Cellulose-lignin interactions during catalytic pyrolysis with different zeolite catalysts

Interactions between cellulose and lignin under catalytic pyrolysis condition were investigated to identify the impact of zeolite catalysts on products distributions. Thermogravimetric Analysis (TGA) and Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS) were used to investigate cellulose-lignin interactions. The mixing ratio of cellulose and lignin was 1:1 and the pyrolysis temperature was 600 °C. The results showed that interactions did exist under both non-catalytic and catalytic pyrolysis condition. Decomposition of cellulose during catalytic co-pyrolysis was inhibited. For some research-focused products from cellulose, the interactions between cellulose and lignin under catalytic process all inhibited the formation of levoglucosan, but interactions under H-beta catalyst promoted the formation of furfural. Meanwhile, for lignin-derived products, the catalytic interactions all inhibited the formation of phenol and guaiacol with all the tested catalysts. This is opposite to the results from non-catalytic condition, where the cellulose-lignin interactions promoted the formation of phenol and guaiacol. A statistic method-correlation coefficient R was introduced to evaluate the interaction strength under different catalysts pyrolysis; strongest catalytic interaction was found when H-beta was used, followed by HZSM-5 and SAPO-34.