Empirical approach to determine molecular weight distribution using MALDI-TOF analysis of petroleum-based heavy oil

In this short communication, vacuum residue, bitumen, and pyrolized fuel oil were analyzed using matrix-assisted laser desorption/ionization - time of flight (MALDI-TOF) analysis to investigate the molecular weight distribution (MWD) variation of heavy oil during visbreaking. The visbreaking of vacuum residue was carried out at 350 °C, 400 °C and 450 °C. Vacuum residue products were studied based on MWD obtained by MALDI-TOF analysis. The separation of MWD was carried out in 8 sections, and each area of the range was calculated. According to our study, the cracking reaction dominated, even though condensation and polymerization were carried out simultaneously. It was noted that the relatively high molecular ranges of 3 and 4 were shifted to the light molecular range of 2. The MWD separation method obtained by MALDI-TOF is a potential analytical tool for investigating the MWD variation of heavy oil.