CPD model prediction of oil sand pyrolysis based on structural parameters from 13C NMR and FTIR measurements

Abstract

Here, carbon-13 nuclear magnetic resonance spectroscopy (13C NMR) and Fourier transform infrared spectroscopy (FTIR) techniques were used to study the chemical structure characteristics of oil sand and its pyrolysis oil. The FTIR results showed that the values of the CH2/CH3 ratio, A-factor, and DOC1 of the pyrolysis oil decreased during the pyrolysis process, while the C-factor showed a maximum value with increasing pyrolysis temperature. The 13C NMR results showed that methylides and methylides were mainly contributed to oil production. The aliphatic chain in the pyrolysis oil has little alterations during pyrolysis, while the extent of aromatic ring substitution increases from 0.46 to 0.58. Furthermore, a correlation was obtained between the chemical structure of oil and the pyrolysis product yields of oil sand. Moreover, using chemical structure parameters investigated with FTIR and 13C NMR and kinetic parameters based on the thermogravimetric data, the chemical percolation devolatilization (CPD) model was applied to simulate the pyrolysis of oil sand. The results showed that the simulated results for tar and light gas were in good agreement with the experimental data, while those for char underpredicted the experimental data. Overall, the CPD model can effectively predict the pyrolysis of oil sand.