455 / 2018-09-06 10:57:26

Study on the characteristics of separation, purification of pyroligneous acids

全体主题 > 生物质液体燃料

Crude pyroligneous acids was prepared by pyrolysis of poplar wood as raw material at 500℃. The present work was aim to investigate the characteristics of the separation, purification of pyroligneous acids. Three purified treatment methods, including activated carbon adsorption method, distillation method and organic solvent extraction assisted with an ultrasonic generator, were adopted to purify pyroligneous acids. The physicochemical properties and main organic components of crude and purified pyroligneous acids were analyzed comparatively. The results showed main organic components in crude pyroligneous acids were alcohols, phenols, ketones, aldehydes, esters, alkanes, alkenes and organic acids. The highest yield of refined pyroligneous acids was obtained from active carbon adsorption purification, followed by vaccum distillation and organic extraction purification. The pH of crude and purified pyroligneous acids were as follows: orgainc extraction < vacuum distillation < crude wood vinegar < activated carbon adsorption purification; the density of that were orgainc extraction < vacuum distillation < activated carbon adsorption purification < crude wood vinegar. Purified pyroligneous acids by activated carbon adsorption with high total acid content and lowest tar removal. However, the lowest total acid content obtained from organic extraction due to parts of the organics were extracted and lowest pH was also proved that. High total acid content and a low tar content in purified pyroligneous acids obtained by vacuum distillation. Therefore, vacuum distillation is a relatively good purification method for the refining effect of crude wood vinegar.