Numerical Analysis for Coal Gasification Performance in a Lab-Scale Gasifier: Effects of the Wall Temperature and Oxygen/Coal Ratio

The optimization of multiple factors for gasification performance using a 3D CFD model with advanced sub-models for single-stage drop tube coal gasification was compared with experimental results. A single-stage down-drop gasifier with multiple coal injectors and a single oxygen injector at the top of the gasifier was investigated at different temperatures and O-2/coal ratios. A finite rate/eddy dissipation (FR/ED) model was employed to define the chemical reactions. Kinetic data for the various reactions were taken from previous work. The realizable k-epsilon turbulent model and Euler-Lagrangian framework were adopted to solve the turbulence equations and solid-gas interaction. First, various preliminary reactions were simulated to validate the reaction model with experimental data. Furthermore, various cases were simulated at various O/C ratios and wall temperatures to analyze the syngas species, temperature profile in the whole gasifier, exit temperature, carbon conversion, turbulent intensity, and velocity profile. The maximum CO was found to be 75.06% with an oxygen/coal ratio of 0.9 at 1800 degrees C. The minimum and maximum carbon conversions were found to be 97.5% and 99.8% at O/C 0.9 at 1200 degrees C and O/C 1.1 at 1800 degrees C, respectively.

Automated summary

The optimization of gasification performance using a 3D CFD model for single-stage drop tube coal gasification is compared with experimental results. The study investigates a single-stage down-drop gasifier with multiple coal injectors and a single oxygen injector at different temperatures and O-2/coal ratios. The results show that the maximum CO production and carbon conversion can be achieved under specific temperature and O-2/coal ratio conditions.