Journal of Thermal Analysis and Calorimetry

, Volume 120, Issue 2, pp 1427–1433 | Cite as

Utilization of DSC, NIR, and NMR for wax appearance temperature and chemical additive performance characterization

  • Yansong Zhao
  • Kristofer Paso
  • Jens Norrman
  • Hassan Ali
  • Geir Sørland
  • Johan Sjöblom


Wax crystallization processes are investigated using differential scanning calorimetry, near-infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The performance of a chemical additive is assessed using calorimetry and NMR. Heat flows of model waxy oils are obtained using differential scanning calorimetry, providing the wax appearance temperature and crystallization profiles. The effect of cooling rate, wax content, asphaltene, and chemical additive on the wax appearance temperature is investigated. The wax appearance temperature increases with increasing wax contents. The wax appearance temperature decreases in the presence of chemical additive, effectively increasing the instantaneous supersaturation. Furthermore, near-infrared spectroscopy and nuclear magnetic resonance spectroscopy are utilized to determine wax appearance temperature. The NMR experiments quantify liquid and solid fractions at thermal equilibrium conditions, effectively circumventing the need for dynamic thermal techniques.


DSC NIR NMR Wax appearance temperature Wax crystallization 

List of symbols


Planck’s constant 6.626 × 10−34 (m2 kg s−1)


Diffusion coefficient (m2 s)


Energy level (m2 kg s−2)


External magnetic field strength (A m−1)


Spin (dimensionless)


Integration constant (A m−1)


Magnetization (A m−1)


Integration constant (A m−1)


Characteristic relaxation time (s)


Magnetogyric ratio (A s kg−1)


Velocity (m s−1)


Frequency (s−1)

Del operator


x, y, z

Cartesian coordinates


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2015

Authors and Affiliations

  • Yansong Zhao
    • 1
    • 3
  • Kristofer Paso
    • 1
  • Jens Norrman
    • 1
  • Hassan Ali
    • 1
  • Geir Sørland
    • 2
  • Johan Sjöblom
    • 1
  1. 1.Ugelstad Laboratory, Department of Chemical EngineeringNorwegian University of Science and Technology (NTNU)TrondheimNorway
  2. 2.Anvendt Teknologi ASTrondheimNorway
  3. 3.Energy and Climate Group, Department of Physics and TechnologyUiT The Arctic University of NorwayTromsøNorway

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