Time filter

Source Type

Harouna I.G.,University of Ouagadougou | Sanogo O.,Institute Of Recherche En Science Appliquees Et Technologies | Daho T.,University of Ouagadougou | Ouiminga S.K.,University of Ouagadougou | And 3 more authors.
Energy for Sustainable Development | Year: 2015

In this work, the technical feasibility of cotton stalk carbonization and torrefaction was studied. A metallic homemade cylindrical furnace 60. cm in diameter and 90. cm in height was used for the experiments. A partial combustion process was used both for carbonization and torrefaction. Three carbonization methods were defined based on the amount of air supplied and cotton stalks introduced in the kiln. Torrefaction process was based on a shorter combustion time of 2. min during the partial combustion, in order to avoid cotton stalk carbonization. Mass and energy yield, proximate analysis and the unburnt cotton stalks proportion (ratio of non-carbonized cotton stalks over carbonized cotton stalks) for each process were determined. In order to avoid the burning of the loaded cotton stalk, and to optimize charcoal quality, an appropriate combustion time of 7. min was found for the carbonisation process. The anhydrous mass yield for the best carbonization process selected is about 28.4% while energy yield is 45.8%. The carbonized cotton stalk has 24.15% and 67.44% of volatile matter and fixed carbon content respectively. The carbonized cotton stalks are suitable for cooking purpose because their volatile matter content allows a rapid ignition. The torrefaction process has a mass and energy yields of 64.1% and 75.3% respectively. Torrefied cotton stalks are more appropriate for gasification compared to carbonized cotton stalks. © 2014 Elsevier Inc.

Nitiema-Yefanova S.,University of Ouagadougou | Coniglio L.,CNRS Reactions and Process Engineering Laboratory | Schneider R.,CNRS Reactions and Process Engineering Laboratory | Nebie R.H.C.,Institute Of Recherche En Science Appliquees Et Technologies | Bonzi-Coulibaly Y.L.,University of Ouagadougou
Renewable Energy | Year: 2016

By starting first at the laboratory scale, optimal operating conditions for the reaction unit aimed at producing ethyl biodiesels from non-edible vegetable oils (NEVO) were determined with the ultimate objective of proposing an on-farm processing technology that should be sustainable for emerging countries. Three NEVO widely available in Burkina Faso were selected: Balanites aegyptiaca (BA), Azadirachta indica (AI), and Jatropha curcas (JC) oils. Their conversion to fatty acid ethyl esters (FAEE) was conducted via a two-stage procedure under atmospheric pressure: an alkali-catalyzed ethanolysis at ambient temperature for the BA and AI oils (leading to 93 and 87 wt.% FAEE respectively) and an acid-catalyzed ethanolysis at the normal boiling of the alcohol for the JC oil (leading to 89 wt.% FAEE). Based on the intermediate addition of glycerol at ambient temperature, the two-stage procedure combines chemical kinetics, chemical equilibrium, and phase equilibrium phenomena. © 2016 Elsevier Ltd.

Bado S.,International Atomic Energy Agency | Bazongo P.,University of Ouagadougou | Son G.,Institute Of Recherche En Science Appliquees Et Technologies | Kyaw M.T.,No. 5 Ziwaka Road | And 5 more authors.
Journal of Analytical Methods in Chemistry | Year: 2015

Tuber characteristics and nutrient composition of three morphotypes of Cyperus esculentus tubers and tuber oils were determined. The mean value for length and width of the tuber and one thousand dried tuber weights ranged from 0.98 to 1.31 cm, 0.90 to 1.19 cm, and 598 to 1044 g, respectively. Tubers displayed high level of starch (30.54-33.21 g 100 g-1), lipid (24.91-28.94 g 100 g-1), and sucrose (17.98-20.39 g 100 g-1). The yellow tubers had significantly higher content in lipid compared to black ones. Levels of ascorbic acid, tocopherol, and β-carotene of the three morphotypes differed significantly. Yellow ones (morphotypes 1 and 2) were the richest in tocopherol and the poorest in β-carotene. Saturated fatty acid content of morphotype 2 was significantly lower than that of morphotypes 1 and 3. Morphotype 3 had the significantly lowest PUFA content compared to morphotypes 1 and 2. Morphotype 1 was found to be richer in Ca, Cu, and Mn contents. Al, Mg, P, S, and Si were most abundant in morphotype 2. Morphotype 3 had the highest content of Cl, K, and Zn. © 2015 Souleymane Bado et al.

Nitiema-Yefanova S.,University of Ouagadougou | Son G.,Institute Of Recherche En Science Appliquees Et Technologies | Ye S.,Institute Of Recherche En Science Appliquees Et Technologies | Nebie R.H.C.,Institute Of Recherche En Science Appliquees Et Technologies | Bonzi-Coulibaly Y.,University of Ouagadougou
Biotechnology, Agronomy and Society and Environment | Year: 2012

Azadirachta indica A.Juss (neem) is a tropical tree, popular for its multiple possible uses. The oil extracted from neem kernels is used in cosmetics, as medicines, as insecticides and for energy needs (biofuel). The oldest oil extraction method is cold pressing. However, the optimal parameters of extraction and the quality of extracted oil are poorly known. The purpose of this research was to identify the optimal extracting parameters of neem oil by cold pressing and to characterize the extracted oil. The results showed that at 25 °C, the optimum yield by pressing of whole kernels was obtained with a pressure of 30.4 MPa ± 4.1 and a maximum degree of filling of the pressing cage. We showed that maintaining this pressure for 6 min could lead to an extraction rate of 40.1% ± 1.1. The oil yield increased with the speed of kernel compression. Reducing the particle size had a positive effect on oil yield when the cage load did not exceed half of the cage capacity. The best oil yield of 40.3% ± 0.0 for ground kernels was obtained with a pressure of 33.7 MPa ± 2.9 and a cage filled in the quarter of its capacity. The content levels of water, iron, copper and phosphorus in the oil extracted by pressing were respectively 0.14%; 11.8; 0.1 and 17 ppm. These characteristics indicate, inter alia, that neem oil obtained by cold pressing is of appropriate quality for use in biodiesel production.

Nitiema-Yefanova S.,University of Ouagadougou | Richard R.,ENSIACET | Richard R.,French National Institute for Agricultural Research | Thiebaud-Roux S.,ENSIACET | And 6 more authors.
Energy and Fuels | Year: 2015

The purpose of this work is to analyze the efficiency of natural adsorbents (rice husk ash (RHA) versus corn husk ash (CHA)) for the dry purification of ethyl biodiesels obtained by transesterification via homogeneous catalysis of nonedible oils (Balagnites aegyptiaca, Azadirachta indica, and Jatropha curcas). The characterization of RHA and CHA was achieved by N2 adsorption/Brunauer-Emmett-Teller analysis and by scanning electron spectroscopy with microanalysis by energy dispersive X-ray spectroscopy. The quality of the three biodiesels, before and after dry treatment on adsorbent, was evaluated by various analytical methods (1H nuclear magnetic resonance, gas chromatography with a flame ionization detector, Karl Fischer titration, and inductively coupled plasma-atomic emission spectroscopy). Several operating conditions (presence of activated carbon in the ashes, temperature, contact time, and number of treatment cycles) were tested in order to define the best procedure. RHA combined with the selected procedure showed very satisfactory results for removal of impurities from the produced biodiesels (residual glycerides, free glycerin, water, catalyst, and metals introduced during the oil extraction) and thus may be an alternative to the conventional wet purification process (acidic water washing). © 2014 American Chemical Society.

Discover hidden collaborations