Carbon Capture Science & Technology最新文献

Considering the role that offshore ${\text{CO}}_2$ storage is expected to play in deploying carbon capture and storage, enabling cost-efficient and flexible solutions for transporting ${\text{CO}}_2$ to relevant storage locations will be crucial. While pipeline and ship-based approaches have long been considered the most relevant options, transport via subsea shuttles is a new concept that has also been proposed in the past couple of years. The present study seeks to understand if this new approach could be cost-efficient compared to current and upcoming ship-based transport concepts.

The result shows that the shuttle concept could be cost-competitive with currently mature 15 barg-based shipping, especially if the subsea shuttle connects to a ${\text{CO}}_2$ pipeline infrastructure rather than to the reservoir directly, although cost-competitiveness is achieved only for a limited range of volumes and distances. However, it is unlikely that this concept would be cost-attractive compared to the upcoming 7 barg-based shipping, and sensitivity analyses highlight that the subsea shuttle investment cost would need to fall to unlikely low levels to reverse this trend. Thus, this study concludes that the subsea shuttle concept is unlikely to become a significant solution for transporting ${\text{CO}}_2$ to offshore storage.

Efficient catalysis of CO₂ hydrogenation holds significant promise for addressing environmental concerns and advancing sustainable energy solutions. In this study, we report the synthesis of a novel series of Ru-supported on graphitic carbon nitride (g-C₃N₄) catalysts, with a focus on the impact of ruthenium (Ru) loading on the thermocatalytic performance. Varying Ru concentrations were introduced, including 0.2, 0.5, 1.0, 2.0, and 5.0 wt%, resulting in different Ru particle sizes on g-C₃N₄ support. Through a multifaceted characterization approach, it was observed that the catalyst containing 1 wt% Ru loading displayed superior performance, with a high density of active sites, indicated by an enhanced CO₂ conversion rate of 36.8 % at 450 °C and a CO yield of 25 %. This catalyst also exhibited remarkable CO selectivity of 83 % at 375 °C. Conversely, lower loadings of 0.2 and 0.5 wt % Ru were found to be less effective, yielding minimal CO₂ conversion. Loadings above 1 wt% Ru, while achieving high CO₂ conversion, demonstrated a preference for CH₄ production over CO, indicating lower selectivity for the desired product. This study elucidates the critical role of Ru nanocluster size in the catalytic activity and selectivity, with 1 wt % Ru-supported g-C₃N₄ emerging as a promising candidate for selective CO generation from CO₂ hydrogenation, offering a pathway for the valorization of CO₂ as a raw material in the chemical industry.

Carbon capture and storage represented as CCS, is a technique that can be used to cut down on emissions of CO₂ from industrial sources. These mechanisms can balance the excess fossil fuel usage and lead to effective carbon capture from the atmosphere and storing it in safe spaces. This can negate global warming and send the carbon back to geological spaces inside the earth. This review covers the operational mechanism of such technologies from its inception to the material innovation along with the transport of CO₂ and its storage options. Breakthroughs in recent years have made it possible to design effective carbon capture and safe spaces for its storage. A comprehensive worldwide case studies are presented for both successful CCS project implementation and their environmental impact assessment. Lessons learned from these case examples are reflected through the challenges and policy hurdles with its impact on the global economy. An outlook is provided for the role of CCS in net zero emissions, renewables integration and advancing CCS research. By leveraging innovation across capture, utilization, and storage stages, CCS holds immense potential to play a transformative role in combating climate change and achieving global sustainability goals.

Higher electrolysis efficiency than that achieved with conventional electrolysis and integrated fuel production would help to reduce dependence on bio-energy further. In this regard, solid oxide electrolyzer (SOEC) technology is of particular interest because of its unrivaled conversion efficiency, due to the favorable thermodynamics and kinetics at higher operating temperatures. In particular, SOEC high-temperature co-electrolysis (HTCE) of CO₂/H₂O can convert CO₂ into valuable chemicals and fuels, which will help to reduce reliance on fossil fuels and mitigate greenhouse gas emissions. In this report, we present a comprehensive overview of recent research progress made with SOEC HTCE of CO₂/H₂O. The main focus areas are the development history, the basic principle and the reaction mechanism of HTCE of CO₂/H₂O using SOEC. The fuel electrode and oxygen electrode materials for SOEC HTCE of CO₂/H₂O are classified and introduced. The factors that affect the co-electrolysis reaction process are also described in detail, and the optimization strategy of the process conditions is explained to provide a better understanding of the SOEC HTCE process. The challenges and possible future development directions are also suggested, as guidance for future research.

Industrial biomass combustion fly ash has been investigated as a precursor for zeolites with a view to evaluate the potential for adsorption of CO₂. The synthesis methodology has been optimised via Design of Experiment by employing a Taguchi L9 array. Three variables were identified as statistically significant, the crystallisation temperature, crystallisation time and the liquid to solid ratio. Analysis of the main effects revealed an optimum set of conditions which produced a sample with the highest adsorption capacity of those prepared, 1.84 mmol g⁻¹ at 50 °C. This was a result of the conversion of the as-received fly ash into type A (LTA) and type X (FAU) zeolites after alkaline fusion with NaOH and hydrothermal treatment. The enthalpy of adsorption was estimated at -40.2kJmol⁻¹ and was shown to be dependent on surface coverage; the isosteric enthalpy of adsorption at zero coverage was -86 kJ mol⁻¹. The working capacity of the adsorbent was maintained at 85 % of the first adsorption uptake after a total of 40 cycles in a simulated temperature swing adsorption process (50 °C/150 °C adsorption/desorption). The equilibrium and kinetic CO₂ adsorption isotherms are presented and modelled through non-linear regression to reveal the adsorption mechanisms demonstrated by the fly ash-derived zeolites. Significant heterogeneity exists within the multi-phase zeolite which presents both micro and mesoporosity. The developed adsorbent presents a feasible route to valorisation of biomass combustion fly ash with good potential for application in the separation of CO₂.

To avoid sintering and carbon deposition of conventionally loaded catalysts, a spatial confinement strategy was employed to design a high-performance catalyst for the dry reforming of methane (DRM) reaction. With tri-metallic Ni-Co-Mg metal-organic framework (MOF-74) as a precursor, a novel nanostructured NiCoMg@C catalyst was synthesized, where the active metals Ni and Co were confined within the carbon framework derived from MOF pyrolysis. Characterization results indicate that the catalyst synthesized with MOF as template has a high specific surface area, well-dispersed metals, and strong metal-support interactions. The introduction of a high content of Mg promoted the dispersion of active metal Ni and Co and increased the number and strength of surface basic sites. Among the catalysts, NiCoMg₂₀@C exhibited optimal catalytic activity, with initial CH₄ and CO₂ conversion rates reaching 75.13 % and 85.29 %, respectively. More importantly, the catalyst showed high stability during 100 h DRM reaction at 700 °C without significant carbon deposition. This research provides a new perspective for the development of DRM catalysts.

Direct air capture (DAC) by solid amine adsorbents is a promising technology to curb the increasing atmospheric CO₂ level. Despite extensive efforts, there are still limited improvements for this type of materials in their CO₂ uptake and adsorption kinetics under ultra-dilute conditions. And most current research focuses on powdered adsorbents, which need to be granulated or fabricated into devices for DAC application, resulting in a further decline in CO₂ uptake. Herein, a series of commercial resin particles (1.0 mm) were used as supports, and it was found that X5 exhibited favorable support characteristics in the preparation of solid amine adsorbents. Notably, X5 possessed a large pore volume of 1.90 cm³/g and featured a hierarchical bimodal porous network comprising mesopores and macropores. The prepared adsorbents (PEI@X5) had considerable polyethyleneimine (PEI) dispersion even at PEI content up to 50 %, and thus demonstrated excellent CO₂ adsorption performances with high CO₂ uptakes of 118 or 108 mg/g in TGA or fixed bed under simulated ambient air conditions (25 °C, 400 ppm CO₂). Additionally, the adsorbents exhibited superb cyclic stability with no decay observed over 10 adsorption-regeneration cycles. The introduction of 25 % relative humidity (RH) of water vapor significantly improved the CO₂ uptake of the adsorbent to 130 mg/g, with a lifting efficiency of 20.4 %. However, further increases in RH reduced the CO₂ uptake and adsorption rate due to the excessive adsorption water, which leached part of PEI from the pores of 50 %PEI@X5. Considering the commercial production of raw materials, the facile synthesis of 50 %PEI@X5, and its superior CO₂ capture efficiency, these findings open up new avenues for DAC technology.

In recent years, a discernible surge in greenhouse gas emissions has precipitated severe global warming, with the construction industry identified as a notable contributor, particularly through carbon dioxide emissions from cement production. As concrete stands as the second most extensively utilized material globally, its pervasive use amplifies the release of potent greenhouse gases. This paper introduces a novel approach to carbon capture in concrete materials by employing CO₂ adsorbents that synergistically enhance the carbonization reaction, thereby augmenting capture efficiency. Biochar emerges as a promising candidate for carbon capture due to its robust CO₂ adsorption capacity and its eco-friendly, cost-effective, and low-carbon production process. For instance, typically 1 ton of biochar has potential to sequester 3 ton of carbon dioxide from the environment. Various studies have explored the integration of biochar into concrete materials, aiming to improve mechanical, durability, and thermal properties, as well as the overall functionality of formed concrete composites. Beyond its role in enhancing concrete properties, biochar presents itself as an effective carbon sequestering agent with or without modification which is also reviewed in this paper. Concurrently, research efforts are underway to investigate the reinforcement properties and selective CO₂ sorption capabilities of cellulose-based materials in concrete composites. Noteworthy attributes such as abundance, biodegradability, renewability, and cost-effectiveness position cellulose-based materials as promising alternatives to traditional reinforcing agents. This paper provides a comprehensive review of the latest advancements in the utilization of biochar and cellulose materials in concrete composite applications. Emphasis is placed on evaluating the durability, mechanical properties, and carbon capture potential of concrete composites augmented with biochar and cellulose. The synthesis of research progress in this domain serves to elucidate the current state of knowledge and offers insights into the future prospects of biochar and cellulose-enhanced concrete composites in the context of sustainable construction practices.

Industrial sectors, pivotal for the economic prosperity of nations, rely heavily on affordable, reliable, and environmentally friendly energy sources. Industries like iron and steel, oil refineries, and coal-fired power plants, while instrumental to national economies, are also the most significant contributors to waste gases that contain substantial volumes of carbon monoxide (CO). CO can be converted to a highly efficient and carbon free fuel, hydrogen (H₂) through a well-known water gas shift reaction. However, the untapped potential of H₂ from waste industrial streams is yet to be explored. This is the first article that investigates the potential of H₂ production from industrial waste gases. The available resource (i.e., CO) and its H₂ production potential are estimated. The article also provides insights into the principal challenges and potential avenues for long-term adoption. The results showed that 249.14 MTPY of CO are available to produce 17.44 MTPY of H₂ annually. This suggests a significant potential for H₂ production from waste gases to revolutionize industrial waste management and contribute significantly towards Sustainable Development Goals 7, 9, and 13ensuring access to affordable, reliable, sustainable, and modern energy for all and taking decisive climate action, respectively.