M.B. Kulkarni; P.M. Ghanegaonkar
Abstract
There is a great need to implement low-cost and user-friendly methods for further propagation of biogas technology in India. Environment unfriendly disposal of floral waste causes serious environmental pollution. Literature shows a limited research work regarding the anaerobic ...
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There is a great need to implement low-cost and user-friendly methods for further propagation of biogas technology in India. Environment unfriendly disposal of floral waste causes serious environmental pollution. Literature shows a limited research work regarding the anaerobic digestion of floral waste for biogas generation. The present experimental work aims to propagate floral waste as a sustainable source of biogas energy in India. Using different techniques like novel alkaline pretreatment, solar heating of the digester and co-digestion with food waste give enhanced biogas production from floral waste. A novel alkaline pretreatment of the floral waste using sodium carbonate and sodium bicarbonate gives an improvement in biogas output by 106%, with a saving in the cost of chemical pretreatment up to 96%, compared to traditional sodium hydroxide pretreatment. Also, solar heating of the digester increases the biogas output by 122% as compared to digesters in ambient conditions. Co-digestion of the floral waste with food waste also improves biogas output by 32.6%. Raw biogas from floral waste contains over 57% methane, which is higher than the previous studies. Large-scale application of the techniques can benefit the society.
D. Pham Van; M.G. Hoang; S.T. Pham Phu; T. Fujiwara
Abstract
Coming out from the growth kinetics, the Gompertz model has been developed and considered as the best one for simulating the biogas production from anaerobic digestion. However, the model has failed to describe the starting point of the process, and no-sense of lag phase constant has been pointed out. ...
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Coming out from the growth kinetics, the Gompertz model has been developed and considered as the best one for simulating the biogas production from anaerobic digestion. However, the model has failed to describe the starting point of the process, and no-sense of lag phase constant has been pointed out. Thus, the goal of this study is to develop a new kinetic model of biogas production with meaningful constants that can alternate the Gompertz model. The kinetic constants of the model were determined by applying the least squares fitting method for experimental data. The experimental data were taken from running seven batch reactors of co-digestion of vegetable, sludge and horse manure under 37oC, pH of 6.7, and total solids of 2.5%. The result of the high coefficient of determination (0.9611-0.9906) demonstrated that the new biogas production kinetic model was feasible to simulate the biogas generation process. This finding has opened a new choice that can deal with simulation of the biogas production. Moreover, co-digestion of vegetable, horse manure, and sludge was also evaluated under strong attention. The biogas potential was in the range of 183-648 Nml/g-VS with the best carbon-to-nitrogen ratio of 16. Vegetable waste played a major role in producing the biogas yield while horse manure and sludge contributed to balancing nutrient of the digestion process. Also, the strong correlation between carbon-to-nitrogen ratio and kinetic constants confirmed that the carbon-to-nitrogen ratio was the key factor that influenced biogas generation.
