Advancing Renewable Energy Through Open Tanks Microalgae Cultivation for Biofuel Production: Opportunities, Challenges, and Innovative Solutions
Authors: Bahrim Ridhwan Zhafri Kamarul , Wazir Norhidayah Ahmad , Jaapar Azima Syafaini , Abidin Qamarul Hafiz Zainol , Wahab Nurul Farahin Abdul , Khairulanwar M. Khairumuzdanial M. , Jalil M. Mohsin , Bakri Fatin A'lia M. , Harom Zulkarnain , Nor M Ghadaffi M , Ramli Agos Sawal , Hamid Pauziyah Abdul 
Published: February 2024

Renewable energy sources, especially microalgae, have gained popularity due to their high productivity, adaptability for production on non-arable land, and capacity to collect carbon dioxide as the world's energy needs increase and environmental concerns over fossil fuels grow. However, there are substantial financial and technological barriers to overcome when scaling up microalgae culture, particularly in open tank systems. This project aims to establish a large-scale, sustainable biofuel system based on microalgae by addressing these issues and offering a strategy through laboratory research and field trials.

Optimizing conditions for microalgae growth, lipid production, and CO2 utilization efficiency is a major focus of the research. To determine how the diverse external pressures, such as fluctuating weather, nutrient levels, and flocculation processes, affect the productivity and lipid production for biofuel, laboratory experiments expose different microalgae strains to these stresses. Furthermore, the efficiency of CO2 carbonation is assessed, offering insights into the possibility of enhancing microalgae growth. The development of improved flocculation techniques to enhance biomass separation during harvesting is another aspect of this research. To monitor development and determine the best time to harvest, an algae detection system must be integrated into the culture process. This will ensure maximum lipid yield and improve system efficiency.

Field trials in varied climates and open tank systems offer practical evaluations of these methodologies. Results indicate that cultivation parameters significantly affect algae biomass growth, lipid yield, and biofuel production. Introducing CO2 into cultivation systems markedly increases algae growth rates, while short-duration exposure to various conditions affects lipid production. Certain strains demonstrate improved resilience and productivity, leading to an increase in lipid yield for biofuel extraction. Advanced cultivation and harvesting techniques, including the algae detection system, contribute to maintaining productivity over extended operation periods. Challenges such as environmental variability and contamination arise, yet the study's mitigative strategies demonstrate potential in sustaining algae biomass productivity and lipid content for biofuel extraction.

To sum up, the open tank cultivation technique has several benefits, including as affordability, scalability, strain adaptability, organic nutrient cycling, and the ability to sequester carbon. This technology accommodates several microalgae strains with desirable properties and offers a cost-effective, scalable alternative for large-scale biofuel production. This study's integration of lab and field applications offers vital insights for the large-scale replication of microalgae-to-biofuel operations in the future, greatly improving the field of renewable energy sources.