Determination of the Intrinsic Gasification Kinetics of a Bituminous Coal Including Product Gas Inhibition and Char Deactivation Under Entrained Flow Conditions

摘要

This work provides experimentally obtained data concerning the gasification of bituminous coal under entrained-flow conditions. The main focus lies on the determination of reaction kinetics with and without product gas inhibition as well as on thermal deactivation behavior. For this reason, experiments were carried out in a pressurized high-temperature entrained-flow reactor. The reactor is designed for temperatures of up to 1800 °C and pressures of up to 50 bar. In this study, char samples with different residence times at temperatures between 1200 °C and 1600 °C and a pressure of 10 bar were obtained. Pyrolysis experiments were performed in pure nitrogen, while an O/C ratio of one was selected for the gasification. In addition to ultimate, proximate, and structural analyses of the char samples, e.g., to calculate conversion according to the ash tracer method, intrinsic reaction kinetics of the pyrolysis chars with carbon dioxide and steam were determined in a high-pressure thermogravimetric analyzer. The influence of carbon monoxide inhibition on carbon dioxide gasification and of hydrogen on steam gasification was quantified using the Langmuir-Hinshelwood equation. Further, the deactivation behavior of the pyrolysis chars was analyzed by measuring their reactivities under constant reaction conditions and plotting them as a function of residence time. The presented results give an overview about factors like temperature, pressure, gas composition, and residence time affecting fuel conversion. Furthermore, constants describing the reaction behavior of the fuel were determined, which can be used for future simulation of gasification processes.