The Challenge
REHEATZ addresses the challenge of carbon emissions and air pollution from heating of hot-water in industrial processes in Zambia, where coal and charcoal are the primary fuel sources.
Emissions from coal and charcoal combustion accounts for >32% of total emissions in Zambia, with industry being the largest contributor to this.
Charcoal production drives deforestation, another cause of climate change.
We found during our field visit in April 2023 that significant volumes of hot wastewater are generated in the process of steam production and food processing. This heat is discharged to local streams or public sewers. These discharges waste energy, fossil fuels, and money.
They also damage waterways and public infrastructure locally, as well as impact on climate change.
The Solution
In response, the REHEATZ solution will contribute to addressing the identified challenge by reducing the coal or charcoal required to produce the steam and hot water for food processing.
This reduction will be achieved by preheating the cold-water supply to boilers in Zambian food processing plants with heat captured from hot wastewater discharges within the facilities. Where cold-water supply is preheated above ambient temperatures, less energy will be needed to raise the temperature of this water further to steam. Therefore, less fuel will be required and less GHG emissions, and air pollution will be created. Read more here.
Correspondingly, wastewater discharges to the natural environment will be cooler with fewer impacts on aquatic life and biodiversity. The challenge team measured wastewater discharges to natural water bodies in Zambia over 40oC during field investigations in April.
Where wastewater is discharged to public sewer systems our solution will reduce the damage (melting) of public infrastructure by hot wastewater, which has been reported to us by ZEMA (Zambian Environmental Management Agency).
Furthermore, reducing the quantify of fuel needed for food processing will improve the profitability of companies, increase the potential for investment in corporate social responsibility initiatives or reduce the cost of food, and in the case of charcoal use, contribute towards reducing deforestation in Zambia.