Process for gasification of cellulosic materials

In a process for high methane content gas production, the improvement comprising gasification of cellulosic materials feed in a single gasification and combustion vessel comprising the steps:

• introducing cellulosic materials feed of up to about 50 weight percent moisture directly into a single highly back-mixed fluidized bed of high heat capacity inert solids in said vessel;
• maintaining said fluidized bed at temperatures of about 1200.degree. to about 1600.degree. F., said highly back-mixed fluidized state maintaining the temperature variation throughout the height of said fluidized bed at less than about 90.degree. F., at a pressure of up to about 500 psig, and providing a hydrogen-containing gaseous atmosphere in a portion of said bed above a combustion zone for hydrodevolatilizing said cellulosic materials converting it to methane, heavier hydrocarbons, carbon oxides, steam, hydrogen and devolatilized cellulosic materials;
• reforming a substantial portion of said heavy hydrocarbons into methane, carbon oxides and steam within said fluidized bed and in the head space of said vessel;
• mixing said devolatilized cellulosic materials throughout said fluidized bed and gasifying a substantial portion of said devolatilized cellulosic materials by reaction with hydrogen and steam producing methane, carbon oxides, hydrogen and cellulosic materials residue;
• combusting said cellulosic materials residue in an oxygen-rich atmosphere in a combustion zone in a lower portion of said bed to principally form heat and cellulosic materials ash, said heat being directly transferred to said inert solids in said single bed to maintain said fluidized bed temperatures;
• introducing and distributing oxygen containing gas to said combustion zone to maintain said oxygen-rich atmosphere, said oxygen introduced in an amount which is sutstantially less than stoichiometrically required for combustion of said cellulosic materials residue, so that said oxygen containing gas is substantially consumed in said combustion zone;
• removing formed gases, vapor and substantially all of said cellulosic materials ash in a gas stream from the top of said gasification vessel;
• and
• maintaining said introduction of cellulosic materials to said bed at a point where said combustion consumes principally cellulosic materials residue.

In a process for methanol production, the improvement comprising gasification of cellulosic materials in a single gasification and combustion vessel comprising the steps:

• introducing cellulosic materials feed of up to about 50 weight percent moisture directly into a single, highly back-mixed fluidized bed of high heat capacity inert solids in said vessel;
• maintaining said fluidized bed at temperatures of about 1200.degree. to about 1600.degree. F., said highly back-mixed fluidized state maintaining the temperature variation throughout the height of said fluidized bed at less than about 90.degree. F., a pressure of up to about 500 psig, devolatilizing said cellulosic materials in a portion of said bed above a combustion zone forming methane, heavier hydrocarbons, carbon oxides, steam, hydrogen and devolatilized cellulosic materials;
• reforming a substantial portion of said heavy hydrocarbons into methane, carbon oxides and steam within said fluidized bed and in the head space of said vessel;
• mixing said devolatilized cellulosic materials throughout said fluidized bed and gasifying a substantial portion of said devolatilized cellulosic materials by reaction with hydrogen and steam within said portion of said bed above said combustion zone producing methane, carbon oxides, hydrogen and cellulosic materials residue;
• combusting said cellulosic materials residue in an oxygen-rich atmosphere in a combustion zone in a lower portion of said bed to principally form heat and cellulosic materials ash, said heat being directly transferred to said inert solids in said single bed to maintain said fluidized bed temperatures;
• introducing and distributing oxygen containing gas to said combustion zone to maintain said oxygen-rich atmosphere, said oxygen introduced in an amount which is substantially less than stoichiometrically required for combustion of said cellulosic materials residue, so that said oxygen containing gas is substantially consumed in said combustion zone;
• removing formed gases, vapor and substantially all of said cellulosic materials ash in a gas stream from the top of said gasification vessel;
• and
• maintaining said introduction of cellulosic materials to said bed at a point where said combustion consumes principally cellulosic materials residue;
• and
• reforming said formed gases to CO and H.sub.2 and catalytically reacting said CO and H.sub.2 to produce said methanol.