Search

Your search keyword '"Aranda, Donato A.G."' showing total 36 results
Start Over Author "Aranda, Donato A.G." Publication Type Academic Journals
36 results on '"Aranda, Donato A.G."'

33. Glycerol conversion in the experimental study of catalytic hydrolysis of triglycerides for fatty acids production using Ni or Pd on Al2O3 or SiO2.

Author

Díaz, Gisel Chenard, Tapanes, Neyda de la C. Om, Câmara, Leôncio Diógenes T., and Aranda, Donato A.G.

Subjects
*CATALYTIC hydrolysis, *GLYCERIN, *ENERGY conversion, *TRIGLYCERIDES, *FATTY acids, *SILICA, *METALLIC oxides
Abstract

Abstract: In many reactions to produce biodiesel the glycerol represents 10 wt% of the total products therefore it is important to find an adequate destination of such byproduct. The catalytic hydrolysis of triglycerides is another way to produce biodiesel from fatty raw materials. This work shows the catalytic hydrolysis of triglycerides (soybean oil and tallow) with nickel (NiO) or palladium (PdO) catalysts supported on Al2O3 or SiO2. The results showed the direct conversion of in situ generated glycerol into hydrogen (H2) and carbon dioxide (CO2). The glycerol conversion was evaluated through the capacity to hydrogenate the unsaturated fatty acids leading to the formation of stearic acid (saturated compound). The catalyst, temperature and time were varied and evaluated in the experiments utilizing the two different kinds of raw materials (beef tallow and soybean oil). Selectivity and statistical planning studies were performed to optimize the formation of stearic acid as it is linked to the hydrogenation of unsaturated compounds by hydrogen generated from the glycerol liquid reforming. [Copyright &y& Elsevier]

Published
2014
Full Text
View/download PDF

34. Biodiesel production from soybean oil and methanol using hydrotalcites as catalyst

Author

Silva, Carla Cristina C.M., Ribeiro, Nielson F.P., Souza, Mariana M.V.M., and Aranda, Donato A.G.

Subjects
*BIODIESEL fuels, *SOY oil, *METHANOL, *TRANSESTERIFICATION, *METAL catalysts, *X-ray diffraction, *ACID basicity, *FOSSIL fuels
Abstract

Abstract: Esters of fatty acids, derived from vegetable oils or animal fats, and known as biodiesel, are a promising alternative diesel fuel regarding the limited resources of fossil fuels and the environmental concerns. In this work, methanolysis of soybean oil was investigated using Mg–Al hydrotalcites as heterogeneous catalyst, evaluating the effect of Mg/Al ratio on the basicity and catalytic activity for biodiesel production. The catalysts were prepared with Al/(Mg+Al) molar ratios of 0.20, 0.25 and 0.33, and characterized by X-ray diffraction (XRD), textural analysis (BET method) and temperature-programmed desorption of CO2 (CO2-TPD). When the reaction was carried out at 230°C with a methanol:soybean oil molar ratio of 13:1, a reaction time of 1h and a catalyst loading of 5wt.%, the oil conversion was 90% for the sample with Al/(Mg+Al) ratio of 0.33. This sample was the only one to show basic sites of medium strength. We also investigated the reuse of this catalyst, the effect of calcination temperature and made a comparison between refined and acidic oil. [Copyright &y& Elsevier]

Published
2010
Full Text
View/download PDF

35. Selective CO oxidation in the presence of H2 over Pt and Pt-Sn catalysts supported on niobia

Author

Marques, Príscila, Ribeiro, Nielson F.P., Schmal, Martin, Aranda, Donato A.G., and Souza, Mariana M.V.M.

Subjects
*CARBON monoxide, *CATALYSTS, *ORGANIC compounds, *HYDROCARBONS
Abstract

Abstract: An essential requirement for the proton exchange membrane fuel cell (PEMFC) is to deliver clean H2 to the anode electrode, the kinetics of which are greatly hindered by traces of CO present from the upstream hydrocarbon reforming and water–gas shift processes. The removal of CO from hydrogen-rich stream to a PEMFC tolerant level, by selective oxidation (SELOX) of CO, has been studied over 1%Pt/Al2O3, 1%Pt-1%Sn/Al2O3, 1%Pt/Nb2O5 and 1%Pt-1%Sn/Nb2O5 catalysts. The Nb2O5-supported catalysts presented higher activity in SELOX reaction at low temperatures, but with lower CO selectivity. The results were explained in terms of platinum modification by the presence of niobia (SMSI effect) and tin (bimetallic effect). [Copyright &y& Elsevier]

Published
2006
Full Text
View/download PDF

36. Transalkylation of polyalkylbenzenes catalyzed by Lewis acids

Author

Marques-Alvarez, Heiddy, Silva, A.D., Souza, Priscilla H.G., Constantino, Alex M., Hernandez-Valdes, Ricardo, Aranda, Donato. A.G., and Antunes, O.A.C.

Subjects
*ALKYLATION, *LEWIS acids, *CATALYSIS, *ATMOSPHERIC pressure
Abstract

Transalkylation of polyalkylbenzenes into monoalkylbenzenes (LABON) in the presence of benzene (B) using Lewis acids as catalysts have been studied. The effect of changes on reaction parameters such as amount, type of catalysts and feed composition mixture was considered. The transformation proceeded with good conversion using different Lewis acid catalysts [AlCl3, AlC2H5Cl2 or Al(C2H5)2Cl]. The reactions were carried out in closed systems with continuous stirring under low temperatures (300–363 K) and atmospheric pressure. [Copyright &y& Elsevier]

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results