LBL Continuous Bench-Scale Liquefaction Unit, Operation and Results

摘要

A bench-scale continuous liquefaction unit (CLU) is now fully operational. The CLU is a flexible system capable of examining feedstocks introduced in slurry form by various liquefying techniques. It is the only continuous biomass liquefaction unit currently in use. Emphasis has been on the liquefaction of aqueous slurries (about 20% organics) of prehydrolyzed Douglas fir wood, without recycle, under the following conditions: 330 to 360 exp 0 C; 3000 to 3400 psig; pH 6 to 9 (Na sub 2 CO sub 3 , 5 to 10% of wood); CO-H sub 2 ratios in reactant gas 1:0, 1:1, 0:1; and experiment duration 10 to 24 hours. Results show about 30% of feed organics is converted to CO sub 2 plus H sub 2 O, with crude wood oil yields 20 to 35% and water-soluble organic products 20 to 30%. Atom balances and difference calculations indicate that the estimates of oil yield are low. The ratio of water-solubles to oil is higher than in the oil recycle, or PERC process. Direct reduction by CO and usage of feed gas are less than in PERC. A variety of analytical techniques is used to characterize both wood-oil and water-solubles. The SESC technique, developed for coal liquefaction products, combined with size exclusion chromatography, is especially useful for showing effects of process variable changes on product oil.