Carbon Capture Science & Technology最新文献

Catalyst-assisted amine regeneration has emerged as a prominent strategy for enhancing the desorption rate of CO₂ from amine solutions at lower temperatures (<100 °C), thereby reducing the massive energy penalty of post-combustion carbon capture process. To make this strategy practical and commercially relevant, it is crucial to develop economically viable, abundant, and eco-friendly catalysts. In this context, we synthesized catalysts from fly ash (FA) through treatment with three acidic solutions of H₂SO₄, H₃PO₄, and HNO₃ and used them in amine regeneration process with evaluating their catalytic performance in terms of CO₂ desorption rate, desorbed CO₂ quantity, and regeneration heat duty. The acid treatment increased the BET surface area and generated surface acid sites of the FA, both of which played a vital role in increasing the CO₂ desorption from monoethanolamine (MEA) solution at 86 °C. The prepared catalysts increased the CO₂ desorption rate by up to 91 % and desorbed CO₂ amount by up to 61 %, while reducing the regeneration heat duty by up to 38 % compared to the uncatalyzed amine solution. The studied catalysts could be easily separated and used in successive amine regeneration cycles, which makes them suitable for industrial application.

Capture and storage of CO₂ from gas turbine power plants can be an alternative to electrification from shore to reduce the emissions from petroleum production facilities on the Norwegian Continental Shelf. The objective of this work was to analyse and rank various options for storage using technical economic analyses. The following alternatives were considered:

• 1.

  Dissolution of CO₂ in sea water and aquifer storage of carbonated water

• 2.

  Injection of pure CO₂ into an aquifer

• 3.

  Compression of CO₂ and pipeline transport to a collection centre

• 4.

  Liquefaction of CO₂ and ship transport to a collection centre

• 5.

  Dissolution of CO₂ in sea water and injection into oil fields (carbonated water injection, CWI)

The economic calculations show that alternatives 1 – 4 have negative net present values. A higher future CO₂ tax than presently envisaged will be needed to make the alternatives economically viable. All cases related to Alternative 5 (project lifetime, heterogeneous and homogeneous reservoir models, green and brown fields) exhibit positive net present values due to incremental oil production. Most, but not all, injected CO₂ remained in the reservoir, depending on the injection period.

Oxygen in the captured CO₂, formation of gas hydrates and corrosion of well materials may cause operational problems of injecting sea water with dissolved CO₂. These aspects have been briefly discussed. Some additional measures may have to be taken to alleviate undesired effects, but none of the issues are likely to prohibit implementation of CWI.

The results obtained suggest that CWI into producing oil reservoirs offers an economic viable and safe way for disposal of CO₂ captured from offshore petroleum production plants provided that a capture plant can be installed, and that the remaining lifetime of the reservoir is so long that the benefits of improved oil recovery can be realised.

Catalytic carbon dioxide (CO₂) conversion technologies can be important components in carbon capture, storage and utilization for CO₂ mitigation and possible future economic activity and have gained significant attention globally in past decades. Electrified non-thermal plasma (NTP) catalysis enables CO₂ hydrogenation into value-added chemicals under mild conditions. If the hybrid process is coupled with renewable energy and green hydrogen, it can be the promising solution to address the energy and carbon emission challenges. To enhance the energy efficiency of NTP-catalytic systems, bespoke catalyst design and process optimization are necessary. Here, using Ni catalysts supported on mesoporous MCM-41 and NTP-catalytic CO₂ methanation as the model systems, the effects of Ni metal dispersion, argon (Ar) addition and residence time on the NTP catalysis were also studied. The findings show that (i) increased metal dispersion alone did not lead to significant enhancement in the performance of NTP catalysis (e.g., CH₄ production rate: 31.4 × 10⁻⁵ mol/(s·g_Ni) for 42.6 % Ni dispersion vs. 26.8 × 10⁻⁵ mol/(s·g_Ni) for 25.1 % dispersion), (ii) Ar addition to the system led to the decreased methane production rate (e.g., CH₄ selectivity decreased by ∼19 % due to the increase in Ar addition to the system from 5 to 50 mL/min), and (iii) optimization of the residence time could improve the performance of NTP-catalytic CO₂ methanation (i.e., an extension of the residence time to 0.69 s resulted in the higher CO₂ conversion of 72.7 % and CH₄ selectivity of 95.9 % at 9.6 kV than that at 0.49 s and 11 kV).

Urgent actions are needed to reduce CO₂ emissions and mitigate the increasingly severe impacts of climate change. Since the 1990s, the membrane research group (MEMFO) at the Norwegian University of Science and Technology has been committed to developing effective membranes and membrane processes for CO₂ separation. MEMFO's research can be categorized into five main themes: facilitated transport membranes, hybrid membranes, carbon membranes, membrane contactors, and related modeling and process simulation. These themes are tied to industrial applications in CO₂ capture from flue gas, biogas upgrading, natural gas sweetening, and hydrogen purification. Promising membranes, identified based on their laboratory-scale performances, have been selected for onsite testing in industrial processes to validate their performances as well as stability and durability. Verified membranes are upscaled for pilot tests. This account paper summarizes MEMFO's research and development outcomes over the past decade and discusses our research strategies and perspectives for future work.

Photocatalytic reduction of carbon dioxide (CO₂) presents a pivotal solution to address meteorological and ecological challenges. Currently, metal-organic frameworks (MOFs) with their crystalline porosity, adjustable structures, and diverse chemical functionalities have garnered significant attention in the realm of photocatalytic CO₂ reduction. This review provides a brief introduction to CO₂ reduction and MOF material and their applications in CO₂ reduction. Then, it undertakes a comprehensive examination of MOFs, summarizing their key attributes, including porosity, large surface area, structural multifunctionalities, and responsiveness to visible light, along with an analysis of heterojunctions and their methods of preparation. Additionally, it elucidates the fundamental principle of photocatalysis and CO₂ reduction, encompassing both half and overall reactions. Furthermore, the classification of MOF-based materials is explored, along with the proposed mechanism for CO₂ reduction and an update on recent developments in this field. Finally, this review outlines the challenges and potential opportunities for utilizing MOFs in CO₂ reduction, offering valuable insights to scholars seeking innovative approaches not only to enhance CO₂ reduction but also to advance other photocatalytic processes.

The current political discussion in the United States around carbon capture and storage includes statements that suggest a need for a technical review to clarify the expected air pollution impacts of amine scrubbing. The Center for International Law and 50 other organizations published an open letter claiming that “CCS is not consistent with the principles of environmental justice… CCS makes dirty energy even more dangerous for frontline communities. Facilities equipped with carbon capture technology have to burn more fossil fuel to get the same energy output, resulting in increased emissions of toxic and hazardous pollutants, like fine particulates (PM2.5).”

This paper reviews air pollutants produced by the use of amine scrubbing on coal- and gas-fired power plants in the U.S. and the process features and mitigation strategies that will minimize their impact on air quality. Even with atmospheric reactions, emissions of amine, nitrosamine, and other air toxics are likely to have insignificant environmental and health impacts. Stacks will disperse emissions with a dilution factor greater than 8000. Water wash with or without acid will reduce emissions of amine and nitrosamine that is produced from atmospheric reactions. Nitrosamine emissions will be managed with selective catalytic reduction (SCR) to reduce the NO/NO₂ and/or selection of primary or non-volatile amines. With coal-fired power plants, amine aerosols, Hg, SO₃, and fine particulate emissions will probably be managed by a fabric filter with alkali addition. Carbon capture by amine scrubbing will reduce significantly the effect of the power plant emissions on ambient levels of PM2.5. With coal-fired power plants, the application of amine scrubbing will significantly reduce SO₂ emissions. NO_x emissions will usually be minimized by selective catalytic reduction (SCR) in both gas- and coal-fired plants. Ammonia emissions will be minimized by managing amine oxidation, and if necessary, by adding an acid wash or other controls.

A multi-objective optimisation model for CCS chains, aiming to minimise costs and greenhouse gas emissions, considering various transport options is presented. The model builds upon previous work and covers the CCS chain elements after CO₂ is captured, including conditioning, pipeline and batch-wise transportation, intermediate hub storage and injection at CO₂ storage fields. A prospective Life Cycle Inventory is integrated to evaluate emissions from batch-wise transportation. The model is parameterised for accurate estimations based on site-specific characteristics and is implemented in two standalone CCS chains, that are analogues to the Northern Lights project with dominant ship transport and the Stella Maris concept with direct injection ship transport, also incorporating distinct emission profiles, intermediate storage hubs and injection sites. A third implementation combining both chain concepts is implemented. By increasing in a step-wise manner the weight of the emissions in the objective function, the model evaluates cost and emission trade-offs. The optimisation selects costlier wells to minimise emissions and shifts from batch-wise ships to cross-continent pipelines. Chain emissions decrease over time with CO₂ supply increase. Shipping operation dominates emissions, followed by well construction and infrastructure construction. Across all the implementations, the GHG emission intensity of the chain, after CO₂ is captured, ranged from 3.3 to 14.2 %, depending on the concept and transport option adopted and accounting for regional characteristics (i.e., the electricity supply mix per country).

In this study, a parametric experimental analysis is performed to investigate the adsorption and desorption processes by evaluating CO₂ concentration, sorbent temperature, adsorption, and desorption capacities, and desorption efficiency using Zeolite 13X with a modified multimode microwave oven. Four parameters varied: average microwave powers (336 to 504 W), gas flow rate (60 to 100 ml/min), regeneration temperature (80–120 °C) as well as the presence of moisture with an initial CO₂ concentration of 20 %. This work is the first study that investigates these four main parameters’ effects together on the characteristics of CO₂ desorption process of Zeolite 13X. While the adsorption was completed faster with higher flow rates with a faster breakthrough curve, the highest CO₂ adsorbed amount was found at the lowest flow rates. The moisture effect on the adsorption capacity was also found to be negative with an adsorption capacity reduction of 20 % under wet conditions. The MW power was the key parameter since it controls the process (temperature), and the desorption stage in all conditions were completed faster with higher microwave power rates. However, low MW power always provided better results in terms of CO₂ desorbed amount and desorption efficiency. Moreover, while higher flow rate speeded up the desorption process, it reduced the desorption efficiency. Moisture impact was found to be quite significant with a desorption efficiency reduction of 25 %. It was assumed that this reduction is attributed to the competition between the thermal desorption of CO₂ and the absorption of CO₂ by extra water in the system. Overall, while the amount of desorbed CO₂ varied between 1.13 and 1.76 mmol CO₂/g, the desorption efficiency changed from 51 % to 75 %.

The quest to decarbonize the lime and cement industry is challenging because of the amount and the nature of the CO₂ emissions. The process emissions from calcination are unavoidable unless carbon capture is deployed. Nevertheless, the majority of the available carbon capture technologies are expensive and energy inefficient. The indirectly heated carbonate looping (IHCaL) process is a promising technology to capture CO₂ from the lime and cement production, featuring low penalties in terms of economics and energy utilization. Previous works have highlighted the potential of the IHCaL, but the optimization of the process has not been discussed in enough detail and techno-economic implications are not yet fully understood. Within this work, ten scenarios using IHCaL technology to capture CO₂ from a lime plant were simulated. Hereby, different process configurations, heat recovery strategies and fueling options were computed. The calculations for the capture facilities were performed with Aspen Plus® software and EBSILON®Professional was used to simulate the steam cycles. A techno-economic assessment was included as well, aided by the ECLIPSE software.

The results demonstrate that the selection of the fuel for the combustor not only affects the CO₂ balance and energy performance but is also an important cost driver —there were considerable economic advantages for the computed cases with middle-caloric solid recovered fuel (SRF). The analysis shows how the heat recovery strategy can be optimized to achieve tailored outcomes, such as reduced fuel requirement or increased power production. The specific primary energy consumption (from −0.3 to +2.5 MJ_LHV/t_CO2,av) and cost for CO₂ avoided (from −11 to +25 €/t_CO2,av) using SRF are considerably low, compared with other technologies for the same application. The sensitivity study revealed that the main parameters that impact the economics are the discount rate and the project life. The capture plants are more sensitive to parameter changes than the reference plant, and the plants using SRF are more sensitive than the lignite-fueled plants. The conclusions from this work open a new pathway of experimental research to validate key assumptions and enable the industrial deployment of IHCaL technology before 2030.

CCS (Carbon Capture and Storage) is a major technology aiming to reduce greenhouse gases and reduce carbon footprint. In these applications, Oil Country Tubular Goods (OCTG) and associated premium connections are used to inject industrial CO₂ into stable geological formations such as depleted oil and gas fields or saline aquifers, in liquid or dense phase to permanently store it. While current standards (API RP 5C5, ISO 13,679) allow qualification of premium connections for Oil & Gas application, no standard exists for CCS applications. In that frame, a new test methodology was developed to evaluate the impact of Joule-Thomson effect on premium connection, in the scenario of a CO₂ blow-out and intermittent operation of the injection wells, such as shut-in of the subsurface safety valve (SSSV) or injection phase. To confirm that premium connections remain tight and safe after being exposed to a rapid depressurization of CO₂, they have been physically tested in a horizontal load frame. The test consisted in the filling of the sample with CO₂ up to a minimum of 100 bar and a temperature below 30 °C to ensure liquid state, or above 32 °C to ensure supercritical state inside the sample, and then depressurizing the sample through an orifice of 2 or 4 mm until complete drop of pressure. Minimum measured temperature on outer pipe wall reached around -50 °C before dry ice CO₂ formation. Maximum measured gradient of temperature observed was around 70 °C. No leakage nor connection damages were observed during the pressure release sequences. Sealability was then confirmed during the internal pressure and external pressure test performed afterwards.