Separation technologies

Overview

The Separation  technologies theme focuses on commercial and emerging separation technologies to  improve the recovery of dairy products, reduce waste disposal costs and reduce  environmental impact (Figure 1). The  focus is on a sustainable and cost effective approach. The work includes  scoping studies of separation technologies not previously applied to dairy  streams, such as membrane distillation and capacitive deionisation for recovery  of salt and charged proteins from dairy solutions. Advanced nanofiltration  technology and electrodialysis are also being studied as potential methods for  salt reduction and for the removal of lactic acid from acid whey.

Figure 1. Overview of separation  technologies used to analyse acid, sweet and salty whey streams.

Capabilities  and technologies

Ultrafiltration

A process  used for the recovery of protein from whey.

Nanofiltration

A process used for the concentration of lactose and partial  demineralisation of sweet and acid whey.

Figure 2. Ultrafiltration/nanofiltration  unit.

Electrodialysis

A process used for the demineralisation of sweet and acid  whey and clean salt production from salty whey (Figure 3).

Figure 3. Diagram  of an electrodialysis cell.

When used in conjunction with nanofiltration for the  recovery of protein and milk sugar from acid whey (Figure 4), this technique has the potential to become a  multi-million dollar commercial opportunity.

Figure 4. The  energy consumption for demineralisation of acid whey is comparable to that of  sweet whey using electrodialysis.

Membrane distillation

A process used for the concentration of high salinity  effluent. This methodology can  concentrate effluent beyond the limits of reverse osmosis. It can be used in  conjunction with a crystallisation unit to remove the salt from salty whey (brine)  leading to a reduction in both waste volume (up to three times) and solid  content (Figure 5b). Membrane  distillation uses minimal energy and also has the potential to use waste heat (Figure 5a). This technique has the  ability to reduce the disposal costs and environmental impact of dairy  byproducts.

Figure 5. (a)  Process for membrane distillation and (b) cryo scanning electron microscopy  (cryo SEM) images of salt crystals.

Forward osmosis

A process used for the pre-concentration of dairy whey. This  technology has the ability to reduce the energy consumption of evaporators and  generate a potential saving of 0.5–1.0 MJ/tonne of dairy powder produced.

Capacitive deionisation

A process used for the removal and/or recovery of specific salts  from dairy solutions.

Ultrasound

A process  used to increase shear in intensive dairy processing.

Outcomes

  • We have conducted an industry survey on salty  waste stream management in the Australian dairy industry.
  • We have conducted an extensive technology review  into technologies for wastewater recovery and reuse in the dairy industry.
  • The team has been working closely with industry  partners to ensure industry needs are addressed.
  • The team has evaluated the feasibility and  commercial applicability of various separation technologies.

Publications

2020

Wang, Q., Chen, G. Q. & Kentish, S. E. (2020) Isolation of lactoferrin and immunoglobulins from dairy whey by an electrodialysis with filtration membrane process. Separation and Purification Technology, 233, 115987.

Chen, G. Q., Gras, S. L. & Kentish, S. E. (2020) The application of forward osmosis to dairy processing. Separation and Purification Technology, 246, 116900. https://doi.org/10.1016/j.seppur.2020.116900.

Chen, G. Q., Gras, S. L. & Kentish, S. E. (2020) Eutectic freeze crystallisation of saline dairy effluent. Desalination, 480, https://doi.org/10.1016/j.desal.2020.114349.

Chen, G. Q., Wei, K., Hassanvand, A., Freeman, B. D. & Kentish, S. E. (2020) Single and binary ion sorption equilibria of monovalent and divalent ions in commercial ion exchange membranes, Water Research, 175, 115681. https://doi.org/10.1016/j.watres.2020.115681.

Talebi, S., Suarez, F., Chen, G. Q., Chen, X., Bathurst, K. & Kentish, S. E. (2020) Pilot study on the removal of lactic acid and minerals from acid whey using membrane technology, ACS Sustainable Chemistry & Engineering, 8, 7, 2742–2752.

2019

Talebi, S., Chen, G. Q., Freeman, B., Suarez, F., Freckleton, A., Bathurst, K. & Kentish, S. E. (2019) Fouling and in-situ cleaning of ion-exchange membranes during the electrodialysis of fresh acid and sweet whey. Journal of Food Engineering, 246, 192–199.

Talebi, S., Kee, E., Chen, G. Q., Bathurst, K., Kentish, S. E. (2019) Utilisation of salty whey ultrafiltration permeate with electrodialysis. International Dairy Journal, 99, 104549.

Hassanvand, A., Chen, G. Q., Webley, P. A. & Kentish, S.E. (2019) An investigation of the impact of fouling agents in capacitive and membrane capacitive deionisation. Desalination, 457, 96–102.

Chen, G. Q., Artemi, A., Lee, J., Gras, S. L. & Kentish, S. E. (2019) A pilot scale study on the concentration of milk and whey by forward osmosis. Separation and Purification Technology, 215, 652–659.

Chen, G. Q., Leong, T. S. H., Kentish, S. E., Ashokkumar, M. & Martin, G. J. O. (2019) Chapter 8 – Membrane separations in the dairy industry. In: Galanakis, C. M. (Ed.) Separation of Functional Molecules in Food by Membrane Technology, (pp. 267–304), Academic Press, https://doi.org/10.1016/B978-0-12-815056-6.00008-5.

2018

Chen, G. Q., Talebi, S., Gras, S. L., Weeks, M. & Kentish, S. E. (2018) A review of salty waste stream management in the Australian dairy industry.  Journal of Environmental Management, 224, 406–413.

Hassanvand, A., Chen, G. Q., Webley, P. A. & Kentish, S.E. (2018) A comparison of multicomponent electrosorption in capacitive deionization and membrane capacitive deionization. Water Research, 131, 100–109.

Chen, G. Q., Gras, S. L. & Kentish, S. E. (2018) Separation technologies for salty wastewater reduction in the dairy industry, Separation and Purification Reviews, 48, 325–353.

2017

Deng, H., Chen, G. Q., Gras, S. L. & Kentish, S.E. (2017) The effect of restriction membranes on mass transfer in an electrodialysis with filtration membrane process. Journal of Membrane Science, 526, 429–436.

Hassanvand, A., Chen, G. Q., Webley, P. A. & Kentish, S. E. (2017) Improvement of MCDI operation and design through experiment and modelling: Regeneration with brine and optimum residence time. Desalination, 417, 36–51.

Hassanvand, A., Wei, K., Talebi, S., Chen, G. Q. & Kentish, S. E. (2017) The role of ion exchange membranes in membrane capacitive deionisation. Membranes, 7, 54.

Kezia, K., Lee, J., Zisu, B., Chen, G. Q., Gras, S. L. & Kentish, S. E. (2017) Solubility of calcium phosphate in concentrated dairy effluent brines, Journal of Agricultural and Food Chemistry, 65, 4027–4034.

Kentish, S. E. (2017) Chapter 1 – Engineering principles of ultrasound technology. In: Bermudez-Aguirre, D. (Ed.) Ultrasound: Advances in Food Processing and Preservation, (1st edition, pp. 1–13), Academic Press.

2016

Chandrapala, J., Chen, G. Q., Kezia, K., Bowman, E. G., Vasiljevic, T. & Kentish, S. E. (2016) Removal of lactate from acid whey using nanofiltration. Journal of Food Engineering, 177, 59–64.

Chen, G. Q., Eschbach, F. I. I., Weeks, M., Gras, S. L. & Kentish, S. E. (2016) Removal of lactic acid from acid whey using electrodialysis. Separation and Purification Technology, 158, 230–237.

Kezia, K., Lee, J., Zisu, B., Weeks, M., Chen, G. Q., Gras, S.L. & Kentish, S. E. (2016) Crystallisation of minerals from concentrated saline dairy effluent. Water Research, 101, 300–308.

Chandrapala, J., Ong, L., Zisu, B., Gras, S. L., Ashokkumar, M. & Kentish, S. (2016) The effect of sonication and high pressure homogenisation on the properties of pure cream. Innovative Food Science & Emerging Technologies, 33, 298–307.

2015

Kezia, K., Lee, J., Weeks, M. & Kentish, S. E. (2015) Direct contact membrane distillation for the concentration of saline dairy effluent. Water Research, 81, 167–177.

Hu, K., Dickson, J. M. & Kentish, S. E. (2015) Chapter 1 – Microfiltration for casein and serum protein separation. In: Hu, K. & Dickson, J.M. (Eds.) Membrane Processing for Dairy Ingredient Separation, (pp. 1–34), Oxford, UK: John Wiley & Sons, Ltd.

Kentish, S. E. & Rice, G. (2015) Chapter 5 – Demineralisation of dairy streams and dairy mineral recovery using nanofiltration.  In: Hu, K. & Dickson, J.M. (Eds.) Membrane Processing for Dairy Ingredient Separation, (pp.112–138), Oxford, UK: John Wiley & Sons, Ltd., https://doi.org/10.1002/9781118590331.ch5.

2014

Kentish, S. E. & Feng, H. (2014) Applications of power ultrasound in food processing. Annual Review of Food Science and Technology, 5, 263–284.

Researchers