REMOVAL OF ASPHALTENES FROM HEAVY OIL BY NICKEL NANO AND MICRO PARTICLE ADSORBENTS

摘要

In this work nickel nano and micro particle adsorbents were employed for removing asphaltenes from heavy oil model solution by adsorption. The approach comprises the following: dispersing nickel particles into heavy oil matrixes, and relying on the surface activity of asphaltene molecules, attract them onto the surface of the nickel particles. Nickel particles were chosen due to their potential application as catalysts in heavy oil upgrading.rnThe adsorption was investigated by adding nickel particles, with different sizes (from 100 nm to 3 μm), to model solutions of heavy oil consisting of asphaltenes in toluene. After shaking the suspension for specific times, the particles with adsorbed asphaltene molecules were separated by centrifuge. Adsorption kinetics and isotherms were constructed using UV-Vis spectrophotometry. The effect of contact time, initial asphaltene concentration, particle size and mass of nickel particles were evaluated using batch kinetic runs. Using 10 g of particles per liter of model solution, equilibrium was approached in nearly 2.5 h, within which over 85% of the asphaltenes in the original solution were removed. Asphaltene adsorption capacity onto nickel nanoparticles compared favorably with nickel micro particles. Higher percent removal was achieved when higher mass of nanoparticles was employed. The adsorption isotherms showed a maximum in both cases, nickel nano and micro particles, which did not follow Langmuir or Freundlich types.