HYDROTHERMAL LIQUEFACTION OF FOOD PROCESSING RESIDUES: APPLICATION TO BLACKCURRANT POMACE

摘要

This study reports hydrothermal liquefaction of blackcurrant pomace to produce bio-oil, focusing onrnthe influence of several process parameters on yields and carbon distribution between phases: holding time (0-240rnmin), temperature (290-335℃), and addition of sodium hydroxide NaOH to vary the initial pH (3.1-12.8). Bio-oilrnyields up to 34 wt. % on a dry matter basis were obtained. An optimum temperature of 310℃ corresponding to 30 wt.rn% bio-oil yield was observed, while higher temperatures decrease bio-oil recovery. At 300℃, holding time does notrnhave a significant influence on the results: short holding times already achieve biomass conversion and relativelyrnhigh bio-oil yields. Finally, increasing the initial pH of the feed by addition of NaOH inhibits char formation andrnenhances the bio-oil yield as well as the transfer of carbon to the aqueous phase. The char yield drops from 35 wt. %rnat pH = 3.1 (case without NaOH) to 24 wt. % at pH = 12.8 (corresponding to a NaOH/dry matter ratio of 9 wt. %). Atrnthe same time, the fraction of carbon remaining in the aqueous phase increases from 12 wt. % at pH = 3.1 to 25 wt. %rnat pH = 12.8.