Detailed CFD simulations of a 5-MW industrial-scale entrained-flow gasifier using intrinsic char conversion kinetics

The present study is a CFD investigation of the gasification behaviour of different coals at high pressure in the Siemens 5-MW pilot-scale entrained-flow reactor. The detailed models for char conversion kinetics are adjusted based on laboratory investigations of the same coals and then coupled to the CFD framework for the full-scale simulations. The gasification reactions in entrained-flow reactors predominantly take place in the socalled pore-diffusion regime. In order to correctly predict the carbon conversion, suitable models for intrinsic char kinetics and pore evolution are required for each feedstock under the operating conditions considered. In this work, the char gasification kinetics of the investigated coals are first characterized in separate laboratory-scale experiments for the kinetic and pore diffusion regimes. This data is used to calibrate the char conversion models, which are then coupled to the CFD code. This comprehensive modelling framework is finally used to simulate the conversion behaviour of the coals in the Siemens 5-MW pilot-scale gasifier. In particular, the numerical results are compared to the measured carbon conversions under different operating conditions (equivalence ratios) and the syngas composition after quench. The analysis carried out in this work demonstrates that accurate predictions of carbon conversion in industrial-scale gasifiers can be obtained using advanced intrinsic char gasification models when calibrated with laboratory-scale experiments.