Underground coal gasification (UCG) is more advantageous than conventional coal combustion processes, as the first requires lower investment/ handling costs and operates environmentally friendly. Lignite is of utmost importance for the Turkish economy as Turkey has ~15 billion tons of lignite reserves. In this work, we have performed ex-situ reactor experiments to explore the gasification ability of Turkish lignite and to simulate and characterize the UCG process. Preliminary coal gasification tests were carried out with oxygen and steam for Malkara Pirinccesme (Turkey) lignite, which is characterized by high ash contents and low moisture. During the gasification experiments, temperature distribution inside the coal seams was monitored and the syngas outflow rate was measured. Additionally, syngas compositions were analysed using an MRU Varioplus Syngas analyser and an Agilent 7890B gas chromatograph. Results represent that the Turkish lignite sources are suitable for gasification. Experiments were divided into several phase: 1) oxygen phase 2) air- oxygen mixture phase, 3) steam-oxygen mixture phase, 4) air-oxygen-steam mixture phase, The syngas produced in the oxygen gasification stage was characterized by high calorific values of 6-9 MJ/Nm~3, carbon monoxide contents of 23-33 vol.%, and hydrogen contents of 20-30 vol.%. Also, computational models of the experimental setup was built and simulations were performed in ANSYS Fluent to elucidate the optimal parameters required for the high calorific syngas production; such as gasification agent rates, shape of the gasification channel, etc.
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