Gauteng and NW Province

Meeting water and energy challenges in agri-food sector with technology

Innovations in sugar cane processing to reduce water use and produce energy will help to meet future agricultural product demands.

Wayne Visser, Guardian Professional,

Worldwide, the overall growth in demand for agricultural products will require a 140% increase in the supply of water over the next 20 years compared to the past 20 years. While the bulk of this demand will be from irrigation, food processing plants can also be water intensive. So, any technological innovations in the industry that save water are welcome.

One such innovation is by Mars Petcare, which has developed a recirculation system that reduces the potable water used for cooling in its pet food production process by 95%. Wastewater is also down by 95% and gas by 35% through the use of a treatment method that keeps the water microbiologically stable.

In Brazil, water used in sugar cane processing has gone down from 5.6 to 1.83 cubic metres (m3) per ton in recent years, due to improved technologies and practices in waste water treatment.

Further reductions can be made by replacing the standard wet cane washing process with a new technique of dry cane washing. Costa Rican company Azucarera El Viejo SA has found that this switch has resulted in more than 6m gallons of water being saved each day during the harvest season, netting savings of approximately USD54,000.

Of course, in food processing, it is not only volume of water that is important, but also the quality of water effluent associated with the manufacturing process. In Brazil, sugar cane is partly processed into ethanol. Vinasse is a byproduct of this process that pollutes water. Technological innovation shows that, while in Brazil emissions of 10 – 12 litres of vinasse per liter of ethanol are standard, levels of 6 litres can be achieved.

Other examples of innovative water quality solutions in the agri-foods sector are Briter-Water, which has been piloted in the EU and uses intensified bamboo-based phytoremediation for treating dairy and other food industry effluent; and the Vertical Green Biobed, developed by HEPIA, a school from the University of Applied Sciences of western Switzerland, to improve water treatment of agricultural effluents.

Generating energy from agricultural waste

Besides water issues, agriculture is also very energy intensive, accounting for 7% of the world’s greenhouse gas emissions, according to 2010 figures. Even carbon emissions associated only with direct energy use by the sector stand at 1.4% of the world’s total. Energy efficiency technologies will certainly help, but there is an equally big innovation opportunity in generating energy from agricultural waste.

It is estimated that the global biofuels market could double to USD185.3bn by 2021 and that next generation sugar cane bagasse-to-biofuels technologies could expand ethanol production in key markets like Brazil and India by 35% without land or water intensifictaion. Experiences in this rapidly growing industry suggest some lessons which can be applied to sustainable technology innovation more generally.


Rain water harvesting is essential in a country like South Africa which is a semi arid country. Whether for irrigation or household use, every drop matters. Water Rhapsody also has various water recycling systems; from small gray water for irrigation to larger washbay recycling systems.




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