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Research Article
Control of the Molecular Weight Distribution of Petroleum Pitches via Dense-Gas Extraction
Article first published online: 30 MAY 2007
DOI: 10.1002/ceat.200700024
Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Issue
Chemical Engineering & Technology
Special Issue: Hight Pressure Technology
Volume 30, Issue 6, pages 742–748, June, 2007
Additional Information
How to Cite
Cervo, E. G. and Thies, M. C. (2007), Control of the Molecular Weight Distribution of Petroleum Pitches via Dense-Gas Extraction. Chem. Eng. Technol., 30: 742–748. doi: 10.1002/ceat.200700024
Publication History
- Issue published online: 30 MAY 2007
- Article first published online: 30 MAY 2007
- Manuscript Accepted: 7 FEB 2007
- Manuscript Received: 18 JAN 2007
Funded by
- Funding Agency AFOSR. Grant Number: FA9550-05-1-0060
- U.S. Department of Energy, Division of Materials Sciences and Engineering
- Funding Agency Engineering Research Centers Program of the National Science Foundation. Grant Number: NSF Award Number EEC-9731680
- Abstract
- References
- Cited By
Keywords:
- Extraction;
- Packed columns;
- Petroleum;
- Supercritical fluids
Abstract
Dense-gas extraction (DGE) was used to fractionate an isotropic petroleum pitch (number-average molecular weight Mn = 516) into oligomeric cuts. A countercurrent-flow packed column was used to effect the separation, with supercritical toluene being used as the dense-gas solvent and commercially available M-50 or A-240 pitch being used as the feed. Isothermal operation at 330, 350, and 380 °C was investigated, as well as operation with a linear positive temperature gradient (+ΔT), with the bottom of the column at 330 and the top at 380 °C. For isothermal operation, the molecular weight distribution of the bottom products consisted primarily of dimer (Mn = 508) and trimer (Mn = 759) species, with pressure changes of as little as 5 bar producing significant changes in their relative distribution, as observed by MALDI mass spectrometry. On the other hand, by operating with a +ΔT, we could produce a bottom product consisting primarily of trimers and tetramers (Mn = 997).