Production of alkylbenzenes and alkylnaphthalenes upon pyrolysis of unsaturated fatty acids. A model reaction to understand the origin of some pyrolysis products from humic substances?

The chemical structure of humic substan- ces, as revealed by pyrolysis, has been a subject of controversial debate during the last few years [1-5]. Saiz-Jimenez [6] suggested that the series of alkylated benzenes and naphthalenes obtained in pyrolysates of humic substances prob- ably originated from aliphatic precursors due to unwanted thermal reactions. These assumptions were based on the study of the pyrolysates of plant biomass (stems of Chrysanthemum segetum and Vitis vinifera and charred debris of C. segetum) which yielded alkylbenzenes and alkylnaphthalenes, supporting the fact that pyrolysis of plant materials, other than lignins, originated the alkyl- aromatics.