Open AccessHINDERED DIFFUSION OF ASPHALTENES AT ELEVATED TEMPERATURE AND PRESSURE
Author(s) -
J.A. Guin,
Ganesh Ramakrishnan
Publication year - 1999
Language(s) - English
Resource type - Reports
DOI - 10.2172/816519
Subject(s) - asphaltene , quinoline , cyclohexane , adsorption , toluene , chemistry , chemical engineering , coal , diffusion , activated carbon , catalysis , organic chemistry , carbon fibers , materials science , thermodynamics , composite material , physics , engineering , composite number
During this time period, experiments were performed to study the diffusion controlled uptake of quinoline and a coal asphaltene into porous carbon catalyst pellets. Cyclohexane and toluene were used as solvents for quinoline and the coal asphaltene respectively. The experiments were performed at 27 C and 75 C, at a pressure of 250 psi (inert gas) for the quinoline/cyclohexane system. For the coal asphaltene/toluene system, experiments were performed at 27 C, also at a pressure of 250 psi. These experiments were performed in a 20 cm{sup 3} microautoclave, the use of which is advantageous since it is economical from both a chemical procurement and waste disposal standpoint due to the small quantities of solvents and catalysts used. A C++ program was written to simulate data using a mathematical model which incorporated both diffusional and adsorption mechanisms. The simulation results showed that the mathematical model satisfactorily fitted the adsorptive diffusion of quinoline and the coal asphaltene onto a porous activated carbon. For the quinoline/cyclohexane system, the adsorption constant decreased with an increase in temperature. The adsorption constant for the coal asphaltene/toluene system at 27 C was found to be much higher than that of the quinoline/cyclohexane system at the same temperature. Apparently the coal asphaltenes have a much greater affinity for the surface of the carbon catalyst than is evidenced by the quinoline molecule