Effect of Chemical Structure on the Cracking and Coking of Archipelago Model Compounds Representative of Asphaltenes

Abstract

Cracking and coke formation of a series of pyrene-based model compounds were investigated by thermogravimetric analysis (TGA) and microreactor experiments. The structure of the model compounds is that of a three-island archipelago, consisting of two pyrenyl groups joined to a central aromatic or heteroaromatic group by ethano bridges. The molecular weights of these compounds range from 459–679 g/mol and have sufficiently high boiling points to remain liquid under the reaction conditions. TGA measured the cracking kinetics and the coke yield of each compound, where coke yield was defined as the solid residue remaining after a 10 °C/min ramp to 500 °C, followed by isothermal heating at 500 °C for 15 min. Microreactor experiments provided the yield and structure of both cracked and addition products. Analysis of the reaction products by gas chromatography, mass spectrometry (MS), high-pressure liquid chromatography, matrix-assisted laser desorption/ionization MS, and tandem MS/MS show that the initial cracke...