Imperial College London
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George JACKSON BSc DPhil FRSC FRS

Faculty of Engineering, Department of Chemical Engineering

Professor of Chemical Physics
 
 
 
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Contact

 

+44 (0)20 7594 5640g.jackson Website

 
 
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Location

 

RODH 605Roderic Hill BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Headen:2017:10.1021/acs.energyfuels.6b02161,
author = {Headen, T and Boek, E and Jackson, G and Totton, T and Muller, EA},
doi = {10.1021/acs.energyfuels.6b02161},
journal = {Energy & Fuels},
pages = {1108--1125},
title = {Simulation of asphaltene aggregation through molecular dynamics: insights and limitations},
url = {http://dx.doi.org/10.1021/acs.energyfuels.6b02161},
volume = {31},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - We report classical atomistic molecular dynamics simulations of four structurally diverse model asphaltenes,  a  model  resin,and  their respective mixtures  in  toluene  or  heptane  at  ambient conditions. Relatively large systems (~50,000 atoms) and long timescales(> 80 ns)are explored. Whereever possible,comparisons are madeto available experimental observations asserting the validity of the models. When the asphaltenes are dissolved in toluene, a continuous distribution of  cluster  sizesis  observed with  average  aggregation  number  ranging  between  3.6and 5.6,monomers  and  dimers being  thepredominantspecies.  As  expected  for  mixtures in  heptane the asphaltene  molecules tend  to  aggregate  to  form  a  segregated  phase.  There  is  no  evidence  of  a distinct  formation  of  nanoaggregates,  the  distributions  of  clusters is  found  to  becontinuous in character.The analysis of the shape of the clusters of asphaltenes suggests that they are generally spherical  incharacter,  with  the  archipelago  models  favouring  longer  prolate structuresand  the continental modeltending  towards oblate structures.  The  aggregates  areseen  to  bediffuse  in nature,  containing  at  least  50%  solventon  average,  being  denser  in  heptane  than  in  toluene. Mixtures  of  asphaltenes  with  different architectureare  found  to  have cluster  properties  that  are intermediate between those of the individual components. The presence of resins in the mixture does not appear to alter the shape of the asphaltene aggregates, their size or density when toluene is  the  solvent; on  the  otherhand  theresins lead  to  an increase in the  density  of  the  resulting aggregatesin  heptane. Quantification  of  these  observations  is  made from  the histograms  of cluster  distributions, the potential  of  mean  force  calculations,and an analysis  of the shape factors. We illustrate howthe time scales for complete aggregationof molecules in heptanearelarger t
AU  - Headen,T
AU  - Boek,E
AU  - Jackson,G
AU  - Totton,T
AU  - Muller,EA
DO  - 10.1021/acs.energyfuels.6b02161
EP  - 1125
PY  - 2017///
SN  - 1520-5029
SP  - 1108
TI  - Simulation of asphaltene aggregation through molecular dynamics: insights and limitations
T2  - Energy & Fuels
UR  - http://dx.doi.org/10.1021/acs.energyfuels.6b02161
UR  - http://hdl.handle.net/10044/1/43754
VL  - 31
ER  -
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