n-alkylbenzenes and ω-phenylcarboxylic acids from the thermal treatment of fatty acids with kraft lignin

A series of homologousn-alkylbenzenes and ω-phenylcarboxylic acids were detected and identified from the pyrolysis reaction of tall oil fatty acids and several pure fatty acids, respectively, with kraft lignin. Different reaction conditions (e.g., varying amounts of lignin) and different reaction times were applied. Temperatures were kept constant at 280 C. Products were distilled at 0.1 Pa and 150 C. After methylation, the distilled fractions were analyzed by gas chromatography-mass spectrometry (GC-MS). The method of detection and identification of the different substances by GC-MS is described. Pure singly and double unsaturated fatty acids (99.9% gas chromatographic purity) showed reactions to the title products (up to 4% total amount), whereas saturated fatty acids did not react at all. A possible reaction scheme taking quantitative parameters into account is suggested.