Biogas Production from Animal Waste
Biogas Production from Animal Waste report
The lack of energy sources in this century stimulates the researchers to research alternative energy sources. In recent years, studies on the waste recovery and alternative energy sources have been popular in the scientific area. Many studies argue about biogas production from different type of organic wastes and plants. Obiukwu and Nwafor investigated the production of biogas, an alternative source of energy from animal wastes in the laboratory scale. Results showed that biogas containing the methane content of 65% was produced at temperature of 310 K proven as most efficient for stable continuous digestion process . Biogas Production from Animal Waste-Isci and Demirer studied the anaerobic treatability and methane generation potential of three different cotton wastes namely, cotton stalks, cotton seed hull and cotton oil cake were determined in batch reactors. For this purpose biochemical methane potential experiments were performed for two different waste concentrations, namely 30 and 60g/l. The results revealed that, approximately 65, 86 and 78 mL CH4 were produced in 23 days from 1g of cotton stalks, cotton seed hull and cotton oil cake in the presence of basal medium, respectively . Okeh et al. studied the laboratory scale biogas production from rice husks generated from different rice mills was investigated using cow rumen fluid as a source of inoculum. Feedstock to water dilution ratio of 1:6 w/v and initial pH 7 gave the maximum biogas yield of 382 and 357mL/day, respectively. The maximum values of biogas production rate were 30 and 69 mL/day for the control and poultry droppings, respectively, after two days while urea gave 8 mL/day on day four. Mashad and Zhang studied the biogas production potential of different mixtures of unscreened dairy manure and food waste and compared them with the yield from manure or food waste alone. The methane yields of fine and coarse fractions of screened manure and unscreened manure after 30 days were 302, 228, and 241 L/kg, respectively.The cumulative biogas production during the study period is shown in Figure-1. It was observed that biogas production was actually slow at starting and the end of observation. This is predicted because biogas production rate in batch condition is directly equal to specific growth of methanogenic bacteria . During the first 3 days of observation, there was less biogas production and mainly due to the lag phase of microbial growth. Whereas, in the range of 4 to 6 days of observation; biogas production increases substantially due to exponential growth of methanogens. Highest biogas production rate of 3.4 L was measured on day 6. On the commencement of semi-continuous digestion, biogas production was observed to decrease considerably and, this is probably due to unregulated pH region employed, which concurrently leads to increase in concentration of ammonia nitrogen that might be assumed to inhibit the process.