Effects of Single Super Phosphate and Wood Ash on Biogas Production Using Chicken Droppings with Digitaria Smuts Ii (Wooly Finger Grass)

Abstract

This study was carried out to examine the catalytic effects of Single Super Phosphate and Wood ash on biogas production from co digestion of Chicken Droppings with Digitaria Smooth II. Apre designed digester was adopted and fabricated using locally available materials. The study was carried out in four identical reactors to enable variation of the catalyst combination (100gSSP/50gWoodash, 150gSSP/75gWoodash and 200gSSP/100gWoodash). The research showed that SSP and Wood ash could reduce the lag phase in anaerobic digestion.The Modified Gompertz equation was used to adequately describe the cumulative biogas production.The control had the longest lag phase 8.9 days as compared to 7.9 days with catalyst.At the end of 32 days digestion period, there was significant difference in volume of biogas produced across the digesters from 0.0646m3 (no catalyst) to 0.1087m3 (200gSSP/100gWood ash), indicating 40.6% increment.The Modified Gompertz equation was applied to describe the cumulative biogas generation. The estimated Kinetic Constants using linear regression and other characteristics of the four digesters were obtained. 0.0025m3, 0.0028m3, 0.0031m3, and 0.0046m3 for Biogas Production Rate and 0.0647m3, 0.0737m3, 0.0808m3 and 0.1088m3 for Biogas Production Potential. The average temperatures of the digesters recorded were 35.25 0C, 35.28 0C, 35.30 0C, and 35.40 0C respectively while the average ambient temperature observed during the study was 36 0C which were within the mesophilic range.