Biogas Production from Sugar Beet Wastes in an Overload Bioreactor with pH Adjustment

Subject Areas : Renewable Energy

Misagh Keramati ¹ (M.Sc., Student, Chemical Engineering, Quchan University of Technology, Quchan, Iran)
Hossein Beiki ² (Assistant Prof., Department of Chemical Engineering, Quchan University of Technology, Quchan, Iran. *(Corresponding Auther))

Received: 2017-04-01 Accepted : 2017-10-25 Published : 2020-09-22

Keywords: pH Adjustment, Anaerobic digestion, Sugar Beet Wastes, Biogas,

Abstract :

Background and Objective: Considering the importance of environmental protection and necessity of using new energy sources and innovative fuels, in this study, biogas production from sugar beet wastes using a batch lab-scale bioreactor was investigated experimentally. Method: All experiments were done at constant temperature of 37±1 oC with using water bath. Four reactors with the same feed concentration and condition put in a circulated water bath. pH was adjusted in the reactors for the first 4 days on 7, 8 and 9. Substrate to inoculum (S/I) ratio in the reactors was constant and equal to 6:1. Finding: In the over load mono-digester system with high S/I ratio, due to the sharp drop in pH, biogas couldn’t be produced. By adjusting the pH, even for such a system, biogas production can be achieved, although the efficiency of the process is low.  Discussion and Conclusion: The results revealed that, whilst biogas was not produced in the reactor with high S/I ratio, pH adjustment made it possible to generate biogas. Mole fraction of methane in biogas produced in the reactors with pH adjustment were 35-50%. Biogas production occurred with long time delay, so that after 14 days, very little or no biogas was produced. Maximum volume of biogas was produced in reactor with pH=8. Whilst in the reactor with pH=9, biogas produced with high methane purity.  

References:

1. Syndicate, I.S.F. Iranian Sugar Factories Syndicate. 2015  [cited 2015; Available from: www.isfs.ir.


2. Beiki, H., M. Dadvar, R. Halladj, 2009, Pore network model for catalytic dehydration of methanol at particle level, AIChE Journal. Vol. 55(2), pp. 442-449.


3. Beiki, H., Keramati, M., 2019, Improvement of methane production from sugar beet wastes using TiO₂ and Fe₃O₄ nanoparticles and chitosan micropowder additives, Applied Biochemistry and Biotechnology, Vol. 189, pp. 13-25.


4. Aboudi, K., Álvarez-Gallego, C.J, Romero-García, L.I., 2015, Improvement of exhausted sugar beet cossettes anaerobic digestion process by co-digestion with pig manure, Energy & Fuels, Vol. 29(2), pp. 754-762.


5. Alkaya, E., Demirer, G.N., 2011, Anaerobic mesophilic co-digestion of sugar-beet processing wastewater and beet-pulp in batch reactors, Renewable Energy, Vol. 36(3), pp. 971-975.


6. Keramati, M., Beiki, H., 2017, The effect of pH adjustment together with different substrate to inoculum ratios on biogas production from sugar beet wastes in an anaerobic digester,Journal of Energy Management and Technology, Vol. 1(2), pp. 6-11.


7. Hutnan, M., Drtil, M., Mrafkova, L., 2000, Anaerobic biodegradation of sugar beet pulp, Biodegradation, Vol. 11(4), pp. 203-211.


8. Montañés, R., Solera, R., Pérez, M., 2015, Anaerobic co-digestion of sewage sludge and sugar beet pulp lixiviation in batch reactors: effect of temperature, Bioresource technology, Vol. 180,pp. 177-184.


9. Yang, L, Huang, Y., Zhao, M., Huang, Zh., Miao, H., Xu, Zh., Ruan, W., 2015, Enhancing biogas generation performance from food wastes by high-solids thermophilic anaerobic digestion: Effect of pH adjustment, International Biodeterioration & Biodegradation, Vol. 105, pp. 153-159.


10. Chen, X., Yan, W., Sheng, K., Sanati, M., 2014, Comparison of high-solids to liquid anaerobic co-digestion of food waste and green waste, Bioresource technology, Vol. 154, pp. 215-221.


11. Demirel, B., Scherer, P., 2008, Production of methane from sugar beet silage without manure addition by a single-stage anaerobic digestion process,Biomass and Bioenergy, Vol. 32(3), pp. 203-209.


12. Suhartini, S., Heaven, S., Banks, C. J., 2014, Comparison of mesophilic and thermophilic anaerobic digestion of sugar beet pulp: performance, dewaterability and foam control, Bioresource technology. Vol. 152, pp. 202-211.


13. Federation, W.E., 2005, Standard methods for the examination of water and wastewater, American Public Health Association (APHA): Washington, DC, USA.


14. Liu, C. f., Yuan, X., Zeng, G., Li, W., Li, J., 2008, Prediction of methane yield at optimum pH for anaerobic digestion of organic fraction of municipal solid waste, Bioresource Technology, Vol. 99(4), pp. 882-888.


15. Yuan, H., Chen, Y., Zhang, H., Jiang, S., Zhou, Q., Gu, G., 2006, Improved bioproduction of short-chain fatty acids (SCFAs) from excess sludge under alkaline conditions, Environmental science & technology, Vol. 40(6), pp. 2025-2029.


16. Izumi, K., Okishio, Y., Nagao, N., Niwa, Ch., Yamamoto, Sh., Toda, T., 2010, Effects of particle size on anaerobic digestion of food waste, International biodeterioration & biodegradation, Vol. 64(7), pp. 601-608.


17. Wang, K., Yin, J., Shen, D., Li, N., 2014, Anaerobic digestion of food waste for volatile fatty acids (VFAs) production with different types of inoculum: effect of pH,Bioresource technology, Vol. 161, pp. 395-401.


18. Hutnan, M., Drtil, M., Derco, J., Mrafkova, L., Hornak, M., Mico, S., 2001, Two-Step Pilot-Scale Anaerobic Treatment of Sugar Beet Pulp, Polish Journal of Environmental Studies, Vol. 10, No. 4, pp. 237-243


19. Suhartini, S., Heaven, S., Banks, C. J., 2014, Comparison of mesophilic and thermophilic anaerobic digestion of sugar beet pulp: Performance, dewaterability and foam control, Bioresource Technology, Vol. 152, pp. 202–211.