Chemical composition and diluted acid hydrolysis pretreatment of Acacia mellifera sawdust as a raw material for bioethanol production

• Authors: Buzayehu Desisa , Abraham Dilnesa
• Languages of publication: EN

Abstracts

EN

Biofuels are alternatives to fossil fuels for ensuring energy security and for mitigating climate change. Currently, most biofuels are in the form of a bioethanol that is generated from starch or sugar. Increasing energy demand, food insecurity and ecological concerns leads to evaluating agricultural, forestry and urban lignocellulosic wastes as being very important for energy production. This is because all celluloses and hemicelluloses of lignocellulosic wastes can be converted into bioethanol reducing sugars. Hence, the current study was initiated to determine the chemical composition and best diluted acid hydrolysis pretreatment of Acacia mellifera sawdust for bioethanol production. Our study indicates that the chemical composition of Acacia mellifera sawdust exhibits different composition in extractives such as alcohol, cellulose, lignin and ash. Accordingly, the extractive content of the sawdust was 6.3% soluble alcohol toluene, 52.9% cellulose, 23.9% lignin, 4.2% ash, and 6.92% moisture content, respectively. In our experiment, the biomass at a solid loading rate of 0.66% was pretreated at 121 °C with different sulfuric acid concentrations (0.5, 0.75, and 1 %, w/w) and residence times (10, and 20 min). Total reducing sugars in the hydrolyzed sample with acid and time were then analyzed. The reducing sugars obtained at 0.50%, 0.75% and 1% dilute sulfuric acid concentration with time residence of 10 min and 20 min were, 7.39±0.24 and 8.4±0.9, 8.03±0.64 and 9.18±0.43, 9.68±1.30 and 10.23±0.80, respectively. With the increasing acid concentration and residence time, the amount of glucose in the filtrates increased. Therefore, the total reducing sugar concentration in the hydrolysate of Acacia mellifera saw dust was significantly influenced by the sulfuric acid concentration and residence time. From this study, it can be concluded that total reducing sugars in lignocellulosic wastes are widely available and easily obtainable, they can be considered as potential feedstocks for bioethanol production.

Keywords

EN

Acacia mellifera; Pretreatment; bioethanol production; lignocellulose; reduced sugar

Discipline

• BIOCHEMISTRY: BIOCHEMISTRY

• Publisher: Scientific Publishing House „DARWIN”
• Journal: World News of Natural Sciences
• Year: 2017
• Volume: 14
• Pages: 36-46

Contributors

author

Buzayehu Desisa

• Bioenergy and Biochemical Research Division, Ethiopia Environment and Forest Research Institution, P.O. Box 2322, Addis Ababa, Ethiopia

author

Abraham Dilnesa

• Bioenergy and Biochemical Research Division, Ethiopia Environment and Forest Research Institution, P.O. Box 2322, Addis Ababa, Ethiopia

References

• [1] Szulczyk, K. R., Which is better transportation fuel-butanol or ethanol. International Journal of Energy and Environment 1(3) (2010) 501-512.
• [2] Millati, R., C., Niklasson and Taherzadeh, M. J, Effect of pH, time and temperature of over liming on detoxification of dilute-acid hydrolysates for fermentation by Saccharomyces cerevisiae. Process Biochemical 38(4) (2002) 515-522.
• [3] McMillan, J. D., Bioethanol production: Status and prospects. Renewable Energy 10(2) (1997) 295-302.
• [4] Khider, T.O. Omer, S.H and Elzaki, O. T, Pulping and Totally Chlorine Free (TCF) Bleaching of Acacia mellifera from Sudan. World Applied Sciences Journal 16 (9) (2012) 1256-1261.
• [5] Katrin, M. W, Moustakas, A. and Wiegand, K, Big is not better: small Acacia mellifera shrubs are more vital afterfire. African Journal of Ecology 43 (2005) 131-136.
• [6] TAPPI Method T210 om-58. 1991, TAPPI Method T210 om-58. Weighing, Sampling and Testing Pulp for Moisture. Technical Association of the Pulp and Paper Industry Standard Methods (1991).
• [7] Nikitin, V. M, 'Hirnia drevesini telliuloze', Goslesbumiz dat, M _LPg 233. Chimia Lemnului SI A Celluloze 1 (1960) 1973.
• [8] ASTM D 1106-84, Standard test method for acid –insoluble lignin in wood, Philadelphia, Pa, U.S.A, (1989).
• [9] Albalasmeh A. A., Berhe A. A, Ghezzehei T. A, A new method for rapid determination of carbohydrate and total carbon concentrations using UV spectrophotometry. Carbohydr. Polym. (97) (2013) 253-261.
• [10] Liu, B. Y., Shi, H. Q., Li, X.Q., and Xu, L.q, Analysis of lignin content in waste liguor of rice straw pulp by ultraviolet spectrometer. China pulp and paper 22(6) (2003) 19-22.
• [11] Tarig, O. Khider and Osman, T., Journal of forest products & industries 1(2) (2012) 5-9.

• Document Type: article