Optimisation of anaerobic digestion of layer manure, breeding manure and cow dung using grey relational analysis

• Published in: Biomass conversion and biorefinery 2024-02, Vol.14 (4), p.4715-4727
• Main Authors: Sandhu, Sonam, Kaushal, Rajneesh
• Format: Article
• Language: English
• Subjects: Biotechnology; Energy; Original Article; Renewable and Green Energy
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-022-02677-w

A variety of feedstock materials have been investigated for biogas production, some of which have never been rigorously studied. In the present study, biogas was produced using three different feedstock materials, namely layer manure, breeding manure and cow dung. Each of these materials was analysed individually using the Taguchi method. The design of experiments (DOE) recommended tests were carried out in a systematic manner. The multi-objective method of grey relational analysis (GRA) was utilised to determine the optimal level of process parameters. It was found that biogas production from layer manure, breeding manure and cow dung was affected by different parameters. Moreover, operating parameters like temperature (25 °C, 35 °C and 45 °C), hydraulic retention time (1–30 days) and pH (5–7) were varied to obtain the maximum yield of biogas. The L 9 orthogonal array was selected to conduct the experiment. In addition, the analysis of variance (ANOVA) was used to determine every factor’s percentage contribution. The correlation coefficients R 2 , Adj- R 2 and Pred- R 2 were found to be statistically significant, indicating that the model was remarkable. It was discovered that biogas and methane yields were at their highest for breeding manure followed by layer manure and cow dung. Meanwhile, the results revealed that pH was the most influential factor, followed by temperature and hydraulic retention time (HRT). The optimum values of methane and biogas for breeding manure have been obtained as 1104.77 ml and 1465.22 ml, respectively while the optimum values of methane and biogas for breeding manure have been obtained as 426.55 ml and 832.013 ml respectively. Graphical abstract