Abstract
Asphaltenes from an atmospheric residue of heavy crude were precipitated with n-heptane. Part of the isolated asphaltenes was washed under Soxhlet reflux to remove adsorbed maltenes. Comparison among washed and unwashed asphaltenes was carried out and both samples were characterized by atomic absorption, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and differential scanning calorimetry.