Modeling reaction kinetics of steam gasification for a transport gasifier

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 H2O, CO, CO2, H2, and N2. The steam gasification reaction rate for a North Dakota lignite at 815–950 °C can be estimated asdX/dt=1.4×107×e(−2.0×104/T)×PH2O0.63×PTotal−0.70×[CO/(CO+CO2)]−1.91.This rate law was used to predict the fraction of carbon steam gasified per minute based on steam concentration.