Quantitative determination of species production from phenol-formaldehyde resin pyrolysis

Batch pyrolysis of a commercial resole type phenol-formaldehyde resin was performed using a step-wise heating procedure in a temperature increment of 50 K from 320 to 1290 K. A resin sample of 50 mg was loaded in a reactor assembly specifically designed and built for this study. Mass loss was measured after each 50 K step and the production of pyrolysis products was quantified using gas chromatography techniques. The overall mass loss from the samples reached 39.2% after the entire procedure. Three major product families were identified: 1) water is the most dominant product at a pyrolysis temperature below 800 K; 2) phenol derivatives (aromatic alcohols) have significant yields at a pyrolysis temperature between 500 and 850 K; 3) permanent gases such as hydrogen, methane, carbon monoxide, and carbon dioxide have the highest yields at a temperature above 800 K. Minor products observed include aromatics, which are formed between 700 and 850 K, and C₂ to C₄ light hydrocarbons, which are only formed above 800 K and peak at 1000 K.