Cattle paunch content, a significant waste product from meat processing factories, poses a considerable environmental challenge due to its indiscriminate disposal. However, this waste is also a potential goldmine for renewable energy production, specifically biogas. A recent study published in ACS Omega by Daniel Peter, Aliyu Mohammed, Jack Kufre Esenowo, Mohammed Ibrahim Shaba, and Aminu Abdulkarim investigates the effectiveness of sorghum stalk biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More in enhancing biogas production from this often-underutilized resource.

The researchers explored two main application methods for sorghum stalk biochar: a single addition of 5 grams to a digester and periodic additions of 1 gram at four-day intervals, comparing these to a control digester with no biochar. The anaerobic digestion process was carried out in 1000 mL digester bottles. The results clearly demonstrated that the 5-gram one-time biochar addition significantly outperformed the other treatments, yielding 22.79 mL/g VS of biogas. In contrast, the 1-gram periodic biochar addition yielded 13.83 mL/g VS, and the control produced 11.67 mL/g VS. This means the 5-gram one-time application resulted in approximately 95% more biogas than the control.

A key finding from the study’s statistical analysis, a one-way ANOVA test, revealed a significant difference between the 5-gram one-time biochar addition and both the 1-gram periodic addition and the control group at a 5% level of significance. There was no significant difference in biogas yield between the 1-gram periodic biochar addition and the control. This underscores the importance of the initial dosage for maximizing biogas output. The Gompertz model, widely used for describing biogas production kinetics, was applied to the experimental data, showing an excellent fit with R-squared values of 0.991 for the 5-gram addition, 0.969 for the 1-gram periodic addition, and 0.990 for the control, indicating the model accurately described the cumulative biogas production over time.

The success of biochar in boosting biogas production can be attributed to its unique properties. The sorghum stalk biochar produced for this study had a high surface area of 217.20 m2/g and an alkaline pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More of 9.07. A large surface area facilitates greater interaction with microbial communities, promoting processes crucial for biogas production. Furthermore, biochars with ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion.   Ash Ash is the residue that remains after the complete More content exceeding 20% have been shown to improve and accelerate biomethane generation. The biochar used here had an ash content of 32.36%. The alkaline nature of the biochar likely contributed to its buffering effect, helping to maintain a stable pH within the digesters and alleviate inhibition caused by volatile fatty acid accumulation. This buffering capacity is vital, as the initial pH of the paunch content was 6.56, which is lower than the recommended range of 6.8 to 7.3 for digester stability.

The daily biogas yield data showed an initial peak on day two, followed by a decline due to substrate limitation. However, the digester with the 5-gram one-time biochar addition showed fluctuating increases in biogas production up to day 23, suggesting that the biochar helped sustain the process by providing a favorable environment for methanogens. In contrast, the control digester failed by day 15, likely due to methanogen inhibition from the lack of biochar. The cumulative biogas yield clearly illustrated the sustained enhancement with the 5-gram biochar treatment, consistently yielding more biogas than both the 1-gram periodic addition and the control.

This research highlights a practical and effective approach to converting cattle paunch content into a valuable renewable energy source. By demonstrating that a single 5-gram application of sorghum stalk biochar significantly boosts biogas production, this study offers a compelling solution for sustainable waste management in abattoirs, simultaneously reducing environmental pollution and generating green energy.

Source: Peter, D., Mohammed, A., Esenowo, J. K., Shaba, M. I., & Abdulkarim, A. (2025). Effect of Biochar Application on Biogas Production From Cattle Paunch Content. ACS Omega.