How do biomass boilers work?

Anti-freeze answered the question "How do biomass boilers work?"

there are various types of biomass boiler, mainly pellets, wood chip and log gasification. Pellet boilers are usually self feeding from a day hopper or bulk store silo. chip boilers are self feeding wood chips from a large store via an auger and usually with an agitator on the store floor to move chips onto the auger, chips should be usually below 21% moisture content. log gasification boilers are bulk loaded where you fill the combustion chamber with logs, it burns from the bottom and achieves high efficiencies and heat output from the fuel.