Integrated Biogas and Organic Fertilizer Production: A Review

Abstract

The increasing demand for sustainable energy and environmentally responsible waste management has accelerated interest in integrated waste-to-energy systems. This review critically examines the production of biogas through anaerobic digestion of biodegradable waste, including human waste, cow dung, and kitchen waste, with a focus on co-digestion strategies and process optimization. The study evaluates key operational parameters such as temperature, pH, carbon-to-nitrogen ratio, and retention time, and their influence on methane yield and system stability. A comparative analysis of mono-digestion and co-digestion systems reveals that co-digestion enhances biogas production by improving nutrient balance and microbial activity. Furthermore, the review explores the potential of digestate as an organic fertilizer, highlighting its nutrient composition and role in improving soil fertility and crop productivity. Emerging technologies, including IoT-based monitoring and artificial intelligence for process optimization, are also discussed. The integration of biogas production with agricultural applications supports circular economy principles by converting waste into valuable energy and bio-inputs. Despite its advantages, challenges such as process inefficiencies, high initial investment, and lack of standardization remain. The paper identifies key research gaps and provides future directions for enhancing system performance and scalability. The findings indicate that integrated biogas systems offer a sustainable solution for renewable energy generation, waste management, and eco-friendly agriculture.
ENVIRONMENTAL IMPACT STATEMENT
This review highlights the potential of integrated biogas systems as a sustainable solution for managing biodegradable waste while generating renewable energy. By analyzing co-digestion strategies and process optimization, the study demonstrates improved methane yield and system efficiency. The utilization of digestate as an organic fertilizer further supports soil health and reduces reliance on chemical inputs. The incorporation of IoT-based monitoring enhances process control and scalability. Overall, the study contributes to circular economy practices by converting waste into valuable energy and agricultural inputs, thereby reducing environmental pollution and promoting sustainable development.

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