Integrated Carbon Capture Research Articles

Novel design of a CCHP system to boost nearly zero-carbon building concept

The accumulation of carbon dioxide in the atmosphere is responsible for global warming. To address this issue, this study develops and optimizes a novel and economically viable combined cooling, heating, and power (CCHP) system for an educational building with minimal CO2 emissions. The main components of the system include a gas turbine cycle, a molten carbonate fuel cell, a heating system, an electric chiller, and an absorption chiller. Optimization is conducted based on a 4E (energy, exergy, economic, and environmental) analysis using TRNSYS and MATLAB software. The optimized CCHP system has a unit product cost of $52.44/h with an overall exergy efficiency of 44.34 %, generating 0.39 kg of CO2/kWh. Furthermore, the objective of a nearly zero-carbon system is achieved by integrating carbon capture and storage (CCS) into the original CCHP system. A novel cryogenic carbon capture unit is implemented to capture CO2 from the flue gas. Integrating CCS reduces CO2 emissions by up to 91 %, presenting a cost-effective approach to carbon offset. Although there is a modest increase in operational costs ($53.46/h) and a slight decrease in exergy efficiency (43.3 %), these trade-offs are necessary to attain an environmentally responsible system. Overall, the optimized CCHP system with the integrated CCS shows potential as an energy-efficient solution for the selected educational building while reducing CO2 emissions.

Enhanced CO2 capture and reverse water gas shift reaction using CaO in NaCl-CaCl2 molten salt medium

This study introduces an Integrated Carbon Capture and Utilisation-Reverse Water Gas Shift (ICCU-RWGS) approach, a novel method for in situ CO2 adsorption and conversion, leveraging the synergistic effects of CaO within a NaCl-CaCl2 molten salt blend to enhance CO2 capture and conversion efficiency. Building upon this foundation, we optimize CaO concentration and operating temperature to maximize CO2 uptake and conversion performance. The research focuses on integrating CaO with a NaCl-CaCl2 molten salt blend (mass ratio 4:6) to improve CO2 sorption and conversion performance. Findings show significant enhancements in CO2 uptake and CO yield with the presence of molten salt compared to systems without it. The optimal operating temperature and CaO concentration are identified for maximum CO yield. Characterisation techniques like in-situ infrared spectroscopy, XRD, and SEM provide insights into the behavior of CaO in the molten salt, revealing the solubility of the partial carbonate formed from CO2 and CaO, dispersion of CaO particles, and their morphological characteristics. Overall, the study demonstrates the potential of CaO-molten salt integration in improving ICCU-RWGS process efficiency and contributes to the development of more effective and sustainable ICCU technologies.

Integrated CO2 capture and conversion by Cu/CaO dual function materials: Effect of in-situ conversion on the sintering of CaO and its CO2 capture performance

The integrated carbon capture and utilization (ICCU) technology has been considered a prospective strategy for mitigating carbon emissions issues. Compared to conventional CO2 capture and utilization, the ICCU process reduces transporting, product purification, construction, and operation costs. However, few works focus on investigating the effect of in-situ CO2 conversion on the sintering of CaO at high temperatures. In this work, Cu/CaO dual functional materials (DFMs) were synthesized and used in the Calcium Looping-Reverse Water-Gas Shift (CaL-RWGS) process at 650 °C. The results showed that it is thermodynamically feasible to couple the CaL with the RWGS reaction. In the cyclic CO2 capture test, Ca1Cu0.1 DFMs showed desirable CO2 capture performance (11.34 mmol/gDFMs) and self-activated phenomenon in the first 15 cycles. Moreover, Cu nanoparticle catalysts in the DFMs effectively inhibited the sintering of CaO by accelerating the desorption of CO2 from the CaO surface and converting it to CO during the conversion stage. In-situ DRIFTS of Ca1Cu0.1 DFMs revealed that formates might be the RWGS intermediates in CaL-RWGS.

Carbon capture integration in seismic interpretation: Advancing subsurface models for sustainable exploration

Sustainable exploration in the energy industry necessitates innovative approaches that address environmental concerns without compromising the efficiency (or robustness) of subsurface modeling. This paper explores the integration of carbon capture technologies into seismic interpretation as a means to advance subsurface models for sustainable exploration. The study leverages existing seismic interpretation techniques and incorporates carbon capture data to enhance the accuracy and environmental sustainability of exploration practices. The key concepts discussed include an overview of seismic interpretation methods, an introduction to carbon capture technologies, and the rationale for integrating carbon capture into seismic models. The practical application section provides insights into the proposed integration method, supported by real-world examples showcasing successful applications and potential benefits for sustainable exploration. Challenges and considerations in the integration process are identified, accompanied by strategies to overcome obstacles and considerations for industry-wide adoption. A detailed case example illustrates the step-by-step application of the integration, emphasizing its impact on subsurface models. The paper concludes with a forward-looking perspective, outlining potential technological advancements for further integration, suggesting areas for future research and development, and anticipating improvements in sustainability and exploration practices. This paper aims to contribute to the ongoing discourse on sustainable exploration by providing a practical framework for integrating carbon capture in seismic interpretation, paving the way for environmentally conscious and efficient subsurface modeling in the energy sector.

Dicalcium ferrite: A chemical heat pump in integrated carbon capture and chemical looping combustion for the steel industry

An integrated calcium and chemical looping combustion using dicalcium ferrite (Ca2Fe2O5, C2F), a mixed phase from iron and calcium oxides, is proposed here to remove carbon (CO + CO2) contained in the blast furnace gas from the steel industry. C2F is particularly attractive in chemical looping hydrogen production due to its lower PO2, therefore C2F can split steam into H2. Here, the low PO2 property allows C2F to have endothermic combustions in CO and H2 combustion (Stage 1 in the carbonator). The heat of combustion is chemically stored as reduced-carbonated C2F to be utilised for sorbent regeneration (Stage 2 in the calciner), essentially pumping the heat from the carbonator to the calciner. Combustion that occurred at PCO/PCO2 of the typical BFG in which the C2F should have not been able to combust CO, suggesting an enhanced combustion phenomenon. Experiments demonstrated in a fluidised bed and a thermogravimetric analyser led to indications that rather than following reaction pathways in an order of (i) C2F is reduced into CaO and metallic Fe and (ii) the CaO is absorbed CO2 in Stage 1, C2F might directly form Fe + CaCO3 under a mixture of CO and CO2, allowing the C2F to react with BFG. Reincorporation of the reduced-carbonated oxides into C2F drives lower decarbonation temperatures compared to CaO alone, suggesting a promising route to improve energy efficiency in capturing carbon in the hard-to-decarbonise steel industry.

Sensitivity study of integrated carbon capture and methanation process using dual function materials

Integrated Carbon Capture and Methanation (ICCM) is a promising technology to produce Synthetic Natural Gas (SNG) via captured CO2 and renewable hydrogen. This work performed a sensitivity study on how operation pressure, the types of DFM and point source, and the catalytic metal loading in DFMs affect the performance of ICCM process. As Na-Ru/Al2O3 (Na-DFM), (Li-Na-K)NO3-MgO-Ni/CeO2-phy (Mg-DFM), and Ni5-CeLi (Li-DFM) were adopted as DFMs, the performances of ICCM process were investigated in the range of 0.1 Mpa-5.0 Mpa, showing elevated pressure is favorable to improving capture efficiency and the quality of SNG products, and reducing hydrogen consumption. Under the optimized operation conditions, Na-DFM based ICCM system shows the better overall performance than ICCM system using Mg-DFM or Li-DFM, which energy conversion efficiency, comprehensive energy consumption, and net CO2 emission are 82.74 %, –14.61 MJ/kg CO2, and –1.18 kg CO2/kg CO2, respectively. Circulation rate is the amount of DFMs necessary to be transferred between reactors to ensure the desired CO2 capture efficiency or SNG productivity; it heavily depends on the type of adsorbent component, capture/hydronation reactions, and the fraction of active adsorbent component in DFMs for CO2 transport. Na-DFM based ICCM systems using different point sources (Power Plant, Steel Plan, and Cement Plant) possess the approximate performances in terms of energy conversion efficiency, comprehensive energy consumption, net CO2 emission, and SNG composition; but when Steel Plan is the point source, Na-DFM based ICCM process features of low electricity and hydrogen consumptions. Cyclic redox reactions of catalytic metal and the cycled capture/hydrogenation proceed in parallel in ICCM process. The increased hydrogen consumption and strong exothermic effects arising from the redox reactions of catalytic metal leads to profound performance changes of ICCM system. Overall, the present work is providing comprehensive information and necessary data to guide the design and operation of an ICCM plant.

Dual Functional Materials: At the Interface of Catalysis and Separations.

Dual functional materials (DFMs) are a promising approach to increase the energy efficiency of carbon capture and utilization by combining both steps into a single unit operation. In this Perspective, we analyze the challenges and opportunities of integrated carbon capture and utilization (ICCU) via a thermally driven process. We identify three key areas that will facilitate research progress toward industrially viable solutions: (1) selecting appropriate DFM operating conditions; (2) designing and characterizing interfacial site cooperativity for CO2 adsorption and hydrogenation; and (3) establishing standards for rigorous and comprehensive data reporting.

Novel SOFC system concept with anode off-gas dual recirculation: A pathway to zero carbon emission and high energy efficiency

In recent years, the potential of Solid oxide fuel cell (SOFC) technologies as energy conversion devices with high efficiency and zero‑carbon emissions has been underestimated, where high fuel utilization plays a crucial role. Although the SOFC system with anode off-gas single recirculation has received much attention as a means to increase fuel utilization, this problem is not thoroughly addressed. To overcome this limitation, this paper proposes a novel SOFC system concept featuring anode off-gas “dual” recirculation, designed to maximize fuel utilization up to the theoretical limit of 100%. This innovative approach inherently eliminates carbon dioxide emissions through an integrated carbon capture process, thereby maintaining systematic carbon balance. A comparative analysis among the novel dual recirculation system, traditional single-pass, and other anode off-gas recirculation systems, reveals that the proposed system outperforms existing configurations. It achieves electrical and overall combined heat and power efficiencies of 49.6% and 85.7%, respectively, even after accounting for the energy required for carbon capture. This represents a 21.5% increase in electric efficiency over the single recirculation system, with a six-fold increase in tail-gas CO2 concentration, reaching 26.3%. The study categorizes the four analyzed systems into “open” or “closed” based on whether the anode off-gas is directly discharged into the environment. Systematic investigations into carbon deposition potential, fuel utilization, flow rate, operating voltage, carbon capture ratio, and condensation temperature disclose distinct patterns between open and closed systems. The closed configurations exhibit superior performance, suggesting they are more suitable for SOFC applications.

Integrated Carbon Capture and Utilization in the Cement Industry: A Comparative Study

Integrated Carbon Capture and Utilization in the Cement Industry: A Comparative Study

Optimal Scheduling Considering Carbon Capture and Demand Response under Uncertain Output Scenarios for Wind Energy

In light of the uncertainties associated with renewable energy sources like wind and photovoltaics, this study aims to progressively increase their proportion in the energy mix. This is achieved by integrating carbon capture devices into traditional thermal power plants and enhancing demand-side management measures, thereby advancing low-carbon objectives in the energy and electricity sectors. Initially, the research proposes utilizing the K-means clustering algorithm to consolidate and forecast the fluctuating outputs of renewable energies such as wind and photovoltaics. Further, it entails a comprehensive analysis of low-carbon resources on both the supply and demand sides of the electricity system. This includes installing carbon storage and power-to-gas facilities in carbon capture plants to create a versatile operating model that can be synchronized with wind power systems. Additionally, the limitations of carbon capture plants are addressed by mobilizing demand-side response resources and enhancing the system’s low-carbon performance through the coordinated optimization of supply and demand resources. Ultimately, this study develops an integrated energy system model for low-carbon optimal operation, aimed at minimizing equipment investment, carbon emission costs, and operational and maintenance expenses. This model focuses on optimizing the load and supply distribution plans of the electrical system and addressing issues of load shedding and the curtailment of wind and solar power. Validation through three typical scenarios demonstrates that the proposed scheduling method effectively utilizes adjustable resources in the power system to achieve the goal of low-carbon economic dispatch.

Integrated carbon capture and CO production from bicarbonates through bipolar membrane electrolysis

Bicarbonate electrolysis with integrated carbon capture (BE-ICC) enables direct conversion of a carbon capture solution.

Effects of Ni loading and Ce doping on a CaO-based dual function material for integrated carbon capture and in situ methanation

A Ni/CeNiCa dual-function material featuring a Ce promoter and Ni pre-doping shows an impressive CO2 capture capacity and in situ CH4 production.

A minireview on electrochemical CO2 conversion based on carbonate/bicarbonate media

(Bi)Carbonate electrochemical conversion has emerged as a promising technology. Studies on mechanisms, along with latest progress in catalyst design and working electrode optimization. are summarized. Challenges and opportunities are also discussed.

Unravelling the effect of H2O and O2 in flue gas on Integrated carbon capture and dry reforming of methane

Integrated carbon capture and utilization by dry reforming of methane (ICCU-DRM) is an efficient technology for concentrating and utilizing diluted CO2 from flue gas. Significant progresses have been made in developing efficient adsorption-catalytic dual functional materials (DFMs) for ICCU-DRM. However, reaction characteristics are mainly obtained under the idealized flue gas, disregarding the presence of H2O and O2 in industrial flue gases, which may lead to notable distinctions on ICCU-DRM reactions. Herein, reaction characteristics of ICCU-DRM with the presence of single steam or O2 and their coexistence in flue gas are comprehensively investigated using a Ni-CaO DFM. Results show that steam promotes the cladding effect of CaO on catalyst, resulting in the delay of in-situ DRM. Meanwhile, the oxidation of DFM by O2 deactivates the catalyst in DFM, and the increase of O2 concentration in flue gas leads to an aggravated deactivation. With the presence of both steam and O2 in the flue gas, the delayed in-situ DRM is intensified, and O2 dominates the negative effect.

Simple marble dust for integrated carbon capture and utilization with simulated flue gas containing oxygen and water

Marble dust is a low-cost, robust, and environmentally friendly natural material for integrated carbon capture and utilization (ICCU). This study demonstrates the effect of oxygen and water in the flue gas on the ICCU performance of marble dust when it is integrated with reverse water gas shift reaction (RWGS), which could potentially be scaled up for the application of marble dust. The inclusion of water vapor in flue gas augmented the capture ability of calcined marble (CM) to eliminate 12.8 mmol g−1 CO2 from flue gas and achieved the highest CO yield of 10.2 mmol g−1 with almost 100 % CO selectivity. The introduction of O2, despite lowering CO2 capture efficiency, retained the pore structure of CM, boosting a lasting CO producing. With inert MgO as a stabilizer in CM, the segregation between two-layered CaO and MgO crystalline structure alleviated the sintering and carbon deposition, enhanced diffusion and retained superior structural stability over consecutive cycles than raw CaO.

First principle-based rate equation theory for the carbonation kinetics of CaO with CO2 in calcium looping

Calcium oxide (CaO), a CO2 sorbent and key ingredient in the process of making cement, exhibits excellent potential for carbon capture, utilization, and storage (CCUS) applications through calcium looping and integrated carbon capture and utilization, owing to its outstanding kinetic properties and high recyclability. From a fundamental standpoint, it is important to establish a comprehensive and precise carbonation kinetic model for CaO. In the present study, a density functional theory (DFT)-based rate equation was developed to predict the gas–solid reaction kinetics of CaO carbonation with CO2 in calcium looping. The reaction pathway of CaO carbonation, including surface reactions and structural transformations, was obtained by a transition state search of DFT calculations, and the transition state theory was used to calculate the reaction rate constants. The nucleation model was implemented in the mean-field surface reaction model to describe the nucleation of the CaCO3 product at the gas–solid interface. A grain model was developed to couple the surface reaction and CO2 diffusion through the product layer. The developed theory was validated using a wide range of experimental data, and the negative activation energy of CaO carbonation close to equilibrium was accurately predicted. The developed first principle-based rate equation provides a detailed theoretical framework for predicting CaO performance and optimizing the microstructure of Ca-based sorbents.

Techno-economic analysis on CO2 mitigation by integrated carbon capture and methanation

Carbon capture and utilization (CCU) by methanation combines CO2 capture and Power-to-Gas (PtG) routes, and could simultaneously realize excess clean energy storage and industrial flue gas carbon mitigation. However, a problem of large energy consumption is associated with the long-chain CCU-methanation process. In contrast, integrated carbon capture and utilization (ICCU) could largely reduce energy consumption by integrating CO2 capture and methanation in just one reaction device. Although progressive work has been done on the development of ICCU-methanation, it still lacks of quantitative evaluation on the energy consumption and production cost. Herein, techno-economic analysis is conducted on calcium looping-based ICCU-methanation and the reference CCU-methanation. Results show that ICCU-methanation only requires 1/3 coal consumed by CCU-methanation to complete carbon capture of a 1000 MWe coal-fired power plant. When waste heat recovery is considered, the plant equipped with ICCU releases 83.6 kg CO2 per 1 MWe h−1 of electricity comparing to 148.93 kg of CCU. Meanwhile, CH4 cost by ICCU scheme is 837.1 € t−1, much lower than the 962.86 € t−1 of CCU. After taking the recovery of waste heat and carbon tax into account, the cost of CH4 produced by ICCU becomes to be 443.26 € t−1, approaching the market price of natural gas (429 € t−1), showing a promising application perspective.

An experimental and kinetic modeling study of CO2 hydrogenation to CO over Cu-Al catalyst utilizing MFB-TGA-MS

Carbon capture, utilization, and storage (CCUS) are essential technologies for realizing carbon neutrality in the context of fossil fuel decarbonization. Integrated carbon capture and utilization, in conjunction with the reverse water gas shift reaction (ICCU-RWGS), presents a promising strategy for the in-situ conversion of CO2. This approach mitigates the energy penalties associated with CO2 capture and eliminates the additional costs associated with storage and transportation. In this study, we employed a Cu-Al composite catalyst, prepared using the impregnation method, for ICCU-RWGS, with a specific focus on CO2 hydrogenation. The kinetics of hydrogenation for the Cu-Al catalyst were comprehensively investigated using micro-fluidized bed thermogravimetric analysis coupled with mass spectrometry (MFB-TGA-MS). The results indicate that, when subjected to experimental conditions involving 800 °C, 20 vol.% CO2, 30 vol.% H2, and a sample mass of 1 g, the comprehensive evaluation reveals a CO2 conversion rate of 43.67 %. This conversion is accompanied by 100 % CO selectivity and a reaction rate of 0.10 mmol·g−1·s−1, respectively. Furthermore, we calculated the kinetic parameters for the CO2 hydrogenation by analyzing the MFB-TGA-MS data, utilizing the simplified K-L model for fluidized beds. The results indicated an activation energy of 55.8 kJ∙mol−1. These findings highlight the effectiveness of ICCU-RWGS methodologies, especially concerning CO2 hydrogenation, and present a compelling case for their further commercialization.

Exploring carbon sequestration potential through 3D concrete printing

ABSTRACT As global CO2 concentrations rise, there is a pressing need for sustainable alternatives in the construction sector as many countries are striving to attain net carbon neutrality. Integrating carbon capture and sequestration (CCS) technologies directly into 3D concrete printing offer a promising solution to reduce the carbon footprint in the construction sector. This paper investigates a novel printing technique involving the purging of pressurised CO2 gas was demonstrated and the various process parameters were evaluated for its effectiveness in promoting carbon sequestration. Results show that the carbon-sequestrated sample has a 15% increase in carbon uptake as compared to the control sample. The method can be complementary to existing sequestration technologies, facilitating large-scale carbon sequestration without chamber size limitations. Nevertheless, further research and development are necessary to optimise the various printing parameters and achieve a more balanced and efficient integration of carbon capture and sequestration technologies with 3DCP.

Conceptual design and assessment of Integrated capture and methanation of CO2 from flue gas using chemical-looping scheme of dual function materials

Integrated Carbon Capture and Methanation (ICCM) with renewable hydrogen is considered a promising Power-to-Gas technology. Although ICCM is expected to reduced CO2 emission, the potentials of net CO2 reduction and economic feasibility are still unrevealed by careful assessments. This study developed three ICCM processes at industrial scale, and performed an assessment in terms of energy conversion efficiency, comprehensive energy consumption, net CO2 emission, and levelized cost of CO2 conversion. Special attentions were paid to investigate the effects from electricity and hydrogen sources, and plant configuration on the technical, environmental, and economic feasibilities. This work also identified the opportunities and challenges as operation pressure, SNG price, and carbon tax are consideredthe primary factors. A comparison was made between ICCM processes and the reference process that combines CO2 capture with aqueous solutions and CO2 catalytic hydrogenation for CH4 fuels. 89.0 % of energy conversion efficiency could be achieved with ICCM processes, much higher than that of reference process. When ICCM processes are driven by renewable energy, the best comprehensive energy consumption is estimated to be –20.68 MJ/kg CO2; negative CO2 emissions could be easily achieved for ICCM processes, and the best net CO2 emissions is –1.57 kg CO2/kg CO2 when powered by wind energy, demonstrating the technical and environmental feasibility as ICCM process is coupled with renewable energy. The levelized costs of CO2 conversion are in the range of 0.98–2.0 US$/kg CO2. The economic feasibility of ICCM process is primarily limited by H2 production cost. But the levelized costs of CO2 conversion decreases rapidly with H2 production cost, and the ICCM processes could become profitable if the cost of H2 production from renewable energy drops to the same level of coal-based hydrogen (<1.4 US$/kg H2). It is possible for European Union to deploy ICCM plants to bring economic revenues because of its high SNG price and carbon tax.