DESIGN AND INITIAL OPERATION OF A HIGH-SOLIDS, PILOT-SCALE REACTOR FOR DILUTE-ACID PRETREATMENT OF LIGNOCELLULOSIC BIOMASS

A recently installed 100-L horizontal shaft custom-fabricated mixer/re actor, made of Carpenter 20 Cb-3 stainless steel and designed for high -solids, dilute-acid pretreatment of lignocellulosic biomass, is descr ibed. Several preliminary runs with a hardwood and a herbaceous feedst ock are reported; the results show the operation to be reliable with g ood reproducibility. No significant differences between comparable pre treatments in the high-solids reactor and a 1-L laboratory-scale react or are apparent. Pretreatment efficiency is not affected by 10-15% (w/ w) solids loading or biomass particle size of up to -10 mm. Mass balan ces are closed reasonably well, with improvement in reactor contents h andling and biomass analytical methods desirable.