Analysis on Pyrolysis Products from Black-liquor Solid and Technical Lignin

The pattern of pyrolysis products distribution from purified technical alkali lignin and black-liquor solid under different temperatures were studied.The composition of liquid product(pyrolysis oil) and solid residue from pyrolysis process were analyzed by pyrolysis-gas chromatography-mass spectrometry(Py-GC-MS),elementary analysis and ICP plasma emission spectrum.Results showed the maximum yield of pyrolysis oil was obtained at 600 ℃,and the pyrolysis oil from alkali lignin was higher than that from black-liquor solid.The chemical composition of pyrolysis oil was very complicated,and components of pyrolysis oil from purified technical alkali lignin had lots of difference from that of black-liquor solid.The pyrolysis oil from purified technical alkali lignin was mainly consisted of low molecular phenolics,ketones,organic acids,etc.The relative contents of phenolics and organic acids in pyrolysis oil from technical lignin were obviously higher than those from black liquor solid.The relative content of laevoglucose was found to be higher in pyrolysis oil from black liquor solid than that from technical lignin,but biphenyl structure compound was detected in pyrolysis oil from technical lignin,which might be generated from condensation of intermediate products.The results give us the hint that it may be possible to control the composition of pyrolysis oil by suitable pretreatment of the black liquor.