A Sustainable Process to Capture and Store CO2 to Produce More Renewable Bio-Energy

This study aims to integrate different individual processes to utilize micro-algae for production and storage of CO2 (CO2 battery) and further utilise the algal biomass to produce methane by anaerobic digestion for combustion (in addition to treatment of biomass and/or wastewater sludge from different sources). The study will also aim in utilising micro-algae as tertiary water treatment for nitrogen and phosphorus removal. Most wastewater treatment facilities (municipal and industrial) have anaerobic syst ems in their facilities and such a process will be ideal as only micro-algal systems would be the main retrofitting unit. Environmental conditions for photosynthetic growth of algae require light, CO2 (carbon source), water and inorganic salts. Nutrient water containing high amounts of nitrogen and phosphorus will be fed into the algal chamber for micro-algae growth. Micro-algae is harvested on a timely basis and is either dewatered and stored in tanks or is supplied to the anaerobic reactor for producti on of biogas. Biomass either from wastewater sludge or organic waste source and harvested micro-algae can be treated in an anaerobic digester for biogas production. Biogas (70% methane and 30% CO2) is stripped of hydrogen sulphide gas and is combusted in to the combined heat and power (CHP) unit for energy generation. Methane on combustion produces high amounts of CO2 which is recycled into the algal system for further micro-algal growth. These types of wastewater treatment plants are plenty and serve l arge and small communities around United States, Europe (Norway and others), Asia and Oceania, where this technology can be applied.