Biomass energy conversion apparatus and method

Abstract

Method and apparatus are disclosed to utilize the energy in biomass (waste agricultural products). The inventive method and apparatus utilized heat and mass flow to efficiently generate a variety of products from biomass. In various embodiment, the invention may generate a liquid fuel (such as methanol or dimethyl ether), pure liquid CO2 (intended for CO2 sequestration), a soil enhancement product (intended to return to the agricultural site), process heat, and/or electricity. In one embodiment, the process requires no external energy inputs, and preserves a large percentage (ie. >50%) of the energy contained in the biomass. In another embodiment, the inventive method and apparatus can selectively be operated to produce electricity and or liquid fuels.

1 . A method of operating a biomass energy conversion system, said method comprising:
 receiving a biomass;   selectively generating output from the biomass energy conversion system, where said output is one or more of electric power or liquid fuel; and   providing said output.   
     
     
         2 . The method of  claim 1 , where said biomass energy conversion system includes a biomass gasification unit to accept a biomass and produce a gas, an electric power generator and a fuel synthesis reactor, and where said selectively generating includes selectively providing said gas to said electric power generator or said fuel synthesis reactor. 
     
     
         3 . The method of  claim 2 , where said method includes exchanging heat from said electric power generator to at least a portion of said fuel synthesis reactor. 
     
     
         4 . The method of  claim 2 , where said method further includes generating products of biomass gasification by thermally reacting said biomass. 
     
     
         5 . The method of  claim 4 , where said generating further includes pyrolyzing the biomass. 
     
     
         6 . The method of  claim 5 , where said generating further includes partially oxidizing the pyrolyzed biomass. 
     
     
         7 . The method of  claim 3 , where said method further includes exchanging heat from said electric power generator or said fuel synthesis reactor to heat the biomass. 
     
     
         8 . The method of  claim 1 , where said biomass is rice straw. 
     
     
         9 . An apparatus for generating either electric power or liquid fuel from a biomass, said apparatus comprising:
 a biomass gasification unit to accept biomass and produce a gas stream;   a generator to produce electric power from said gas stream;   a synthesis unit to produce a liquid fuel from said gas stream; and   one or more valves to selectively provide said gas stream to one or more of said generator or said synthesis unit,   where said one or more valves controls the amount of electric power and the amount of liquid fuel provided from the biomass.   
     
     
         10 . The apparatus of  claim 9 , further comprising a heat exchanger to provide thermal energy from said generator to said synthesis unit. 
     
     
         11 . The apparatus of  claim 9 , where said gasification unit includes a torrefaction unit, and where said apparatus further includes a heat exchanger to provide thermal energy from said generator or said synthesis unit to said torrefaction unit. 
     
     
         12 . A method for utilizing biomass, said method comprising:
 a torrefaction process;   one or more additional processes; and   providing heat from at least one of said one or more additional processes to said torrefaction process.   
     
     
         13 . The method of  claim 12 , where said method produces a synthetic fuel, and where said one or more additional process is a fuel synthesis process. 
     
     
         14 . An apparatus for utilizing a biomass comprising:
 an oxygen separation unit to produce oxygen-enriched gases from air;   a partial oxidation unit to accept a biomass stream and said oxygen-enriched gases; and   a thermoelectric generator,   where said thermoelectric generator accepts heat from said partial oxidation unit and provides electricity for at least partially operating said oxygen separation unit.