Assessment of glycerol gasification: devolatilization kinetics and parametric analysis

The forecasted need for diesel fuel continues to rise, and likewise, the competitive biodiesel demand in the middle- to long-term future remains promising. Unfortunately, biodiesel production generates a significant amount of crude glycerol with the byproduct typically exceeding 10% of the biodiesel produced. The current glycerol market cannot accommodate the use of waste crude glycerol; therefore, an alternative solution is needed for the utilization of the crude glycerol and gasification is a potential pathway. In this work, the technical feasibility of gasification of crude glycerol is assessed at two levels: equilibrium modeling which was conducted under ideal conditions and high-fidelity reactive flow modeling in a tubular reactor. Results revealed that elevated steam ratios are required for the gasification of glycerol to reach high conversion rates of 99% and an acceptable cold gasification efficiency of 40%. Although this value is far off from the conventional coal gasification that hovers around 60%, the analysis suggests that gasification of crude glycerol can be accepted as an intermediate solution to the expected flood of glycerol generated by the biodiesel transesterification industry before becoming a waste burden.