Experimental results of CO 2 post-combustion capture for a TSA process including an internal heat-exchanger (indirect heating/cooling) are presented. The comparative experimental study is carried out on 13X and 5A zeolites, with a mixture 90% N 2 -10% CO 2 modeling the flue gas. With 5A zeolite having given the best performances, we tested it with various operating conditions including one with nitrogen purge during desorption. This one showed a good compromise between CO 2 capture rate, purity of the desorbate, volumetric productivity, and specific-heat consumption. We obtained a volumetric productivity of 37 kg CO2 /m 3 ads ‚h and a specific-heat consumption of 6 MJ/kg CO2 at our laboratory scale and 4.5 MJ/kg CO2 for the adiabatic estimate (in the same order of magnitude as those obtained industrially with the reference MEA amine process). These results are promising because our process is not optimized yet and the scale-up on an industrial version involves a reduction in specific-heat consumption.

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a b s t r a c tPost-combustion CO 2 capture remains one of the most-challenging issue to lower CO 2 emissions of existing power plants or heavy industry installations because of strong economy and energy efficiency aspects. The major issue comes from CO 2 dilution (4% for NGCC and 14% for PC) and the high flow rates to be treated. Furthermore, CO 2 purity has to be higher than 95% with recovery at 90%, to match the transportation/injection requirements.The MEA absorption process remains the reference today but its energy consumption (about 3 MJ/kg CO2 ) and the amine consumption are still challenging drawbacks.The interest of CO 2 capture by indirect TSA (Temperature Swing Adsorption) was demonstrated experimentally in a previous work. The aim of this paper is to present the results of a numerical parametric study. Two main parameters are explored: the desorption temperature (100-200 • C) and the purge flow rate (0.1-0.5 Ndm 3 min −1 ). Four performance indicators are evaluated: CO 2 purity, recovery, productivity and specific energy consumption.Results show that purity above 95% can be achieved. Keeping the 95% target, it is possible to achieve recovery at 81% with productivity at 57.7 g CO2 /kg ads h and a specific energy consumption of 3.23 MJ/kg CO2 , which is less than for the reference MEA process.Comparison with other adsorption processes exhibits that this process has good potential especially since some improvements are still expected from further research.

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The kinetics of enzyme catalyzed alcohol oxidation has been measured in liquid water/ethanol/Brij 35 and water/1-pentanol/Brij 35 systems, essentially in the water-rich regions. For the ethanol systems it was found that the enzymatic activity sharply decreases with increasing alcohol concentration independently of the surfactant concentration between 0 and 22 mass %. In the case of the 1-pentanol systems the enzymatic activity decreases also with increasing alcohol concentration, but this decrease can considerably be attenuated by adding increasing amounts of surfactant. To explain these results at the nanometer level, small-angle neutron scattering (SANS) experiments have been carried out on these systems. The comparison of the scattering and the kinetic measurements suggests the following interpretation. In all cases, the enzymatic activity depends on the concentration of the alcohol in the aqueous phase or in the aqueous pseudophase containing the enzyme. A certain amount of alcohol may be present in an organic pseudophase formed by direct micelles. In the case of the 1-pentanol systems the alcohol participates in the structuration of the micelles and is concentrated in the micelles, whereas in the case of the ethanol systems the alcohol remains essentially in the aqueous pseudophase and even destroys the micelles. These results suggest that in some cases enzymatic activity can be used as a probe to detect some aspects of the molecular organization of a complex liquid.

From a thorough study of many systems incorporating water, the ionic surfactant sodium dodecylsulfate, straighter or branched alkanols and aliphatic or aromatic hydrocarbons, it clearly appears that the molecular structure of the alkanol used as the cosurfactant is the composition factor that primarily determines the configuration of the microemulsion domain and, correlatively, the type of the microemulsion electroconductive and viscous behavior.Key words: Microemulsion(s), phase diagram(s), viscosity, electrical conductivity, water, sodium dodecylsulfate, straight alkanol(s), branched alkanol(s), aliphatic hydrocarbon(s), aromatic hydrocarbon(s).The realms-of-existence of monophasic, stable, fluid, transparent and isotropic media, (so-called "microemulsions" [1]), were delineated, at T = 25 ~ for a great number of systems incorporating water, sodium dodecylsulfate, straight or branched alkanols with number of carbons ranging from 2 to 10, and aliphatic, (n-octane, n-dodecane, n-hexadecane), or aromatic, (benzene, toluene), hydrocarbons. It has thus been possible to evidence the influence of different composition factors upon the general configuration of the microemulsion domain, e. g. straight alkanol number of carbons, alkanol isomery, aliphatic hydrocarbon chain-length, and aliphatic hydrocarbon-aromatic hydrocarbon substitution [2][3].It clearly appears from this study that, in any case, the three-dimensional microemulsion domain is the volumic extension of the realm-of-existence of the water/surfactant/alkanol micellar solutions. The micro-1) Present addresses: A. Zradba, Ecole Normale Sup~rieure de Casablanca, Avenue Victor Hugo, Casablanca, Maroc (Morocco).L. Nicolas-Morgantini, L'Or~al, 1, Avenue Saint Germain, 93600 Aulnay-sous-Bois (France). W950emulsion domain configuration is influenced, primarily, by the alkanol molecular structure, and, to a lesser degree, by that of the hydrocarbon. As a general rule, the microemulsion domain existing in the phase tetrahedron of systems incorporating long straight alkanols, (number of carbons no1 > 6), appears to consist of two disjoined volumes, V1 and V2, respectively built on the regions L1 and L2 corresponding, in the water/ surfactant/alkanol phase diagram, to direct and inverse ternary micellar solutions. Per contra, the microemulsion domain of systems incorporating short straight alkanols, (nc~ < 3), forms in the phase tetrahedron an all-in-one-block volume built on the "monophasic" area that exists in the water/surfactant/alkanol phase diagram, as the result of the merging of the L1 and L2 regions. In the case of medium straight alkanols, (3 < nca < 6), the microemulsion domain also forms an allin-one-block volume but exhibits configuration irregularities that reflect peculiarites of the water/surfactant/alkanol "monophasic" area.For the four systems water/sodium dodecylsulfate/ C4 to C7 straight alkanols/n-dodecane, details of the microemulsion domain configuration were obtained from systematic determinations of the microemulsion

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The aim of this article is to investigate the performances of an indirect temperature swing adsorption process for CO 2 removal from nitrogen using 13X zeolite. Breakthrough experiment, with a 10% CO 2 -N 2 mixture, were performed showing that thanks to the cooling, the adsorbent capacity is preserved and close to that of an isothermal adsorption. For the desorption step, CO 2 at a concentration of nearly 100% is recovered thanks to the indirect heating and the non-use of purge gas. During the cycle experiments, we obtained 7.9 MJ/kg CO 2 for the specific heat consumption. This value is slightly higher than amine absorption ones, which is the reference process for CO 2 capture. However, it has to be taken into account that there is a good potential of energy saving because our process configuration (adsorbent choice, number of beds, step duration, etc.) has not been optimized yet. Moreover, in scaled-up process, the heat losses are of less importance, which will decrease the specific heat consumption. This is confirmed by a first estimation, which gives a value of 5.9 MJ/kg CO 2 .