F-30-TR Evaluation of Measurement Techniques for Crude Oil Particles
Developing effective fouling mitigation techniques for crude oils requires a fundamental understanding of particulate matter in heat exchanger flows, as well as experimental methods that accurately measure particle sizes and concentration distributions. HTRI previously determined that the ASTM F-312 method is unable to characterize differences in particle size distributions among crudes. For this study, we evaluated various particle characterization techniques, most of which require diluting a crude sample with organic solvents (e.g., n-heptane or toluene). Using such solvents can adversely affect test results. For example, n-heptane causes asphaltene particles in a crude to precipitate, and toluene dissolves asphaltenes. In this study, we focused on toluene-insoluble particles. Among the several techniques investigated, HTRI prefers flow imaging microscopy (FIM). Measured data show that FIM can produce accurate and repeatable measurements, differentiate between crudes, and characterize the impact of fouling on particle size and concentration.