Study on pyrolysis of heavy fractions of bio-oil by using TG-FTIR analysis

The pyrolysis behaviors of model compounds of bio-oil heavy fractions (Eugenol, Levoglucosan and 3, 4-Dimethoxybenzaldehyde) were studied at different heating rates (10°C/min, 20°C/min, 30°C/min) by thermogravimetric (TG) analysis coupled with Fourier Transform Infrared Spectroscopy (FTIR). The curves of TG and corresponding DTG were analyzed. The results showed that the hydroxybenzenes had the greatest tendency to decompose, followed by the aldehydes and carbohydrate. The pyrolysis reactions were accelerated by increasing heating rate. However, there were no differences among the ultimate weight losses. The qualitative analysis of various phases in levoglucosan pyrolysis was based on online FTIR. It indicated that levoglucosan pyrolysis occurs in two steps: First, it was dehydrated into small molecules such as aldehydes; and then followed by the cracking of aldehydes. The products mainly consisted of unsaturated hydrocarbon, carbon dioxide, minor ethers and free water.