Biomass gasification system and opeating method thereof

Abstract

A biomass gasification system, which generates fuel gas from the thermal treatment of biomass in a gasification furnace thermally powered by a thermal airflow generator, incorporates a slag feed system which supplies slag S generated in the gasification furnace to the thermal airflow generator for use as combustible fuel therein. A vertical hopper is installed to the slag feed system for accumulating the slag to provide a sealing function which separates and seals the respective internal environments of the gasification furnace and thermal airflow generator. A detector is provided in the form of electrodes 9, 10 and 11 which are used to monitor the amount of slag in the vertical hopper by contacting the slag to establish conductivity in the electrode circuit.

1 . A biomass gasification system in which thermal energy from a thermal source is applied to a gasification furnace to generate fuel gas, and in which a slag feed system is incorporated to supply slag generated in the gasification furnace to the thermal source for use as a heat-generating fuel therein comprising: 
 a slag holding part installed to the slag feed system and accumulating the slag.    
   
   
       2 . The biomass gasification system according to  claim 1 , wherein the slag which has accumulated in the holding part forms a seal between internal environments of the gasification furnace and the thermal source.  
   
   
       3 . The biomass gasification system according to  claim 1 , further comprising a detector to monitor an amount of slag in the holding part.  
   
   
       4 . The biomass gasification system according to  claim 3 , wherein the detector is structured as at least a pair of electrodes which come into contact with the slag to form an electrically conductive circuit.  
   
   
       5 . The biomass gasification system according to  claim 3 , further comprising a transporter between the holding part and the thermal source to transport slag from the holding part to the thermal source when the amount of slag, as monitored by the detector, exceeds an amount required to form a seal between the internal environments of the gasification furnace and the thermal source.  
   
   
       6 . A biomass gasification system operating method applied to a biomass gasification system in which thermal energy from a thermal source is applied to a gasification furnace to generate fuel gas, and in which a slag feed system is incorporated to supple slag generated in the gasification furnace to the thermal source for use as a heat-generating fuel therein, comprising: 
 accumulating slag in a holding part installed to the slag feed system and forming a seal between internal environments of the gasification furnace and the thermal source.    
   
   
       7 . The biomass gasification system operating method according to  claim 6 , wherein the slag is transported from the holding part to the thermal source when the amount of slag in the holding part exceeds that required to maintain a seal between the internal environments of the gasification furnace and the thermal source.  
   
   
       8 . A biomass gasification system comprising: 
 a gasification furnace that generates fuel gas and slag from biomass;    a thermal generator;    a slag feed system that supplies slag generated in the gasification furnace to the thermal generator for use as a heat-generating fuel therein; and    a slag holder connected between the slag feed system and gasification furnace that accumulates the slag.    
   
   
       9 . The biomass gasification system according to  claim 8 , wherein the slag which has accumulated in the holder forms a seal between internal environments of the gasification furnace and the thermal generator.  
   
   
       10 . The biomass gasification system according to  claim 8 , further comprising a detector to monitor an amount of slag in the holder.  
   
   
       11 . The biomass gasification system according to  claim 10 , wherein the detector comprises at least a pair of electrodes which contact the slag to form an electrically conductive circuit.  
   
   
       12 . The biomass gasification system according to  claim 10 , further comprising a transporter between the holder and the thermal generator to transport slag from the holder to the thermal generator when the amount of slag, as monitored by the detector, exceeds an amount required to form a seal between internal environments of the gasification furnace and the thermal generator.  
   
   
       13 . The biomass gasification system according to  claim 8 , further comprising a thermal energy supply conduit connected between the thermal generator and the gasification furnace to supply thermal energy to the gasification furnace.  
   
   
       14 . A biomass gasification system operating method comprising: 
 supplying a biomass to a gasification furnace;    generating fuel gas and slag in the gasification furnace;    accumulating the slag in a holder connected to a slag feed system downstream of the gasification furnace and upstream of a thermal generator into which the slag is fed; and    forming a seal between internal environments of the gasification furnace and the thermal generator by accumulating the slag in a selected amount.    
   
   
       15 . The biomass gasification system operating method according to  claim 14 , wherein the slag is transported from the holder to the thermal generator when the amount of slag in the holder exceeds that required to maintain a seal between the internal environments of the gasification furnace and the thermal generator.