Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30840
Investigation of Heat Loss in Ethanol-Water Distillation Column with Direct Vapour Recompression Heat Pump

Authors: Christopher C. Enweremadu, Hilary L. Rutto


Vapour recompression system has been used to enhance reduction in energy consumption and improvement in energy effectiveness of distillation columns. However, the effects of certain parameters have not been taken into consideration. One of such parameters is the column heat loss which has either been assumed to be a certain percent of reboiler heat transfer or negligible. The purpose of this study was to evaluate the heat loss from an ethanol-water vapour recompression distillation column with pressure increase across the compressor (VRCAS) and compare the results obtained and its effect on some parameters in similar system (VRCCS) where the column heat loss has been assumed or neglected. Results show that the heat loss evaluated was higher when compared with that obtained for the column VRCCS. The results also showed that increase in heat loss could have significant effect on the total energy consumption, reboiler heat transfer, the number of trays and energy effectiveness of the column.

Keywords: Compressor, distillation column, heat loss, vapourrecompression

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4462


[1] McMillan, J.D. 1997. Bioethanol production: Status and prospects. Renewable Energy, Vol.10. No.2/3, pp. 295-302.
[2] Pfeffer, M, Wukovits W, Beckmann G & Friedl, A. 2007. Analysis and decrease of the energy demand of bioethanol production by process integration. Applied Thermal Engineering. Vol. 27. pp. 2657-2664.
[3] Null, HR. 1976. Heat Pumps in Distillation. Chemical Engineering Progress. pp.58 -64.
[4] Meili, A. 1990. Heat pumps for distillation columns. Chemical Engineering Progress. Vol.6. pp. 60 - 65.
[5] Fonyo, Z, Benko, N. 1998. Comparison of various heat pump-assisted distillation configurations. Transactions of Institution of Chemical Engineers. No.76. Part A. pp. 348-60.
[6] Enweremadu, CC, Waheed, MA & Ojediran, JO. 2008.Parametric study of pressure increase across a compressor in ethanol-water vapour recompression distillation. Scientific Research and Essay. Vol. 3. No.9, pp.231-241.
[7] Enweremadu, CC, Waheed, MA & Ojediran, JO. 2009. Parametric study of an ethanol-water distillation column with direct vapour recompression heat pump. Energy for Sustainable Development. Vol. 13. pp. 96-105.
[8] Hanley, B. 2001. Calculation of the HETP at total reflux: generalization of the Fenske equation. Proceedings of the 2001 AIChE Annual meeting: distillation equipment and application. Wichita, Kansas.
[9] Jevric, J, Fayed, ME. 2002. Shortcut distillation calculations via spreadsheets. Reactions and separations. pp. 60-67.
[10] Gani R, Ruiz CA & Cameron, IT. 1986. A generalised model for distillation column I: model description and applications. Computers and Chemical Engineering. Vol.10. No.3. pp.181-98
[11] Holman, JP .2005. Heat transfer. 9th edition. New York: McGraw-Hill.
[12] Cutlip, MB, Shacham, M & Elly M.2006.POLYMATH numerical solution for scientific problems. Professional Release 6.10, 2006.
[13] Enweremadu, CC. 2007. Simulation of an ethanol-water distillation column with direct vapour recompression heat pump. PhD thesis. Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
[14] Oliveira, SBM, Marques, RP & Parise, JAR. 2001. Modelling of an ethanol - water distillation column with vapor recompression. International Journal of Energy Research. Vol. 25. pp. 845 -58.
[15] Oliveira, SBM, Marques RP & Parise, JAR. 2002. Modelling of an ethanol - water distillation column assisted by an external heat pump. International Journal of Energy Research. Vol. 26. pp.1055 -72.
[16] Liu X, Quian, J. 2001. Modelling, control and optimization of ideal internal thermally coupled distillation columns. Chemical Engineering and Technology. Vol. 23. No.3. pp. 235 - 41.