Abstract
Traces of particulate mercury sulfide in stabilized crude oils transform
to elemental mercury below 400°C in refinery distillation units. We
evaluated this transformation and measured reaction rates and activation
energies in crude oil and mercury spiked mineral oil using glass vessel
at atmospheric pressure and a microunit at 1000 psig. Results show that
mercury sulfide decomposes irreversibly above ˜150°C. The data indicates
the presence of two mercury species. Approximately 88% of the mercury
sulfide decomposed with an activation energy of 56±7 kJ mol
-1. The remaining 12% decomposed with an activation
energy of 130±10 kJ mol -1. Near-identical kinetic
parameters were found with differential measurements at atmospheric
pressure and with integral measurements in the liquid phase at over 1000
psig, indicating that mild pressures do not change the reaction
kinetics. The results show that >99% of mercury sulfides
in crude oil decompose in a typical crude distillation unit.