZIF‐8‐DA dispersed more uniformly in aqueous solution.

Examining the Causal and Heterogeneous Influence of Three-Dimensional Urban Forms on CO2 Emissions in 285 Chinese Cities

Despite the efforts to examine the influence of urban forms on CO2 emissions, most studies have mainly measured urban forms from a two-dimensional perspective, with relatively little attention given to three-dimensional urban forms and their causal relationships. Utilizing the built-up area dataset from the Global Human Settlement Layer (GHSL) project and the carbon emission dataset from the China City Greenhouse Gas Working Group (CCG), we examine a causal and heterogeneous effect of three-dimensional urban forms on CO2 emissions—specifically urban height, density, and intensity—in 285 Chinese cities. The empirical results reveal a robust and positive causal effect of 3D urban forms on carbon emissions. Even when incorporating the spatial spillover effect, the positive effect of 3D urban forms remains. Moreover, GDP per capita and total population have a greater impact on urban CO2 emissions. Additionally, we find that the influence of 3D urban forms on CO2 emissions is U-shaped, with total population serving as a moderating factor in this effect. Importantly, there is significant geographic and sectoral heterogeneity in the influence of 3D urban forms on CO2 emissions. Specifically, the influence of 3D urban forms is greater in eastern cities than in non-eastern cities. Furthermore, 3D urban forms primarily influence household carbon emissions rather than industrial and transportation carbon emissions. Therefore, in response to the growing challenges of global climate change and environmental issues, urban governments should adopt various strategies to develop more rational three-dimensional urban forms to reduce CO2 emissions.

Coal Phase-Out and Carbon Tax Analysis with Long-Term Planning Models: A Case Study for the Chilean Electric Power System

Large CO2 emissions constitute a significant problem today due to their effect on climate change, and the need to design appropriate energy policies to mitigate their consequences and reduce emissions requires a detailed analysis of one of the main sources of such emissions: the electricity system. Thus, this paper presents a study on the effects of energy policies on decarbonization by comparing the detailed phase-out of coal-fired power plants across a range of cases with the implementation of a carbon tax to meet Nationally Determined Contributions (NDCs). The case study focuses on the Chilean electricity system, using a long-term generation and transmission expansion planning model (GTEP) that incorporates a wide range of generation technologies. The study examines the long-term effects of these policies, including costs, investments, and CO2 emissions, as well as their impact on consumer prices reflected in the marginal costs of the system. The transmission system modeling covers various regions of Chile and significant projections for renewable energy sources. It evaluates three economic scenarios based on generation technology costs, fuel prices, and electricity demand under four different closure schemes and fourteen different carbon tax levels. The results indicate that implementing a carbon tax can be more cost-effective for the system than the implementation of a phase-out schedule for coal plants, taking the form of reduced CO2 emission and overall system costs, with an optimal carbon tax value of 37 USD/tCO2. Additionally, the study reveals significant effects on consumer prices, showing that a carbon tax as an energy policy leads to lower prices compared to a phase-out scheme.

The Role of Low-Carbon Fuels and Carbon Capture in Decarbonizing the U.S. Clinker Manufacturing for Cement Production: CO2 Emissions Reduction Potentials

Low-carbon fuels, feedstocks, and energy sources can play a vital role in the decarbonization of clinker production in cement manufacturing. Fuel switching with renewable natural gas, green hydrogen, and biomass can provide a low-carbon energy source for the high-temperature process heat during the pyroprocessing steps of clinker production. However, up to 60% of CO2 emissions from clinker production are attributable to process-related CO2 emissions, which will need the simultaneous implementation of other decarbonization technologies, such as carbon capture. To evaluate the potential of fuel switching and carbon capture technologies in decarbonizing the cement industry, a study of the facility-level CO2 emissions is necessary. This study evaluates the potential for using a single low-carbon fuel as an energy source in clinker production for cement manufacturing compared to conventional clinker production (which uses a range of fuel mixes). In addition, conventional carbon capture (operated with natural gas-based steam for solvent regeneration) and electrified carbon capture configurations were designed and assessed for net-zero emission targets. Carbon emissions reductions with and without biogenic emissions credits were analyzed to ascertain their impact on the overall carbon accounting. Results show that carbon emissions intensity of cement can vary from 571 to 784 kgCO2eq/metric ton of cement without carbon capture and from 166.33 to 438.66 kgCO2eq/metric ton of cement with carbon capture. We find that when biogenic carbon credits are considered, cement production with a sustainably grown biomass as fuel source coupled with conventional carbon capture can lead to a net-negative emission cement (−271 kgCO2eq/metric ton of cement), outperforming an electrified capture design (35 kgCO2eq/metric ton of cement). The carbon accounting for the Scope 1, 2, and biogenic emissions conducted in this study is aimed at helping researchers and industry partners in the cement and concrete sector make an informed decision on the choice of fuel and decarbonization strategy to adopt.

Waste-to-Ammonia: A sustainable pathway for energy transition

Ammonia, with its exceptional storage and transportation characteristics, emerges as a promising hydrogen carrier that can play a crucial role in this transition. This study investigates the techno-economic and environmental feasibility of utilizing produced water (PW), a waste product in oil and gas production, for ammonia production (AP). Accordingly, three distinct scenarios of utilizing the PW to produce ammonia are analyzed: i) fossil fuel-based (FF) AP without CO2 capture (gray), ii) FF-based AP with CO2 capture module (blue), and iii) a solar-thermal based AP (green). Results suggest that the blue system offers a compromise between environmental impact and economic feasibility, achieving a significant reduction in CO2 emissions of 0.605 kg CO2/kg NH3 compared with the 1.87 kg CO2/kg NH3, where gray, blue, and green AP are associated with the values of $435.63/tNH3, $480.41/tNH3, and $955.05/tNH3, respectively. Moreover, this study highlights the influence of carbon tax policy on the cost of the FF-based gray systems, while becoming unprofitable above $104.75/tCO2. Analysis of AP costs across shale formations reveals variations in product cost with salt concentrations, with the Bakken and Haynesville formations exhibiting the highest cost per ton of ammonia of $433 and $426/tNH3 for blue and gray systems, respectively. Notably, it is observed that the formations with high solar radiation and low salinity including Permian and Niobrara show potential for green ammonia with payback periods of 13 and 15 years, respectively. This can be used as reliable benchmark to propose a model for achieving sustainable society.