Modelling and Multi-stage Design of Membrane Processes Applied to Carbon Capture in Coal-fired Power Plants

AbstractAccording to recent predictions, energy generation from coal will continue to play a key role in the next decades. The UK 2008 Climate Change Act requires a reduction of 80% of greenhouse gases emissions by 2050, and carbon capture and storage will have a key role in order to meet this target.This work focuses on post-combustion capture from coal-fired power plants based on membrane separation. Adetailed multi-stage design is presented: the developed flowsheet includes cross-flow and countercurrent-sweep stages. The cross-flow stages are based on a 2D model implemented by our research group able to predict the separation through spiral-wound permeators. Different process configurations are analysed, with the aim of reducing both energy consumption and membrane area.An economic analysis is also included: both capture and avoidance costs are evaluated. The estimated values are compared with data available in the literature for processes based on amine capture technology

Process intensification for post combustion CO₂ capture with chemical absorption: a critical review

The concentration of CO₂ in the atmosphere is increasing rapidly. CO₂ emissions may have an impact on global climate change. Effective CO₂ emission abatement strategies such as carbon capture and storage (CCS) are required to combat this trend. Compared with pre-combustion carbon capture and oxy-fuel carbon capture approaches, post-combustion CO₂ capture (PCC) using solvent process is one of the most mature carbon capture technologies. There are two main barriers for the PCC process using solvent to be commercially deployed: (a) high capital cost; (b) high thermal efficiency penalty due to solvent regeneration. Applying process intensification (PI) technology into PCC with solvent process has the potential to significantly reduce capital costs compared with conventional technology using packed columns. This paper intends to evaluate different PI technologies for their suitability in PCC process. The study shows that rotating packed bed (RPB) absorber/stripper has attracted much interest due to its high mass transfer capability. Currently experimental studies on CO₂ capture using RPB are based on standalone absorber or stripper. Therefore a schematic process flow diagram of intensified PCC process is proposed so as to motivate other researches for possible optimal design, operation and control. To intensify heat transfer in reboiler, spinning disc technology is recommended. To replace cross heat exchanger in conventional PCC (with packed column) process, printed circuit heat exchanger will be preferred. Solvent selection for conventional PCC process has been studied extensively. However, it needs more studies for solvent selection in intensified PCC process. The authors also predicted research challenges in intensified PCC process and potential new breakthrough from different aspects

Team One Carbon Catcher Design Report

Overview The burning of fossil fuels largely contributes to the increase of CO2 in the atmosphere. The US Department of Transportation alone contributed almost 6 million metric tons of carbon dioxide emissions in 2018 (EIA). Due to this, this report proposes recycling captured CO2 into a base for cleaner burning fuel in order to reduce emissions from the transportation industry and many others, which has the potential to impact many areas. Extraction of atmospheric CO2 is possible through a membrane filtration system based on traditional nitrogen generation. The passive filtration system autonomously separates the CO2 from other air components, thereby reducing energy consumption. The system's working sensors and actuators utilize similar energy saving strategies, such as distributing cloud-computing services over multiple servers and mainframes to reduce computing power. The movement of air is directed by a scalable fan device, which is presented as a modular design to allow customization of fan parts to specific size and installation requirements. As an integrated device, Team 1’s Carbon Catcher operates with a high efficiency in order to maximize the commercial opportunity of converting captured CO2 into cleaner fuel while also reducing CO2 emissions and the greenhouse effect. Goal The goal of Team 1’s Carbon Catcher project proposal is to design a cost-effective, scalable, and modular atmospheric carbon dioxide removal system that is capable of being utilized in a range of urban environments and may fit a variety of different customer requirements or requests

An overview of current status of carbon dioxide capture and storage technologies

AbstractGlobal warming and climate change concerns have triggered global efforts to reduce the concentration of atmospheric carbon dioxide (CO2). Carbon dioxide capture and storage (CCS) is considered a crucial strategy for meeting CO2 emission reduction targets. In this paper, various aspects of CCS are reviewed and discussed including the state of the art technologies for CO2 capture, separation, transport, storage, leakage, monitoring, and life cycle analysis. The selection of specific CO2 capture technology heavily depends on the type of CO2 generating plant and fuel used. Among those CO2 separation processes, absorption is the most mature and commonly adopted due to its higher efficiency and lower cost. Pipeline is considered to be the most viable solution for large volume of CO2 transport. Among those geological formations for CO2 storage, enhanced oil recovery is mature and has been practiced for many years but its economical viability for anthropogenic sources needs to be demonstrated. There are growing interests in CO2 storage in saline aquifers due to their enormous potential storage capacity and several projects are in the pipeline for demonstration of its viability. There are multiple hurdles to CCS deployment including the absence of a clear business case for CCS investment and the absence of robust economic incentives to support the additional high capital and operating costs of the whole CCS process

Carbon Catcher Design Report

Overview. The design of the overall Carbon Catcher project can be separated into four distinct systems, each of which is assigned a specialized committee. The committee names and responsibilities are listed below: Air Mover The overall goal for the Air Mover committee is the design of the turbine assembly. As the overall goal of the project is to collect and separate carbon dioxide from the air, one of the most important parts is to actually get the air to pass through the carbon-catching membrane. Passive air would not give a significant enough yield rate to make the carbon dioxide collection rate impactful, thus air must be sucked through a vacuum/turbine. Membrane The goal of Membrain is to create a membrane that can filter out CO2 through various methods. These methods are limited, due to there being such variety, to certain techniques and membrane material types that have been decided, prior, by the committee. Most membranes will be geared towards utilizing temperature and pressure along with gaseous speed and flow rate. In addition, examining certain treatments, such as regeneration of material, and replacements will be looked into as well, to see how it fares in sustainability. Carbon Storer The Carbon Storer committee will design a store and transport system for fluid CO2 after it is extracted from the atmosphere. Primary considerations include geological solutions, cost-effective materials, and analysis methods to improve overall capacity and efficiency. Additionally, the committee will select an environmentally and economically sustainable method of recycling the captured CO2. PyControl The PyControl committee will design a series of sensors and actuators, which will primarily support the sequestration and pipeline systems present in the Carbon Storer Committee and direct air capture system in Air Mover. The design can be broken into four control layers: Input/Output, Field Controllers, Data, and Supervisory. Goal The overarching goal of Carbon Catcher is to design a cost-effective, scalable atmospheric carbon dioxide removal system that is capable of being deployed in a variety of urban environments and may fit a variety of different customer requirements or requests

Modelling and simulation of adsorption process for removal of CO2 from natural gas in an offshore platform

The presence of CO2 in natural gas causes pipeline corrosion and increases operating costs during transfer from the offshore production platforms to the storage terminal. Due to space limitation and harsh operating environment, a robust and compact process such as pressure swing adsorption is preferable. To facilitate the study of process dynamics, simulation studies based on a derived mathematical model on a MATLAB software is presented. The effect of design parameters, focusing on the column height is considered, and it is found that for a typical laboratory scaled apparatus having diameter of 0.5 m. The maximum height required to adsorb 99 % CO2 is 3 m when the feed flow rate is fixed at 2.5 m3/s. The size of adsorbent particles is also impacting separation efficiency, and the optimum particle radius is found to be 1.25x10-3 m and the bed porosity was 0.2. Sensitivity analyses on the main operating parameters are also investigated. It is found that the initial CO2 feed composition has positive relationship to the adsorption efficiency. The 0.4 mole fraction was found to have sufficient separation efficiency of 90 %. The model is also tested for representing a typical industrial operation with 120 mmscfd. In this case, for a 4 m diameter column, a column height of 20 m is required. This is achieved with a 4 bed PSA system at a flow rate of 10.05 m3/s for each, and an optimum separation of 87 % is established. Based on the results obtained in this work it can be concluded that the model is a reasonable representation of the system and can be used to obtain the necessary process insights for further process development

Simultaneous production of high-quality CO2 and CH4 via multistage process using chitosan-based membranes

The use of biopolymers as membrane materials is a recent approach for reducing the environmental impact of CO2 separation processes. By considering previous process engineering tasks, it was concluded that no membrane currently provides sufficient purity and recovery to meet the requirements for the simultaneous direct separation of CO2 and CH4 in a single stage. The aim of this study is to simulate and optimise the separation of CO2 and CH4 from different sources using a simple multistage process, considering up to three stages. A chitosan biopolymer-based composite membrane with organic (ionic liquid) and different inorganic fillers in the selective layer was used to tune the selectivity and robustness of commercially available membranes. The process configuration utilized membrane units operating in series to enrich CO2 in the product stream from the permeate line, whereas the retentate line produced a CH4-enriched stream by mixing the retentate units of each stage. The target objectives were up to 95% purity and recovery of CO2 in the permeate outlet, corresponding to a recovery of CH4 higher than 97% in the retentate outlet stream of the multistage process. The decision variables included the permeance of each component, and thus the pair selectivity (CO2/CH4) and process-related parameters, such as the stage cut of each stage. Economic evaluation of the proposed three-stage separation process was performed for different process scales, from small installations to large plants. The total costs, the contribution of each term to the total costs, and the unitary costs were estimated for each operational scale, with reference to the feed flow rate based on the plant capacity. The lowest total cost was 0.3 € (Nm3)-1 for a large plant with a flow rate of 1000 Nm3 h-1.This research was funded by the Spanish Ministry of Science and Innovation, grant number PID2019-108136RB-C31/AEI/10.13039/501100011033, and European Union Next Generation EU/PRTR, grant number EIN2020-112319/AEI/10.13039/501100011033. A.T.C. acknowledges the Ministry for the Early Stage researcher contract (FPI grant no. PRE2020-09765/AEI/10.13039/501100011033). A.T.C. also thanks to the Scientific Committee of the International Separation and Purification Technology Congress (ISPT 2022, Elsevier) for the Best Poster Award

Optimized modeling of membrane gas phase separation processes

Le schéma traditionnel d'utilisation de l'énergie est désormais considéré comme un problème sérieux en raison de sa relation directe avec le changement climatique. Actuellement, notre dépendance vis-à-vis des combustibles fossiles augmente de façon spectaculaire, ce qui peut être attribué à la croissance de la population mondiale et à la forte demande d'énergie pour le développement économique. Ce modèle semble être préférable uniquement pour une économie florissante, mais ses perspectives pour les générations futures seront sans aucun doute décevantes. Dans ce scénario, un volume gigantesque de CO₂ produit par la combustion des combustibles fossiles dans les industries chimiques, les cimenteries et les centrales électriques, est rejeté de manière irresponsable dans l'atmosphère. Il ne fait aucun doute qu'une telle exploitation des combustibles fossiles nous conduit à des catastrophes environnementales sans précédent en ce qui concerne l'émission de CO₂, qui est le principal contributeur aux gaz à effet de serre (GES). L'une des solutions disponibles pour faire face à cette situation critique est de moderniser les centrales existantes qui émettent du CO₂ avec des technologies de capture et de stockage du carbone (CSC) afin de lutter systématiquement contre le changement climatique. Toutefois, les technologies actuelles de CSC présentent encore des problèmes techniques et des limites opérationnelles qui entraînent un surcoût pour les dépenses d'une usine et une augmentation de sa consommation d'énergie. La technologie membranaire est actuellement considérée comme une méthode de séparation prometteuse pour la séparation des gaz en raison de la simplicité de son procédé et de son mécanisme écologique. Par rapport aux autres méthodes de séparation, cette technologie est encore en cours de développement. Actuellement, la recherche se concentre sur l'amélioration des caractéristiques des membranes afin de faire face à un compromis bien connu entre la perméabilité et la sélectivité décrit par les graphiques de Robeson. Cette approche pourrait viser à commercialiser cette technologie plus efficacement dans le domaine de la séparation des gaz, tandis qu'une technologie d'absorption à base d'amines sera encore utilisée de manière dominante à cette fin pendant plusieurs années. Malgré cela, il est également nécessaire d'évaluer la performance des membranes fabriquées pour la séparation de différents mélanges de gaz avant de les utiliser pour des projets industriels réalistes. Pour ce faire, un outil de simulation est nécessaire pour prédire la composition des composants gazeux dans les flux de produits du rétentat et du perméat dans différentes conditions de fonctionnement. Ainsi, au chapitre 1, un modèle fiable est développé pour la simulation de la séparation des gaz à l'aide de modules de membranes à fibres creuses. Ensuite, ce modèle permet d'identifier les propriétés requises de la membrane, ce qui permet d'obtenir des performances intéressantes pour le module. Un procédé membranaire à plusieurs étapes est nécessaire pour atteindre les spécifications du produit qui sont une pureté et une récupération élevées du CO₂ dans le cas de projets de capture du CO₂. Dans ce cas, au chapitre 2, un modèle d'optimisation est proposé pour déterminer les valeurs optimales des paramètres de fonctionnement pour chaque étape et surtout pour déterminer une disposition optimisée à différents taux de récupération tout en minimisant le coût de la capture du CO₂. Dans le chapitre 3, nous comparons les performances de séparation de la technologie membranaire et du procédé d'absorption enzymatique en effectuant plusieurs analyses technico-économiques. Cette approche vise à démontrer la viabilité technique et l'efficacité économique de ces méthodes pour la modernisation d'une centrale électrique de 600 MWe par rapport aux procédés traditionnels d'absorption à base d'amines. Enfin, au chapitre 4, un système hybride est présenté en combinant les procédés d'absorption membranaire et enzymatique pour capturer le CO₂ des gaz de combustion d'une centrale électrique de 600 MWe. Ce système hybride est ensuite évalué pour révéler la faisabilité du procédé et pour étudier les performances de séparation en partageant la capture partielle du CO₂ entre ces deux unités de séparation. Dans l'ensemble, cette thèse de doctorat contribue à tirer parti de la fusion de la technologie membranaire avec d'autres méthodes de séparation conventionnelles telles que le procédé d'absorption enzymatique pour faciliter plus rapidement son intégration industrielle et sa commercialisation sur le marché de la séparation des gaz.The traditional pattern of energy use is now regarded as a serious problem due to its direct relationship to the climate change. Currently, our dependency on fossil fuels is dramatically increasing which can be attributed to the world population growth and heavy energy demand for economic development. This model appears to be preferable only for flourishing economy but undoubtedly its outlook for the future generations will be disappointing. Under this scenario, a gigantic volume of CO₂ produced by burning the fossil fuels in chemical industries, cement manufactures, and power plants, is recklessly released in the atmosphere. Undoubtedly, such exploitation of the fossil fuels is bringing us further to unprecedented environmental disasters pertaining to the emission of CO₂ which is the major contributor to the greenhouse gases (GHGs). One of the available solutions to deal with this critical situation is to retrofit existing CO₂ emitter plants with carbon capture and storage (CCS) technologies in order to systematically combat with the climate change. However, the current CCS technologies still have technical issues and operational limitations resulting in incurring extra cost to a plant’s expenditures and increasing its energy consumption. Membrane technology is currently regarded as a promising separation method for gas separation due to its process simplicity and eco-friendly mechanism. In comparison to other separation methods, this technology is still under progress. Currently, the research focus is on the enhancement of membrane characteristics in order to deal with a well-known trade-off between permeability and selectivity described by Robeson plots. This approach might aim at commercializing this technology more efficiently in the gas separation area while an amine-based absorption technology will still be dominantly utilized for this purpose for several years. Despite this, it is also needed to evaluate the performance of fabricated membranes for the separation of different gas mixtures prior to utilizing for realistic industrial projects. To do so, a simulation tool is required to predict the composition of gas components in retentate and permeate product streams under different operating conditions. Thus, in Chapter 1, a reliable model is developed for the simulation of gas separation using hollow fiber membrane modules. Later, this model allows identifying the required membrane properties hence, resulting in module performances of interest. A multi-stage membrane process is required to hit product specifications which are high CO₂ purity and recovery in the case of CO₂ capture projects. In this case, an optimization model is proposed in Chapter 2 to determine the optimal values of operating parameters for each stage and more importantly to determine an optimized layout at different recovery rates while CO₂ capture cost is minimized. In Chapter 3, we compare the separation performance of membrane technology and the enzymatic-absorption process through performing several techno-economic analyses. This approach aims at demonstrating the technical viability and economic efficiency of these methods for retrofitting to a 600 MWe power plant compared to traditional amine-based absorption processes. Finally, a hybrid system is introduced in Chapter 4 by combining membrane and enzymatic-absorption processes to capture CO₂ from flue-gas of a 600 MWe power plant. This hybrid system is then assessed to reveal the process feasibility and to investigate separation performance through sharing partial CO₂ capture between these two separation units. Overall, this PhD thesis contributes to leverage the merge of membrane technology with other conventional separation methods such as the enzymatic-absorption process to more rapidly facilitate its industrial integration and commercialization in the gas separation market

The Systematic Design of CO2 Capture Processes Applied to the Oxidative Coupling of Methane

The oxidative coupling of methane is the catalytic conversion of methane into ethene. Carbon dioxide is generated as a reaction by-product and must be removed from the gaseous stream. In this paper, the application of a hybrid carbon dioxide removal process including absorption with amines and gas separation membranes is investigated through simulations and cost estimations.DFG, 53182490, EXC 314: Unifying Concepts in Catalysi