Determining the Particle Size of Asphaltenes

Abstract

Study of heavy organics and their behavior is of great importance while occurrence of their deposition in production and processing of hydrocarbon fluids. The physical properties of heavy organics, especially asphaltenes, have been a subject of controversy for several years. The aim of the present work is to determine and measure particle size of asphaltenes. Several mixtures of crude oil and n-heptane were prepared with various dilution ratios (R_v ). Two different techniques were employed to determine and measure the particle size of asphaltenes. The first was utilizing an OLYMPUS BX60, a polarizing microscope with an appropriate magnification, and the second was using high-resolution scanning electron microscopy (SEM) and X-ray diffraction techniques. The results revealed that the size of asphaltene particles is in the range of 1–4 μm for each mixture, regardless of its n-heptane content. Although the quantity of deposited asphaltene was increased by increasing the concentration of n-heptane in mixture, the particle size of asphaltene was independent of the n-heptane concentration.

Keywords:

• asphaltene
• dilution ratio
• particle size
• polarizing microscope
• scanning electronic microscope
• X-ray diffraction