Hydrothermal treatment of wheat straw at pilot plant scale using a three-step reactor system aiming at high hemicellulose recovery, high cellulose digestibility and low lignin hydrolysis.
A pilot plant (IBUS) consisting of three reactors was used for hydrothermal treatment of wheat straw (120-150 kg/h) aiming at co-production of bioethanol (from sugars) and electricity (from lignin). The first reactor step was pre-soaking at 80 degrees C, the second extraction of hemicellulose at 170-180 degrees C and the third improvement of the enzymatic cellulose convertibility at 195 degrees C. Water added to the third reactor passed countercurrent to straw. The highest water addition (600 kg/h) gave the highest hemicellulose recovery (83%). With no water addition xylose degradation occurred resulting in low hemicellulose recovery (33%) but also in high glucose yield in the enzymatic hydrolysis (72 g/100g glucose in straw). Under these conditions most of the lignin was retained in the fibre fraction, which resulted in a lignin rich residue with high combustion energy (up to 31 MJ/kg) after enzymatic hydrolysis of cellulose and hemicellulose.
Thomsen
Mette Hedegaard
MH
Biosystems Department, Risø National Laboratory, Technical University of Denmark P.O. Box 49, DK-4000 Roskilde, Denmark.
Thygesen
Anders
A
Thomsen
Anne Belinda
AB
D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002480:Cellulase / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D004736:Energy-Generating Resources; D004798:Enzymes / Q000737:chemistry; D000431:Ethanol; D005947:Glucose / Q000737:chemistry; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D019800:Phenol / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics; D014908:Triticum
D004798:Enzymes; D011134:Polysaccharides; D019800:Phenol; D000431:Ethanol; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin; D002480:Cellulase; D005947:Glucose