Multi-faceted gasifier and related methods

A gasifier having a two-stage fixed bed gasification section and an entrained flow gasification section comprising:

• a coarse fuel inlet;
• a two-stage fixed bed gasification section that receives coarse fuel from the coarse fuel inlet, said fixed bed gasification section comprising:
• an upper fixed bed section in which the coarse fuel is devolatilized to form volatilized gases which flow downward;
• an internal cross-section constriction in the upper fixed bed section;
• a lower fixed bed section;
• and
• an upper plenum disposed adjacent the internal cross-section constriction;
• an entrained flow gasification section disposed in a lower plenum adjacent the lower fixed bed section which volatilizes fine fuel, wherein fine fuel is fed into the entrained flow gasification section by at least one tangentially fired burner;
• a plurality of injection ports configured to introduce oxygen, steam, or air into different sections of the gasifier;
• a plurality of pulsating jets disposed about the lower fixed bed section which agitate coarse fuel or ash within the fixed bed section;
• and
• a gas effluent site from which gases obtained from the coarse and fine fuels are collectively discharged, wherein effluent gas from the fixed bed gasification section and the entrained flow gasification section collect within the upper plenum and wherein the gas effluent site is located adjacent the upper plenum.

A gasifier comprising:

• a coarse fuel inlet;
• a two-stage fixed bed gasification section that receives coarse fuel from the coarse fuel inlet, said fixed bed gasification section comprising:
• an upper fixed bed section in which the coarse fuel is devolatilized to form volatilized gases which flow downward;
• an internal cross-section constriction in the upper fixed bed section;
• a lower fixed bed section;
• and
• an upper plenum disposed adjacent the internal cross-section constriction;
• a plurality of injection ports configured to introduce oxygen, steam, or air into different sections of the gasifier, wherein a portion of the ports are located adjacent the coarse fuel inlet;
• and
• a gas effluent site from which gases obtained from the coarse fuel is discharged, wherein effluent gas from the fixed bed gasification section collect within the upper plenum and wherein the gas effluent site is located adjacent the upper plenum.

A method of gasifying a carbonaceous fuel feedstock comprising the steps of:

• feeding coarse fuel into a gasifier having a two-stage fixed bed gasification section comprising:
• an upper fixed bed section that receives the coarse fuel, wherein the upper fixed bed section operates at a temperature sufficient to devolatilize the coarse fuel and form volatilized gases which flow downward;
• an internal cross-section constriction in the upper fixed bed section;
• a lower fixed bed section;
• and
• an upper plenum disposed adjacent said constricted cross-section;
• introducing oxygen, steam, or air into the upper fixed bed section and lower fixed bed section control the temperature within the gasifier;
• and
• withdrawing effluent gas from the gasifier.

A method of producing activated carbon in a gasifier device comprising the steps of:

• feeding coarse fuel into a gasifier having a fixed bed gasification section comprising:
• an upper fixed bed section that receives the coarse fuel, wherein the upper fixed bed section operates at a temperature sufficient to devolatilize the coarse fuel and form volatilized gases which flow downward;
• an internal cross-section constriction in the upper fixed bed section;
• and
• a lower fixed bed section through which volatilized gases flow upward;
• introducing oxygen, steam, or air into the upper fixed bed section and lower fixed bed section control the temperature within the gasifier, wherein the upper fixed bed section is operated at a temperature which converts a portion of the coarse fuel into activated carbon.

A gasifier that produces activated carbon comprising:

• a coarse and fuel inlet port;
• a fixed bed gasification section where coarse fuel is gasified and which is configured to operate at a temperature that devolatilizes coarse fuel to form volatilized gases, said fixed bed gasification section further comprising a carbon activation zone configured to operate at a temperature that destroys and cracks tars and oils remaining in the volatilized gases and coarse fuel, thereby converting the coarse fuel into activated carbon;
• a plurality of injection ports configured to introduce oxygen, steam, or air into different sections of the gasifier to control operating conditions within the gasifier;
• and
• a gas effluent port where gases generated from coarse fuel are discharged.

A gasifier that produces activated carbon comprising:

• a fine fuel inlet port;
• an entrained flow gasification section where fine fuel is gasified, wherein a portion of the fine fuel is sized to ensure incomplete carbon combustion of the fine fuel which results in the generation of activated carbon particles entrained with the effluent gas;
• and
• a gas effluent port where gases generated from fine fuel are discharged, wherein the discharged gases comprise entrained activated carbon.