Study On Separation Acetol And Acetic Acid From Water Phase Of Bio-oil

Catalytic pyrolysis of biomass could produce liquid product, whichpromoted the useful value and competitive of biomass, and receivedextensive attention. However, the viscosity, oxygen content and acid contentof bio-oil was too high to apply difficultly. People put forword catalyticmethod to enrich effective component of bio-oile, such as acetol. Howeverthe method of separating these conponents needed further research.According to water phase which our team studied, this paper tried to studythe method of separating acetol and HAC from the bio-oil-water system byion exchange resin.Through the resin selection experiments，the705macro porous weakbasic anion resin showed a better capability among the six kind resins ofD301,705,701,719, D001and717. In the static adsorption experiment，effects of adsorption time，temperature on behavior were investigated. Theresults indicated that the adsorption amount of acetol and acetic acidincreased with a increase of the adsorption time，the equilibrium time wasabout40minutes; the adsorption amount of acetol and acetic acid increasedwith the increasing of the temperature，higher temperature were beneficialfor the adsorption，and the process was endothermic.The thermodynamic study of the adsorption process showed freundlichisotherm was more suitable for describing the adsorption process, andadsorption-ion exchange process of acetol and acetic acid is spontaneousand endothermic，and the entropy is positive. The dynamic study showed aone-order adsorption-ion exchange kinetic equation was developed for theprocess，and the apparent activation energy is33.062kJ/mol。In the dynamic adsorption experiment，in order to make rection fully,effects of solution initial concentration，flow fate and temperature onbreakthrough curve were investigated. The results showed that lower concentration, lower flow rate and higher temperature were beneficial forimproving the utilization of exchange column resin. Through acomprehensive consideration of adsorption effect and operating cycle, onexperimental range,and the suitable conditions were as follows: theconcentration of acetol and acetic acid respectively21.64mg/mL and20.98mg/mL,the flow rate2ml/min， the temperature303K.In the dynamic desorption experiment, acetol and acetic acid should bedesorped step by step. The desorption agents of acetol and acetic acid usethe water and ethanol respectively. Lower temperature and lower flow ofdesorption agent are helpful in the desorption of acetic acid, Lowertemperature, lower flow and higher concentration of desorption agent arehelpful in the desorption of acetol, and the suitable desorption conditionswere as follows: the temperature288K, the flow rate2ml/min,ethanolconcentration70wt%. On this condition, the best desorption rate of aceticacid is98.26%; the best desorption rate of acetol is94.76%, and the yield ofacetol is69.52%finally.