Researchers from Trinity’s School of Engineering, School of Natural Sciences, and Trinity Business School, have secured second place in the Science Foundation Ireland-Irish Aid Sustainable Development Goals Challenge, which was focused on SDG 13 (Climate Action).

The REHEATZ team, led by Professors Aonghus McNabola, Padraig Carmody and Paul Coughlan, have worked to develop the first hybrid wastewater heat recovery technology for application in Zambian food production.

The team, which worked closely with Dr Godfrey Hampwaye of the Southern African Institute for Policy and Research (Zambia) and in partnership with Mangiza Chirwa Chongo, will now use additional funding of €650,000 over two years to complete the project’s pilot plants and hope to create green jobs locally. 

REHEATZ team members from Trinity with some of their Zambian partners in Africa.

The team also worked closely with Zambeef PLC, the largest vertically integrated food retailing company in Zambia, in piloting the technology.

Zambian food processing relies heavily on the use of coal boilers to produce hot water. Emissions from coal combustion account for >32% of national total emissions, so reducing coal use would substantially cut national emissions. During food production, hot water from coal boilers is used at temperatures of 60-90^oC, and then discharged as wastewater at 30-70^oC.

Wastewater heat recovery (WWHR) technology transfers heat from hot wastewater to incoming cold feedwater, reducing the fuel required to heat the resulting lukewarm feedwater to temperatures required for food processing.

First ever installation of WWHR technology

The team’s pilot plants will be the first ever installations of WWHR technology demonstrated in an operational food processing environment in a tropical climate. They will build on the project’s success, raising awareness of the potential wastewater heat recovery technology for societal benefit in Zambia and, more broadly, southern Africa.

Prof McNabola said: “We are delighted to have been awarded the runner-up prize in the SFI SDG13 challenge competition. It has been a real privilege to have the opportunity to work on climate emission reductions and develop green-tech solutions for the food industry in Zambia.

"We are very grateful to SFI and Irish Aid for having given us the opportunity to investigate the potential of wastewater heat recovery in Zambia to begin with – and for the opportunity now to deploy the solution in practice. We are also very grateful to the Irish Ambassador to Zambia H.E. Bronagh Carr, and the Embassy team for the excellent support we received in making key connections in Zambia.

“We expect the technology will reduce the cost and emission arising from steam production in Zambian food processing by up to 15%, and that we will be able to establish a new Zambian-led, non-profit venture to roll out the technology in the sector, as well as provide new skills training and green jobs locally. We also expect the technology to result in increased opportunities for corporate social responsibility investments in related areas.

“Personally I am very proud of the work the team has done here. The project is a great example of the positive change that can be achieved with strong collaboration across academic disciplines and with industry in the developing world.”