Effect of conditions on fast pyrolysis of bamboo lignin

摘要

Products derived from bamboo EMAL pyrolysis were investigated by means of pyrolysis-gas chromatog-raphy/mass spectrometry (Py-GC/MS) and the effects of temperature and catalyst (sodium chloride, permutite) on the yields of pyrolysis products were probed in detail. The results showed that thermal degradation of EMAL mainly occurred at the temperature range from 250 ℃ to 600 ℃, and both the temperature and catalyst in EMAL pyrolysis were important factors in the formation or inhibition of products. The products that derived from p-hydroxyphenylpropanoid, guaiacylpropanoid, and syringylpropanoid of lignin units by pyrolytic reactions were classified as the heterocycle (2,3-dihydrobenzofuran), phenols, a small quantity of acetic acid and furans, etc. With an increase of pyrolysis temperature, the amount fraction of 2,3-dihydrobenzofuran (DHBF) decreased from 66.26% to 19.15%. Moreover, when the additive catalyst increased from 5% to 20%, permutite catalyst improved in the formation of DHBF from 19.15% to 24.19%, whereas NaCl catalyst was effective to inhibit the production of DHBF from 19.15% to 13.08%. Permutite promoted the production of coke from EMAL pyrolysis, conversely, NaCl had an inhibiting effect on the generation of coke. And NaCl catalyst had a significant catalytic effect on raising or reducing of the product yields in bamboo lignin pyrolysis.