Integrated Marine Biogas: A Promising Approach towards Sustainability

Abstract

Fossil fuel depletion, climate change, and increased global energy demands are the driving forces to find alternative sources of energy. Marine-based biorefinery has been recently discussed as a promising route to mitigate the environmental challenges, enhance the energy recovery, and provide a potential source for value-added products. Anaerobic digestion is a promising technology that can convert the organic compounds of marine ecosystems into biogas. To date, a comprehensive review incorporating integrated biogas potential and effective approaches to enhance seaweed digestibility for biogas production from marine resources has not been reported. Thus, the present review aims to explore and comprehensively present seaweed and other marine resources for potential biogas production. The basics and challenges of biogas production from seaweed are elucidated. The impact of biochemical composition on biogas and the microbial communities involved in anaerobic digestion of seaweed are discussed. Utilization of different techniques such as pretreatment, co-digestion, and sequential extraction of seaweed biomass to enhance the biogas yield and to mitigate the effect of inhibitors are presented. Specifically, this article evaluates the co-digestion of seaweed with other biomass feedstocks or liquid biowastes. Integration of marine microalgae cultivation on anaerobic digestate for value-added compound production, biogas upgrading, and bioenergy recovery provides a promising approach towards a zero-waste marine-based system.