Method for inhibiting occurrence of pyrolysis deposit in pyrolysis gasification system, and pyrolysis gasification system
This method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system includes: gasifying biomass (S 2 ) through pyrolysis in a pyrolysis gasification furnace ( 5 ); separating, in a solid-gas separation unit ( 7 ), a pyrolysis gas (G 1 ) and a carbide (C) continuously formed through pyrolysis of the biomass (S 2 ); feeding an oxygen-containing gas (G 3 ) to the separated pyrolysis gas (G 1 ); and introducing the pyrolysis gas (G 1 ) together with the oxygen-containing gas (G 3 ) to a combustion furnace ( 6 ) through a pipe ( 9 ) which constitutes a pyrolysis gas line ( 8 ).
1. A method for inhibiting occurrence of a pyrolysis deposit in a pyrolysis gasification system, the method comprising the steps of:
gasifying biomass through pyrolysis in a pyrolysis gasification furnace;
separating, in a solid-gas separation unit having a heat resistance, a pyrolysis gas and a carbide continuously formed through pyrolysis of the biomass;
feeding an oxygen-containing gas to the solid-gas separation unit during operation of the pyrolysis gasification furnace; and
introducing a mixed gas from the solid-gas separation unit to a combustion furnace through a pipe which constitutes a pyrolysis gas line,
wherein the mixed gas is a mixture of the pyrolysis gas and the oxygen-containing gas.
2. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 1 , wherein
the oxygen-containing gas is a gas having an oxygen concentration of at least 15 volume %.
3. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 1 , wherein
the oxygen-containing gas is fed to the pyrolysis gas so that the mixed gas has a temperature of from 500 to 650° C.
4. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 2 , wherein
the oxygen-containing gas is fed to the pyrolysis gas so that the mixed gas has a temperature of from 500 to 650° C.
5. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 1 , wherein
the oxygen-containing gas is fed to the pyrolysis gas so that a ratio of an actual feed rate of the oxygen-containing gas to a rate sufficient to provide a stoichiometric amount of oxygen for full combustion of hydrocarbons present in the pyrolysis gas is 0.1 or less.
6. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 2 , wherein
the oxygen-containing gas is fed to the pyrolysis gas so that a ratio of an actual feed rate of the oxygen-containing gas to a rate sufficient to provide a stoichiometric amount of oxygen for full combustion of hydrocarbons present in the pyrolysis gas is 0.1 or less.
7. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 3 , wherein
the oxygen-containing gas is fed to the pyrolysis gas so that a ratio of an actual feed rate of the oxygen-containing gas to a rate sufficient to provide a stoichiometric amount of oxygen for full combustion of hydrocarbons present in the pyrolysis gas is 0.1 or less.
8. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 4 , wherein
the oxygen-containing gas is fed to the pyrolysis gas so that a ratio of an actual feed rate of the oxygen-containing gas to a rate sufficient to provide a stoichiometric amount of oxygen for full combustion of hydrocarbons present in the pyrolysis gas is 0.1 or less.
9. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 1 , wherein
oxygen-containing gases having different oxygen concentrations are prepared, and an oxygen-containing gas having a low oxygen concentration and an oxygen-containing gas having a high oxygen concentration of the oxygen-containing gases are selectively fed to the pyrolysis gas.
10. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 2 , wherein
oxygen-containing gases having different oxygen concentrations are prepared, and an oxygen-containing gas having a low oxygen concentration and an oxygen-containing gas having a high oxygen concentration of the oxygen-containing gases are selectively fed to the pyrolysis gas.
11. The method for inhibiting the occurrence of a pyrolysis deposit in a pyrolysis gasification system according to claim 3 , wherein
oxygen-containing gases having different oxygen concentrations are prepared, and an oxygen-containing gas having a low oxygen concentration and an oxygen-containing gas having a high oxygen concentration of the oxygen-containing gases are selectively fed to the pyrolysis gas.
12. A pyrolysis gasification system comprising:
a pyrolysis gasification furnace that gasifies biomass through pyrolysis;
a solid-gas separation unit that has a heat resistance and separates a pyrolysis gas and a carbide continuously formed through pyrolysis of the biomass;
a nozzle that feeds an oxygen-containing gas to the solid-gas separation unit during operation of the pyrolysis gasification furnace;
a pipe which is configured to carry a mixed gas from the solid-gas separation unit, the mixed gas being a mixture of the pyrolysis gas and the oxygen-containing gas; and
a combustion furnace which is configured to combust the mixed gas,
wherein the mixed gas is introduced into the combustion furnace via the pipe.