Comprehensive two dimensional gas chromatography with fast-quadrupole mass spectrometry detector analysis of polar compounds extracted from the bio-oil from the pyrolysis of sawdust

In this paper it is studied the most polar fractions of bio-oil produced by fast pyrolysis of Lignocel BK40-90 (sawdust from forest timber). The biomass was submitted to the pyrolysis in an existing FCC pilot plant that was adapted for this procedure. The equipment consists of a fluidized bed reactor with nitrogen injection. The unit operates with continuous biomass feeding and continuous solids circulation. The produced bio-oil was submitted to an aqueous alkaline extraction, isolating the acidic compounds that were analyzed by one-dimensional gas chromatography and comprehensive two-dimensional gas chromatography with quadrupole mass spectrometry detection (qMS). One hundred and thirty compounds (mainly phenols and ketones) were tentatively identified in the extract, some of them by the use of retention indexes. The main differences between chromatographic techniques were the substantial increasing in the peak capacity of GC × GC and the resolution of some co-elutions that occurred in GC/qMS. It is also possible to conclude that this extract is rich in important raw materials for the chemical industry and can be used for this end.