Upflow hydrolysis reactor system for hydrolyzing cellulose

Abstract

A process for the enzymatic hydrolysis of cellulose to produce a hydrolysis product from a pre-treated cellulosic feedstock is provided. The process comprises introducing an aqueous slurry of the pre-treated cellulosic feedstock at the bottom of a hydrolysis reactor. Axial dispersion in the reactor is limited by avoiding mixing and maintaining an average slurry flow velocity of about 0.1 to about 20 feet per hour, such that the undissolved solids flow upward at a rate slower than that of the liquid. Cellulase enzymes are added to the aqueous slurry before or during the step of introducing. An aqueous stream comprising hydrolysis product and unhydrolyzed solids is removed from the hydrolysis reactor. Also provided are enzyme compositions which comprise cellulase enzymes and flocculents for use in the process. In addition, a kit comprising cellulase enzymes and flocculent is provided.

1 . (canceled) 
     
     
         2 . The system according to  claim 58 , wherein the feedstock slurry is introduced at the bottom of the hydrolysis reactor with a uniform radial distribution. 
     
     
         3 - 47 . (canceled) 
     
     
         48 . The system according to  claim 58 , wherein the average slurry flow velocity is between about 0.1 and about 12 feet per hour. 
     
     
         49 . The system according to  claim 48 , wherein the average slurry flow velocity is between about 0.1 and about 4 feet per hour. 
     
     
         50 - 57 . (canceled) 
     
     
         58 . A system for hydrolyzing cellulose to glucose, cellobiose, glucose oligomers, or a combination thereof, the system comprising a feedstock slurry supply line in fluid communication with an input to an upflow hydrolysis reactor, a solids-liquid separator in fluid communication with the upflow hydrolysis reactor and comprising a first output for withdrawing a slurry comprising unhydrolyzed solids and a second output for withdrawing a stream comprising hydrolysis product, the hydrolysis product comprising glucose, cellobiose, glucose oligomers, or a combination thereof, wherein the feedstock supply line, the upflow hydrolysis reactor, or both the feedstock supply line and the upflow hydrolysis reactor, comprise an enzyme composition comprising cellulase enzymes and one or more than one flocculent. 
     
     
         59 . The system of  claim 58 , wherein the feedstock supply line comprises a pre-treated feedstock. 
     
     
         60 . The system of  claim 58 , wherein the solids-liquid separator is selected from the group consisting of a settling tank, a clarifier, a clarifier zone, a centrifuge and a filter. 
     
     
         61 . The system of  claim 60 , wherein the solids-liquid separator is a settling tank. 
     
     
         62 . The system of  claim 60 , wherein the solids-liquid separator is a clarifier zone. 
     
     
         63 . The system of  claim 60 , wherein the solids-liquid separator is a filter. 
     
     
         64 . The system of  claim 58 , wherein the cellulase enzymes are present at a dosage from about 1.0 to about 40.0 FPU per gram of cellulose of the pre-treated feedstock. 
     
     
         65 . The system of  claim 58 , wherein the one or more than one flocculent is present at a dosage from about 0.1 to about 4.0 kg per tonne solids of the pre-treated feedstock. 
     
     
         66 - 68 . (canceled)