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Recent California regulatory efforts, United States goals, and industry roadmaps all target net-zero greenhouse gas (GHG) emissions from the cement and concrete industries within a few decades. While changes in production of cement and concrete, including varying constituents, can greatly reduce GHG emissions, carbon dioxide removal (CDR) will be needed to meet this net-zero goal. Hydrated cement in concrete can carbonate (i.e., form carbon-based minerals with atmospheric CO2) and thus act as a CDR mechanism. This process occurs faster with a large surface area, such as crushed concrete at its end-of-life (EoL), which can be uniquely leveraged by transportation infrastructure projects. In this work, a literature review of key parameters that can facilitate desired CO2 uptake for transportation projects at their end of life is conducted and an initial meta-analyses of data from the literature to inform CO2 uptake for individual projects is performed. Initial considerations for what concomitant impacts may arise from this process are presented. Finally, experiments to fill a key gap in understanding how thin crushed concrete must be spread to maximize uptake reactions are conducted. Cumulatively, findings will inform whether carbonation can be implementedin a way that would support policies that include carbonation as a route for reducing emissions from cement-based materials in transportation applicationsView the NCST Project Webpage

Governments around the world are looking to ensure their transition to full low-carbon economies whilst tackling climate change by implementing offshore carbon capture and storage (CCS) – a method of permanently removing carbon dioxide (CO2) from the burning of fossil fuels and burying it deep below the seabed in suitable geological formations. Among the main targets of such geological formations are depleted, or nearly depleted, offshore oil and gas reservoirs within existing oil-producing fields. However, such reservoirs will frequently transcend maritime boundaries and jurisdictions, ie a shared geological formation could be used on both sides of the maritime boundary for CO2 sequestration and storage. This raises the potential for disputes among nations, transboundary environmental degradation, and business disruption. The paper discusses the role of CCS in the low-carbon energy transition, focusing specifically on international legal aspects related to the storage of CO2 in sub-seabed geological formations of the continental shelf. Ongoing CO2 storage projects are examined to showcase critical technical aspects, including reservoir selection, well design, and post-injection monitoring. The analysis highlights the need for international coordination in situations where CO2 storage occurs across an international boundary and the importance of consent from all states with jurisdiction over the relevant CO2 storage formations. The paper concludes that existing maritime boundary agreements, including those with straddling deposit clauses, are unlikely to cover transboundary CO2 storage operations, except if they are considered incidental to ongoing petroleum operations. [ABSTRACT FROM AUTHOR]

Green hydrogen (GH2) is emerging as a key driver of global energy transition, offering a sustainable pathway to decarbonize energy systems and achieve climate objectives. This review critically examines the state of GH2 research production technologies and their integration into renewable energy systems, supported by a bibliometric analysis of the recent literature. Produced via electrolysis powered by renewable energy, GH2 shows significant potential to decarbonize industries, enhance grid stability, and support the Power-to-X paradigm, which interlinks electricity, heating, transportation, and industrial applications. However, widespread adoption faces challenges, including high production costs, infrastructure constraints, and the need for robust regulatory frameworks. Addressing these barriers requires advancements in electrolyzer efficiency, scalable fuel cell technologies, and efficient storage solutions. Sector-coupled smart grids incorporating hydrogen demonstrate the potential to integrate GH2 into energy systems, enhancing renewable energy utilization and ensuring system reliability. Economic analyses predict that GH2 can achieve cost parity with fossil fuels by 2030 and will play a foundational role in low-carbon energy systems by 2050. Its ability to convert surplus renewable electricity into clean energy carriers positions it as a cornerstone for decarbonizing energy-intensive sectors, such as industry, transportation, and heating. This review underscores the transformative potential of GH2 in creating a sustainable energy future. By addressing technical, economic, and policy challenges and through coordinated efforts in innovation and infrastructure development, GH2 can accelerate the transition to carbon-neutral energy systems and contribute to achieving global climate goals. [ABSTRACT FROM AUTHOR]

This study illuminates the mineral carbonation potential of zeolite minerals. Zeolite minerals are common alteration products of basaltic rocks and are known for their ability to rapidly exchange their interstitial cations with those in aqueous solutions. A series of closed system batch reactor experiments was conducted at 60 °C by combining stilbite, a Ca-bearing zeolite, with 0.1 mol/kgw aqueous sodium carbonate solutions. The individual batch reactor experiments ran from 2 to 225 days. Scanning electron microscope images of the solids recovered from the experiments reveal the presence of extensive calcite crystals, suggesting rapid and efficient carbonation. The total mass of CO2 mineralized during the experiments, determined from the direct analysis of the solids by thermogravimetric analysis and organic carbon analysis, equaled more than 5% of that of the original stilbite within a month. This is approximately equal to maximum CO2 mineralization possible if all of the Ca in the original stilbite was incorporated into calcite. Chemical analysis of reacted stilbite shows that approximately 2 Na atoms were incorporated into stilbite for each Ca atom incorporated into the precipitated calcite. These observations indicate that the carbon removal by stilbite proceeded by the rapid exchange of Na for Ca in its structure. This process results in carbonation rates that are far faster than those achieved by a silicate dissolution-carbonate precipitation mechanism. These results, consequently, compel consideration of targeting subsurface mineral carbonation efforts into zeolite-rich rocks. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) is an advanced technological solution that captures carbon dioxide (CO2) emissions from sources such as power plants and industrial facilities, storing them underground to prevent atmospheric release and mitigate climate change. Despite its potential to significantly reduce greenhouse gas emissions, CCS faces challenges like high costs and environmental concerns. Simultaneously, the circular economy model offers a transformative approach by minimizing waste and maximizing resource efficiency through strategies like recycling, reusing, and redesigning products for extended lifecycles. Integrating CCS within the circular economy framework presents a unique opportunity to enhance sustainability by repurposing captured CO2 for applications in chemical production, fertilizers, and other industrial processes, thereby aligning with circular principles of resource optimization. This synergy not only reduces carbon footprints but also supports Sustainable Development Goals by addressing economic, environmental, and social challenges. Furthermore, the combined approach can create socio-economic benefits, such as generating new green jobs and fostering a more resilient and sustainable future. This paper explores the integration of CCS with the circular economy, demonstrating how these combined initiatives contribute to a balanced relationship with the environment and promote a holistic pathway toward achieving sustainable development goals. Highlights: • Innovative fusion: uniting carbon capture and circular economy for sustainability. • Novel framework: bridging carbon capture and storage (CCS) carbon-neutrality with circular economy practices. • SDG roadmap: simultaneous progress in economic, environmental, and social dimensions. • Integrated strategy: tangible solutions for policy-makers and industries. • Environmentally conscious growth: CCS in circular economy for resilient futures. [ABSTRACT FROM AUTHOR]

Demand for low-carbon sources of hydrogen and power is expected to rise dramatically in the coming years. Individually, steam methane reformers (SMRs) and combined cycle gas power plants (CCGTs), when combined with carbon capture utilisation and storage (CCUS), can produce large quantities of on-demand decarbonised hydrogen and power respectively. The ongoing trend towards the development of CCUS clusters means that both processes may operate in close proximity, taking advantage of a common infrastructure for natural gas supply, electricity grid connection and the CO2 transport and storage network. This work improves on a previously described novel integration process, which utilizes flue gas sequential combustion to incorporate the SMR process into the CCGT cycle in a single "combined fuel and power" (CFP) plant, by increasing the level of thermodynamic integration through the merger of the steam cycles and a redesign of the heat recovery system. This increases the 2nd law thermal efficiency by 2.6% points over un-integrated processes and 1.9% points the previous integration design. Using a conventional 35% wt. monoethanolamine (MEA) CO2 capture process designed to achieve two distinct and previously unexplored CO2 capture fractions; 95% gross and, 100% fossil (CO2 generated is equal to the quantity of CO2 captured). The CFP configuration reduces the overall quantity of flue gas to be processed by 36%–37% and increases the average CO2 concentration of the flue gas to be treated from 9.9% to 14.4% (wet). This decreases the absorber packing volume requirements by 41%–56% and decreases the specific reboiler duty by 5.5% from 3.46–3.67 GJ/tCO2 to 3.27–3.46 GJ/tCO2, further increasing the 2nd law thermal efficiency gains to 3.8%–4.4% points over the un-integrated case. A first of a kind techno economic analysis concludes that the improvements present in a CO2 abated CFP plant results in a 15.1%–17.3% and 7.6%–8.0% decrease in capital and operational expenditure respectively for the CO2 capture cases. This translates to an increase in the internal rate of return over the base hurdle rate of 7.5%–7.8%, highlighting the potential for substantial cost reductions presented by the CFP configuration. [ABSTRACT FROM AUTHOR]

Utilizing wind power alongside flexible resources such as power‐to‐gas technology, gas‐fuel generator, demand response (DR) program, grid‐enhancing technologies, and carbon capture and storage can help to low carbon operation of integrated electricity‐gas systems (IEGSs). Accordingly, this paper proposes a low‐carbon economic dispatch model for the IEGS, in which gas‐fuel generators, DR, and gas‐fuel generator are considered to realize the economic and environmentally friendly operation of these systems. Also, the flexible AC transmission system device as one of the grid‐enhancing technologies is innovatively included in IEGSs to guarantee that wind power is deliverable entire the electricity system. Besides, power‐to‐gas equipped with hydrogen storage is used to absorb the excess wind power to produce CH4. On the other hand, to capture the inherent flexibility of the gas network, the gas‐storing characteristic of pipelines is shown by line pack modelling. To manage uncertainties associated with wind power and DR program, the proposed model is formulated as an IGDT‐stochastic problem. For efficient computation purposes, the present work follows the mixed‐integer linear programming framework. Different case studies are performed on an integrated test system. Numerical simulation results show that the proposed model leads to reducing the total cost, carbon emissions, and wind curtailment by 29%, 16.4%, and 100%, respectively. It can be seen that the proposed low‐carbon ED model is environmentally friendly and has economic benefits. [ABSTRACT FROM AUTHOR]

With increasing energy demands and depleting oil accessibility in reservoirs, the investigation of more effective enhanced oil recovery (EOR) methods for deep and tight reservoirs is imminent. This study investigates a novel hybrid EOR method, a synergistic approach of nonionic surfactant flooding with intermediate CO2-based oil swelling. This study is focused on the efficiency of surfactant flooding and low-pressure oil swelling in oil recovery. We conducted a fluorescence-based microscopic analysis in a microchannel to explore the effect of sodium dodecyl sulfate (SDS) surfactant on CO2 diffusion in Texas crude oil. Based on the change in emission intensity of oil, the results revealed that SDS enhanced CO2 diffusion at low pressure in oil, primarily due to SDS aggregation and reduced interfacial tension at the CO2 gas–oil interface. To validate the feasibility of our proposed EOR method, we adopted a 'reservoir-on-a-chip' approach, incorporating flooding tests in a polymethylmethacrylate (PMMA)-based micromodel. We estimated the cumulative oil recovery by comparing the results of two-stage surfactant flooding with intermediate CO2 swelling at different pressures. This novel hybrid approach test consisted of a three-stage sequence: an initial flooding stage, followed by intermediate CO2 swelling, and a second flooding stage. The results revealed an increase in cumulative oil recovery by nearly 10% upon a 2% (w/v) solution of SDS and water flooding compared to just water flooding. The results showed the visual phenomenon of oil imbibition during the surfactant flooding process. This innovative approach holds immense potential for future EOR processes, characterized by its unique combination of surfactant flooding and CO2 swelling, yielding higher oil recovery. [ABSTRACT FROM AUTHOR]