Two-stage equilibrium model for a coal gasifier to predict the accurate carbon conversion in hydrogen production

The performance of the Texaco gasifier in hydrogen production was studied numerically. To estimate the accurate carbon conversion, a two-stage equilibrium model was proposed. In the proposed model, the two reactions which determined the carbon conversion were separated from other vapor–vapor reactions. The governing equations of the proposed model were derived and a self-consistent method was developed to solve the governing equations. The %AAD of the calculated carbon conversions from the measured values was 2.89 and that of the calculated gas production rate was 0.64. Calculated gas compositions showed a fairly good agreement with the experimental ones for commercial scale plants. It was found that the chemical reactions that occurred in the Texaco gasifier possess a mechanism for keeping the carbon conversion close to unity against a wide variation in the H2O to coal ratios.