By Energy Partners Refrigeration
Marquis Macadamias (previously Global Macadamia), has built one of the largest macadamia curing and processing facilities in the world, located in the Alkmaar region of Mpumalanga.
The volume and value of macadamia’s being processed at this site alone has the potential to provide a much-needed economic boost to the area by acting as a catalyst for creating new opportunities for local businesses. According to Macadamias South Africa (SAMAC), current rains in provinces might be a bonus as their crop estimates for 2021 is over 57 000 tonnes of nut in shell (this is 18.2% higher than the 2020 crop of 48 925 tonnes).
To handle most of the macadamia processing operations, a unique plant built in line with global industry standards in sustainable practices, was required. This newly commissioned project houses a combined heating and cooling plant that sets a new benchmark for facilities of this kind in South Africa.
This is according to Dawie Kriel, Head of Business Development at EP Refrigeration – a division of Energy Partners and part of the PSG group of companies. “The most unique feature of this plant is the sustainable measures it has implemented to cut energy consumption for both refrigeration and heating operations. This innovation was an industry-first and will most definitely be adapted to inform future projects,” he says.
Macadamia processing involves both heating and cooling, which is usually very energy-intensive. Most processing plants have separate heating and cooling plants which are costly to run from an energy standpoint. These systems normally do not accommodate much heat storage required for the drying process and therefore do not maintain a constant temperature, particularly during the transition from day to night.
Kriel notes that the design of the facility itself also provides a great advantage for maintaining a low energy-consumption profile, as well as consistent temperatures. “The bins for processing the macadamias are constructed from concrete as opposed to the conventional steel option – this offered us a unique opportunity to use the inertial properties of the bins to provide passive heating and cooling control. Concrete loses and gains heat at a slow rate and as a result smaller quantities of additional energy sources are required to maintain the temperature in the building if the outside temperature changes. This steady temperature control is particularly advantageous for the curing operations of the plant”.
While one of the air handling units provides clean conditioned air for the processing and warehouse areas, the second unit provides a controlled atmosphere to the bulk storage room. The system simultaneously supplies 768kW of heat to generate hot water at 57°C to the curing/drying area coolers and air-handling units, as well as hot water for domestic use. Energy Partners worked with world leading macadamia expert Dorran Bungay, who provided the design outline for this facility.
The South African macadamia industry is experiencing growth with high demand for export, which in turn contributes to the country’s economic development. Kriel notes that EP Refrigeration’s presence at Marquis Macadamias is also creating opportunities in the area. “From a support perspective, our footprint has certainly grown in the Nelspruit region as a result of this mammoth project. We now have capacity to provide refrigeration and heating services to other food processing facilities operating in the area.”
The Marquis Macadamias facility is setting the benchmark for sustainable heating and cooling solutions at food processing plants. “We are already involved in other projects that will benefit greatly from our learnings at this site. Ultimately, we hope to see many more operations in the food processing industry follow suit and reduce un-necessary energy expenditure through implementing more sustainable solutions,” Kriel concludes.