-
Evaluation of Adsorption Capacity of Methylene Blue in Aqueous Medium by Two Adsorbents: The Raw Hull of Lophira Lanceolata and Its Activated Carbon
Elie Sogbochi,
Clément Kolawolé Balogoun,
Cocou Pascal Agbangnan Dossa,
Dominique Codjo Koko Sohounhloue
Issue:
Volume 6, Issue 5, October 2017
Pages:
76-87
Received:
20 September 2017
Accepted:
30 September 2017
Published:
10 November 2017
Abstract: The purpose of this study is to evaluate the adsorption capacity of two adsorbents from the lignocellulosic residues of Lophira Lanceolata. The raw hull of Lophira Lanceolata and its activated carbon produced by chemical activation with orthophosphoric acid (H3PO4) at 50% (Vacid/Vwater) of the said hull. The ratio of impregnation to orthophosphoric acid used is 4.5. Activation and carbonization were carried out at 400°C. The physicochemical properties of the prepared activated carbon were determined and methylene blue adsorption tests were performed. On the basis of the results obtained, the iodine test revealed that the activated carbon produced had a microporosity of 646.81 mg/g, a density of 0.3156, a moisture content of less than 15% and ash content equal to 2%. Regarding the adsorption, results showed that methylene blue (100 ppm) adsorbed more easily on the activated carbon produced than on the crude residues with respective contact time of 10 minutes and 40 minutes. The removal rate was of the order of 100% for the activated carbon and of 83.56% for the raw hulls. Furthermore, an influence of the mass of the support, of the initial concentration and of the pH on the kinetics and on the adsorption capacity was observed. Kinetics obeyed to the pseudo-second order model; the diffusion was intra-particular and the Freundlich and Langmuir models satisfactorily described the adsorption of methylene blue respectively on the crude residues and on the produced activated carbon.
Abstract: The purpose of this study is to evaluate the adsorption capacity of two adsorbents from the lignocellulosic residues of Lophira Lanceolata. The raw hull of Lophira Lanceolata and its activated carbon produced by chemical activation with orthophosphoric acid (H3PO4) at 50% (Vacid/Vwater) of the said hull. The ratio of impregnation to orthophosphoric...
Show More
-
Catalytic Hydrogenation of Dimethyl-Nitrobenzene to Dimethyl-Aniline in a Three-Phase Reactor: Reaction Kinetics and Operation Condition
Issue:
Volume 6, Issue 5, October 2017
Pages:
88-96
Received:
2 October 2017
Accepted:
20 October 2017
Published:
27 November 2017
Abstract: The catalytic transfer hydrogenation of dimethyl-nitrobenzene (DN) to Dimethyl-aniline (DA) was studied in the temperature range 343–403°K, pressure range of 4–10 bar H2 and ethanol as solvent using Ni on alumina-silicate as catalyst above agitation speed 800 rpm. The substrate feed concentration was varied in the range from 0.124 to 0.745 kmol/m3 while catalyst loading was in the range 4–12% (w/w) of dimethyl-nitrobenzene. Dimethyl-aniline was the only reaction product, generated through the hydrogenation of the Nitro group of dimethyl-nitrobenzene. The effects of hydrogen partial pressure, catalyst loading, dimethyl-nitrobenzene concentration and temperature on the reaction conversion have been reported. Near first-order dependence on dimethyl-nitrobenzene concentration and hydrogen pressure were observed for the initial rate of dimethyl-nitrobenzene hydrogenation over the Ni catalyst. Furthermore, an increase in the catalytic activity as the reaction temperature, pressure and weight of catalysts was observed. Conventional Arrhenius behavior was exhibited by catalyst, Ni showed activation energies of 808 J/mol.
Abstract: The catalytic transfer hydrogenation of dimethyl-nitrobenzene (DN) to Dimethyl-aniline (DA) was studied in the temperature range 343–403°K, pressure range of 4–10 bar H2 and ethanol as solvent using Ni on alumina-silicate as catalyst above agitation speed 800 rpm. The substrate feed concentration was varied in the range from 0.124 to 0.745 kmol/m3 ...
Show More
-
Damping Properties of Aluminum/ Duralumin Multi-Layered Graded Structures Fabricated by Hot Rolling
Issue:
Volume 6, Issue 5, October 2017
Pages:
97-102
Received:
13 March 2017
Accepted:
23 March 2017
Published:
28 November 2017
Abstract: This study aims to fabricate aluminum (A1050)/ duralumin (A2017) multi-layered structures with interface composition gradient by hot rolling, and investigate their nanoindentation properties, and macro-mechanical property such as damping. 2- and 6-layered aluminum/ duralumin graded structures with asymmetric lay-ups from one side of aluminum to another side of duralumin have been fabricated, which suffer from three different heat-treatments such as (1) as-rolled (no heat-treatment), (2) annealed at 400°C and (3) homogenized at 500°C followed by water quenching and aging (T4 heat treatment). Nanoindentation demonstrated higher hardness and elastic modulus correspond to higher Cu content in annealed and aged samples. Duralumin in annealed samples shows much lower hardness and elastic modulus than those in as-rolled and aged ones. For damping properties, 2-layered graded structures show higher values than 6-layered graded structures, which are lower than single layers of aluminum.
Abstract: This study aims to fabricate aluminum (A1050)/ duralumin (A2017) multi-layered structures with interface composition gradient by hot rolling, and investigate their nanoindentation properties, and macro-mechanical property such as damping. 2- and 6-layered aluminum/ duralumin graded structures with asymmetric lay-ups from one side of aluminum to ano...
Show More
