<p>A pressurized alkali dispersion supply system (1) for use in permeabilizing a coal seam (2), and in particular for connecting together open zones in a coal seam (2) using a (almost horizontal) linkage channel comprising a multitude of fine cracks (27). The system (1) includes a source of alkali/alkali solution (4), a source of pressurized air (5), a supply pipe (6) and a fogger (7) for forming an alkali mist that is dispersed within the pressurized air. Cracks/fractures (27) open up in the coal seam (2) (ie. permeabilization) under the influence of the compressed air together with dissolution of humic acids by the alkali mist.</p>