The Effect of Nitrogen Gas Flushing on Intermediate Products Formation in Acidogenic Stage of Anaerobic Process of Cocoa Sweatings

Mindriany Syafila, Marisa Handajani, Adearty Prayascitra

Abstract


Cocoa is one of Indonesian-main plantation commodities. During the cocoa seed drying process, there are two types of waste that are cocoa pod and cocoa sweating. Since the organic compounds contained in cocoa sweating is high enough, it is possible to anaerobically treat this wastewater in order to recover either intermediate or end products. Preliminary study showed that the existence of H2 in the reactor would block acetic acid formation. Therefore, the aim of this current experiment was to decrease hydrogen partial pressure by flushing various nitrogen gas flow rate to shift the intermediate products during the cocoa sweating anaerobic treatment. The experiments were carried on a Circulating Bed Reactor (CBR) which contained organic compounds around 100,000 mg/l COD. Then, the reactor was flushed continuously with nitrogen gas as without flushing, 125 ml/min, 500 ml/min and 750 ml/min. The results show there was a possibility that the introduction of nitrogen gas into the reactor could shift the profile of the intermediate product formation. At lower nitrogen gas flow rate more ethanol was formed than acetate formation, although at higher nitrogen gas flow rate the formation of acetate was still low enough. 


Full Text:

PDF

References


Direktorat Jenderal Perkebunan (Ditjenbun), Road Map Kakao 2005-2025. Departemen Pertanian. Jakarta, 2006.

Buamah, R., Dzogbefia, V.P. & Oldham, J.H., Pure yeast culture fermentation of cocoa (Theobroma cacao L): effect on yield of sweatings and cocoa bean qual, World Journal of Microbiology and Biotechnology, 13(4), 457-462, 1997.

Thompson, S.S., Miller, K.B. & Lopez, A.S., Cocoa and Coffee, in Doyle, M.P., Beuchat, L.R. & Montville, T.J., (eds.), Food Microbiology: fundamentals and frontiers, ASM Press, Washington D.C., pp. 721-733, 2001.

Lyberatos, G. & Skiadas, I.V., Modelling of anaerobic digestion – a review, Global Nest Int. J, 1(2), 63-76, 1999.

Collet, C., Gaudard, O., Peringer, P. & Schwitzguebel, Jean-Paul, Acetate production from lactose by Clostridium thermolacticum and hydrogenscavenging microorganisms in continuous culture-Effect of hydrogen partial pressure, Journal of Biotechnology, 118(3), 328-338, August 2005.

Fynn, G. & Syafila, M., Hydogen regulation of acetogenesis from glucose by freely suspended and immobilisedacidogenic cells in continuous culture, Biotechnology Letters, ISSN 0141-5492, 12(8), 621-626, August 1990.

Kim, Dong-Hoon., Han, Sun-Kee., Kim, Sang-Hyoun & Shin, Hang-Sik, Effect of gas sparging on continuous fermentative hydrogen production, International Journal of Hydrogen Energy, 31(15), 2158-2169, December 2006.

Kraemer, Jeremy T. & Bagley, David M., Optimisation and design of nitrogen-sparged fermentative hydrogen production biorectors, International Journal of Hydrogen Energy, 33(22), 6558-6565, November 2008.

Handajani, M., Syafila, M. & Bilqies, M., The acetic acid formation as intermediate compound from acidogenesis process of cocoa sweatings for recovery purpose, Proc. the 6th International Symposium on Southeast Asian Water Environment, pp. 222-225, Bandung, 29-31 Oktober 2008.

Inanc, B., Matsui, S. & Ide, S., Propionic acid accumulations and controlling factors in anaerobic treatment of carbohydrate: effects of H2 and pH, Water Sci.Technol., 34(5), 317-325, 1996.

Valdez-Vazquez, I., rios-Leal, E., Carmona-martinez, A., Munoz-Paez, K.M. & Poggi-Varaldo, H.M., Improvement of biohydrogen production from solid wastes by intermittent venting and gas flushing of batch reactors headspace, Environ. Sci. Technol., 40(10), 3409-3415, 2006.

Alshiyab, H.S., Kalil, M.S., Hamid, A.A. & Wan Yusoff, W.M., Improvement of biohydrogen production under increased the reactor size by C.acetobutylicum NCIMB 13357, American J. Environ Sci., 5(1), 33-40, 2009.




DOI: http://dx.doi.org/10.5614%2Fitbj.eng.sci.2010.42.2.2

Refbacks

  • There are currently no refbacks.