Win Robbins

Advanced Characterization - petroleum at Carmagen Engineering

Ahmed,

Mansoori makes a valiant effort to come up with a universal model based on phase transitions; however, his references to asphaltene composition and structure is 10-20 years out of date. The only recent reference that he cites for the "continental" model is Mullins (2006). Over the past 20 years the consensus has grown to prefer a mixed model with both continental and "archipelago"( model with a maximum of 6 fused aromatic rings linked by short C-C bonds or naphthenes.) Rodgers (FSU) and Qian (Exxon) have separately used different MS techniques to demonstrate the latter is the dominant structure in most cases. The more open structure is supported by Exxon asphaltene models (Siskin, 2006) and Exxon papers by Freund supporting a patented model for the fragmentation of kerogen and asphaltenes.(US 7,334,889). As for Mansoori's Figure 8, GCP or SEC is not adequate for determining the MW of asphaltenes, it only reveals the apparent molecular size for the asphaltene aggregates at the concentration and in the solvent used for the test.

Oil Techie04:37, 4 December 2013

Ahmed Helmi

Adjunct Professor at Pharos University

Win: I was about to shutdown my Laptop, take a break, then I made a visit to the Group to see if any comment. I am now fully alert and thanks again and again for your generous information about the latest updates in Asphaltenes' research. Mansoori is depending on the PT diagram and its Gas Envelope to characterize the separation of different phase/s per given change in PT and I was about to consider the extension of his approach when it comes to Asphaltenes as exaggeration; but I recalled a scene during a visit to the Lab of a Gas Separation plant west of Alexandria a couple of years ago. An experimentalist chief chemist of that Lab showed me his separated Asphaltenes out of Natural Gas Condensates with Gas Oil at its tail end. He managed to concentrate these Asphaltenes by several consequent distIllations starting with a Large quantity of Condensates. I was shocked as I used to tell my students that Asphaltenes can be found only in Crudes/Residues. Could these separated Asphaltenes precipitated out of the Condensates according to the PT Diagram? Rephrasing; could this support Mansoori's claim? Win: it seems that I always manage to drag you for deeper insights, will this one work?

Oil Techie04:38, 4 December 2013