Study on the preparation of wood vinegar from biomass residues by carbonization process

• Cotton stalk was used to produce wood vinegar by carbonization process.
• The highest yield of the refined wood vinegar reaches 25% at 350 °C.
• The main organic components in the wood vinegars are acids, phenols and ketones.
• The presence of potassium restrains the formation of ketones.

In the paper, the production of wood vinegar from Chinese fir sawdust (FS), cotton stalk (CS) and bamboo sawdust (BS) by carbonization process was addressed. The wood vinegar yield was investigated and the organic compounds contained were determined by gas chromatography and mass spectrometry. It was found that the refined wood vinegar yield of FS increased firstly and then decreased with increasing carbonization temperature and the highest yield reached about 25% in 350–450 °C. The relative contents of acids and ketones from FS decreased and that of phenols increased with increasing temperature. The relative contents of acids and phenols in the wood vinegars produced from the samples were in the order of BS > CS > FS and that of ketones reversed. KCl solution treatment caused a decrease in the relative contents of the phenols and ketones, but an increase in that of the acids in FS wood vinegar.