| Abstract:The alkali lignin was separated from eucalyptus alkaline peroxide mechanical pulping (APMP) spent liquor by acid precipitating method. Then the pyrolysis characteristics of the alkali lignin were investigated using a thermogravimetric analyzer (TGA) and the releasing mechanisms of main volatile products during pyrolysis were on-line measured by Fourier Transform Infrared (FTIR) Spectrometer. The TG results showed that the pyrolysis of alkali lignin could be approximately described by three stages, which included glass transition stage, main pyrolysis stage, and residue decomposition stage. The FTIR results indicated that H2O, CO2, CO, CH4, aldehydes and ketones, alcohols and phenols were the main volatile products at the main pyrolysis stages. CO and CO2 were main products after 2000 s. It was also obvious that CH4, aldehydes and ketones, alcohols and phenols were released concentrically in 300~600℃ with considerably high yield. |
