abstract
activated
adsorber
ash
background
bbq
black
bonfire
burnt
carbon
catalyst
charcoal
coal
combustion
cooking
copy
cost
cube
dark
deposits
dirty
ecology
energy
extraction
flat
fuel
gas
heap
lay
lignite
material
mine
natural
particles
pattern
pieces
porous
pure
purity
resources
smoke
soot
space
stone
stove
surface
texture
textured
trunk
wood