Experimental study on composition evolution of biomass pyrolysis vapors with condensing temperature in a vertical tubular condenser.

The experiments on bio-oil recovery in a vertical tubular condenser with two flumes were conducted for speculating the componential distribution of walnut shell pyrolysis vapors during condensation. Bio-oil elements and functional groups from different locations of condenser were compared with each other. Aromatic H and H in phenolic OH were concentrated in the top and middle bio-oil and their percentage were improved with increasing water bath temperature. Ten representative compounds in bio-oil were chosen for quantitative analysis. As water bath temperature increased from 273 K to 353 K, the recovered water decreased by 85% whereas the guaiacol and its derivatives (guaiacols) merely decreased by 40%. Vapor distributions of water, acetic acid, furfural and guaiacols were simulated by the back analysis of bio-oil components. According to the simulated results, tubular condenser can be properly lengthened for promoting the recovery of specific components at high water bath temperatures.