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1. Analysis of Electrochemical Capture of CO2 From Oceanwater Coupled With Hydrates-Based Seabed Sequestration

   https://doi.org/10.1115/ES2024-132209  

   Hamalian, Mark; Bhati, Awan; Bahadur, Vaibhav (July 2024, American Society of Mechanical Engineers)

   Abstract Novel energy efficient and scalable carbon capture and sequestration technologies are critical to meeting the goals of the Paris Agreement. In this study, we present a first-order system-level assessment of an integrated carbon capture and carbon sequestration plant that couples electrochemical CO2 capture from oceanwater with co-located long-term carbon sequestration as CO2 hydrates (ice-like solids) on the seabed. Separate recent experimental results associated with electrochemical capture and hydrate formation form the basis for this energetics-focused analysis, which evaluates power consumption of all the key components associated with capture and sequestration. Hydrates can be formed from both pure water as well as seawater, and the implications of including a desalination plant to provide pure water for hydrate formation are studied. All analysis is conducted for a 1 plant which captures and sequesters 1 megaton CO2 annually. Our results indicate the carbon capture will consume significantly more energy than carbon sequestration despite the use of a low-energy consuming electrochemical technique. From a sequestration standpoint, there are clear benefits to forming hydrates at high pressures, since the elevated formation rates reduce the number of hydrate formation reactors significantly. It is also seen that the addition of a desalination plant to provide pure water for hydrate formation (which speeds up hydrate formation) will not affect the energetics of the overall process significantly; however the CAPEX and operational aspects of including a desalination plant need to be analyzed in greater detail. Overall, this study seeds a novel CCS concept which can be deployed via decommissioned oil-gas platforms to capture CO2 from surface oceanwater and store CO2 right below on the seabed after appropriate sealing (artificial or natural). 

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2. Directing the wind: Techno-economic feasibility of green ammonia for farmers and community economic viability

   https://doi.org/10.3389/fenvs.2022.1070212  

   Ofori-Bah, Catherine Obiribea; Amanor-Boadu, Vincent (January 2023, Frontiers in Environmental Science)

   There has been increasing interest in low-carbon technologies to reduce climate change impacts. However, careful assessments of their implications for the vibrancy of local economies are rare. This paper employs techno-economic analysis to assess the technical and economic feasibility of investment in one such technology: local green ammonia production and its contribution to the economic viability of the local economy. The analysis considers price projection and debt financing options, and alternative energy-to-ammonia technologies. The approach is broadly applicable and is illustrated here using a case study in which 248,188 MT of traditional ammonia are replaced with local wind energy-produced ammonia for farmers in Southwest Kansas, United States. Economic feasibility is defined as the ability to accrue enough discounted cash flow at the end of the turbines’ 25-year lifespan to enable their replacement. The alternative technologies are the traditional Haber-Bosch and the emerging solid oxide electrolysis cell (SOEC). The total plant capital cost amounted to $781.72 million while the plant operating costs were set at $100/MT with the energy supplied by the project’s energy system. The results show how economic feasibility sensitivity to technology and financing options are evaluated and communicated to scientists, policymakers, and farmers. The 6.5 MWh/MT wind energy-to-ammonia SOEC technology presented the best economic results under all price projections. The community’s investment yielded the highest return when debt was used to finance 50% of the capital investment. Returns exceeded the average annual S&P return of about 7% from 1957 to 2021. The work shows how consideration of technology efficiencies and creative financing strategies can contribute to the economic welfare of farmers and their communities even as they contributed to reducing crop production’s carbon footprint. 

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3. A Membraneless Electrochemically Mediated Amine Regeneration for Carbon Capture

   https://doi.org/10.1038/s41467-025-61525-3  

   Hassan, Ahmad; Afshari, Mohsen; Rahimi, Mim (July 2025, Nature Communications)

   Electrochemical carbon capture (ECC) processes offer efficient, scalable, and modular alternatives to conventional thermal-based methods. Among ECCs, electrochemically mediated amine regeneration (EMAR) reached higher technology readiness levels, moving from small-scale laboratory studies toward pilot-scale implementations. Previous EMAR systems rely on ion-selective membranes, which contribute significantly to the cost and present challenges for long-term operation. This study presents a membraneless EMAR system by fundamentally redesigning the process configuration and using gas diffusion electrodes (GDEs) as both the anode and cathode. This setup eliminates the membrane and the need for additional equipment such as the absorption column, flash tank, and pumps, significantly reducing the process footprint and simplifying the flow diagram. Two GDE configurations, mesh-attached and electrodeposited, are tested and compared in terms of CO2 removal efficiency, current density, and energy consumption. Electrodeposited GDEs achieve CO2 removal efficiencies above 90% with energy consumption as low as 60 kJ/mol CO2. A techno-economic analysis estimates a levelized cost of capture of ~$70/tonneCO2, compared to $137/tonneCO2 for conventional EMAR. Further improvements in current density and removal efficiency may enable costs below $50/tonneCO2. These results position the membraneless EMAR as a potentially promising approach for cost-effective and scalable point-source carbon capture. 

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4. Understanding the effect of moderate concentration SDS on CO2 hydrates growth in the presence of THF

   https://doi.org/10.1016/j.jcis.2023.11.136  

   Cai, Xinrui; Worley, Joshua; Phan, Anh; Salvalaglio, Matteo; Koh, Carolyn; Striolo, Alberto (March 2024, Journal of Colloid and Interface Science)

   Hypothesis: Additives like Tetrahydrofuran (THF) and Sodium Dodecylsulfate (SDS) improve Carbon Dioxide (CO2) hydrates thermal stability and growth rate when used separately. It has been hypothesised that combining them could improve the kinetics of growth and the thermodynamic stability of CO2 hydrates. Simulations and Experiments: We exploit atomistic molecular dynamics simulations to investigate the combined impact of THF and SDS under different temperatures and concentrations. The simulation insights are verified experimentally using pendant drop tensiometry conducted at ambient pressures and high-pressure differential scanning calorimetry. Findings: Our simulations revealed that the combination of both additives is synergistic at low temperatures but antagonistic at temperatures above 274.1 K due to the aggregation of SDS molecules induced by THF molecules. These aggregates effectively remove THF and CO2 from the hydrate-liquid interface, thereby reducing the driving force for hydrates growth. Experiments revealed that the critical micelle concentration of SDS in water decreases by 20% upon the addition of THF. Further experiments in the presence of THF showed that only small amounts of SDS are sufficient to increase the CO2 storage efficiency by over 40% compared to results obtained without promoters. Overall, our results provide microscopic insights into the mechanisms of THF and SDS promoters on CO2 hydrates, useful for determining the optimal conditions for hydrate growth. 

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5. Exploring sustainable electricity system development pathways in South America’s MERCOSUR sub-region

   Chowdhury, A.F.M. Kamal (September 2023, Energy strategy reviews)

   We explore sustainable electricity system development pathways in South America’s MERCOSUR sub-region under a range of techno-economic, infrastructural, and policy forces. The MERCOSUR sub-region includes Argentina, Brazil, Chile, Uruguay, and Paraguay, which represent key electricity generation, consumption, and trade dynamics on the continent. We use a power system planning model to co-optimize investment and operations of generation, storage, and transmission facilities out to 2050. Our results show that, under business-as-usual conditions, wind and solar contribute more than half of new generation capacity by 2050, though this requires substantial expansion of natural gas-based capacity. While new hydropower appears to be less cost-competitive, the existing high capacity of hydropower provides critically important flexibility to integrate the wind and solar and to avoid further reliance on more expensive or polluting resources (e.g., natural gas). Over 90% emission cut by 2050 could be facilitated mostly by enhanced integration (predominantly after 2040) of wind, solar, and battery storage with 11%–28% additional cost, whereas enhanced expansion of hydropower reduces the cost of low-carbon transition, suggesting trade-off opportunities between saving costs and environment in selecting the clean energy resources. Achieving high emission reduction goals will also require enhanced sub-regional electricity trade, which could be mostly facilitated by existing interconnection capacities. 

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