Biogas innovation for a circular economy: overcoming challenges and enhancing efficiency

Anaerobic digestion (AD) offers an effective solution for waste management and carbon emission reduction, generating biogas—a viable alternative to nonrenewable energy sources—due to its high heat capacity and fuel efficiency. However, its full potential remains underutilized due to operational challenges, policy constraints, and societal acceptance issues. This paper explores the key challenges in biogas production and examines innovations that support a circular economy. One major hurdle is the resistance of lignocellulosic components in biowaste, limiting efficient AD. Various pretreatment techniques are assessed to enhance the digestibility of these materials. Additionally, microalgal culture is discussed as a promising approach for clean energy production through waste treatment and biogas enhancement. Impurities in biogas often limit its usability, necessitating advanced upgrading techniques, such as nanocellulose membranes, for efficient gas purification. While biogas offers a sustainable alternative to fossil fuels, widespread adoption faces technological and policy barriers. This review analyzes the technological aspects of biogas generation and its role in achieving the United Nations’ Sustainable Development Goals, addressing key challenges, potential solutions, and the broader sustainability impact of biogas technology.