Analysis of suitable regions for microalgae cultivation and harvesting potential for carbon capture: A global feasibility study

Abstract

Microalgae, have the ability to capture CO2 and the potential for biofuel production. However, scaling up capturing carbon by microalgae is not feasible worldwide because of difference in weather conditions. Hence, identifying favorable regions for capturing carbon by microalgae is the initial step in commercializing this industry. In this research, a global feasibility study has been conducted to analyse the potential of microalgae cultivation and harvesting to capture CO2, based on carbon emissions, weather conditions, and the boundary of countries. A total of 454 cities were selected for this research, and the amount of microalgae productivity and carbon capture rate in each area was calculated according to the optimal environmental conditions for microalgae growth. Methodology and results have been illustrated using Geographical Information System (ArcGIS 10.8) to provide better visual insight for researchers. The results showed that the average microalgae productivity in Open Ponds (OP) and Tubular Photobioreactors (TPBR) is 132.63 T/ha/y and 78.26 kg/m3/y, respectively. Additionally, the average carbon capture rate by microalgae in OP and TPBR is 37.60 T/ha/y and 40.83 kg/m3/y, respectively. The study also revealed that microalgae will have a higher productivity in OP than in TPBR for 158 regions according to the first scenario, while the number of these areas will decrease to 58 and 29 under the second and third scenarios, respectively. Moreover, the global average potential energy content resulting from microalgae cultivation in OP is 4.854*106 MJ/ha/y. Therefore, selecting suitable regions regarding weather condition and type of cultivation system, is the most significant factors in outdoor commercial scaling up of carbon capture by microalgae.