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Sharp increase in the molar ratio between the gas/liquid flow rate (kmol/h). Blue line indicates the jump in inlet gas flow. Green line is the constant inlet liquid solvent rate.
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In this work, a dynamic model is developed in the CO2SIM framework for transient modelling of CO2 absorbers and desorbers. Validation of code towards pilot data is presented, and the applicability of the model is shown with two examples of usage. Emphasis has been on developing flexible coding architecture for further development into dynamics and...
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Rapid screening experiment has been used to acquire first-hand information on the precipitation characteristics of 14 aqueous amino acid salt systems. Absorption tests at 40°C have shown that at high concentrations, amino acid salt systems forms precipitate in the presence of CO2 resulting to 2 or 3 solid-liquid phase formation. Potassium salt of t...
High operating cost and significant decrease in net power generation are major barriers to the implementation of post- combustion amine scrubbing for CO2 capture from coal-fired power plants. To improve efficiency and make the process more attractive economically, alternative process configurations and second generation solvents are being investiga...
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A large-scale CCS demonstration project is currently being undertaken by the Japanese government in the Tomakomai area, Hokkaido prefecture, Japan. The project is scheduled to run for the period JFY 2012 - 2020 to demonstrate the viability of CCS system from CO2 capture through to injection and storage. 100,000 tonnes per year or more of CO2 derive...
In the selection of candidates for post-combustion CO2 absorption, solvent degradation has become a general concern due to the significant impact on operational cost and the intention to use thermal compression from high temperature stripping to minimize the overall process energy. In this research, structural analogs of amino acid salts, alkanolam...
Citations
... Further description of the specifics of underlying models used in CO2SIM can be found in Tobiesen et al. (2007Tobiesen et al. ( , 2008Tobiesen et al. ( , 2018 and Tobiesen and Schumann-Olsen (2011). The framework is also applied for dynamic simulations for advanced process control (Tobiesen et al., 2012). The simulator includes optimization procedures and methods for automatic handling of data obtained from different sources, such as pilot plants or industrial process data. ...
An early phase feasibility study was carried out for offshore CO2 capture from ship engines of a CO2 transport ship. A flexible in-house process simulator was applied in the assessments. Parametric studies of the overall onboard process were enabled by a fast data-driven capture plant model derived from supervised machine learning by PLS regression of a large dataset of rigorous simulations. The results show, based on the given models and assumptions, that the thermal energy coming from the ship engine exhaust gas is not sufficient alone to cover the thermal energy demand of an absorption-based CO2 capture unit operating above 50% capture rate using 30 wt% MEA (mono-ethanolamine) as solvent. The thermal energy demand can be met using a fuel afterburner as heat source. The added fuel consumption is estimated to increase the fuel consumption by 6–9% when operating with liquefied natural gas (LNG) as fuel source, while an increase of 8–12% is expected with diesel as fuel source. The effect of absorber height on energy consumption at a given CO2 capture rate is limited, especially for lower capture rates, and may be an important degree of freedom for optimizing the CAPEX/OPEX trade-offs. Use of state-of-the art solvents with lower specific energy consumptions will shift the results towards higher capture rates before a fuel afterburner is required to meet the thermal energy demands.
... For each flue gas case, a separate simulation is performed in CO2SIM (Luo et al., 2009;Tobiesen et al., 2012Tobiesen et al., , 2007. The selected gas sources are presented in Table 1. ...
Undesired aerosol formation in gas–liquid contact devices has been a well-known phenomenon in the chemical
industry for several decades and can cause severe problems in industrial gas cleaning processes. Several studies
indicate that aerosols can govern the total amine emissions from amine based CO2 capture (PCCC) plants.
Despite the importance of aerosol formation and mitigation for the design of a PCCC plant, very little knowledge
is available on the characterization and growth of these aerosols.
Four different atmospheric flue gases were modelled in this work, ranging from 4 to 20% in CO2 content and
representing natural gas, oil and coal fired power plants, and gas from the cement industry. Inlet droplets of size
0.15 μ were tested in number concentrations from 1 to 107 droplets/cm3
. For 20% CO2, the effect of intercooling
was studied.
The findings are: Aerosol droplets grow from their initial size regardless of their initial composition and type
of flue gas processed. The initial composition of the droplets has a significant effect on emissions.
With increasing CO2 concentration, more carbamate is formed relative to free MEA. This leads to less effective
water wash and significantly higher final emissions.
With low droplet number concentration no visible depletion of MEA in the absorber and water wash sections
was found for any of the CO2 concentrations. At 107 droplets/cm3
, gas phase MEA partial pressure changes are
clearly seen, first in the water wash, and then, at higher contents, the effect starts lower and lower down in the
absorber.
The carry-over of amine into the water wash increases with increasing gas phase CO2 content. However, the
effect on the gas phase MEA content in the water wash goes through a maximum caused by strong carbamate
formation at high CO2 concentrations.
The droplet temperature profiles are unaffected by number concentration and initial composition of aerosol
droplets.
It is found that the water wash section reduces significantly the aerosol-based, and thereby the total, amine
emissions. The effect of the water wash is reduced when the flue gas CO2 content increases.
Intercooling lowers the partial pressure of MEA in both absorber and water wash significantly. This reduces
the droplet growth and MEA content. The combined effect is a strong reduction in MEA emissions; in the case of
20% CO2 in the flue gas, by a factor of 5–10.
... The development of rigorous rate-based process models helps to gain more knowledge about the effect of different process operating variables on the performance of the process. The main components of the CO 2 capture rate-based process model are [5][6][7] The thermodynamic framework of the reactive equilibrium models is based on two types of equilibrium, the dissociation and reaction equilibrium of the species in the bulk liquid solution, and the vapor liquid equilibrium of the molecular species. The model consists of equilibrium relationships for each reaction involved, mass balances of the amine or amines, total elemental balances, as well as total and local electro-neutrality. ...
A two-dimensional discretized rate-based model was used for assessing the impact of correlations and/or models for VLE (thermodynamics), solubility (CO2 henry’s law constant), reaction rate kinetic models and diffusivity of CO2 in aqueous MEA solutions on the absorber model predictions for CO2 capture. Experimental data from four different set-ups covering a wide range of conditions were utilized for the assessment. Four different thermodynamic models and eight different Henry’s constant correlations/models including the Aspen Plus V8.6 e-NRTL-RK model was used in the study. Even though the individual sub-models, e.g. solubility, physical properties, were validated with independent experimental data, the use of a random selection of these models will give different predictions when used in a rate-based simulation. It was seen that using different Henry’s law constant correlations had a huge effect on model predictions. Seven different reaction rate kinetic models were used and it was found that no single kinetic model was able to predict the experimental data from all the sources better than the chosen base case kinetic model. It was also seen that transport property (CO2 diffusivity in MEA) correlations could have a large impact on the outcome of model predictions and correlations based on the N2O analogy were better than the ones based on a modified Stokes-Einstein correlation. As a special case, frequently used kinetic models were used with the thermodynamic model and transport properties taken from Aspen Plus V8.6. It was found that two of the kinetic models predicted the experimental data with acceptable accuracy.
... Erikøi [107] analyzed the performance of equilibrium and rate based models of ASPEN Plus with HYSYS. Tobiesen et al. [108] introduced a new in-house software CO 2 SIM designed only for capture process. From the summary presented in Table 6, the trends of usage of the different software packages (steady-state & dynamic) by different researchers can be picked up. ...
This paper reviews research trends in modeling for low-carbon energy production. The focus is on two currently significant low-carbon energy processes; namely, bioenergy and post-combustion carbon capture (PCC) processes. The fundamentals of these two processes are discussed and the role of modeling and simulation tools (MSTs) is highlighted. The most popular modeling software packages are identified and their use in the literature is analyzed. Among commercially available packages, it is found that no single software package can handle all process development needs such as, configuration studies, techno-economic analysis, exergy optimization, and process integration. This review also suggests that optimal modeling results reported in literature can be viewed as optimal at the individual plant level, but sub-optimal for plant superstructure level. This review has identified key gaps pertinent to developing hybrid models that describe integrated energy production processes. ASPEN Plus is found to be dominant for modeling both bioenergy and PCC processes for both steady-state and dynamic modes respectively.
... Today, a number of software programs can be successfully used to simulate the CO 2 capture processes with reactive solvents and to compliment laboratory and pilot plant tests. The examples of these software are Aspen Plus, Aspen HYSYS, ProMax, CHEMASIM, ProTreat and CO2SIM (Freguia and Rochelle, 2003;Mangalapally et al., 2009;Weiland et al., 2009;Amrollahi et al., 2011;Tobiesen et al., 2012;Gao et al., 2014;Øi et al., 2014). ...
Currently, post-combustion carbon capture (PCC) is the only industrial CO2 capture technology that is already demonstrated at full commercial scale in the TMC Mongstad in Norway (300,000 tonnes per year CO2 captured) and BD3 SaskPower in Canada (1 million tonnes per year CO2 captured). This paper presents a comprehensive review of the most recent information available on all aspects of the PCC processes. It provides designers and operators of amine solvent-based CO2 capture plants with an in-depth understanding of the most up-to-date fundamental chemistry and physics of the CO2 absorption technologies using amine-based reactive solvents. Topics covered include chemical analysis, reaction kinetics, CO2 solubility, and innovative configurations of absorption and stripping columns as well as information on technology applications. The paper also covers in detail the post build operational issues of corrosion prevention and control, solvent management, solvent stability, solvent recycling and reclaiming, intelligent monitoring and plant control including process automation. In addition, the review discusses the most up-to-date insights related to the theoretical basis of plant operation in terms of thermodynamics, transport phenomena, chemical reaction kinetics/engineering, interfacial phenomena, and materials. The insights will assist engineers, scientists, and decision makers working in academia, industry and government, to gain a better appreciation of the post combustion carbon capture technology.
... Today, a number of software programs can be successfully used to simulate the CO 2 capture processes with reactive solvents and to compliment laboratory and pilot plant tests. The examples of these software are Aspen Plus, Aspen HYSYS, ProMax, CHEMASIM, ProTreat and CO2SIM (Freguia and Rochelle, 2003;Mangalapally et al., 2009;Weiland et al., 2009;Amrollahi et al., 2011;Tobiesen et al., 2012;Gao et al., 2014;Øi et al., 2014). ...
Currently, post-combustion carbon capture (PCC) is the only industrial CO2 capture technology that is already demonstrated at full commercial scale in the TMC Mongstad in Norway (300,000 tonnes per year CO2 captured) and BD3 SaskPower in Canada (1 million tonnes per year CO2 captured). This paper presents a comprehensive review of the most recent information available on all aspects of the PCC processes. It provides designers and operators of amine solvent-based CO2 capture plants with an in-depth understanding of the most up-to-date fundamental chemistry and physics of the CO2 absorption technologies using amine-based reactive solvents. Topics covered include chemical analysis, reaction kinetics, CO2 solubility, and innovative configurations of absorption and stripping columns as well as information on technology applications. The paper also covers in detail the post build operational issues of corrosion prevention and control, solvent management, solvent stability, solvent recycling and reclaiming, intelligent monitoring and plant control including process automation. In addition, the review discusses the most up-to-date insights related to the theoretical basis of plant operation in terms of thermodynamics, transport phenomena, chemical reaction kinetics/engineering, interfacial phenomena, and materials. The insights will assist engineers, scientists, and decision makers working in academia, industry and government, to gain a better appreciation of the post combustion carbon capture technology.
... Today, a number of software programs can be successfully used to simulate the CO 2 capture processes with reactive solvents and to compliment laboratory and pilot plant tests. The examples of these software are Aspen Plus, Aspen HYSYS, ProMax, CHEMASIM, ProTreat and CO2SIM (Freguia and Rochelle, 2003;Mangalapally et al., 2009;Weiland et al., 2009;Amrollahi et al., 2011;Tobiesen et al., 2012;Gao et al., 2014;Øi et al., 2014). ...
Currently, post-combustion carbon capture (PCC) is the only industrial CO 2 capture technology that is already demonstrated at full commercial scale in the TMC Mongstad in Norway (300,000 tonnes per year CO 2 captured) and BD3 SaskPower in Canada (1 million tonnes per year CO 2 captured). This paper presents a comprehensive review of the most recent information available on all aspects of the PCC processes. It provides designers and operators of amine solvent-based CO 2 capture plants with an in-depth understanding of the most up-to-date fundamental chemistry and physics of the CO 2 absorption technologies using amine-based reactive solvents. Topics covered include chemical analysis, reaction kinetics, CO 2 solubility, and innovative configurations of absorption and stripping columns as well as information on technology applications. The paper also covers in detail the post build operational issues of corrosion prevention and control, solvent management, solvent stability, solvent recycling and reclaiming, intelligent monitoring and plant control including process automation. In addition, the review discusses the most up-to-date insights related to the theoretical basis of plant operation in terms of thermodynam-ics, transport phenomena, chemical reaction kinetics/engineering, interfacial phenomena, and materials. The insights will assist engineers, scientists, and decision makers working in academia, industry and government, to gain a better appreciation of the post combustion carbon capture technology.
... Figure 5 shows the effect of CO 2 concentration in flue gas on the temperature profile of the absorption column. CO 2 reacts with MEA, which is exothermic [44,47,49,50]. Therefore, flue gas with high CO 2 concentration will exhibit a higher peak in the temperature profile of the absorption column. ...
The role of temperature is important in CO2 capture processes. Unfortunately, detailed analysis on the temperature profile of the absorption column is scarce in the literature. Important factors like CO2 capture capacity and corrosion rate directly depend on temperature of the column. Many side reactions such as solvent degradation, formation of stable salts, corrosion and reduction in CO2 capture are prominent at a higher temperature. This study reports a broad study on the temperature profile for CO2 capture process based on a detailed mathematical model, Kent-Eisenberg vapor-liquid equilibrium (VLE) model. This model is quite accurate in calculating CO2 capture for any specific operating condition. Results produced from Kent-Eisenberg VLE model are consistent with experimental data. This study reports temperature profiles of an absorption column for different operating conditions. Moreover, it was found that CO2 absorption is more effective at low and ambient temperatures than at high temperature confirmed by a peak temperature in all cases and in the lower section of the column, which is attributed to exothermic CO2 absorption in monoethanolamine. This temperature variation of the column will be helpful in designing CO2 capture plants.
... The dynamic column model was further compared transient performance data obtained in the absorber of the VOCC pilot rig at NTNU and SINTEF. Some results are shown in Tobiesen et al. (2011) [1]. ...
In this work, a system of unit operations is modeled and implemented in MATLAB for dynamic simulation of the regeneration part of the CO2 capture process. The system consists of a stripper, a reboiler and a condenser, and it is solved by a simultaneous equation based method. The method proves to be suitable for solving the regeneration part of the CO2 capture process and it shows numerically stable behavior in general. Further, two dynamic simulation cases are carried out and compared to steady state simulation results from CO2SIM. The dynamic simulation results show reasonably good agreement with steady state simulations, even though a very simplified flash tank model is used for simulation of reboiler and condenser and a simplified thermodynamic model is applied compared to the more robust CO2SIM model. Due to lack of dynamic pilot data, validation of the dynamic regeneration model has been difficult at this point. However, this is necessary for a thorough validation of the model for transient conditions.
... Besides equilibrium data, the physicochemical properties of the two-phase system were measured to ensure validated data for process simulation. The data were modelled using empirical and semi-empirical correlations and then implemented into the NTNU/SINTEF in-house simulation tool CO2SIM [4]. Optimisation of the overall process, however, requires consideration of the impact of process characteristics not only on the CO 2 capture system itself but also on the overall process in a holistic approach. ...
In this work the potential of a novel post-combustion CO2 capture process is analysed with respect to the integrated overall process. As solvent a blend of two amines (DEEA/MAPA) which forms two liquid phases under CO2 loading is used. The two phases have distinct physical characteristics. Only the heavy phase, rich in CO2 loading, is led to the desorber. The novel solvent combination promises very low energy consumption compared to a 30 wt.-% MEA solution. The efficiency penalty, taking into account the integrated overall process, is very low too. Furthermore, different integration configurations in the overall process are investigated to show the effect in greenfield and retrofit power plant cases.
