Joana Silva, Salah Akkache, Ana Araújo, Yasmine Masmoudi, Rui Reis, et al.. Development of innovative medical devices by dispersing fatty acid eutectic blend on gauzes using supercritical particle generation processes. Materials Science and Engineering: C, 2019, 99, pp.599-610. ⟨hal-02016548⟩ Plus de détails...
Joana Silva, Salah Akkache, Ana Araújo, Yasmine Masmoudi, Rui Reis, et al.. Development of innovative medical devices by dispersing fatty acid eutectic blend on gauzes using supercritical particle generation processes. Materials Science and Engineering: C, 2019, 99, pp.599-610. ⟨hal-02016548⟩
H. Riahi, Marcello Meldi, Julien Favier, Eric Serre, Eric Goncalves da Silva. A pressure-corrected Immersed Boundary Method for the numerical simulation of compressible flows. Journal of Computational Physics, 2018, 374, pp.361-383. ⟨10.1016/j.jcp.2018.07.033⟩. ⟨hal-01859760⟩ Plus de détails...
The development of an improved new IBM method is proposed in the present article. This method roots in efficient proposals developed for the simulation of incompressible flows, and it is expanded for compressible configurations. The main feature of this model is the integration of a pressure-based correction of the IBM forcing which is analytically derived from the set of dynamic equations. The resulting IBM method has been integrated in various flow solvers available in the CFD platform OpenFOAM. A rigorous validation has been performed considering different test cases of increasing complexity. The results have been compared with a large number of references available in the literature of experimental and numerical nature. This analysis highlights numerous favorable characteristics of the IBM method, such as precision, flexibility and computational cost efficiency.
H. Riahi, Marcello Meldi, Julien Favier, Eric Serre, Eric Goncalves da Silva. A pressure-corrected Immersed Boundary Method for the numerical simulation of compressible flows. Journal of Computational Physics, 2018, 374, pp.361-383. ⟨10.1016/j.jcp.2018.07.033⟩. ⟨hal-01859760⟩
Salah Akkache, Ana-Belen Hernandez, Gabriel Teixeira, Franck Gelix, Nicolas Roche, et al.. Co-gasification of wastewater sludge and different feedstock: Feasibility study. Biomass and Bioenergy, 2016, 89, pp.201 - 209. ⟨10.1016/j.biombioe.2016.03.003⟩. ⟨hal-01458422⟩ Plus de détails...
Gasification experiments were performed for several feedstocks alone (wastewater sludge, waste wood, reeds, olive pomace, solid recovered fuel, paper labels and plastic labels) using a fixed bed reactor operating in semi-batch conditions. In order to combine them in an optimal gasifying blend, the gasification behavior of each feedstock was compared with that of wastewater sludge through the following criteria: the raw feedstock proximate and ultimate composition, the solid conversion, the gas heating value, the pollutants release and the ashes melting. Operated alone, the conversion rate of the feedstocks after 58 min of solid residence time was over 77% of initial mass. The Syngas low heating value produced at 1123 K was in the range of 9.0 to 11.9 MJ m À3. The major concerns regarding the wastewater sludge were the pollutants precursors' release (NH 3 , COS…) and the ash slagging and fouling. The calculated slagging and fouling indexes were high also for olive pomace and for waste wood. Finally, among the possible blends studied the paper labels and plastic labels can be co-gasified with secondary and digested wastewater sludge without any restriction, reeds and solid recovered fuel can be blinded with secondary wastewater sludge without any restriction, a specific attention have to be taken to fouling when they are blended with digested wastewater sludge. The blend based on waste wood and olives pomace should be avoided for instance due to their ash slagging and fouling tendency.
Salah Akkache, Ana-Belen Hernandez, Gabriel Teixeira, Franck Gelix, Nicolas Roche, et al.. Co-gasification of wastewater sludge and different feedstock: Feasibility study. Biomass and Bioenergy, 2016, 89, pp.201 - 209. ⟨10.1016/j.biombioe.2016.03.003⟩. ⟨hal-01458422⟩
A.-B. Hernandez, J.-H. Ferrasse, S. Akkache, Nicolas Roche. Thermochemical Conversion of Sewage Sludge by TGA-FTIR Analysis: Influence of Mineral Matter Added. Drying Technology, 2015, 33 (11), pp.1318-1326. ⟨10.1080/07373937.2015.1036283⟩. ⟨hal-01297640⟩ Plus de détails...
Thermal treatments, such as combustion, gasification, and pyrolysis, have been proven to be a convenient alternative to conventional sludge disposal technologies. Today, process development implies scaling up and so improving the reactor's design. In continuously operated reactors, fresh sewage sludge is in contact with solid residues (reacted material rich in mineral matter and char). Mineral matter has been reported to catalyze the thermo-chemical reactions involved but few works focus on this aspect. In this work, sewage sludge residues were added to fresh sewage sludge. Non-isothermal thermo-gravimetric analysis (TGA) coupled with infrared spectrometry (FTIR) showed that added residues reduce the characteristic reaction temperatures during char combustion and gasification (air, air-N2, and CO2 atmospheres). However, any considerable influence of residues was observed during pyrolysis experiments (N2 atmosphere). The analysis of gas produced during those experiments revealed further details about the solid decomposition, showing considerable differences between different atmospheres.
A.-B. Hernandez, J.-H. Ferrasse, S. Akkache, Nicolas Roche. Thermochemical Conversion of Sewage Sludge by TGA-FTIR Analysis: Influence of Mineral Matter Added. Drying Technology, 2015, 33 (11), pp.1318-1326. ⟨10.1080/07373937.2015.1036283⟩. ⟨hal-01297640⟩
S. Akkache, I. Seyssiecq, Nicolas Roche. Effect of exo-polysaccharide concentration in the rheological properties and settling ability of activated sludge. Environmental Technology, 2013, 34 (22), pp.2995 - 3003. ⟨10.1080/09593330.2013.798001⟩. ⟨hal-01666325⟩ Plus de détails...
S. Akkache, I. Seyssiecq, Nicolas Roche. Effect of exo-polysaccharide concentration in the rheological properties and settling ability of activated sludge. Environmental Technology, 2013, 34 (22), pp.2995 - 3003. ⟨10.1080/09593330.2013.798001⟩. ⟨hal-01666325⟩
S. Akkache, Isabelle Seyssiecq, Nicolas Roche. Effect of exo-polysaccharide concentration in the rheological properties and settling ability of activated sludge. Environmental Technology, 2013, 34 (22), pp.2995-3003. ⟨10.1080/09593330.2013.798001⟩. ⟨hal-00968262⟩ Plus de détails...
The non-Newtonian properties of activated sludge (AS) suspension lead to transfer limitations (oxygen, substrate...) and operation difficulties in Waste Water Treatment Plants (WWTP). The current approach involves assuming the sludge behaves like water on a rheological point of view, and then oversizing pumping and aeration devices, which represent over 60% of the operating cost in WWTP. The objective of this work is to understand the effect of bioflocculation on the rheological properties and the settling ability of AS suspensions, by means of variations in concentration of exo-cellular polysaccharides. Experiments have been conducted in a 20 L laboratory scale bioreactor at a constant retention time of 20 days and with a total suspended solid concentration between 15 and 20 g L−1.
S. Akkache, Isabelle Seyssiecq, Nicolas Roche. Effect of exo-polysaccharide concentration in the rheological properties and settling ability of activated sludge. Environmental Technology, 2013, 34 (22), pp.2995-3003. ⟨10.1080/09593330.2013.798001⟩. ⟨hal-00968262⟩
