| 1. |
- Moshi, Anselm, et al.
(författare)
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Characterisation and evaluation of a novel feedstock, Manihot glaziovii, Muell. Arg, for production of bioenergy carriers: Bioethanol and biogas.
- 2014
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Ingår i: Bioresource Technology. - : Elsevier BV. - 1873-2976 .- 0960-8524. ; 172, s. 58-67
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to characterise and evaluate a wild inedible cassava species, Manihot glaziovii as feedstock for bioenergy production. Tubers obtained from 3 different areas in Tanzania were characterised and evaluated for bioethanol and biogas production. These bioenergy carriers were produced both separately and sequentially and their energy values evaluated based on these two approaches. Composition analysis demonstrated that M. glaziovii is a suitable feedstock for both bioethanol and biogas production. Starch content ranged from 77% to 81%, structural carbohydrates 3-16%, total crude protein ranged from 2% to 8%. Yeast fermentation achieved ethanol concentration of up to 85g/L at a fermentation efficiency of 89%. The fuel energy of the bioethanol and methane from flour-peels mix ranged from 5 to 13 and 11 to 14MJ/kgVS, respectively. Co-production of bioethanol and biogas in which the peels were added to the fermentation residue prior to anaerobic digestion produced maximum fuel energy yield of (15-23MJ/kgVS).
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| 2. |
- Moshi, Anselm, et al.
(författare)
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Combined production of bioethanol and biogas from peels of wild cassava Manihot glaziovii
- 2015
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 279, s. 297-306
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Tidskriftsartikel (refereegranskat)abstract
- Cassava peels were pre-treated with alkali, enzyme and in sequential combination of alkali and enzyme, and used for production of bioethanol or biogas, or both (in sequence, bioethanol followed by biogas). The Biogas Endeavour and Automatic Methane Potential Test Systems were used for production of bioethanol and biogas, respectively. The bioethanol yield and volumetric productivity achieved with alkali pre-treatment combined in sequence with enzyme pre-treatment were 1.9 mol/mol and 1.3 g/L/h which was higher than the yield (1.6 mol/mol) and volumetric productivity (0.5 g/L/h) obtained from only enzyme pre-treated peels. Alkali combined in sequence with enzyme was proven to be the best treatment showing a 56% improvement in methane yield compared to the yield from untreated sample. Combined ethanol and methane production resulted in 1.2-1.3-fold fuel energy yield compared to only methane and 3-4-fold compared to only ethanol production. This study therefore provides practical data on the scenario best suited for the harnessing of energy from cassava peels. (C) 2015 Elsevier B.V. All rights reserved.
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| 3. |
- Moshi, Anselm, et al.
(författare)
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High temperature simultaneous saccharification and fermentation of starch from inedible wild cassava (Manihot glaziovii) to bioethanol using Caloramator boliviensis.
- 2015
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Ingår i: Bioresource Technology. - : Elsevier BV. - 1873-2976 .- 0960-8524. ; 180, s. 128-136
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Tidskriftsartikel (refereegranskat)abstract
- The thermoanaerobe, Caloramator boliviensis was used to ferment starch hydrolysate from inedible wild cassava to ethanol at 60°C. A raw starch degrading α-amylase was used to hydrolyse the cassava starch. During fermentation, the organism released CO2 and H2 gases, and Gas Endeavour System was successfully used for monitoring and recording formation of these gaseous products. The bioethanol produced in stoichiometric amounts to CO2 was registered online in Gas Endeavour software and correlated strongly (R(2)=0.99) with values measured by HPLC. The organism was sensitive to cyanide that exists in cassava flour. However, after acclimatisation, it was able to grow and ferment cassava starch hydrolysate containing up to 0.2ppm cyanide. The reactor hydrogen partial pressure had influence on the bioethanol production. In fed-batch fermentation by maintaining the hydrogen partial pressure around 590Pa, the organism was able to ferment up to 76g/L glucose and produced 33g/L ethanol.
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| 4. |
- Moshi, Anselm, et al.
(författare)
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Production of raw starch-degrading enzyme by Aspergillus sp. and its use in conversion of inedible wild cassava flour to bioethanol.
- 2015
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Ingår i: Journal of Bioscience and Bioengineering. - : Elsevier BV. - 1347-4421 .- 1389-1723.
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Tidskriftsartikel (refereegranskat)abstract
- The major bottlenecks in achieving competitive bioethanol fuel are the high cost of feedstock, energy and enzymes employed in pretreatment prior to fermentation. Lignocellulosic biomass has been proposed as an alternative feedstock, but because of its complexity, economic viability is yet to be realized. Therefore, research around non-conventional feedstocks and deployment of bioconversion approaches that downsize the cost of energy and enzymes is justified. In this study, a non-conventional feedstock, inedible wild cassava was used for bioethanol production. Bioconversion of raw starch from the wild cassava to bioethanol at low temperature was investigated using both a co-culture of Aspergillus sp. and Saccharomyces cerevisiae, and a monoculture of the later with enzyme preparation from the former. A newly isolated strain of Aspergillus sp. MZA-3 produced raw starch-degrading enzyme which displayed highest activity of 3.3 U/mL towards raw starch from wild cassava at 50°C, pH 5.5. A co-culture of MZA-3 and S. cerevisiae; and a monoculture of S. cerevisiae and MZA-3 enzyme (both supplemented with glucoamylase) resulted into bioethanol yield (percentage of the theoretical yield) of 91 and 95 at efficiency (percentage) of 84 and 96, respectively. Direct bioconversion of raw starch to bioethanol was achieved at 30°C through the co-culture approach. This could be attractive since it may significantly downsize energy expenses.
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