Hindered Diffusion of Asphaltenes at Elevated Temperature and Pressure Progress Report (open access)

Hindered Diffusion of Asphaltenes at Elevated Temperature and Pressure Progress Report

During this past six months we continued our ongoing studies of the diffusion controlled uptake of coal and petroleum asphaltenes into a porous carbon catalyst. Toluene was used as the solvent for experiments at 20 C and 75 C while 1-methylnaphthalene was the solvent for the higher temperature experiments at 100 C, 150 C and 250 C. All runs were made at a pressure of 250 psi (inert He gas). Experiments were performed at 20 C and 75 C, for the petroleum asphaltene/toluene system. For the coal asphaltene/toluene system, experiments were performed at 75 C. Experiments were performed at 100 C, 150 C and 250 C for the coal asphaltene/1-methylnaphthalene system. A comparison between the experimental data and model simulated data showed that the mathematical model satisfactorily fitted the adsorptive diffusion of both the coal and petroleum asphaltenes onto a porous activated carbon. The adsorption constant decreases with an increase in temperature for both, the coal asphaltene/1-methylnaphthalene system as well as the petroleum asphaltene/toluene system. It was found that the adsorption constant for the coal asphaltene/toluene system at 75 C was much higher than that of the petroleum asphaltene/toluene system at the same temperature providing evidence of the greater affinity …
Date: April 7, 2000
Creator: Guin, James A.; Ramakrishnan, Ganesh & Asada, Keiji
System: The UNT Digital Library
Hindered Diffusion of Asphaltenes at Elevated Temperature and Pressure Progress Report (open access)

Hindered Diffusion of Asphaltenes at Elevated Temperature and Pressure Progress Report

The mathematical model which we have developed previously for diffusion controlled adsorption was extended to allow for the inclusion of the effects of extraparticle film mass transfer resistance as embodied in a finite Sherwood number. A Mathcad based program was used to simulate the experimental data using summation of a large number of terms in the infinite series solution. Parametric studies and accompanying plots revealed that the effects of film resistance on the uptake process were found to increase in significance as the adsorption capacity parameter in the model decreased. In addition, the two carbon catalyst supports prepared in our own laboratory were tested for their diffusional characteristics in uptake experiments using petroleum asphaltenes dissolved in toluene at three temperatures. The resulting experimental data were simulated with the mathematical model developed in the report.
Date: April 1, 2001
Creator: Guin, James A.; Ramakrishnan, Ganesh; Asada, Keiji & Mosley, Brian
System: The UNT Digital Library