Preparation and Performance Evaluation of Low Density Briquettes of Multinutrient Feed for Biogas Plants

Densification of the feeds could be a solution to feedstock deficiency for biogas plants and ultimate option for waste management. This paper deals with development of a environmentally and farmer’s friendly technology for sustainable use of waste,through densification and development of a package of integration of nutrients, alternate waste and binder etc with cow dung for biogas plant. The lab study was conducted to examine the feasibility of dry and powdered optimal mix feeds with cow dung to form low-density quality briquettes using starch as binder for accelerating biogas production. The optimal mix feeds of C/N balanced mixture of wastes found suitable for enhancing gas production. The optimal mix was densified into multinutrient briquettes by adding Mg metal nutrient/catalyst. The density, water solubility of the briquettes and volatile fatty acid content of the supernatant were the parameters used to evaluate performance of briquettes after addition of binder in different proportions. All the proportions formed good quality briquettes. The water solubility was almost same for all the ratios of mix feed and starch and was highest for cow dung to starch ratio of 3:1. The volatile fatty acids were also highest for feed to starch ratio of 3:1, concluding the ratio of 3:1 to be optimum for forming good quality briquette and providing environment for maximal bacterial growth for ultimate enhanced biogas production. The economic analysis of the whole process concludes it is a beneficial activity which can be popularized and commercialized for extension and demonstration for mass adoption and for upliftment of the poor in rural areas.