Assessment of glycerol gasification: devolatilization kinetics and parametric analysis

Abstract

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 anlysis 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.