Use of Microalgae for the Development of Carbon Neutral Bio-CNG Process

The comprehensive chapter focuses on the upgradation techniques and conversion of the biogas generated from the huge amount of biowaste, to methane-enriched bio-compressed natural gas (bio-CNG). The sustainable bio-fixation of the extracted CO2 by employing various algal strains for carbon capture and utilization (CCU) along with the culture conditions has been discussed. The comparative analyses highlight that the integrated biorefinery approach does not involve harmful chemicals, high energy utilization and high operating expenses. The post-treatment and consumption of biogas-separated CO2 by algae make the process carbon neutral. The potential algal strains, their CO2 utilization capacity, and subsequent formation of high algal biomass along with several significant value-added products such as biofuels, biochemicals and biofertilizers in different types of photobioreactors and other process parameters, are also elaborated. The emerging role of efficient algal species in reducing greenhouse gas emissions and addressing the climate change issue has been illustrated for making it an eco-friendly strategy. The systematic valorization of algal biomass contributes to promising resource regeneration and promotes a circular economy in the sector of bioenergy industries to sustainably fulfill the global energy demand.