Murray Goulburn cuts carbon emissions with compressed air upgrade

CompAir’s Quantima compressor system has helped Australia’s largest milk processor, Murray Goulburn (MGC), reduce costs and carbon emissions.

Murray Goulburn processes 37% of Australia’s milk supply and is the nation’s biggest exporter of processed food. It is committed to the environmental sustainability of its business and has a continuous development program in place to reduce its carbon footprint. This program, in conjunction with the availability of state funding towards the purchase of energy-efficient technologies, prompted MGC’s Group Maintenance Manager, Mark Gurney, to consider replacement options for the existing compressed air system at the company’s Leongatha plant in Victoria.

The company decided to implement a completely new system to supply all of the factory’s compressed air requirements for both plant and packaging processes, including new compressor units, air supply pipes and dryers.

An example of a Quantima air compressor.

CompAir Australasia put forward a proposal for the new system that involved replacing the four existing compressor units with just one 300 kW Quantima compressor and leaving two units for standby air.

A detailed audit was taken before and after the installation and submitted to the state government, proving that the new installation has enabled MGC to meet its power reduction target with an overall energy saving of more than 35%.

“By combining the innovative Quantima compressor with all downstream equipment, including desiccant dryers and new air distribution pipes, we have been able to reduce pressure drops and air leaks dramatically,” said Gurney.

“Prior to the installation, our compressed air system was using 9.1 kW to generate each cubic metre of air per minute. Now, with Quantima, this specific power consumption has reduced significantly to just 6.12 kW/Nm³/min. In simple terms, we are now producing compressed air at best practice levels and with much better efficiency - to the effect it is now taking 33% less power for us to generate a higher air output.”

MGC has already realised CO₂ savings of 1908 tonnes - equivalent to planting over 2805 trees or taking 440 cars off the road.

The Quantima saves energy through its Q-drive, a centrifugal compression assembly that consumes significantly less power than conventional technologies. Q-drive’s rotor shaft is its only moving part, reducing friction contact that can result in energy losses and performance degradation over time. A variable speed drive allocates airflow according to plant demand to further save energy.

The Quantima has not only saved MGC energy, its predictive maintenance solution, Q-life, also saves on servicing costs. CompAir engineers monitor the machine’s performance remotely, moderating it where necessary to prevent a fault occurring or arranging a local engineer for remedial repairs.

CompAir had already been providing regular servicing to MGC’s plant, carried out by local CompAir engineers. Q-life also comes with risk-free, fixed price servicing, a solution which has saved MGC 64% on its service costs. Another bonus is that Quantima’s oil-free system negates the need for disposal and treatment of waste oil and condensate - and all the associated costs.

To further reduce energy consumption and the reliance on chilled water supply, MGC and CompAir are working together to design water cooling towers. These will enable water to be taken straight into the process, which can be up to 8% more energy efficient than using a separate factory chiller to cool the mains water. The towers are projected to save another 71 kW of installed power, meaning a further 677 tonnes of CO₂ savings each year.

MGC also has the requirement to use contaminant-free air. With no gearbox and therefore no need for oil lubrication, the new compressor is also completely oil free, to guarantee air purity and eliminate the need for additional compressed air filtration.

Gurney is happy with the new system: “Instead of simply replacing one or two of our existing compressors, we chose to install a complete new system that would deliver a low cost of ownership, with the maximum energy savings possible. We are very pleased with the results.

“After only five months, the Quantima compressor has already delivered the energy-saving and carbon footprint reductions that we expected. Overall the project will pay back, pre-tax, in 22 months.”