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[Display omitted] • CO 2 capture performance of DEEA-HMDA solution is comprehensively investigated. • Comparison of DEEA-HMDA solution with conventional amines is fully discussed. • Guidelines for the screening of promising amines are presented. • A comprehensive technical evaluation of DEEA-HMDA for is proposed. Comprehensive technical analysis is vital for the large-scale industrialization of a certain potential amine solvent. This paper proposes a technical evaluation method to assess amine-based CO 2 capture processes thoroughly. The method's validity was also verified by using the DEEA-HMDA as an example, compared with various conventional amine solutions in terms of the above three technical properties. Based on the technical properties analysis, a new rapid screening assessment method for amines based on technical indicators proposed. In addition, eight conventional amine solvents selected to calculate the technical indicators (including packed column design, solvent consumption, and regeneration energy consumption) reflected by these three technical properties. The packed column volume (44.5 m3), solvent consumption (2.28 kg/tCO 2), and regeneration energy consumption (18.64 KW·h/tCO 2) of using DEEA-HMDA as a CO 2 absorbent were lower than the most commonly used MEA. In conclusion, the blended amine DEEA-HMDA is a potential carbon capture alternative solvent. [ABSTRACT FROM AUTHOR]

Abstract: The calcium-looping process is a promising technique for CO2 capture from coal-fired power plants and for reducing GHG emissions from the power generation sector. This paper presents a calculation model of the carbonator, the key reactor of the Ca-looping process, where CO2 is captured as a result of its reaction with CaO. The model presented is based on the Kunii–Levenspiel theory for circulating fluidized bed and on the recent findings on the properties of CaO as a CO2 sorbent, while taking into account the effects of coal ash and sulfur species. This model can be used for process optimization and for the prediction of the performance of power plants based on the Ca-looping process. Also presented in this paper are the results of a sensitivity analysis of the primary parameters that influence the performance of the carbonator. These results confirm the feasibility of the Ca-looping process with reactors of reasonable size for industrial applications and highlight the importance of the properties of the Ca-based sorbent as they highly affect the carbonator''s performance. [Copyright &y& Elsevier]

Abstract: In order to optimize the design of gas–liquid packed columns used in distillation or in absorption processes, it is of high importance to be able to predict liquid dispersion. Indeed, dispersion phenomena will impact the choice and design of liquid distributing devices and the height of the packed beds. For this, one mainly relies on industrial feedback and on some experimental results obtained at laboratory scale which cannot be directly extrapolated since their geometric characteristics are at least one order of magnitude less than industrial columns in terms of columns diameter and height. To fill this gap CFD simulation tools should be more used since they can apply to any scale. However the latter option requires adequate modeling in particular for dispersion forces which are little studied due to the lack of data for validation. The present paper aims at developing, from original dispersion experimental measurements, closure laws that can be implemented in CFD codes. Liquid spreading from a source point has been investigated for Mellapak 250.X packing via gamma-ray tomography measurements. Closure laws are discussed from a simple 1D model which enables to go further within the Eulerian two-fluid framework with original user-defined functions and associated models that take into account liquid dispersion in the packed bed. The latter is modeled as a porous medium with appropriate closure laws. The comparison between experiments and CFD results shows that the present approach is adequate and should be further developed in order to be more precise and adapted to more packings. [Copyright &y& Elsevier]

Abstract: Carbon capture and storage for power generation systems is a major issue for achieving greenhouse gas emission reductions. Studies are usually dedicated to coal-fired power plants, but few efforts have addressed the challenge of CO2 capture for a gas turbine. In this paper, a recently reported hybrid process based on oxygen enriched air combustion, flue gas recycling and CO2 capture by membranes is explored for a 250MW open cycle gas turbine. An improved configuration based on an energy recovery system integrated with a heat exchanger offers superior performance compared to the reference gas turbine cycle. It is shown that an overall energy requirement below 2GJth/ton of CO2 captured (i.e. around 205kWhelectrical/ton CO2) can be achieved using a highly selective membrane (CO2/N2 selectivity of 200) operated under optimal process conditions. [Copyright &y& Elsevier]

Abstract: Sorption enhanced methane reforming (SER), employing a CaO-based solid as a high temperature CO2 sorbent, is generally considered to be a promising route for H2 production. In this paper we present a dynamic pseudo-homogeneous model to describe the operation of a packed bed reactor in which the SER reaction is carried out under adiabatic conditions. This reactor can be implemented according to several process schemes, including a novel Ca/Cu looping process for hydrogen generation with inherent CO2 capture. The proposed SER model is based on the well-established principles of gas–solid contact and heat transfer in fixed-bed reactors and on the kinetic expressions published in the literature that describe the main reactions involved in the process. The resulting model describes the transient performance of the SER reaction and confirms the theoretical viability of this critical reaction stage in a large scale H2 production facility. It is demonstrated that the SER process can yield a CH4 conversion and H2 purity of up to 85% and 95%, respectively, under operating conditions of 923K, 3.5MPa, a steam/carbon ratio of 5 and a space velocity of 3.5kg/m2 s. [Copyright &y& Elsevier]

Abstract: A small wetted wall column (WWC) was used to study the kinetics of CO2 absorbed in PZ and NH3/PZ blended solution. The experiments of CO2 absorption into 0.1–0.4M PZ and 0.53–4M NH3/0.1–0.4M PZ mixed solution at 10–40°C have been done in wetted wall column under the driving force of 8–25kPa in this paper. The ‘interface concentration corrected-pseudo first order’ mass transfer model and ‘Ternary-termolecular’ reaction mechanism were proposed to describe the CO2 absorption into NH3/PZ system for the high driving force and low PZ concentration condition. Both of the models in this study used for CO2 with NH3/PZ blended solution were in a good agreement with the experimental results. [Copyright &y& Elsevier]

Abstract: Several studies have been performed to measure pressure drop in packed towers, however, most of them have focused on distillation and random packings and the correlations obtained may not be directly applicable to reactive absorption. In this paper, results from a study of pressure drop in 3 different structured packings; Mellapak 2X from Sulzer, Koch-Glitsch Flexipac 2Y HC, and Montz-Pak B1-250M, are presented. The fluid systems tested were: air/water, air/ aqueous sugar solutions with liquid viscosities from 2.5 to 12cP and finally air/30wt% MEA. The column used had a 5m packing height with an inner diameter of 0.5m. Pressure drop across the packing height was obtained as function of gas and liquid flow rate both as total pressure drop and as pressure change along the packing. A slight influence of viscosity on pressure drop and flooding point was found. The experimental results were compared with estimates made using the software packages provided by the various suppliers for their own packings. Comparisons between estimated and experimental results showed that the selected software in general gives reliable predictions of pressure drop up to an F-factor of about 3Pa0.5, but that deviations may occur even for lower F-factors at high liquid loads. For low liquid loads (<10m3/m2h) the software estimations are good in the whole range of measurements (F-factor <4.5–5Pa0.5). For reactive systems at all liquid loads there is hardly any change at all for the Flexipac 2Y HC and B1-250M. For the Mellapak 2X the effect of the reactive system is significant for high liquid loads. [Copyright &y& Elsevier]

Abstract: In recent years several processes incorporating a carbonation–calcination loop in an interconnected fluidized bed reactor have been proposed as a way to capture CO2 from flue gases. This paper is a first approximation to the modelling of a fluidized bed carbonator reactor. In this reactor the flue gas comes into contact with an active bed composed of particles with very different activities, depending on their residence time in the bed and in the carbonation–calcination loop. The model combines the residence time distribution functions with existing knowledge about sorbent deactivation rates and sorbent reactivity. The fluid dynamics of the solids (CSTR) and gases (PF) in the carbonator are based on simple assumptions. The carbonation rates are modelled defining a characteristic time for the transition between a fast reaction regime to a regime with a zero reaction rate. On the basis of these assumptions the model is able to predict the CO2 capture efficiency for the flue gas depending on the operating and design conditions. Operating windows with high capture efficiencies are discussed, as well as those conditions where only modest capture efficiencies are possible. [Copyright &y& Elsevier]

Abstract: The present paper analyses the gas/liquid mass transfer process employing carbon dioxide as gas phase and ternary water in oil microemulsions as absorbent liquid phases. The liquid phases were obtained by a direct mixing of water, 2,2,4-trimethylpentane and sodium bis(2-ethylhexyl)sulfosuccinate (Aerosol OT). The characteristics of the microemulsions employed as liquid phase have been analysed to interpret the experimental results observed in the absorption process. More specifically, they have been analysed in relation to the percolation phenomenon and the effects produced by this phenomenon upon the different physical properties. Characteristic results have been observed for the gas/liquid mass transfer using microemulsions, because ternary microemulsions with high viscosity values in relation to pure water show a faster absorption process than the carbon dioxide/water system. This characteristic behaviour has been explained on the basis of the microemulsions internal dynamics. [Copyright &y& Elsevier]