Modeling reaction kinetics of steam gasification for a transport gasifier

Abstract

The fraction of carbon in char converted by steam gasification in a transport gasifier such as that being developed by Kellogg Brown and Root (KBR) was kinetically modeled. Char removed during the operation of a transport gasifier was collected, and the rate was determined using thermogravimetric analysis. Tests were performed in a simulated gasification environment containing a mixture of H 2O, CO, CO 2, H 2, and N 2. The steam gasification reaction rate for a North Dakota lignite at 815–950 °C can be estimated as dX/ dt=1.4×10 7× e (−2.0×10 4/T) ×P H2 O 0.63×P Total −0.70×[ CO/( CO+ CO 2)] −1.91. This rate law was used to predict the fraction of carbon steam gasified per minute based on steam concentration.