CARBON CAPTURE AND STORAGE WITH LIPID PRODUCTION IN INTEGRATED SYSTEM OF AQUEOUS AMMONIA WITH MARINE MUTANT SYNECHOCOCCUS PCC 7002 IIUM01

CARBON CAPTURE AND STORAGE IN AQUEOUS AMMONIA WITH MUTANT SYNECHOCOCCUS PCC 7002 IIUM01

Abstract

Carbon capture and storage (CCS) involve capturing, transporting and storing CO₂ underground geological permanently. Carbon capture using solvent such as amine and aqueous ammonia has been extensively studied by many researchers.  However, this capture technology for CCS scheme is comparatively costly.  Alternatively, CO₂ emission can be captured and stored by utilizing the well-understood natural photosynthetic process of marine cyanobacteria. However, the capturing process is very slow compared to chemical absorption. Hence, this study concentrates on carbon capturing and storing using integrated of aqueous ammonia and mutated marine cyanobacteria (Synechococcus PCC 7002 IIUM01). The objective of the study was to identify conditions that would maximize CO₂ reduction under varying conditions namely CO₂ flow rate, absorption temperature and aqueous ammonia concentrations. The effectiveness of the mutant cyanobacteria was quantified by measuring the cell concentration, percentage reduction in carbon dioxide concentration, and lipid content. Synechococcus PCC 7002 IIUM01 showed it robustness by growing in aqueous ammonia solution at concentration between 0.5 to 1%(w/v) which the parent strain was not able to tolerate.  The best conditions maximizing CO₂ capture and storage while sustaining growth optimally and being a potential biofuel source was 0.5 Lpm of 15% CO₂ gas flow rate, 0.75% (w/v) of ammonia concentration and at 33^oC of optimum temperature. At this condition, around 68% of CO₂ removal was achieved with 9% yield of lipid and more than 13% (w/v) of cell concentration