Average molecular structure of heavy oil fractions was constructed by elemental analysis

molecular weight determination

NMR.And then

the rationality of density and molecular structure was justified with molecular simulation.At first

n-tetracontane and 1-dodecyl naphthalene were selected as model compounds to do density simulation

which was used to establish the simulation parameters and calculation process.Under the same simulation condition

the density of heavy oil fractions was simulated

and then compared with the experimental value.The result showed that the relative errors of density of n-tetracontane and 1-dodecyl naphthalene were 0.27% and 0.26% respectively

indicating that the simulated condition was suitable for density characterization.The density values of heavy oil fractions obtained by molecular simulation compared well with the experimental value

and the relative errors were between 2% and 3%.The consistence of simulation density and experimental density confirmed that the average molecular structure of heavy oil fractions were deduced reasonably.Therefore

molecular simulation could be used as a tool to estimate of density

and the result could justify the average molecular structure of heavy oil fractions.