Determining optimal parameters using Taguchi’s design of experiments (DOE) for improving the quality of biogas generation process

Abstract

The use of an anaerobic process of biogas production depends on various parameters. Increasing the methane (CH4) production percentage is a critical task in an anaerobic process. In the present investigation, the role of the four most common process parameters are temperature, pH value, solid concentration, and C/N ratio optimized for two responses i.e. biogas production and higher methane percentage. A Taguchi Design of Experiment (DOE) methodology was used to investigate and analyze the effects of different parameters using an L9 orthogonal array. The investigation results for both responses showed that solid concentration had a higher contribution of 65.37% and 73.37% for biogas production and methane percentage respectively. The second rank responsible parameter for both the responses is pH having the same contribution of 18%. the initial pH and rotation speed of the process was the most effective parameters for comparison with others. While the other factors’ temperature and C/N ratio contribution are 15.54% and 0.13% for biogas production and 3.48% and 4.25% for methane percentage. Biogas production and methane percentage model found with correlation percentage (r2) 0.98 and 0.92 respectively which is agreeable. The confirmation test results with Taguchi’s model show errors of 7.46% and 2.43% for biogas and methane production percentages respectively.