Enhancement of Energy Efficiency at an Indian Milk Processing Plant Using Exergy Analysis

  • Babji Srinivasan
  • Jaideep Pal
  • Rajagopalan Srinivasan
Part of the Green Energy and Technology book series (GREEN)


The dairy sector in India is the largest milk producer in the world. Substantial amounts of freshwater and energy are consumed during milk processing with concomitant impacts on sustainability. In this chapter, we study the energy efficiency at India’s largest milk processing plant and propose retrofits for improving the plant’s sustainability. Specifically, we report on exergy analysis of a milk powder manufacturing unit. Exergy of a system at a certain thermodynamic state is the maximum amount of work that can be obtained when the system moves from that state to one of equilibrium with its surroundings. In contrast to a conventional energy analysis, which maps the energy flows of the system and suggests opportunities for process integration, an exergy analysis pinpoints the locations, causes, and magnitudes of thermodynamic losses. The milk powder plant that is the focus of the current study consists of two sections—an evaporation section and a drying section. Our results reveal that exergy efficiency of certain units is very low (<20%). Significant improvements in energy efficiencies can be achieved through simple, low-cost retrofits to these units.


Energy efficiency Diary industry Process integration Exergy Retrofit 


Letter Symbols


Specific heat capacity at constant pressure (in kJ/kg K)


Specific exergy (in kJ/kg)


Specific enthalpy (in kJ/kg)

\( {\dot{\text{m}}}\)̇

Mass flow rate (in kg/s)


Pressure of a system (in bar)


Heat flow (in kJ/s or kW)


Mass-based (substance dependent) gas constant (in kJ/kg K)


Specific entropy (in kJ/kg K)


Time (in s)


Temperature of a system (in °C or K)

\( {\dot{{W}}}\)

Power (or work per time) (in kW)

Greek Symbols


Change in property


Exergy efficiency








Thermodynamic state with ambient conditions


Thermodynamic state


Thermodynamic state


Fluid a


Fluid b


Control volume






Inlet stream




Outlet stream


Constant pressure





The authors gratefully acknowledge Mr. S.S. Sundaran (OSD, Public Relations) and Mr. Deepak R. Sharma (Deputy Manager, Production) of Amul Dairy, Anand, for their constant support in this project.


  1. 1.
    Bühler F, Nguyen T, Jensen JK, Elmegaard B (2016) Energy, exergy and advanced exergy analysis of a milk processing factory. In: Proceedings of ECOS 2016: 29th International conference on efficiency, cost, optimization, simulation and environmental impact of energy systems.Google Scholar
  2. 2.
    Bulletin of the International Dairy Federation 401/2005, 2005 Energy use in dairy processingGoogle Scholar
  3. 3.
    Deparment of Dairying Fisheries and Animal husbandary (2013) Annual Report—2012–13. Ministry of Agriculture, Government of India 15(1):1.
  4. 4.
    Banerjee A (2001) Dairying Systems in India. FAO Corporate Document RepositoryGoogle Scholar
  5. 5.
    Tiwari S, Srinivasan B (2017) Water conservation, reuse and challenges: a case study performed at Amul dairy. The water-food-energy nexus: processes, technologies and challenges, CRC Press ISBN: 9781498760836Google Scholar
  6. 6.
    National Dairy Development Board (2014) Annual Report, 2013–14Google Scholar
  7. 7.
    Rant Z (1956) Exergy, a new word for “technical available work”. Forschung auf dem Gebiete des Ingenieurwesens (in German) 22:36–37Google Scholar
  8. 8.
    Szargut J (1980) International progress in second law analysis. Energy 5(8–9):709–718CrossRefGoogle Scholar
  9. 9.
  10. 10.
    Kaushik SC, Siva RV, Tyagi SK (2011) Energy and exergy analyses of thermal power plants: a review. Renew Sustain Energy Rev 15:1857–1872CrossRefGoogle Scholar
  11. 11.
    Siva RV, Kaushik SC, Tyagi SK (2012) Exergetic analysis of solar concentrator aided natural gas fired combined cycle power plant. Rene Energy 39:114–125CrossRefGoogle Scholar
  12. 12.
    Nazghelichi T, Aghbashlo M, Kianmehr MH (2011) Optimization of an artificial neural network topology using coupled response surface methodology and genetic algorithm for fluidized bed drying. Comput Electron Agric 75(1):84–91CrossRefGoogle Scholar
  13. 13.
    Aghbashlo M, Mobli H, Rafiee S, Madadlou A (2013) A review on exergy analysis of drying processes and systems. Renew Sustain Energy Rev 22:1–22CrossRefGoogle Scholar
  14. 14.
    Dincer I (2002) On energetic, exergetic and environmental aspects of drying systems. Int J Energy Res 26:717–727CrossRefGoogle Scholar
  15. 15.
    Dincer I, Rosen MA (2007) Exergy: energy, environment, and sustainable development. Elsevier, AmsterdamGoogle Scholar
  16. 16.
    Dincer I (2011) Exergy as a potential tool for sustainable drying systems. Sustain Cities Soc 1:91–96CrossRefGoogle Scholar
  17. 17.
    Pandey AK, Tyagi VV, Park SR, Tyagi SK (2012) Comparative experimental study of solar cookers using exergy analysis. J Therm Anal Calorim 109:425–431CrossRefGoogle Scholar
  18. 18.
    Luis P (2013) Exergy as a tool for measuring process intensification in chemical engineering. J Chem Technol Biotechnol 88(11):1951–1958Google Scholar
  19. 19.
    Luis P, Van der Bruggen B (2014) Exergy analysis of energy-intensive production processes: advancing towards a sustainable chemical industry. J Chem Technol Biotechnol 89:1288–1303CrossRefGoogle Scholar
  20. 20.
    Rosen MA, Scott DS (1988) Energy and exergy analyses of a production process for methanol from natural gas. Int J Hydrogen Energy 13:617–623CrossRefGoogle Scholar
  21. 21.
    Fábrega FM, Rossi JS, d’Angelo JVH (2010) Exergetic analysis of the refrigeration system in ethylene and propylene production process. Energy 35:1224–1231CrossRefGoogle Scholar
  22. 22.
    Sorin M, Hammache A, Diallo O (2000) Exergy load distribution approach for multi-step process design. Appl Therm Eng 20:1365–1380CrossRefGoogle Scholar
  23. 23.
    Leites IL, Sama DA, Lior N (2003) The theory and practice of energy saving in the chemical industry: some methods for reducing thermodynamic irreversibility in chemical technology processes. Energy 28:55–97CrossRefGoogle Scholar
  24. 24.
    Gao L, Jin H, Liu Z, Zheng D (2004) Exergy analysis of coal-based polygeneration system for power and chemical production. Energy 29:2359–2371CrossRefGoogle Scholar
  25. 25.
    Bühler F, Nguyen T, Elmegaard B (2015) Energy and exergy analysis of the danish industry sector. In: Proceedings of the 10th conference on sustainable development of energy, water and environment systemsGoogle Scholar
  26. 26.
    Ertesvåg IS (2001) Society exergy analysis: a comparison of different societies. Energy 26:253–270CrossRefGoogle Scholar
  27. 27.
    Rosen MA, Dincer I (2001) Exergy as the confluence of energy, environment and sustainable development. Exergy Int J 1(1):3–13CrossRefGoogle Scholar
  28. 28.
    Gundersen T (2011) An introduction to the concept of exergy and energy quality. Energy Process Eng version 4Google Scholar
  29. 29.
    Schuck P, Dolivet A, Méjean S, Jeantet R (2008) Relative humidity of outlet air: the key parameter to optimize moisture content and water activity of dairy powders. Dairy Sci Technol 88:45–52CrossRefGoogle Scholar
  30. 30.
    Birchal VS, Passos ML (2005) Modeling and simulation of milk emulsion drying in spray dryers. Braz J Chem Eng 22(2):293–302CrossRefGoogle Scholar
  31. 31.
    Milk Powder—New Zealand Institute of Chemistry Available at:
  32. 32.
    Training Manual—Amul 3 Powder Plant, Amul Dairy, AnandGoogle Scholar
  33. 33.
    Holland CR, McCann JB (1980) Heat recovery in spray drying systems. Int J Food Sci Technol 15:9–23CrossRefGoogle Scholar
  34. 34.
    Mercer AC (1986) Improving the energy efficiency of industrial spray dryers. J Heat Recovery Syst 6:3–10CrossRefGoogle Scholar
  35. 35.
    Miller J (1987) The use of recovered heat for preheating air to spray driers. New Zealand Energy Research and Development Committee Report. Palmerston North, New ZealandGoogle Scholar
  36. 36.
    Atkins MJ, Walmsley MRW, Neale JR (2011) Integrating heat recovery from milk powder spray dryer exhausts in the dairy industry. Appl Therm Eng 31:2101–2106CrossRefGoogle Scholar
  37. 37.
    Robert C (2005) Bulletin of the IDF No. 401/2005- Energy use in dairy processingGoogle Scholar
  38. 38.
    Atkins MJ, Walmsley MRW, Neale JR (2010) The challenge of integrating non-continuous processes—milk powder plant case study. J Clean Prod 18:927–934CrossRefGoogle Scholar
  39. 39.
    Atkins MJ, Walmsley MRW, Neale JR (2012) Process integration between individual plants at a large dairy factory by the application of heat recovery loops and transient stream analysis. J Clean Prod 34:21–28CrossRefGoogle Scholar
  40. 40.
    Walmsley MRW, Walmsley TG, Atkins MJ, Neale JR (2012) Area targeting and storage temperature selection for heat recovery loops. Chem Eng Trans 29:1219–1224Google Scholar
  41. 41.
    Baker CGJ, McKenzie KA (2005) Energy consumption of industrial spray dryers. Drying Technol Int J 23:365–386CrossRefGoogle Scholar
  42. 42.
    Quijera JA, Labidi J (2013) Pinch and exergy based thermosolar integration in a dairy process. Appl Therm Eng 50:464–474. CrossRefGoogle Scholar
  43. 43.
    Fang Z, Larson DL, Fleischmen G (1995) Exergy analysis of a pilot milk processing system. Trans ASAE 38:1825–1832CrossRefGoogle Scholar
  44. 44.
    Erbay Z, Koca N (2012) Energetic, exergetic, and exergoeconomic analyses of spray-drying process during white cheese powder production. Dry Technol 30:435–444. CrossRefGoogle Scholar
  45. 45.
    Quijera JA, Alriols MG, Labidi J (2011) Integration of a solar thermal system in a dairy process. Renew Energy 36:1843–1853. CrossRefGoogle Scholar
  46. 46.
    Vidal M, Martin L, Martin M (2014) Can exergy be a useful tool for the dairy industry? In: 24th European Symposium Computer Aided Process Engineering—ESCAPE 24, vol 33, Elsevier, Amsterdam, pp 1603–1608.
  47. 47.
    Sorgüven E, Özilgen M (2012) Energy utilization, carbon dioxide emission, and exergy loss in flavored yoghurt production process. Energy 40:214–225. CrossRefGoogle Scholar
  48. 48.
    Traegardh C (1981) Energy and exergy analysis in some food processing industries. Leb Und—Technologie 14:213–217Google Scholar
  49. 49.
    Dincer I, Sahin AZ (2004) A new model of thermodynamic analysis of a drying process. Int J Heat Mass Transf 47:645–652.
  50. 50.
    Leo MA (1982) Energy conservation in citrus processing. Food Technol 36:231–233Google Scholar
  51. 51.
    Balkan F, Colak N, Hepbasli A (2005) Performance evaluation of a triple-effect evaporator with forward feed using exergy analysis. Int J Energy Res 29:455–470. CrossRefGoogle Scholar
  52. 52.
    Winchester J (2000) Model based analysis of the operation and control of falling film evaporators. Massey UniversityGoogle Scholar
  53. 53.
    Choi HS, Lee TJ, Kim YG, Song SL (2005) Performance improvement of multiple-effect distiller with thermal vapor compression system by exergy analysis. Desalination 182:239–249. CrossRefGoogle Scholar
  54. 54.
    Bejan A, Dincer I, Lorente S, Reis AH, Miguel AF (2004) Porous media in modern technologies: energy, electronics. Biomedical and environmental engineering. Springer, New York p 396Google Scholar
  55. 55.
    Dincer I, Rosen MA (2005) Thermodynamic aspects of renewables and sustainable development. Renew Sustain Energy Rev 9:169–189CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • Babji Srinivasan
    • 1
  • Jaideep Pal
    • 1
  • Rajagopalan Srinivasan
    • 1
    • 2
  1. 1.Indian Institute of Technology GandhinagarGandhinagarIndia
  2. 2.Department of Chemical EngineeringIndian Institute of Technology MadrasChennaiIndia

Personalised recommendations