| 摘要 |
<p>Underground gasification of coal is carried out by (a) drilling two bores at a distance from each other into the coal bed; (b) making a passage between the two bores; (c) igniting the coal and (d) maintaining the burning and gasification of the coal via one of the boreholes and adding a medium or media which are reactive with coal and removing a gas with calorific value via the other borehole. The process is characterised, by before igniting the passage, inserting a medium (I) which chemical/ physically crushes the coal. The medium and at least part of the crushed coal are then removed. Pref. (i) the (I) is circulated through both boreholes and entrained coal particles are removed from the medium above ground; (ii) and (I) is chosen from alkali solns, and organic hydrogen donors such as anthracene oils, alcohols, amines, acetone, hydrogen peroxide and ammonia; (iii) when using ammonia, the relationship between the prevailing temp. and press. is chosen to satisfy the vapour pressure curve; (iv) crushed coal is removed from the medium with a liq. or gas stream.</p> |
