Method and system for delivering heat through gasification of biomass

Abstract

A method and a system for providing thermal energy to a heat demanding equipment, the system comprising a gasification chamber provided with a fire-tube; a temperature sensor monitoring the temperature within the gasification chamber; a controlled-speed dosing unit conveying biomass powder or pellets to the gasification chamber; an air blower injecting a sub-stoichiometric quantity of air within the gasification chamber with the biomass powder or pellets; a syngas burner receiving hot syngas generated by gasification of the biomass powder or pellets within the gasification chamber, from the fire-tube of the gasification chamber, for combustion; and a control unit monitoring the temperature and oxygen conditions in the gasification chamber, and adjusting the dosing unit according to at least one of: i) the temperature within the gasification chamber and ii) thermal heat demand of the heat demanding equipment.

1 . A method for providing thermal energy to a heat demanding equipment, comprising:
 partial combustion of biomass in a gasification chamber; and   combustion of syngas generated by said partial combustion of the biomass.   
     
     
         2 . The method of  claim 1 , wherein the biomass is one of biomass powder of a moisture content up to 20% and biomass pellets of a moisture content up to 15%. 
     
     
         3 . The method of  claim 1 , wherein said partial combustion of biomass in a gasification chamber comprises:
 monitoring temperature variations within the gasification chamber; and   feeding a mixture of biomass and sub-stoichiometric air into the gasification chamber according to parameters of the heat demanding equipment and the temperature within the gasification chamber.   
     
     
         4 . The method of  claim 1 , wherein said partial combustion of biomass in a gasification chamber comprises:
 monitoring temperature variations within the gasification chamber;   feeding a mixture of biomass and sub-stoichiometric air into the gasification chamber according to parameters of the heat demanding equipment and the temperature within the gasification chamber; and   creating a vortex within the gasification chamber.   
     
     
         5 . The method of  claim 1 , comprising directing the syngas generated by partial combustion of the biomass within the combustion chamber to a syngas burner. 
     
     
         6 . The method of  claim 1 , wherein said partial combustion of biomass in a gasification chamber comprises pre-heating the gasification chamber to a temperature within the gasification chamber in a range between about 580° C. and about 620° C. 
     
     
         7 . The method of  claim 1 , wherein said partial combustion of biomass in a gasification chamber comprises selecting a chamber of a generally circular or cylindrical shape. 
     
     
         8 . The method of  claim 1 , comprising providing a cooling system for the combustion chamber. 
     
     
         9 . The method of  claim 1 , comprising providing a double walled gasification chamber for circulation of a cooling fluid. 
     
     
         10 . The method of  claim 1 , comprising, when the temperature in the gasification chamber falls within a target range between about 600° C. and about 800° C., activating feeding of a controlled mixture of biomass and air into the gasification chamber, and, when the temperature in the gasification chamber falls below about 600° C. or above about 800° C., at least one of i) adjusting said feeding of a controlled mixture of biomass and air into the gasification chamber and ii) activating an auxiliary burner, to return the temperature within the gasification chamber to the range between about 600° C. and about 800° C. 
     
     
         11 . The method of  claim 1 , wherein said feeding comprises using a dosing conveyer for the biomass, said feeding comprising injecting biomass powder within the gasification chamber, tangentially to an inner surface of the gasification chamber. 
     
     
         12 . The method of  claim 1 , wherein said feeding comprises using a dosing conveyer for the biomass and a fan for air, and controlling the speed of the dosing conveyer according to at least one of: i) the temperature variations detected within the gasification chamber and ii) a thermal energy demand of the heat demanding equipment 
     
     
         13 . The method of  claim 1 , wherein said feeding comprises feeding one of: i) biomass powder of a size of at most 3 mm and a moisture content between 15% and 20%, ii) and biomass pellets of a size of up to 8 mm and a moisture content of at most 15%. 
     
     
         14 . The method of  claim 1 , said wherein feeding comprises conveying biomass powder on a pneumatic conveyor and, under action of a fan, feeding a mixture of biomass powder and air within the gasification chamber. 
     
     
         15 . The method of  claim 1 , wherein said feeding comprises feeding biomass pellets and injecting sub-stoichiometric air within the gasification chamber from below in an upward and swirling trajectory. 
     
     
         16 . The method of  claim 1 , wherein said combustion of syngas comprises igniting the syngas to generate thermal energy, the method further comprising directing the generated thermal energy to the heat demanding equipment. 
     
     
         17 . A system for providing thermal energy to a heat demanding equipment, comprising:
 a gasification chamber provided with a fire-tube;   a temperature sensor monitoring the temperature within the gasification chamber;   a controlled-speed dosing unit conveying biomass powder or pellets to the gasification chamber;   an air blower injecting a sub-stoichiometric quantity of air within the gasification chamber with the biomass powder or pellets;   a syngas burner receiving hot syngas generated by gasification of the biomass powder or pellets within the gasification chamber, from the fire-tube of the gasification chamber, for combustion; and   a control unit monitoring the temperature and oxygen conditions in the gasification chamber, and adjusting said dosing unit according to at least one of: i) the temperature within the gasification chamber and ii) thermal heat demand of the heat demanding equipment.   
     
     
         18 . The system of  claim 17 , wherein said gasification chamber has a generally circular or cylindrical shape.