Efficiency gains in the dairy industry – putting mineral scale under the microscope
(Available to domestic & international candidates. Based at Waurn Ponds campus or Warrnambool campus. 3-year PhD scholarship of ~AU$27,000 p.a. tax free plus AU$7,000 p.a. top-up available)
Calcium phosphate scale deposit formation is common in dairy processing, especially where elevated temperatures are involved. Mineral scaling in dairy processing equipment is undesirable because:
1) Scale acts as a surface for bacterial growth, increasing the likelihood of contaminating the product; and
2) Scale reduces the heat transfer efficiency of the surface upon which it forms, which increases energy use and reduces plant life.
Mineral scale is managed using an industry standard cleaning solution that contains sodium hydroxide, nitric acid, phosphoric acid and surfactants. The cost of managing mineral scaling is through the purchase of water softening & cleaning fluids, but importantly, also in the equipment downtime.
Research into cleaning efficiency has taken a process-scale approach – optimising both chemical and physical cleaning parameters (NaOH concentration, temperature of fluid, residence time, flow rate) based on the ability to return a ‘clean’ surface (as determined by macro-scale properties).
The candidate will utilise a number of advanced analytical techniques, including small angle scattering and electron microscopy, combined with lab-and field-based chemistry, to provide our industry partner with a nano-scale assessment of current cleaning processes. This will provide new insights into scale formation and dissolution processes, and will allow for the optimisation of cleaning processes to minimise equipment down time, resulting in more cost-effective cleaning processes.
1. Liaise with our industry partners to understand and document:
a. The key processes & equipment that experience mineral scaling in their operations
b. The current cleaning processes that are employed
2. Explore the current literature on mineral scaling in the dairy industry, with a focus on the molecular-scale mechanisms of nucleation & deposition and fragmentation & dissolution.
3. Design & implement methodologies to:
a. collect, sample and characterise mineral scale from dairy processing
b. measure the efficacy of current cleaning processes
c. identify any relationship between the amount of residual scaling post-clean and the rate at which new scale builds up
d. determine, using industry-available technologies, when a surface is clean at the nano-scale
e. test the efficacy of alternative cleaning processes
(including making use of the advanced characterisation facilities available at Deakin University, the Australian Synchrotron & the Australian Centre for Neutron Scattering).
4. Make recommendations for adaptation of cleaning processes to improve cost-effectiveness.
To apply, please send your Expression of Interest form (download from here: https://bit.ly/2VnWW1q
) and CV to Dr Ellen Moon at [email protected]
. The positions will remain open until suitable candidates are found (don’t delay!).