In the heart of Indonesia, researchers have unlocked a promising pathway to transform waste into valuable resources, potentially revolutionizing the energy sector’s approach to sustainability. Led by Bambang Trisakti from the Department of Chemical Engineering at Universitas Sumatera Utara, a groundbreaking study has demonstrated how biogas purification effluent can be repurposed to cultivate lipid-rich microalgae, paving the way for a more circular and efficient bioeconomy.
The global demand for energy has surged, driven by population growth and economic development, but this reliance on fossil resources has come at a significant environmental cost. Biogas offers a renewable alternative, but its purification process generates CO2-rich effluent that is typically discarded. Trisakti’s research, published in Results in Engineering, addresses this challenge by integrating biogas purification with microalgae cultivation, creating a closed-loop system that maximizes resource utilization and minimizes waste.
At the core of this innovation is the Chlorella vulgaris USU1 strain, a type of microalgae that thrives in the packed absorption column-derived effluent (PACDE) containing KHCO3-PZCOO- complex solutions. By optimizing cultivation parameters such as light intensity, agitation, and initial absorbance, the team achieved impressive results. “We were able to achieve a 58.3% CO2 biofixation efficiency and a maximum biomass concentration of 8.64 g/L,” Trisakti explained. “This not only demonstrates the potential for high-quality biofuel generation but also significant CO2 utilization, which is crucial for absorbent regeneration in a closed-loop system.”
The economic implications of this research are equally compelling. With capital costs estimated at IDR 4505 per liter and operating expenses at IDR 1155 per liter, the system yields a net profit of IDR 3331 per liter. This translates to a substantial annual production of 1175 liters of lipid-rich microalgae oil and 3745 liters of reusable biofertilizer effluent, all while valorizing approximately 2.97 kg of CO2.
The fatty acid profile of the lipid produced is predominantly composed of palmitic, oleic, and linoleic acids, making it suitable for various biofuel applications. Moreover, the USU1 strain’s superior lipid accumulation capability, with a yield of 31.19%, sets a new benchmark for comparable strains.
This research not only highlights the potential for scalable and closed-loop carbon capture and utilization technologies but also underscores the importance of integrated biorefinery approaches. By valorizing waste streams and maximizing resource efficiency, this study lays the groundwork for industrial zero-waste implementation and a more sustainable energy future.
As the energy sector continues to grapple with the challenges of decarbonization and resource scarcity, innovations like Trisakti’s offer a beacon of hope. By transforming waste into valuable resources, this research could shape the future of biofuel production, carbon capture, and the broader bioeconomy, driving us towards a more sustainable and circular future.