SIMULATION STUDY: THE INFLUENCE OF TEMPERATURE AND H2O-O2 MOLE RATIO IN INJECTION GAS TO PRODUCT GAS QUALITY OF UNDERGROUND COAL GASIFICATION

摘要

Surface and underground coal mining have many direct impacts to the environment and the safety of miners. At present the clean coal technologies are rapidly developed and one of these applications is underground coal gasification (UCG). UCG is a coal exploitation technology in which high pressure water vapor-O2 is injected into the coal seam converting it into fuel gas and synthetic gas. It is necessary to understand the influence of temperature and H2O-O2 mole ratio of injection gas on produced gas quality in simulation study. This simulation study was conducted using UCG Reaction and Modeling Simulation Software (URMSS) whose functions to display a numerical simulation of the one dimensional differential equations of species mass, pressure, temperature and reaction kinetics in UCG. It uses a mathematical packed-bed reactor model in steady state condition. The reaction kinetics was modeled in the consideration of heterogeneous reaction between injection gas and solid carbon that using the shrinking core model. The results showed the operating conditions of injection gas with input temperature range of 950 K - 2500 K and the H2O-O2 mole ratio of 15:85 -92:8. The optimum condition found in temperature of 2000 K and H2O-O2 mole ratio 92:8. These conditions produced dry gas containing H2 gas content of 27.1159 % and heating value of 9.6029 MJ/m~3. KUCG;;URMSS