Co-firing of enteromorpha prolifera algae and RTC coal in a down draft gasifier: Material characterization and flow simulation

The potential energy that algae possess has led to re-emergence of a worldwide interest in it as a biofuel feedstock. Algae derived fuel takes many pathways and challenges. Algae are enthusiastically embraced in the energy sector as the feedstock which overcomes the current market and technical hurdles. This is because of its diversity in composition, co-production and conversion pathways. The quest of finding/engineering algae strains that exhibit highest growth, production rate and a lipid content is never ending. In this work, the whole alga is considered for gasification. Due to its low energy density, it is being considered side by side to coal cofiring, thereby reducing the fossil base CO₂ emission additional to its economic gain. Gasification generates syngas that is used to fuel gas turbine at higher conversion metrics than mass incineration. Starting with material characterization and inferring their unit molar formula, gasification under CO₂ and H₂O moderation is perused following equilibrium conditions based on Gibbs energy minimization principle. Metrics are evaluated and accordingly high fidelity reactive flow analysis for the downdraft gasifier is conducted at the optimal conditions. Systematic gasification conditions under H₂O lead to higher gasification efficiency of nearly 8 points compared to CO₂. Results of the two approaches are compared and 5% efficiency difference is calculated using equilibrium based versus CFD.