Investigating the Energy Potential and Degradation Kinetics of Nine Organic Substrates: Promulgating Sustainability in Developing Economies

Abstract

To standardize, systematize, and improve the efficiency of the evaluation of biodegradable materials for large-scale biogas projects to support clean and sustainable energy development in emerging economies from a sub-Saharan African perspective, this paper analyzes and fits the potential for methane production (biochemical methane potential, BMP) and degradation kinetics of materials based on the gas production and degradation dynamics obtained from methane potential experiments. The first-order, modified first-order, and Gompertz models are used for analysis and fitting. The Gompertz model shows higher accuracy in fitting the methane production potential curve of screened materials, and the fitted methane potential values are close to the experimental values. When using BMP1% (cumulative gas production reaching 1% of cumulative gas production per day) as a quantitative indicator for the methane production potential of materials, the cumulative methane production reaches over 85% of the cumulative methane production at the end of the experiment. The BMP test time is shortened by 26.98% to 72.06%. Among the screened materials, the methane production potential (calculated using BMP1%) of dry rice straw, maize leaves, fresh rice, soybean straw, maize stalks, chicken manure hydrolysate, chicken feathers, kitchen/food waste, and chicken offal are 234.14, 241.01, 253.34, 331.40, 305.80, 508.41, 510.10, 630.7, and 621.32 mL/g, respectively. The kinetic parameters show that among the nine materials, cellulose materials (except for maize stalks and soybean straw), chicken manure, and kitchen waste are easily degradable materials. In contrast, chicken feathers and offal are slowly degradable materials. The study posits that comparing standardized methane production potential and methane production kinetic parameters among materials improves the efficiency of screening materials and is critical for biogas projects.