Investigation on Asphaltene and Heavy Metal Removal from Crude Oil Using a Thermal Effect

Removal of asphaltenes and heavy metals, using asymmetric ceramic monolith membranes with pore sizes of 0.2 mu m and 50 nm, was investigated for three Iranian crude oils. The experiments were conducted in a batch filtration unit at a pressure gradient of 200 kPa and temperature range of 75-190 degrees C based on the amount of crude oil asphaltene contents. The investigated crude oils consisted of 1-10 wt % asphaltene contents. During heating of crude oils to specified temperatures, nanometer particles of asphaltene aggregated to micrometer size and then micrometer particles were separated smoothly using the membranes. The obtained results illustrated that asphaltene separation reached 60-87 wt % based on the asphaltene content of crude oils. In addition, the separation of asphaltene and heavy metals, such as nickel and vanadium, increased using the membrane of a smaller pore size. Besides, densities and viscosities of crude oils showed a sufficient decline after filtration through the membrane.