Electricity and Control August 2021

ENERGY MANAGEMENT + THE INDUSTRIAL ENVIRONMENT

Reducing energy usage in macadamia processing

In the Alkmaar region of Mpumalanga, Marquis Macadamias has built one of the largest macadamia curing and processing facilities in the world.

International food producer Global Macadamia (recently rebranded to Marquis Macadamias), has built one of the largest macadamia curing and processing facilities in the world, in the Alkmaar region of Mpumalanga. Built in line with global industry standards in sustainable practices, the newly commissioned facility houses a combined heating and cooling plant that sets a new benchmark for operations of this kind in South Africa.

A ccording to industry organisation South Africa Macadamia (SAMAC), rainfall levels experienced in some provinces might see a bigger macadamia crop this year and its crop estimate for 2021 is 57 834 tonnes of nut in shell (18.2% higher than the 2020 crop of 48 925 tonnes). The volume and value of macadamias being processed at the new Marquis Macadamias site alone have the potential to provide a much-needed economic boost to the area, acting as a catalyst in creating new opportunities for local businesses. According toDawie Kriel, Head of Business Development at EP Refrigeration – a division of Energy Partners and part of the PSG group of companies, “A unique feature of this plant is the sustainable measures implemented to cut energy consumption for refrigeration and heating operations. This marks an industry first and such measures will definitely be adapted to inform future projects.” Kriel explains that macadamia processing involves both heating and cooling, which is usually very energy-intensive. “Most processing plants have separate heating and cooling plants which, from an energy standpoint, are costly to run. These systems normally do not accommodate much heat storage – which is required for the drying process – and therefore do not maintain a constant temperature, particularly through the transition from day to night.” Kriel adds that the facility itself is designed specifically to maintain a low energy consumption profile as well

as consistent temperatures. “For example, the bins for processing the macadamias are constructed from concrete as opposed to the conventional steel option. This offered us the opportunity to use the inertial properties of the bins to provide passive heating and cooling. Concrete loses and gains heat at a slow rate and, as a result, fewer additional energy sources are required to maintain the temperature in the building through the changing outside temperatures.

The newly commissioned facility houses a combined heating and cooling plant that sets a new benchmark for operations of this kind in South Africa.

Electricity + Control AUGUST 2021

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