Role of surface chemistry in predicting viscosity of concentrated carbonaceous solid-water slurries

Amrita Mukherjee, Sarma V. Pisupati

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Viscosity prediction of carbonaceous solid-water slurries is essential to process design and control. Existing viscosity models take into account particle-size distributions but fail to account for the surface chemistry of the solids. Surface chemistry affects inter-particle and particle-water interactions and therefore influences slurry viscosity of concentrated suspensions. On the basis of surface chemistries characterized by contact angle and zeta potential measurements, this study determines the inter-particle interaction energies. Polar interaction energy, observed to be 2-3 orders of magnitude greater than the electrostatic interaction energy and the van der Waal interaction energy, is clearly the dominant interaction energy for such a system. Both hydrophobic and hydrophilic interactions of these particles in water result in microstructures which trap water either in the form of coalescing droplets in aggregation networks or in the form of hydration layers around carbonaceous solids, leading to an increase in the effective solid volume fraction and thus increase in slurry viscosity. The increase in effective solid volume fraction is dependent on the surface chemistry of the solid and thus is specific to a carbonaceous solid. The factor by which solid volume fraction increases for a particular carbonaceous solid was determined using viscosity measurements and Krieger-Dougherty equation and was found to correlate very well with the oxygen to carbon ratio of the solid. Incorporating this factor in the Krieger-Dougherty equation resulted in accurate prediction of slurry viscosity. This modified model was successfully validated using three other concentrated carbonaceous solid-water slurries.

Original languageEnglish (US)
Title of host publication18th Topical Conference on Refinery Processing 2015 - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety
PublisherAIChE
Pages175-187
Number of pages13
ISBN (Electronic)9781510806955
StatePublished - 2015
Event18th Topical Conference on Refinery Processing - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety - Austin, United States
Duration: Apr 26 2015Apr 30 2015

Publication series

Name18th Topical Conference on Refinery Processing 2015 - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety

Other

Other18th Topical Conference on Refinery Processing - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety
Country/TerritoryUnited States
CityAustin
Period4/26/154/30/15

All Science Journal Classification (ASJC) codes

  • General Engineering

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