Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
권호 표지
DOI QR코드

DOI QR Code

Prediction of Precipitated Wax Amounts Using FTIR Spectroscopy

FTIR을 이용한 왁스 침전의 정량적 예측

  • Oh, Kyeongseok (Department of Chemical and Environmental Technology, Inha Technical College)
  • 오경석 (인하공업전문대학 화공환경과)
  • Received : 2013.03.06
  • Accepted : 2013.05.05
  • Published : 2013.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

High molecular weight paraffinic waxes dissolved in oil phases can be precipitated when the surrounding temperature becomes lower than the wax appearance temperature (WAT). While the various methods of WAT determination have been developed, the determination of precipitated wax amount has not been comparably popular at temperatures below the WAT. It is important to predict how much solid wax content precipitates in temperature variance. The study develops the previous method which uses integrated areas determined at a wavenumber range of 735~715 $cm^{-1}$. This method uses two different wavenumber ranges, 735~715 $cm^{-1}$ and 1,402~1,324 $cm^{-1}$. The study shows how the method provides reliable data in the variety of applications regardless of FTIR spectral instability often occurred, such as volume reduction during cooling procedure and existence of emulsified water in oil phase.

원유에 함유된 물질 중 분자량이 큰 파라핀계 왁스성분의 침전 거동을 연구하였다. 용해되어 녹아있는 왁스성분은 주위 온도가 낮아지면 침전을 시작한다. 침전이 시작되는 온도를 왁스침전온도라 하며, 왁스침전온도에 대해서는 다양한 측정 방법들이 연구되어 왔다. 이에 반하여, 온도하강에 따른 왁스 침전량, 즉 온도에 따른 정량화 시도는 상대적으로 많지 않다. 본 연구는 FTIR을 활용하여 온도에 따른 침전된 왁스의 정량화를 시도하였다. 기존에 제안된 방법이 FTIR의 한 밴드영역인 735~715 $cm^{-1}$에서 시도되었던 것과 비교하여, 본 연구에서는 두 밴드영역인 1,402~1,324 $cm^{-1}$와 735~715 $cm^{-1}$을 활용하였다. 이 방법을 이용하여 정량화를 시도하였을 때, 온도에 따른 부피변화가 있을 경우나 시료에 물이 함유된 경우와 같이 기존 방법에서는 측정이 불가능한 경우에도 안정적인 결과를 얻을 수 있었다.

Keywords

References

  1. http://www.basf.com/group/corporate/en/brand/MICRONAL_PCM.
  2. http://www.sasolwax.com.
  3. Pedersen, K. S., Skovborg, P. and Ronningsen, H. P., "Wax Precipitation from North Sea Crude Oils. 4. Thermodynamic Modeling," Energy Fuels, 5, 924-932(1991). https://doi.org/10.1021/ef00030a022
  4. Roehner, R. M. and Hanson, F. V., "Determination of Wax Precipitation Temperature and Amount of Precipitated Solid Wax versus Temperature for Crude Oils Using FT-IR Spectroscopy," Energy Fuels, 15(3), 756-763(2001). https://doi.org/10.1021/ef010016q
  5. Roehner, R. M., Dahdah, N. and Fletcher, J., Hanson, F., "Comparative Compositional Study of Crude Oil Solids from the Trans Alaska Pipeline System Using High Temperature Gas Chromatography," Energy Fuels, 16, 211-217(2002). https://doi.org/10.1021/ef010218m
  6. Golczynski, T. S. and Kempton, E. C., "Understanding Wax Problems Leads to Deepwater Flow Assurance Solutions," World oil, 227, D7-D10(2006).
  7. Annual Book of ASTM-Standards, "Petroleum Products, Lubricants," West Conshohocken, Pa.: American Society for Testing and Materials, Sec. 5.(1999).
  8. Ronningsen, H. P., Bjorndal, B., Hansen, A. B. and Pedersen, W. B., "Wax Precipitation from North Sea Oils. 1. Crysrallization and dissolution temperatures and Newtonian and Non-Newtonian Flow Properties," Energy Fuels, 5(6), 895-908(1991). https://doi.org/10.1021/ef00030a019
  9. Ferworn, K. and Hammami, A. and Ellis, H., "Control of Wax Deposition: An Experimental Investigation of Crystal Morphology and An Evaluation of Various Chemical Solvents," SPE37240. In: SPE International Symposium on Oilfield Chemistry, Houston, TX, February(1997).
  10. Singh, P., Fogler, H.S. and Nagarajan, N., "Prediction of the Wax Content of the Incipient Wax-Oil Gel in Pipeline: An Application of the Controlled-Stress Rheometer," J. Rheol., 43, 1437-1459(1999). https://doi.org/10.1122/1.551054
  11. Oh, K. and Deo, M. D., "Yield Behavior of Gelled Waxy Oil in Water-in-Oil (w/o) Emulsion at Temperatures below Ice Formation," Fuel, 90, 2113-2117(2011). https://doi.org/10.1016/j.fuel.2011.02.030
  12. Oh, K., Jemmett, M. and Deo, M. D., "Yield Behavior of Gelled Waxy Oil: Effect of Stress Application in Creep Ranges," Ind. Eng. Chem. Res., 48, 8950-8953(2009). https://doi.org/10.1021/ie9000597
  13. Oh, K. and Deo, M. D., "Characteristics of Wax Gel Formation in the Presence of Asphaltenes," Energy Fuels, 23(3), 1289-1293 (2009). https://doi.org/10.1021/ef8006307
  14. Coutinho, J. A. P. and Ruffier-Meray, V., "Experimental Measurements and Thermodynamic Modeling of Paraffinic Wax Formation in Undercooled Solutions," Ind. Eng. Chem. Res., 36, 4977-4983(1997). https://doi.org/10.1021/ie960817u
  15. Snyder, R., Maroncelli, M., Strauss, H. L. and Hallmark, V., "Temperature and Phase Behavior of Infrared Intensities: The Poly-(methylene) Chain," J. Phys. Chem., 90, 5623-5630(1986). https://doi.org/10.1021/j100280a030
  16. Oh, K., "Prediction of Wax Appearance Temperature and Solid Wax Amount by Reduced Spectral Analysis using FTIR Spectroscopy," U.S. Patent No. 8,326,548 B2(2012).

Cited by

  1. 베인 레오미터를 이용한 왁스오일의 특성 연구 vol.32, pp.3, 2013, https://doi.org/10.12925/jkocs.2015.32.3.497
  2. 모델오일을 이용한 파라핀 왁스의 침전 연구 vol.34, pp.3, 2013, https://doi.org/10.12925/jkocs.2017.34.3.495