The role of Biochar in anaerobic digestion to enhance the biogas production by focusing on Methanogenic pathway: A review

Abstract

Optimizing the biogas generation process (BGP) during the anaerobic digestion (AD) route is a challenging goal to be achieved through the potential valence of the biochar (BC) application. Anaerobic digestion has become a favored technique aimed at producing clean energy and effectively handling organic waste. Nonetheless, the reactor performance is hindered by the buildup of ammonia, acids and nutrients, resulting in inhibition and instability. Due to its versatility, biochar (BC) has attracted significant attention in biogas production and can be produced by carbonizing biomass and waste materials. Incorporating BC into the anaerobic digestion (AD) process could provide several advantages, such as reducing toxic inhibition, shortening the methanogenic lag phase, immobilizing functional bacteria, and improving the electron transfer rate between methanogenic and acetogenic microorganisms. However, there is still a need for a deeper understanding of the complex role of BC and its detailed mechanisms in biogas production within the AD process. The present brief review paper intends to explore the main role and mechanisms of the BC application as an additive in the AD process, by focusing on how the characteristics of BC affect the AD processes during methanogenic pathways and processes and how they effectively address significant challenges.