Earth, Atmosphere & Environment Sciences

Title :

Strategic enhancement of microalgal biomass production in high rate algal pond integrated with bubble column that is sourced with flue-gas CO?

Area of research :

Earth, Atmosphere & Environment Sciences, Energy Sciences

Focus area :

Microalgal biomass production

Principal Investigator :

Prof. Ramkrishna Sen, Indian Institute of Technology (IIT) Kharagpur

Timeline Start Year :


Contact info :


Executive Summary :

Rapidly increasing global energy demand coupled with its adverse impact on the environment and climate has motivated and driven the world scientific communities to derive innovative and sustainable solutions for green, renewable and economically-viable liquid transportation fuels. Microalgae have recently emerged as potentially sustainable third-generation feedstock for biofuel production, due to their higher growth rates; higher aerial biomass productivities; greater photosynthetic and carbon sequestration efficiencies coupled with comparable ability to accumulate lipid/carbohydrate vis-à-vis terrestrial energy crops. However, microalgal biofuel production is still not economically attractive and sustainable, mainly due to lower yields of biomass/lipid/carbohydrate in cost-effective open-door cultivation systems and higher fossil energy inputs in harvesting/processing of algal biomass. Algal biomass, being the new generation feedstock for food, feed, fuel, fertilizer and other value-added products, has to be sustainably available with consistent quantity and quality. Hence, the project aims to address an important technological challenge in algal biofuel production in a sustainable biorefinery model by developing a bioprocess for strategic enhancement of microalgal biomass production against a globally recognized benchmark of 25 g m–² day–1 in semi-pilot scale high rate algal pond (HRAP) through optimization of CO? recovery from in situ generated flue-gas by purifying it from toxic gases and its efficient delivery into HRAP via bicarbonate-based in situ carbon capture in a bubble column reactor (BCR) integrated with HRAP with/without medium circulation. Optimal CO? recovery and delivery are keys to the success of a bioprocess as algal biomass production is governed by CO? dissolution and transfer rates. Life-cycle analysis (LCA) of the entire bioprocess will be done to check its feasibility and sustainability in terms of biomass production and CO? capture.

Total Budget (INR):


Achievements :

1. Determination of pH optima of the algal strains used for the study: Two strains of microalgae were used in the initial phase of the study namely Chlorella minutesima and Chlorella ellipsoidea. Single colonies of these two strains were isolated from pre-existing cultures and the stains were observed under a light microscope. Subsequently, pH optima of the strains were determined since optimum pH of the growth media is considered to be a key driving force in algal biomass production. The results indicated that for Chlorella minutesima, pH for optimum growth was pH 8 and for Chlorella ellipsoidea, it was found to be pH 10.

Organizations involved