id	keyword
ap-5209	combustion
ap-5209	coal
ap-5209	coal combustion
ap-5209	chamber
ap-5209	fuel
ap-5209	energy
ap-5209	power
ap-5209	combustion chamber
ap-5209	kazakhstan
ap-5209	chemical
ap-5209	mass
ap-5209	boiler
ap-5209	reactions
ap-5209	heat
ap-5209	simulation