Carbon Capture Options Research Articles

A Comprehensive Assessment of Carbon Dioxide Removal Options for Germany

AbstractTo reach their net‐zero targets, countries will have to compensate hard‐to‐abate CO2 emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio‐cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context‐specific feasibility assessment of CDR options for the example of Germany. We assess 14 CDR options, including three chemical carbon capture options, six options for bioenergy combined with carbon capture and storage (BECCS), and five options that aim to increase ecosystem carbon uptake. The assessment addresses technological, economic, environmental, institutional, social‐cultural and systemic considerations using a traffic‐light system to evaluate implementation opportunities and hurdles. We find that in Germany CDR options like cover crops or seagrass restoration currently face comparably low implementation hurdles in terms of technological, economic, or environmental feasibility and low institutional or social opposition but show comparably small CO2 removal potentials. In contrast, some BECCS options that show high CDR potentials face significant techno‐economic, societal and institutional hurdles when it comes to the geological storage of CO2. While a combination of CDR options is likely required to meet the net‐zero target in Germany, the current climate protection law includes a limited set of options. Our analysis aims to provide comprehensive information on CDR hurdles and possibilities for Germany for use in further research on CDR options, climate, and energy scenario development, as well as an effective decision support basis for various actors.

Promotion of CO2 fracturing for CCUS—the technical gap between theory and practice

CO2, used as an environmentally friendly fracturing fluid, has encountered a bottleneck in development in recent years. Despite great efforts in research work, limited progress has been made in field applications. In this study, an extensive literature review of research work and field cases was performed to summarize the technical issues and challenges of CO2 fracturing. The key issues of CO2 fracturing were analyzed to reveal the gap between fundamental research and field operations. The effects of CO2 properties on fracture creation and proppant transport were synthetically analyzed to extract new common research orientations, with the aim of improving the efficiency of CO2 injection. The hydraulic parameters of CO2 fracturing were compared with those of water-based fracturing fluids, which revealed a theory-practice gap. By studying the developing trends and successful experiences of conventional fluids, new strategies for CO2 fracturing were proposed. We identified that the major theory-practice gap in CO2 fracturing exists in pump rate and operation scale. Consequently, the friction reducer, effects of flow loss (due to leak-off) and distribution (within fracture networks), and shear viscosity of thickened CO2 are key factors in improving both fracture propagation and proppant transport. By increasing the scale of injected CO2, the CO2 fracturing technique can be enhanced, making it an essential option for carbon capture, utilization, and storage (CCUS) to reduce carbon emissions and mitigate climate change.

Temperature-vacuum swing adsorption for direct air capture by using low-grade heat

Direct air capture (DAC) is a promising carbon mitigation technology and will likely be part of extensive carbon removal portfolio. Adsorptive DAC is an appropriate option for carbon capture to utilize low-grade heat because of its desirable regeneration temperature and adaptability to be integrated with renewables. Building indoor environment with CO2 concentrations above 1000 ppm provides another suitable scenario for DAC. Herein, DAC using temperature-vacuum swing adsorption (TVSA) is presented and analyzed by integrating various low-grade heat sources in buildings. An amine-functionalized metal organic framework is selected for process simulation, and the performance is compared with those using other sorbents. It indicates that amine-functionalized material has advantages in CO2 productivity and purity. A techno-economic analysis is carried out to explore the benefit of the proposed DAC in buildings. The results show that regeneration by heat pumps at 373 K is the most competitive solution and has 176.7 $·tCO2−1 of the levelized cost of DAC (LCOD). Compared with conventional energy supply, solutions with low-grade heat utilization in buildings could achieve lower carbon intensity and increase by 5.2–25.0% in net LCOD. These results will provide practical guidelines for DAC application with lower energy penalties and costs.

An energy optimization model comparing the use of sugarcane bagasse for power or ethanol production

This work addresses the energy balance of producing ethanol from sugarcane bagasse and using lignin from the bagasse as a source of electrical power through Rankine cycle and oxy-combustion. On ethanol 2 G (second generation) proposed plant, lignin is obtained from the concentration and filtration of vinasse which yields a fuel with good calorific value to be used for power generation. The energy balance for 2 G ethanol production including electric power is calculated based on parameters of a typical operational sugarcane plant, coupled with a 2 G plant whose production was assessed by means of global chemical reactions and conversion coefficients obtained from literature. These reactions permit to calculate ethanol production and electricity generation in terms of a virtually infinite number of scenarios characterized by two controlled variables (burning bagasse and straw mass flow rates) and several uncontrolled variables (biomass composition, cellulose, hemicelluloses and lignin yields, fermentation efficiencies, etc.). Results reveal that when the option for carbon capture and storage is used, net power become available when all tops and leaves plus 10 t/h of bagasse are burned. In this condition availability of ethanol is by and large unaffected, yielding a production about 60 m3/h. The application of carbon capture and storage produces a significant impact on power balance that comes from oxy-combustion use (air split unity) and CO2 compression. Another interesting result concerns biomass composition: for both bagasse and straw, higher lignin contents favor simultaneously 2 G ethanol and electricity.

First-principles based surrogate modeling of pressure swing adsorption processes for CO2 capture

Pressure swing adsorption (PSA) is a highly versatile separate technology and represents a promising option for carbon capture. A dynamic model for a PSA process comprises partial differential equations, which are difficult to use for optimization tasks due to their long computational time and numerical instability problems. A surrogate model for PSA processes which captures the essence of the dynamics to predict key performance measures can enable process optimization to be carried out without the need to evaluate the rigorous model repeatedly. To this end, a surrogate model that predicts energy consumption, removal, purity, and CO2 avoidance cost for given operating conditions is developed as a system of nonlinear equations. The surrogate model is validated and can be used to find optimal operating conditions without having to carry out time-consuming dynamic simulations. It is expected that the ability of fast-optimization brings further opportunities such as screening of adsorbent candidates in material discovery researches.

Accelerated Sea‐Level Rise Limits Vegetation Capacity to Sequester Soil Carbon in Coastal Wetlands: A Study Case in Southeastern Australia

AbstractEstimates of global carbon stocks in coastal wetlands reveal that these are some of the most efficient carbon‐sequestering environments in the world, which has prompted a renewed interest in conservation and restoration programs as an opportunity for greenhouse gas abatement. Accumulation of carbon in coastal wetlands is linked to diverse factors such as the type of vegetation, geomorphic setting, and sediment supply. Feedbacks between these factors and the tidal flow conditions drive the dynamics of carbon accumulation rates. Climate change‐induced sea‐level rise has been shown to increase the vulnerability to submergence of saltmarsh and mangroves in coastal wetlands, even if accommodation and landward colonization are possible. These potential losses of wetland vegetation combined with the reduced productivity of newly colonized areas will directly affect the capacity of the wetlands to sequester carbon from sediments and root growth. Here, we implement an eco‐geomorphic model to simulate vegetation dynamics, soil carbon accumulation, and changes in soil carbon stock for a restored mangrove‐saltmarsh wetland experiencing accelerated sea‐level rise. We evaluate model outcomes for existing conditions and two different management scenarios aimed at mitigating sea‐level rise effects and conserve wetland vegetation. Even though some management measures can result in partial conservation of wetland vegetation, they do not necessarily result in the best option for soil carbon capture. Our results suggest that accelerated sea‐level can trigger accelerated wetland colonization resulting in wetland areas with limited opportunities for soil carbon capture from sediment and root mineralization, an issue that has not been considered in previous studies.

Advanced petroleum coke oxy‐combustion power generation with carbon capture and sequestration: Part II—Environmental assessment and cost of CO2 avoided

AbstractThe life‐cycle environmental impact assessment and cost of the CO2 avoided (CCA) of a petroleum coke oxy‐combustion electric power generation technology operated with and without carbon capture and sequestration (CCS) are discussed. In an extension of our work on the design and economics presented in Part I, the environmental assessment was carried out for three candidate petroleum coke oxy‐combustion designs: petcoke oxy‐combustion operated without carbon capture and sequestration (CCS); petcoke oxy‐combustion operated with CCS; and petcoke oxy‐combustion with CO2 purification by distillation and CCS. The environmental life‐cycle assessment of the designs was computed using both TRACI 2.1 midpoint and ReCiPe 2016 midpoint and endpoint methods. Using a levelized cost of electricity, the CCA was also employed as a performance metric for each of the designs. The results showed a life‐cycle GWP of 1089 kgCO2eq/MWh, 17.32 kgCO2eq/MWh, and 75.65 kgCO2eq/MWh for the petcoke oxy‐combustion design operated without CCS, petcoke oxy‐combustion design operated with CCS, and petcoke oxy‐combustion with CO2 purification by distillation and CCS, respectively. It was also found that acidification potential and particulate matter emissions were higher for the petcoke oxy‐combustion design operated without CCS due to the venting of SO2 to the atmosphere. With a levelized cost of electricity between $90.94/MWh and $102.8/MWh, the CCA of the CCS‐enabled designs were between $10.43/tCO2eq and $24.35/tCO2eq, which is competitive with most other carbon capture options for large‐scale fossil‐based power plants. When the cost parameters were varied at the worst‐case scenario, the highest CCA observed was $115.9/tCO2eq.

CO2 Reutilization in the Residential Sector Through Power to Gas and Oxyfuel Combustion

A novel concept of Power-to-gas (PtG) has been investigated as a versatile technology for storage and utilization of carbon dioxide coming from energy installations. The proposed PtG solution takes advantage of the synergies of different processes to integrate energy storage efficiently with carbon utilization to produce a ‘CO2 neutral’ natural gas. PtG converts surplus electricity into synthetic natural gas by combining H2 from water electrolysis and CO2 through methanation reaction and oxyfuel combustion. This carbon capture option releases thermal energy from the synthetic fuel producing a near-pure stream of CO2 that close the carbon loop used for methanation. Under this framework, the present work proposes to study and validate the hybridization between Power-to-Gas energy storage technology and CO2 oxyfuel combustion in the residential sector. This combination is a novel strategy focused on solving: (i) the intermittent and seasonal electricity generation from renewable resources; (ii) the large energy and economic penalties associated with CO2 capture and utilization (especially at small scale); (iii) and the development of energy storage systems of small-medium size and high flexibility. This hybridization allows managing the excess of renewable electricity in the Power-to-Gas installation and producing hydrogen (stored energy) and oxygen (by-product). Subsequently, oxygen is used to meet the needs of the oxyfuel combustion process, in this case, in the residential sector, with two important advantages: a high concentration CO2 flow is obtained, and the oxygen production neither requires an air separation unit (ASU) nor additional energy requirements. The stored hydrogen and the captured carbon dioxide are combined by methanation to produce synthetic natural gas stored for future uses. From CO2 capture point of view, the proposed hybrid system presents an additional advantage: there would also be no penalty associated with the compression and underground storage of captured CO2, since it is reused in the oxyfuel burner along with the oxygen, obtained in the electrolyzer, closing the carbon cycle. A PtG installation with recycled CO2 utilization has been designed to fully supply the thermal heating demand and partially the electrical demand of a single-family house located in the northeast of Germany, from a photovoltaic generator. The PtG system's characteristics, the CO2 storage and utilization strategy, the equipment necessary and energy balances are presented and illustrated with a case study. The proposed design can supply the 87% of the energy consumed by a single-family home and avoid the emissions of 2.8 tons of CO2 every year.

Assessment of flexible carbon capture and utilization options applied to gasification plants

Assessment of flexible carbon capture and utilization options applied to gasification plants

Least cost energy system pathways towards 100% renewable energy in Ireland by 2050.

Studies focusing on 100% renewable energy systems have emerged in recent years; however, existing studies tend to focus only on the power sector using exploratory approaches. This paper therefore undertakes a whole-system approach and explores optimal pathways towards 100% renewable energy by 2050. The analysis is carried out for Ireland, which currently has the highest share of variable renewable electricity on a synchronous power system. Large numbers of scenarios are developed using the Irish TIMES model to address uncertainties. Results show that compared to decarbonization targets, focusing on renewable penetration without considering carbon capture options is significantly less cost effective in carbon mitigation. Alternative assumptions on bioenergy imports and maximum variability in power generation lead to very different energy mixes in bioenergy and electrification levels. All pathways suggest that indigenous bioenergy needs to be fully exploited and the current annual deployment rate of renewable electricity needs a boost. Pathways relying on international bioenergy imports are slightly cheaper and faces less economic and technical challenges. However, given the large future uncertainties, it is recommended that further policy considerations be given to pathways with high electrification levels as they are more robust towards uncertainties.

Evaluation of cooperative mitigation: captured carbon dioxide for enhanced oil recovery

Robust mitigation options will play significant role in achieving the target of limiting global change to below 1.5 °C above pre-industrial levels by 2100. To support cooperation for mitigation development, we establish a real options-based model to evaluate the rational decisions of exercising the abandon option for carbon capture and storage-enhanced oil recovery (CCS-EOR) projects under oil market and geological uncertainties. Three possible cooperative mechanisms (fixed carbon dioxide (CO2) price, oil-indexed CO2 price, and joint venture contracts) among CO2-EOR stakeholders are evaluated. The results show that the conflicts in profit maximization targets for different stakeholders in cooperative mitigation are to a great extent unable to be avoided. A joint venture business model is preferred in cooperative mitigation as it can effectively weaken such conflicts. And it is more reasonable to provide incentives to the downstream of the CO2-EOR chain than compensating the adoption cost of carbon capture technologies in the upstream. From a global perspective, the inefficient cooperation can be a main barrier that hinders the development of deep-cutting options. Global mitigation strategies should not only focus on promoting technology progress but also the design of innovative business models to balance the benefits among stakeholders. A joint venture business model is recommended in both the developed and developing countries for seizing the early mitigation opportunities.

A review and future prospect of polymer blend mixed matrix membrane for CO2 separation

In recent years, carbon capture technology has received much attention to limit the adverse effect caused by rising carbon dioxide (CO2) concentration in the atmosphere. Membrane technology has risen as an attractive option for carbon capture as it is less energy–intensive and more environmentally friendly compared with adsorption, absorption, and cryogenic separation. Polymeric membranes dominate the gas separation industries as they are cheaper and easier to fabricate compared with inorganic membranes but are bound to the permeance-selectivity trade-off limitation. Recently, researchers have been modifying polymeric membrane by polymer blending and mixed matrix membranes (MMMs) to overcome the limitation. Polymer blending yields a polymer blend that combines the benefits of two or more polymeric material. Polyethylene glycol (PEG) and polyethersulfone (PES) are common polymeric materials used in the gas separation industry for membrane fabrication. PEG and PES were reviewed in this paper as potential polymer blends that efficiently separate CO2 due to their chemical characteristics. Another technique to overcome the trade-off limitation is fabricating MMMs that incorporate both polymeric membrane material and inorganic filler. However, MMM fabrication presents challenges such as polymer-filler incompatibility, void formation, and filler agglomeration due to unsuitable filler. Functionalized multi-walled carbon nanotubes (MWCNTs-F) were reviewed as fillers that are able to overcome the dispersion and polymer-compatibility issues and increase the gas separation performance of membranes. Hence, MMM that is fabricated from PEG, PES, and MWCNTs-F that combines both polymer blending and MMM techniques is believed to be a breakthrough for CO2/N2 separation.

Benchmarking of vertically integrated models for the study of the impact of caprock morphology on CO2 migration

Saline aquifers constitute the most abundant geological storage option for Carbon Capture and Storage (CCS) projects. When injected in the aquifer, due to its lower density in comparison to the in-situ brine, the free phase CO2 tends to migrate upwards. This vertical migration is generally tens of metres depending on the reservoir thickness, despite the plume migration distance in the horizontal direction which could be over hundreds of kilometres (depending on the time horizon, reservoir characteristics, trapping mechanisms involved, etc.). In many situations, the plume ends up as a separate region below a sealing barrier. This large aspect ratio between the plume migration in the horizontal and vertical directions would potentially validate the use of vertical equilibrium (VE) models in CO2 storage studies. In other words, when phase segregation occurs rapidly compared to the time scale studied, vertical equilibrium can be assumed, allowing for the use of specially adapted models. In the VE model, the equilibrium between brine and CO2 is pre-assumed at all times. Under this assumption, the injected CO2 plume flow in 3D can be approximated in terms of its thickness in order to obtain a 2D simulation model, which consequently decreases the computational costs. The time by which phase segregation occurs depends on the aquifer thickness, aquifer permeability, fluid properties, etc. However, the CO2 and in-situ brine are separated considerably fast and form two separate layers, in comparison to the time period for lateral migration.The CO2lab module of the Matlab Reservoir Simulation Toolbox (MRST) used in this work, is a set of open source simulation and workflow tools to study the long-term, large-scale storage of CO2. We employed the VE tool in MRST−CO2lab (MVE) to study the effect of caprock morphology on the CO2 migration. The results have been compared with a number of simulators including ECLIPSE-black-oil (E100), ECLIPSE-compositional (E300) and ECLIPSE-VE (EVE) models and the differences between the approaches are analysed and discussed in detail. In particular, we focused on the impact of caprock morphology and aquifer top-surface slope on the CO2 structural and dissolution trapping mechanisms and plume migration. The results indicated a good agreement for the ultimate plume shapes in all the models. However, the amount of dissolved CO2 in the brine was different.

Multi-Footprint Constrained Energy Sector Planning

Fossil fuels have been heavily exploited since the Industrial Revolution. The resulting carbon emissions are widely regarded as being the main cause of global warming and climate change. Key mitigation technologies for reducing carbon emissions include carbon capture and storage (CCS) and renewables. According to recent analysis of the International Energy Agency, renewables and CCS will contribute more than 50% of the cumulative emissions reductions by 2050. This paper presents a new mathematical programming model for multi-footprint energy sector planning with CCS and renewables deployment. The model is generic and considers a variety of carbon capture (CC) options for the retrofit of individual thermal power generation units. For comprehensive planning, the Integrated Environmental Control Model is employed in this work to assess the performance and costs of different types of power generation units before and after CC retrofits. A case study of Taiwan’s energy sector is presented to demonstrate the use of the proposed model for complex decision-making and cost trade-offs in the deployment of CC technologies and additional low-carbon energy sources. Different scenarios are analysed, and the results are compared to identify the optimal strategy for the energy mix to satisfy the electricity demand and the various planning constraints.

Residence time distribution in a structured packing unit for monitoring aerosol emissions

Solvent absorption in a structured packed column has been demonstrated as a viable option for post-combustion carbon capture. Amine emissions in the form of aerosol particles pose a major challenge that severely impacts the separation efficiency of the packed column. The aerosol particles quickly achieve the motion of the gas flow. In this context, residence time distribution (RTD) of the gaseous phase will provide insights for managing aerosol particles, thereby controlling amine loss in the packed column. Computational fluid dynamics (CFD) modeling of such columns is a multiscale problem because of a wide range of disparity in length scales. Accordingly, three-dimensional CFD simulations in the representative elementary unit of a structured packing are conducted using OpenFOAM. The RTD is analyzed in terms of residence time distribution function, mean residence time and variance. Effects of the diffusivity and flow rates on RTD are extensively studied, and the dispersion coefficient is calculated using a one-dimensional axial dispersion model. RTDs computed in a smaller domain are extrapolated to a larger domain using the convolution integral. The CFD computed and corresponding CFD models derived from the convolution integral match well at different flow rates and domain sizes. A comparison of RTD among diff ;erent packing designs is presented at a fixed number of repeating units and different flow rates. The mean residence time is found to larger than the superficial time, which is a unique behavior of structure packing. For a fixed number of repeating units, a packed column having higher specific area showed broad dispersion and the axial Péclet number decreases.

Synthesis of Carbon Integration Networks Coupled with Hydrate Suppression and Dehydration Options

Abstract The excessive increase in carbon dioxide emissions through the past several decades has raised global climate change concerns. As such, environmental policy makers have been looking into the implementation of efficient strategies that would ultimately reduce greenhouse gas (GHG) emission levels, and meet strict emissions targets. As part of a national emission reduction strategy, the reduction of carbon-dioxide emissions from industrial activities has been proven to be very significant. This instigated the need for a systematic carbon integration approach that can yield cost-effective carbon integration networks, while meeting prescribed carbon dioxide emission reduction targets in industrial cities. A novel carbon integration methodology has been previously proposed as a carbon network source-sink mapping approach using a Mixed Integer Nonlinear Program (MINLP), and was found to be very effective to devise emission control strategies in industrial cities. This paper aims to further improve the design process of carbon integration networks, by coupling carbon integration networks with hydrate suppression/moisture removal options. This was found vital for the prevention of any potential hazards that are associated with the transportation of carbon dioxide in pipelines, such as hydrate formation and various corrosion effects, which may result from moisture retention. An extensive analysis of carbon capture, dehydration, inhibition, compression, and transmission options have all been incorporated into the network design process, in the course of determining cost-optimal solutions for carbon dioxide networks. The proposed approach has been illustrated using an industrial city case study.

Surface and bulk carbonate formation in calcium oxide during CO2 capture

Calcium looping (CaL), the cyclic carbonation and calcination of limestone, is a prominent carbon capture option considering reduced parasitic energy consumption compared to amine scrubbing. The main issue preventing application is sorbent performance decay during cycling. Therefore hydration and extended carbonation reactivation strategies, as well as synthetic approaches to enhance or sustain reactivity, are of interest. Results of an investigation are presented on the impact of reactivation strategies on carbonate formation through detailed study using in-situ infrared spectroscopy. Surface and bulk carbonate formation regimes were readily distinguished allowing the influence of temporal, hydration and thermodynamic conditions within each regime to be studied. Surface chemistry of CaO during two initial cycles was shown to change. Significantly, it was shown that the CaO surface produced from the calcination of Ca(OH)2 possessed more highly reactive sites compared to the surface produced from CaCO3. The presence of water enhanced bulk carbonate formation at 300°C and influenced the complexation of surface carbonates during looping. The results are of interest in the CaL community, offering molecular scale explanations for macroscale observations, whilst also informing on the role of humidity in direct air capture and sorption enhanced reaction processes.

Extraction of magnesium from four Finnish magnesium silicate rocks for CO2 mineralisation - Part 1: Thermal solid/solid extraction

The only option for carbon capture and storage (CCS) in Finland is mineral carbonation, which has been extensively researched at Åbo Akademi University (ÅA). Finding suitable minerals for mineral carbonation in different regions of Finland will keep transportation of either CO2 or the actual mineral at a lowest possible level. Four different rocks from different regions in Finland have been compared with respect to composition and possibility to extract magnesium. This paper presents experiments applying thermal solid/solid extraction. It was found that a mixture of ammonium sulphate (AS) and ammonium bisulphate (ABS) could extract a significant part of magnesium compared to tests using only AS or ABS. Serpentinite rock is also the best option for magnesium extraction while diopside and magnesiohornblende are much less reactive. Continuous mixing during the experiment in a rotary tube and adding some water to the solid/solid mixture gives better extraction results. The binding capacities of CO2 in the serpetinites with respect to the magnesium extractions achieved in this study are 240kg CO2/ton rock (Serp-A) and 207kg CO2/ton rock (Serp-B).

Evaluation of reactive absorption and adsorption systems for post-combustion CO2 capture applied to iron and steel industry

Reducing CO2 emissions from energy sector and other fossil fuel-intensive industrial applications is of main importance today. The iron and steel industry is one of the largest industrial sources of CO2 (about 6% of total CO2 emissions). Two post-combustion CO2 capture methods based on reactive gas-liquid and gas-solid systems are evaluated to be used in an integrated steel mill in conjunction with the plant sub-systems with the highest CO2 emissions e.g., captive power plant, hot stoves, coke ovens, lime kilns, etc. The gas-liquid absorption using chemical solvents (e.g., alkanolamines) and Calcium Looping (CaL) are assessed. The carbon capture rate is set to be at least 90%. The paper evaluates a conventional size of integrated steel mill emphasizing the energy integration aspects and the influence of various carbon capture options on the overall steel mill performances. The evaluated designs (captive power plants and carbon capture units) were modelled and simulated, the results being used to assess the overall indicators. For comparison reason, various captive power plant configurations of integrated steel mill without carbon capture were also considered. The assessments show that CaL system has significant advantages compared not only to benchmark cases without capture but also to the gas-liquid absorption cases.

Evaluating Pressure Swing Adsorption as a CO2 separation technique in coal-fired power plants

The paper provides with a first assessment on the suitability of Pressure Swing Adsorption (PSA) as a valid option for Carbon Capture and Storage (CCS) in coal-fired power plants. A full-plant analysis of an Advanced SuperCritical (ASC) pulverized coal plant and of an Integrated Gasification Combined Cycle (IGCC) plant, operating with a PSA unit, is presented. The systems selected aim to represent the most diffused options for coal-based power generation, respectively in a post- and pre-combustion application of CO2 separation. The definition of the PSA process is tailored for the two different scenarios considered, starting from the adsorbent selected (zeolite 5A and activated carbon, respectively for post- and pre-combustion). The objective is to investigate the competitiveness of PSA with respect to the benchmark technology for CCS, namely absorption. In order to consider the different aspects measuring the effectiveness of a CO2 separation technique, the performance of the power plants is evaluated in terms of CO2 separation performance, energy efficiency and footprint of the technology. The post-combustion scenario analysis shows that PSA can be competitive with regard to the separation and the energy performance. PSA is able to match the CO2 separation requirements, and the relative energy penalty is slightly lower than that resulting from amine-absorption. Despite that, the footprint of the PSA unit demonstrates to be way larger than that related to absorption and unlikely acceptable. PSA in the pre-combustion scenario returns more encouraging results, approaching the outcomes achieved with absorption both in terms of CO2 separation performance and plant energy efficiency. The footprint, even though significantly larger than with absorption, appears to be reasonable for actual implementation.