System for treating biomass

Abstract

A system and corresponding process for treating biomass, including by use of a plurality of pyrolysis treatment steps. The process can be used to provide a first pyrolysis product (e.g., intermediate), in the form of a carbon enriched material that contains substantially less hemicellulose content than the initial biomass, while substantially retaining and optionally enriching cellulose and/or lignin content as compared to the initial biomass. The process also includes a second pyrolysis device, adapted to further pyrolyze the first pyrolysis product in order to provide one or more gasses and/or vapors (e.g., providing condensable or non-condensable bio-products) and solid ash byproduct. The process also permits gasses and/or vapors that are generated in the course of its operation to be used in a variety of ways, including by: (a) recycling the gas/vapor into the system, in order to faciliate pretreatment (drying) of biomass, (b) condensing and recovering the gas/vapor or components thereof, and (c) venting or otherwise disposing of the gas/vapor.

What is claimed is: 
     
         1 . A process for treating biomass comprising the steps of:
 a) providing an initial source of biomass, the biomass having initial characteristics, including particle size, water content, and content of polysaccharide based polymers;   b) optionally and preferably, pretreating the initial biomass source in order to provide it with desired characteristics;   c) optionally and preferably, drying the initial biomass source to reduce its moisture content, under conditions in which gasses and/or vapors can be captured and subjected to one or more processes selected from the group consisting of: (i) recycling the gas/vapor into the system, in order to facilitate pretreatment of biomass, (ii) condensing and recovering the gas/vapor or components thereof, and (iii) venting or otherwise disposing of the gas/vapor;   d) providing a first pyrolysis device adapted to heat the optionally pretreated biomass under controlled conditions;   e) introducing the optionally pretreated biomass into the first pyrolysis device, and operating the device under conditions suitable to preferentially affect the relative content of polysaccharide based polymers, preferably, by providing a first pyrolysis product having substantially reduced hemicellulose content as compared to original content, while substantially retaining the cellulose and lignin content, and driving off volatiles in the form of one or more gasses or vapors;   f) obtaining a first pyrolysis product comprising a carbon enriched material that having an altered of polysaccharide based polymers;   g) providing a second pyrolysis device, adapted to further pyrolyze the first pyrolysis product in order to provide one or more second pyrolysis gasses/vapors and byproduct;   h) introducing the first pyrolysis product into the second device, and operating the device under conditions suitable to:
 i) provide a second pyrolysis product in the form of a solid ash byproduct having substantially reduced carbon content, and 
 ii) drive off volatiles in the form of a gas or vapor, and 
   i) recovering the gas/vapor from the second device in a manner sufficient to recover one or more commercially useful components therefrom.   
     
     
         2 . A process according to  claim 1 , wherein the intermediate product is delivered to the second pyrolysis device while still heated. 
     
     
         3 . A process according to  claim 1 , wherein the first pyrolysis device comprises a cylindrical, heated housing and a high speed rotor with adjustable paddles. 
     
     
         4 . A process according to  claim 1  wherein the first pyrolysis device is used to heat the biomass to a temperature of between about 300 and about 500 C, at a rate of between about 1 and about 60 C/s, and for a heating time of between about 1 and about 120 s. 
     
     
         5 . A process according to  claim 4  wherein the first pyrolysis device is used to heat the biomass to a temperature of between about 325 and about 400 C, at a rate of between about 3 and about 30 C/s, and for a heating time of between about 10 and about 100 s. 
     
     
         6 . A process according to  claim 5  wherein the first pyrolysis device is used to heat the biomass to a temperature of between about 340 and about 360 C, at a rate of between about 5 and about 20 C/s, and for a heating time of between about 15 and about 60 s. 
     
     
         7 . A process according to  claim 1  wherein the second pyrolysis device is used to heat the biomass to a temperature of between about 350 and about 1000 C, at a rate of between about 1 and about 60 C/s, and for a heating time of between about 1 and about 120 s. 
     
     
         8 . A process according to  claim 7  wherein the second pyrolysis device is used to heat the biomass to a temperature of between about 400 and about 800 C, at a rate of between about 3 and about 30 C/s, and for a heating time of between about 10 and about 100 s. 
     
     
         9 . A process according to  claim 8  wherein the second pyrolysis device is used to heat the biomass to a temperature of between about 500 and about 700 C, at a rate of between about 5 and about 20 C/s, and for a heating time of between about 15 and about 60 s. 
     
     
         10 . A process according to  claim 1 , wherein the second pyrolysis device is selected from the group consisting of a paddle drying device, bubbling and circulating fluidized bed reactors, rotating cone reactors, auger reactors, ablative reactors, vacuum reactors, and free fall reactors. 
     
     
         11 . A process according to  claim 1 , wherein the process is used to recover one or more bio-products selected from the group consisting of acids, esters, alcohols, ketones, aldehydes, sugars, furans, phenols, lignin and guaiacols. 
     
     
         12 . A system for performing the process of  claim 1 . 
     
     
         13 . An intermediate obtained from a process according to  claim 1 . 
     
     
         14 . A combination of first and second pyrolysis devices, comprising a first device adapted to pyrolyze biomass to a first temperature, and a second device adapted to pyrolyze the biomass to a second temperature, wherein the biomass is adapted to be transferred from the first to second devices while at or near the first pyrolysis temperature. 
     
     
         15 . A combination according to  claim 14 , wherein the first and second devices are different devices. 
     
     
         16 . A combination according to  claim 14 , wherein the first and second devices are either the same device operated under different corresponding conditions, or are themselves different portions of a single device, the portions being adapted to be operated under different corresponding conditions. 
     
     
         17 . A combination according to  claim 14  wherein the first device comprises cylindrical, heated housing and a high speed rotor with adjustable paddles. 
     
     
         18 . A combination according to  claim 17  wherein the second device is selected from the group consisting of a device comprising a cylindrical, heated housing and a high speed rotor with adjustable paddles; bubbling and circulating fluidized bed reactors; rotating cone reactors; auger reactors; ablative reactors; vacuum reactors; and free fall reactors,
 wherein the first pyrolysis device is adapted to be operated under conditions suitable to preferentially depolymerize and/or decompose the hemicellulose content of the biomass, and the second pyrolysis device is adapted to be operated under conditions suitable to depolymerize and/or decompose the cellulose and lignin content, in order to provide one or more gasses or vapors that can be recovered to provide corresponding bio-products. 
 
     
     
         19 . A bio-product provided by the use of the process of  claim 1 . 
     
     
         20 . A bio-product provided using a system according to  claim 11 .