The present invention provides a char collector (1) for a pyrolysis system (2), the pyrolysis system (2) featuring a pyrolysis reactor (17) comprising a hot char outlet (3), the char collector comprises a container (4) and a longitudinal char conveyor unit (5), and the container (4) comprises a chamber (6), a first inlet (7) connectable to the hot char outlet (3) and a first outlet (8), wherein the first inlet (7) is arranged in an upper portion of the chamber (6) and the first outlet (8) is arranged in a lower portion of the chamber (6); and the char conveyor unit (5) comprises a first end section (9) connected to the first outlet (8), a second end section (10) featuring a second outlet (11) for cooled char and a conveying mechanism (12) configured to transport char from the first end section (9) to the second outlet (11) during use; wherein the second outlet (11) is at a level above the first outlet (8), such that a gas trap is formed between the first inlet (7) and the second outlet (11) when the chamber (6) is filled with water up to a level above the first outlet (8) during use.

A fluidized bed gasification system which comprises a fluidized bed gasification reactor having a bottom ash discharge outlet below the reactor, wherein an L-valve is used to control the rate of bottom ash discharge. The L-valve uses an aeration port located on distal side of the L-valve vertical pipe at a location that is above the center line of the horizontal pipe. Also provided are methods of controlling the bottom ash discharge as well the fluidized reaction bed height of the system.

A fluidized bed gasification system which comprises a fluidized bed gasification reactor having a bottom ash discharge outlet below the reactor, wherein an L-valve is used to control the rate of bottom ash discharge. The L-valve uses an aeration port located on distal side of the L-valve vertical pipe at a location that is above the center line of the horizontal pipe. Also provided are methods of controlling the bottom ash discharge as well the fluidized reaction bed height of the system.