![]() | Only 14 pages are availabe for public view |
Abstract The present thesis contains three main chapters. The first chapter describes the theoretical concepts of the study title and the literature survey on the related works and studies. The second chapter reports the materials and methods employed in this study. The third chapter presents the results obtained during this study. Discussions of these results clarified the following facts: 1 – Thirty eight of sugar beet root samples were collected for determine their quality. Also 38 samples of molasses of the production lines I and II of the Delta Sugar Company were collected during campaign 2010 in order to assessment their ability for the ethanol production. 2 – The quality of beet sugar is depended on potassium, sodium, amino nitrogen level. Also, the quality of beet molasses is depended on the quality of beet sugar. 3 – Routine physical investigations for the different physical properties of the examined samples demonstrate that there is no appreciable variation of the physical properties of these samples at beginning of season and its end. As well as the physical properties of these samples were compared with other beet molasses employed for the fermentation production of ethanol. 4 – The different chemical investigation reflects that the following points: i) The present beet molasses have appreciable fermentable sugar content (nearly 97 % of sugar content) for both production lines I and II. ii) The total nitrogen and amino acids contents are in the suitable level for production ethanol as inferred from analogous previous studies. iii) Although the concentration of the harmful factor for alcoholic fermentation NO2 is apparently high at the first three periods in the two production lines I & II , but these values still in the safe area at the other periods. On the other hand the volatile organic acids concentration is in the safe area at all samples for production of ethanol. iv) The elemental phosphorous and its oxide P2O5 contents of the representative samples are suitable for the yeast growth. v) The useful trace elements Fe, Zn, Cu, Mn and Mo are present in suitable concentration, while the concentration of the toxic elements such as Cd and Pb is in the safe area. 5 – Examination of the presence of microorganisms in the all samples of molasses under study revealed that all samples were completely free form yeast and filamentous fungi contamination. On the other hand, 73.68% and 68.42% of the tested samples of production lines I and II, respectively, were contaminated by bacteria with total counts ranged from 200 to 6800 CFU/100 ml. 6 – The fermentation studies on the various samples of beet molasses from the Delta Sugar Company demonstrated that the ethanol formation from the samples of the first three periods (27/1 – 8/2 2010) were very low and ranged between 4.2 – 7.8% (equal to 37.4 – 69.37% of the theoretical values). While the levels of ethanol production from the samples of other periods (9/2 – 20/6 2010) reached to 79.15 – 96.94% of the theoretical values. However, the ethanol production by this method in this study yielded appreciable levels under the milled conditions. 7 – The optima production conditions for ethanol from Delta beet molasses by the tested yeast strain were: 20% sugar concentration, pH at 5.0 and incubation temperature at 30˚C. 8 – The inhibitory action of the high nitrite levels in the first three production periods were decreased in the mixture of beet molasses from all the samples of production season 2010. So, this mixture of beet molasses was with high quality and gave high fermentation efficiency. Summary The present thesis contains three main chapters. The first chapter describes the theoretical concepts of the study title and the literature survey on the related works and studies. The second chapter reports the materials and methods employed in this study. The third chapter presents the results obtained during this study. Discussions of these results clarified the following facts: 1 – Thirty eight of sugar beet root samples were collected for determine their quality. Also 38 samples of molasses of the production lines I and II of the Delta Sugar Company were collected during campaign 2010 in order to assessment their ability for the ethanol production. 2 – The quality of beet sugar is depended on potassium, sodium, amino nitrogen level. Also, the quality of beet molasses is depended on the quality of beet sugar. 3 – Routine physical investigations for the different physical properties of the examined samples demonstrate that there is no appreciable variation of the physical properties of these samples at beginning of season and its end. As well as the physical properties of these samples were compared with other beet molasses employed for the fermentation production of ethanol. 4 – The different chemical investigation reflects that the following points: i) The present beet molasses have appreciable fermentable sugar content (nearly 97 % of sugar content) for both production lines I and II. ii) The total nitrogen and amino acids contents are in the suitable level for production ethanol as inferred from analogous previous studies. iii) Although the concentration of the harmful factor for alcoholic fermentation NO2 is apparently high at the first three periods in the two production lines I & II , but these values still in the safe area at the other periods. On the other hand the volatile organic acids concentration is in the safe area at all samples for production of ethanol. iv) The elemental phosphorous and its oxide P2O5 contents of the representative samples are suitable for the yeast growth. v) The useful trace elements Fe, Zn, Cu, Mn and Mo are present in suitable concentration, while the concentration of the toxic elements such as Cd and Pb is in the safe area. 5 – Examination of the presence of microorganisms in the all samples of molasses under study revealed that all samples were completely free form yeast and filamentous fungi contamination. On the other hand, 73.68% and 68.42% of the tested samples of production lines I and II, respectively, were contaminated by bacteria with total counts ranged from 200 to 6800 CFU/100 ml. 6 – The fermentation studies on the various samples of beet molasses from the Delta Sugar Company demonstrated that the ethanol formation from the samples of the first three periods (27/1 – 8/2 2010) were very low and ranged between 4.2 – 7.8% (equal to 37.4 – 69.37% of the theoretical values). While the levels of ethanol production from the samples of other periods (9/2 – 20/6 2010) reached to 79.15 – 96.94% of the theoretical values. However, the ethanol production by this method in this study yielded appreciable levels under the milled conditions. 7 – The optima production conditions for ethanol from Delta beet molasses by the tested yeast strain were: 20% sugar concentration, pH at 5.0 and incubation temperature at 30˚C. 8 – The inhibitory action of the high nitrite levels in the first three production periods were decreased in the mixture of beet molasses from all the samples of production season 2010. So, this mixture of beet molasses was with high quality and gave high fermentation efficiency. |