Underground Coal Gasification: 2D Cavity Growth & Syngas Yield

This is the 2D counterpart of the 3D underground coal gasification simulator. Rather than orbiting a rendered process facility, it draws the mechanism itself in schematic cross-section: an injection well feeds oxygen and steam into a coal seam, a burn cavity grows outward from the ignition point over time, and a production well finally taps the syngas once the burn front reaches it. A real engineering-scale reaction model — combustion, the Boudouard reaction, the water-gas reaction and methanation — sets the live CO/H2/CH4/CO2 syngas composition and heating value from the oxygen injection rate and steam co-injection ratio, while the cavity's growth and pre-breakthrough capture efficiency are tracked as their own physical process instead of a single abstract conversion percentage.