Carbon Capture Process Research Articles

Heat integration, process design and techno-economic assessment of post-combustion carbon capture using piperazine for large-scale ethylene plant

With the development of increasingly larger ethylene plants and the associated requirement to reduce carbon emissions effectively, there is a growing need to explore approaches that reduce the cost and energy consumption in carbon capture from ethylene plants. In this study, the flue gas heat recovery (FHR) strategy was proposed and implemented for different configurations of piperazine (PZ)-based post-combustion carbon capture (PCC) process applied to an ethylene plant with a capacity of 60,000 t/year. Four different cases of the PZ-based PCC process with or without FHR were simulated in Aspen Plus® V11 to explore the cost reductions and energy saving potential. The advanced flash stripper (AFS) configuration with FHR and absorber inter-cooling achieves a minimum regeneration energy requirement of 2.28 GJ/tonCO2, a reduction of 37.71 % compared to standard PCC configuration using MEA solvent. The economic evaluation was carried out using Aspen Process Economic Analyzer® (APEA). The results show that the carbon capture cost using AFS configuration with FHR and inter-cooling can reduce to 47.27 $/tonCO2, a reduction of 36.76 % against the standard PCC process using MEA. The proposed technology presents significant technical and economic benefits for the large-scale deployment of carbon capture for ethylene plants.

Energetic–Environmental–Economic Assessment of Integrated Different Carbon Capture and Compression Processes for High CO2 Concentration Gas

Energetic–Environmental–Economic Assessment of Integrated Different Carbon Capture and Compression Processes for High CO₂ Concentration Gas

A CFD study on ultrasound-enhanced CFB riser with calcium oxide and activated coal for CO2 capture application

This numerical study explores techniques for optimizing fluidization in circulating fluidized beds (CFB), which are of significant industrial interest. Various intrusive and non-intrusive approaches have been investigated to mitigate issues such as cluster formation, core-annulus profiles, and solid back-mixing. Specifically, this research focuses on non-intrusive methods, employing ultrasonic waves to enhance solids distribution within a CFB riser by Computational Fluid Dynamics (CFD) simulations. Particulate phases, including calcium oxide and activated carbon particles, were studied alongside a gas phase of air with a 10 % carbon dioxide concentration, commonly encountered in carbon capture processes. A radial ultrasonic device featuring 20 transducers at 20 kHz and 40 kHz was affixed to the CFB to disperse particle flow. Numerical experiments within a 3-D CFD domain employed the URANS-k-ε-KTGF-EMMS mathematical model. Findings reveal that ultrasonic waves significantly influence particle motion, modifying riser flow profiles and enhancing solids distribution. While ultrasounds increase pressure drop within the transducers' region, they decrease it above, reshaping the flow profile for both particle types. Distinct outcomes are observed for calcium oxide and coal particles regarding the radial Péclet number and solids volume fraction dispersion coefficient, suggesting that ultrasounds effectively improve coal particle distribution along the riser's height.

Chemical Looping Strategy in Various Types of Carbon Capture Technologies

Considering the worsening of global warming, development of efficient strategies in carbon capture process is essential. The chemical looping process (CLP) is considered a promising method applicable in various carbon capture strategies. In pre-, post-, or oxy-fuel combustion strategies, the efficiency of CLP has been explored and tested. This review discusses the applied CLP in each type of carbon capture strategy. Chemical looping gasification and reforming are categorized in the pre-combustion system. On the other hand, the popularity of calcium looping and amine looping are recognized as post-combustion strategies. Additionally, numerous oxygen carrier materials have been determined to reach high efficiency in oxy-fuel combustion. The review of the characters and the principle of the method was complemented by justification for real-scale application. Nonetheless, the popularity of CLP’s real implementation as a carbon capture strategy was still limited by several factors, including required cost for the facilities and energy demand. Thus, analysis on the prospect of CLP utilization was also included in this study.

Autocatalysis and CO2: Carbon Capture and Utilization (CCU) Meets Natural Processes

AbstractAutocatalytic reactions were proposed to play a key role at the beginning of life starting from the first reduction of CO2 to formate, acetate and C1−C4 hydrocarbons. In carbon capture and utilization (CCU) processes, the same reactions were demonstrated to be autocatalytic and, in some cases, promoted by catalysts of the same composition. Through evolution, CO2 reduction then turned into complex autocatalytic networks such as photosynthesis, where CCU chemists found inspiration for the development of more advanced systems for the synthesis of value‐added chemicals. Less evolved systems than photosynthesis, however, may be easier to emulate and provide valuable inspiration into CO2 reduction chemistry for CCU. Other synthetic systems were also demonstrated to be autocatalytic demonstrating that CO2 reactions and autocatalysis are closely connected. In this concept article, the relationship between natural, artificial and bio‐inspired autocatalytic CO2 reduction processes is summarized and discussed. The accomplishments resulting from the integration of autocatalysis and CCU strategies, along with their inherent benefits and future prospectives are also outlined.

Green hydrogen production and utilization in a novel SOFC/GT-based zero-carbon cogeneration system: A thermodynamic evaluation

Owing to the rise in global energy demand and environmental issues caused by energy supply and distribution, the attempt to design and develop novel eco-friendly and efficient cogeneration energy systems is one of the current research focuses. In this regard, this study presents a novel zero-carbon cogeneration energy system based on a pressurized solid oxide fuel cell-gas turbine (SOFC/GT) with a carbon capture and storage (CCS) process. The designed system accomplishes the joint production of energy (electricity, cooling, and heating) and matter (hydrogen, oxygen, condensate water recovery, and carbon dioxide). The proposed system also includes an advanced alkaline electrolyzer (AAE) system, an organic Rankine cycle, a LiBr-H2O absorption refrigeration cycle, and an LNG regasification cycle. A combination of a solar concentrated photovoltaic/thermal (CPV/T) system and wind turbines feed the AAE system, resulting in green hydrogen production. According to the simulation results, the suggested system under the design conditions generates power, cooling, and domestic hot water with 315 kW, 137.5 kW, and 1.012 kg/s, respectively. Also, this system can capture and store carbon dioxide, recover condensate water, and supply natural gas to the pipeline with values of 74.88 kg/h, 137.9 kg/h, and 624.24 kg/h, respectively. The results from thermodynamic analysis indicate that the CPV/T system has the highest contribution to the exergy destruction rate, and the presented cogeneration system operates with energy and exergy efficiency of 58.09% and 38.58%, respectively. Furthermore, a comprehensive parametric study has been conducted on the developed system in which the impact of important parameters, such as SOFC operating temperature, current density, solar radiation, air velocity, etc., on the output parameters of the system has been examined.

Metal oxide and nitrate-modified calcium gluconate-based sorbent with high stability for integrated carbon capture and utilization process

In this study, metal oxides (MgO, CeO2, and Al2O3) and metal nitrates (Mn(NO3)2, Al(NO3)3, Mg(NO3)2, and Fe(NO3)3) were used to modify calcium gluconate-based sorbents for the integrated CO2 capture and utilization (ICCU) process. We employed conventional thermogravimetric analysis (TGA) and microfluidized bed thermogravimetric analysis coupled with mass spectrometry (MFB-TGA-MS) to explore the cyclic CO2 capture behavior, physical and chemical properties, and morphology in detail. Our findings reveal that calcium gluconate modified with aluminum nitrate (CG-Al-N) exhibited superior CO2 capture capacity (9.81 mmol∙g−1 over 20 cycles), along with a high surface area (35.67 m2∙g−1) and pore volume (0.16 cm3∙g−1). In comparison, pure calcium gluconate displayed a capacity of 7.09 mmol∙g−1, a surface area of 27.66 m2∙g−1, and a pore volume of 0.06 cm3∙g−1, while commercial calcium oxide demonstrated 1.96 mmol∙g−1, 4.62 m2∙g−1, and 0.01 cm3∙g−1, respectively. Notably, after 100 cycles, CG-Al-N retained a CO2 capture capacity of 11.75 mmol∙g−1, achieving 66% of the capacity of the pure CaO sorbent. This observation strongly suggests that CG-Al-N has excellent anti-sintering properties. Furthermore, data was acquired under fluidized and isothermal conditions by utilizing MFB-TGA-MS. CG-Al-N consistently exhibited an average CO2 capture capacity (9.57 mmol∙g−1), CO yield (5.00 mmol∙g−1), and CO selectivity (∼100%) over 20 ICCU cycles, with the dominant route being the reverse water–gas shift (RWGS) reaction, highlighting the self-catalytic activity of gluconate-based sorbents. Morphological evolution also revealed finer pores and a skeleton structure of cycled CG-Al-N, which affirms the unobstructed gas entry and ensures a continuous gas–solid reaction.

The impact of thermal transport on reactive THMC model for carbon capture and storage

Addressing current limitations in Thermo-Hydro-Mechanical-Chemical (THMC) models is crucial for accurately simulating complex physical and chemical interactions in carbon capture and storage (CCS) processes. This paper presents a new fully coupled THMC model, specifically focusing on investigating thermo-chemo coupling (dissolution) effects for CCS applications. The model is a further extension of the mixture coupling theory, which incorporates entropy and mass balance equations, phenomenological equations, and Maxwell's relations to describe the intricate coupling between mechanical, hydraulic, chemical, and thermal properties. The model considers a two-phase flow, liquid and supercritical. By deriving new coupling terms from the phenomenological equations, the model provides capacity to account for energy losses due to friction between the two phases, along with energy losses arising from the transport of the solute and the evolution of porosity/permeability. Furthermore, the model incorporates an additional coupling term in the mechanical equation to represent the chemical dissolution effect on volumetric strain relief. Two terms added in the liquid equation account for the friction of newly dissolved minerals particles on liquid transport and the effects of porosity changes on liquid flow through dissolution. Finally, Thermal transport coupling is integrated into the model, as it is a crucial part of CCS applications. Numerical results demonstrate that increasing temperature significantly decreases porosity due to thermal expansion, but thermal energy triggers chemical dissolution which in the long run increases both porosity and permeability. Chemical dissolution has the most significant incremental effect on porosity over time, while thermal expansion has the greatest impact until thermal equilibrium is reached, with the direct impacts of pressure and strain on porosity falling in between. This research presents a comprehensive coupling framework that accounts for two-phase friction, the dissolution process, and changing permeability, which gives it potential utility in the planning process for CCS applications.

Organic-inorganic composite membrane-based transport membrane condenser: Performance of waste recovery from hot gas mixture of CO2 and water vapor

Recovering the waste heat from the stripped gas (i.e., the gas mixture of CO2 and water vapor) using the transport membrane condenser is an effective approach to reduce the regeneration heat consumption in CO2 chemical absorption process. To decrease the capital expenditure of transport membrane condenser, this study prepared an inexpensive organic–inorganic composite membrane through adding the hydroxylated boron nitride (BN-OH) into the polyvinylidene fluoride (PVDF) during membrane preparation via nonsolvent induced phase separation. Then the composite membrane was placed in a membrane cell as the transport membrane condenser to recovery the waste heat of simulated stripped gas. The results showed that when compared to the single PVDF membrane, the addition of BN-OH improves the pore uniformity, thermal conductivity, and porosity of membrane. Among all the prepared composite membranes, the composite membrane adding 5 wt% nano-sized BN-OH particles exhibits the best waste heat recovery performance. Furthermore, a decrease in the membrane thickness in addition to an increase in polyvinylpyrrolidone dosage during membrane preparation enhances the waste heat recovery performance, however deteriorates the mechanical strength of membrane. Moreover, the organic–inorganic composite membrane prepared in this study demonstrated a good stability of waste heat recovery performance during a long-term operation, showing a potential in the rich solvent-split modified carbon capture process to achieve a low capital expenditure and a high waste heat recovery performance.

An Optimal Operation Strategy for Collaborative Flexibility Provision of a Carbon Capture and Utilization Process With Wind Energy

Improving power system flexibility by responsive demand is essential for integrating wind energy with a high level of variability in power systems. Carbon dioxide-based chemical processes as energy-intensive industrial loads may offer a vast potential of new forms of flexible operation due to their existing control infrastructure and storage capabilities. However, a collaborative decision model is needed for optimal energy sharing among the chemical plant and the grid under the variations and uncertainties of wind power. This study develops an optimal two-stage stochastic programming model for a novel flexible operation strategy of the chemical process coupled with wind turbines. In the proposed control scheme, a small-scale wind farm provides the power input of a chemical plant. Wind turbines are connected to the grid and actively participate in the day-ahead energy and reserve markets, considering the chemical plant as a source of flexibility. An equivalent scenario-based model of the proposed optimization problem is suggested using the Group Method of Data Handling (GMDH) for a data-driven prediction of stochastic variables. Simulation results demonstrate the effectiveness and significance of the proposed approach for an optimal and collaborative contribution in ancillary market of a carbon dioxide-based chemical plant supplied by wind energy.

Electrifying Carbon Capture by Developing Nanomaterials at the Interface of Molecular and Process Engineering.

ConspectusCarbon capture is an indispensable step toward closing the anthropogenic carbon cycle. However, the large-scale implementation of conventional thermochemical carbon capture technologies is hindered by their low energy efficiency, limited sorbent stability, and complexity in infrastructure integration. A mechanistically different alternative, commonly known as electrochemically mediated carbon capture (EMCC), has garnered increasing research traction over the past few years and relies on electrochemical stimuli instead of thermal or pressure swings for the capture and release of carbon dioxide (CO2). Compared to conventional methods, EMCC can be operated under mild conditions driven by intermittent renewable energy sources and has a flexible design to meet the multiscale demands of carbon capture, offering a potentially sustainable, energy-efficient, and cost-effective solution to CO2 concentration from dilute mixtures or the ambient environment.Nanomaterials have played a crucial role in carbon capture research. For instance, nanoporous materials can provide increased free volumes, surface areas, and active sites for carbon capture through physical or chemical adsorption from the gaseous phase. In contrast, EMCC relies on chemical absorption via acid-base interactions using solubilized CO2 in electrolytes. Therefore, most EMCC sorbents and mediators explored so far have been developed as molecules rather than nanomaterials. In recent years, our team has been focusing on electrifying the carbon capture processes at the molecular, materials, and process levels. We seek to address the most pressing issues associated with EMCC, either in fixed-bed or flow systems, that prevent their practical use. These issues include parasitic reactions with molecular oxygen, insufficient electrode capacity utilization, sorbent crossover, etc. To address these problems, there is an urgent need to develop rationally designed nanomaterials at the interface of molecular electrochemistry and device engineering. This Account provides an overview of recent progress on developing new chemistries and engineering batch/continuous processes for EMCC. We discuss the limitations of current EMCC technology and emphasize why nanomaterials are critical for electrifying carbon capture. First, we introduce the design principles for EMCC sorbents based on redox-active organic CO2 carriers and discuss metrics for their performance evaluation. Second, we showcase how molecular design can tackle problems of sorbent solubility, oxygen stability, and electrolyte compatibility in EMCC. Third, we discuss the early results of nanomaterials as solid sorbents in fixed-bed systems, nonswelling membranes for flow systems, and high-surface-area gas-liquid contactors. Finally, building on the foundation we established through our prior work, we offer perspectives on future directions for nanomaterials to help address the challenges in EMCC.

CO2 Adsorption on Biomass-Derived Carbons from Albizia procera Leaves: Effects of Synthesis Strategies.

CO2 capture is a useful strategy for controlling the risks associated with global warming. The design of an adsorbent is essential for clean and potentially energy-efficient adsorption-based carbon capture processes. This study reports a facile and moderately temperature single-stage combined pyrolysis and activation strategy for the synthesis of nitrogen-doped carbons for high-performance CO2 capture. Using nitrogen-rich Albizia procera leaves as the precursor and carrying out single-stage pyrolysis and activation at temperatures of 500, 600, and 700 °C in the presence NaHCO3 as an activating agent, carbons with different surface characteristics and ultrahigh weight percentage (22-25%) of nitrogen were obtained. The subtle differences in surface characteristics and nitrogen content had a bearing on the CO2 adsorption performance of the resultant adsorbents. Outstanding results were achieved, with a CO2 adsorption capacity of up to 2.5 mmol/g and a CO2 over N2 selectivities reaching 54. The isotherm results were utilized to determine the performance indicators for a practical vacuum swing adsorption process. This study provides a practical strategy for the efficient synthesis of nitrogen-doped carbons for various adsorption applications.

Process design and energy analysis on synthesis of liquid fuels in an integrated CCUS system

Under the high attention of the international community to CO2 emissions, the capture utilization and storage (CCUS) and the CO2 hydrogenation fuel production have become two popular directions, especially for the combination of the two processes. In this paper, the production of liquid fuels via the methanol synthesis pathway in an integrated CCUS system based on Aspen Plus models was studied. The NH3-CO2-H2O absorption was used to capture CO2 and hydrogen was provided by water electrolysis using renewable energy sources. A two-stage reactor with a recirculating stream was specified for the process of CO2 hydrogenation to synthesize methanol, and the liquid fuel dimethyl ether (DME) was reproduced by dehydrating methanol (Power-to-Liquid). The amount of absorbent used for the carbon capture process was determined and the yield differences due to the number of cycles in the intermediate methanol synthesis reaction were analyzed. It is possible to convert 4.15 t of CO2 per tonne of DME produced at the mass material balance of the process. The optimization of the heat exchange network and the energy requirements for the total process were evaluated. It is calculated that the energy involved in producing 1 ton of DME in the process model is 176 GJ. The analysis of the overall process and the evaluation of models could provide options for the possibility of CCUS engineering application.

Comparative techno-economic analysis of CO2 capture processes using blended amines

Blended amines synthesize the absorption characteristics of different amine solvents and show a great potential in carbon capture. However, a comprehensive techno-economic analysis (TEA) of the CO2 absorption process using blended amines is still lacking. In this study, we investigated three blended amine solvents: MEA/MDEA, PZ/MEA, and PZ/MDEA, with commercially available amine MEA used as the benchmark. Rigorous process simulation and techno-economic analysis were applied to evaluate the performance of the carbon capture process in a steel plant. CO2 molar loading in the lean solvent (αlean) and stripper pressure (P) were optimized to minimize the total annualized cost (TAC). The results demonstrated that PZ/MDEA-based process is most cost-effective (31.43$/tCO2) under the operating conditions of αlean = 0.15 and P = 1.25 bar. The cost breakdown analysis revealed that αlean and P significantly impact the TAC through the regeneration heat, equipment investment, and amines make-up cost. Furthermore, the energy analysis indicated that using a solvent with a low reaction enthalpy and heat capacity as well as high reactivity and absorption capacity could minimize the energy consumption of the process.

Probing pH-Dependent Dehydration Dynamics of Mg and Ca Cations in Aqueous Solutions with Multi-Level Quantum Mechanics/Molecular Dynamics Simulations.

The dehydration of aqueous calcium and magnesium cations is the most fundamental process controlling their reactivity in chemical and biological phenomena, such as the formation of ionic solids or passing through ion channels. It holds particular relevance in light of recent advancements in the development of carbon capture techniques that rely on mineralization for long-term carbon storage. Specifically, dehydration of Ca2+ and Mg2+ is a key step in proposed carbon capture processes aiming to exploit the relatively high concentration of dissolved carbon dioxide in seawater via the formation of carbonate minerals from solvated Ca2+ and Mg2+ cations for sequestration and storage. Nevertheless, atomic-scale understanding of the dehydration of aqueous Ca2+ and Mg2+ cations remains limited. Here, we utilize rare event sampling via density functional theory molecular dynamics and embedded wavefunction theory calculations to elucidate the dehydration dynamics of aqueous Ca2+ and Mg2+. Emphasis is placed on the investigation of the effect pH has on the stability of the different coordination environments. Our results reveal significant differences in the dehydration dynamics of the two cations and provide insight into how they may be modulated by pH changes.

Carbon capture from combined heat and power plants – Impact on the supply and cost of electricity and district heating in cities

The capture and storage of biogenic CO2 emissions from large point sources, such as biomass-combusting combined heat and power (CHP) plants, can contribute to climate change mitigation and provide carbon-negative electricity while supplying district heating in urban areas. This work investigates the impact of retrofitting CO2 capture processes to CHP plants in a city energy system context. An energy system optimization model is applied to a case study of the city Västerås, Sweden, with scenarios involving two existing CHP plants in the city, retrofitted with either a heat-driven (MEA) or an electricity-driven (HPC) carbon capture process. The results show that the CHP plants might be retrofitted with either option without significantly impacting the district heating system operation or the marginal costs of electricity and district heating in the city. The MEA process mainly causes a reduction in district heating output (up to 30% decrease on an annual basis), which can be offset by heat recovery from the capture unit. The electrified HPC process does not impact the CHP plant steam cycle but implies increased import of electricity to the city (up to 44% increase annually) compared to a reference scenario.

Application of post-combustion carbon capture process in marine diesel engine

ABSTRACT This study has investigated the effect of using a waste heat recovery system and carbon capture process on carbon reduction efficiency and the Energy Efficiency Design Index (EEDI) to reduce carbon emissions from ships. Organic Rankine Cycle (ORC) was used as waste heat recovery and ORC system turbine power was determined at variable engine loads. The effect of system parameters such as exhaust absorber inlet temperature, MEA concentration and flow rate, number of columns on carbon capture performance has been revealed in the carbon capture process. Furthermore, the EEDI was estimated using the existing system, the ORC system configuration, and the utilization of the carbon capture system. It has been determined that the optimal exhaust absorber inlet temperature is 50°C and the carbon capture performance is 95% on average. In the applied system, the EEDI is reduced by 14% with the ORC system and by 90% with the carbon capture system. ORC system turbine output power ranges from approximately 414 kW to 606 kW for variable CCS inlet temperatures for 100% load condition. Thus, the study predicts that the carbon capture system can effectively meet the regulations in case of using fossil fuels in the future.

Scalable Membrane-Free Electrolyzers for Electrochemical CO2 Conversion

Bicarbonate electrolysis offers an attractive approach to conducting electrochemical carbon dioxide (CO2) conversion within the same working fluid used in commonly considered carbon capture processes. However, conventional membrane-based electrolyzers face significant challenges related to scale-up, durability, and CO2 utilization. Here, we present a scalable packed bed membraneless electrolyzer (PBME) design for which liquid bicarbonate electrolyte flows sequentially through alternating porous flow-through anodes and cathodes. Within this design, hydrogen oxidation at porous anodes is used to produce protons that trigger in situ CO2 release immediately upstream of porous cathodes, where electrochemical CO2 reduction generates the desired product and returns the solution pH back towards its inlet value. By using the sequential flow-cell arrangement, the PBME offers the ability to mitigate large concentration overpotentials and non-uniform current distributions that naturally arise during scale-up of conventional membrane-based electrolyzers that rely on lateral flow of catholyte parallel to the surface of the electrodes. This study uses in situ colorimetric imaging to highlight the ability of PBME to rebalance pH across adjacent electrodes. In addition, results obtained with a multi-cell PBME demonstrate the scalability of this concept and reveal the ability to increase CO2 utilization from 12.9% for a single-cell PBME up to 20.5% for a four-cell PBME operated under baseline conditions. With operating the PBME at elevated pressure, the performance can be further improved by increasing the concentration of CO2 in the dissolved phase, which results in higher CO partial current density.

(Invited) Electro-Swing Adsorption for CO2 Emissions Mitigation – from Concept to Start-up

The increasingly devastating effects of changing climate patterns can be attributed largely to global warming through the continuing accumulation in the environment of anthropogenic greenhouse gases such as carbon dioxide. While reduction of CO2 emissions at relatively concentrated (4-20%) point sources is a crucial component of mitigation strategies for the abatement of the CO2 impact on global temperature rise, it has become increasingly evident that direct removal of accumulated CO2 (at 420ppm, 0.042%) from the environment will also be needed if we wish to limit the global temperature rise by the turn of the century to less that 2°C. Legacy carbon capture processes rely on thermal swings, with elevated temperatures required to break the chemical bonds formed during the cooler capture stage to liberate the CO2 as a pure product stream and regenerate the sorbent. There has recently been a surge of interest in using electrochemically mediated processes for carbon capture and release which can be operated isothermally, are modular, with easy scale out, and can be installed without need for complex heat integration processes. Moreover, they can use renewable and other non-carbon energy resources.In this presentation, we will trace the development of an electrochemical swing adsorption approach for the capture of CO2, originally conceived in 2015, through to the incorporation of a start-up, Verdox, in 2019 to exploit the technology in both point source and direct air capture applications. This approach exploits the ability of certain redox species, such as quinones, to bind strongly with CO2 when in a reduced state, but which have no affinity for the acid gas when oxidized. The activation by reduction and subsequent de-activation by oxidation of the capture agent can be achieved electrochemically with the redox species either in solution or immobilized on electrode surfaces; it is this latter strategy that we will discuss here. The challenges in electrode development, including the identification and economical synthesis of appropriate redox species for the binding of the CO2, and enhancement of chemical and physical robustness with acceptable uptake kinetics, will be discussed, with projections on the future introduction to industrial applications.

Isotherm modeling and techno-economic analysis of a TSA moving bed process using a tetraamine-appended MOF for NGCC applications

Tetraamine-appended metal-organic frameworks (MOF) are a new family of amine-functionalized MOF materials that show potential for CO2 capture from flue gas conditions relevant to natural gas combined cycle (NGCC) power plants. This work presents isotherm modeling of the tetraamine-appended MOF Mg2(dobpdc)(3-4-3)(dobpdc4−=4,4′-dioxidobiphenyl-3,3′dicarboxylate;3-4-3=N,N′bis(3-aminopropyl)-1,4-diaminobutane), process modeling, scale up, and a techno-economic optimization of a moving bed Temperature Swing Adsorption (TSA) process for carbon capture using this sorbent. This MOF exhibits a unique two-step CO2 adsorption profile in three different pressure ranges. Thus, arctangent-based logistic functions and, quadratic and Langmuir models were employed to represent such isotherm behavior. The results of the isotherm model show good fitting vs the experimental data with an RMSE of 0.41. To model the carbon capture process, the isotherm model was embedded into a moving bed contactor model, and this was used to simulate a TSA CO2 capture cycle and evaluate cost-optimal designs considering flue gas from a -650 MWe NGCC power plant. The capital cost model consists of CAPEX correlations for reactors, compressors, ducting, etc., while the operating costs include steam, water, chemicals, and electricity (following NETL's quality guidelines for energy systems studies). A techno-economic optimization of the capture system was performed by using NETL's Framework for the Optimization and Quantification of Uncertainty and Surrogates tool (FOQUS). Results suggest that a moving bed carbon capture system with tetraamine-appended MOF can be competitive compared to conventional MEA solvent-based capture processes for NGCC plants, when a heat recovery efficiency of at least 40% is achieved, and MOF materials can be produced at a cost below -$9/kg.