ABSTRACT

In the present Paper, characteristics of organic materials and lignocellulosic biomasses are examined separately using Combustion analysis & chemical analysis as per standard test procedure. Cow dung and kitchen waste along with lignocellulosic biomass are assessed separately in an anaerobic digester with the objective of generating biogas from it and reduction in the value of oxygen demand. Thus, the main object of the present study is to analyse and find the optimum proportion of organic waste along with lignocellulosic biomass towards generation of biogas and also investigate reduction of oxygen demand during retention period. To evaluate the ability of ligncellulosic biomasses towards biogas generation, rice straw and rice husk (lignocellulosic biomasses) chosen for present study and gathered from central region of India and characterized. Based on the test results obtained from rice straw & rice husk, rice straw as a lignocellulosic biomass has selected for present study towards generation of biogas. Anaerobic digesters are prepared for the separate investigation on biogas generation using cow dung for different feed ratio. Similarly digesters are prepared for the investigation on biogas production using cow dung and kitchen waste for optimum proportion of feed ratio. Similarly, digesters are prepared for the separate investigation on biogas generation using kitchen waste along with rice straw as lignocellulosic biomass for different feed ratio to find out optimum proportion of feed ratio towards biogas generation. Quantity of biogas generated has measured using volumetric method for mesophilic condition. In present study, effect of various parameters such as temperature, feed ratio, pH and reduction in COD and BOD value on biogas generation is also analyzed and studied for different substrate under mesophilic condition. In the present study, optimum biogas generation is observed at 330c of temperature in mesophilic condition and this temperature is maintained by thermal insulation of digester. In thermal insulation, black/ green surface glazing is done and also solar canopy is provided over the digester. Similarly, from present study it is observed that alkaline nature of slurry found to best for optimum biogas generation. It is observed that 9.75% of total solid contents in cow dung slurry for feed ratio of 1:2 generated maximum volume of biogas than other feed ratio. Similarly, it is observed that 10.87 % of total solid contents in co-substrate of cow dung slurry & kitchen waste slurry for feed ratio of 1:2 generated maximum volume of biogas. It is observed that the biogas produced using cow dung slurry is 10% less than the biogas produced from kitchen waste and biogas produced by co-substrate is 5% less than that of kitchen waste. Reduction in the value of BOD and COD has also measured using standard test procedures and it is found that, reduction in BOD & COD value responsible for increment in volume of biogas generation form different substrate. It is observed that percentage COD reduction for cow dung achieved as 42.33% and 45.34% for kitchen waste. Similarly, percentage BOD reduction for cow dung achieved as 58.91% and 67.19 % for kitchen waste

Keyword: Organic waste, lignocellulosic biomass, co-digestion, combustion analysis, chemical analysis, biogas generation, waste minimization