Converting a challenge into an opportunity...

• Regional support and advice triggers energy-saving initiative which helps to meet effluent regulations
• Measures introduced cut CO2 emissions by 1 275 tonnes a year while saving the plant € 150 000 per year

Syral Haussimont, a subsidiary of the Tereos Syral group, produces potato starches for the agri-food, paperboard, bioplastics and co-products industries.

Its industrial process requires a large amount of water. After use, this water becomes a protein effluent that is treated and spread across farmland. The effluent is rich in nitrogen, above the thresholds set by EU regulations. To meet these thresholds and reduce nitrogen levels, the company needed a new evaporation and protein extraction system. This, combined with an energy recovery system, feeds the evaporator itself and the 'red water' separator.

Energy is recovered at three levels of the industrial process:

• When the products are dried, a new hot water loop recovers the evaporation vapours via a plate heat exchanger and the residual hot water (78° C) is collected. The recovered vapour and hot water is then conveyed to preheat the air in the dryers by raising the temperature from 5° C to 63° C.
• On the new evaporator designed to extract more protein and clean the spreading water, the residual water is recovered and used to preheat the red water. Evaporation vapour is also recovered and used via a barometric condenser to continue preheating the red water, raising its temperature from 39° C to 77° C.
• A 'flash tank' has been installed to recover vapour produced during the red-water separation phase, which kick-starts the protein production circuit. The vapour is reused on the same process station to preheat the red water from 77° C to 92° C via a barometric condenser.

Key results

As an indication, before installing the new protein extraction and energy recovery system, the plant consumed 55 GWh of gas to produce the heat needed for its processes.

Thanks to the new equipment, the company saves 6 GWh of gas per year, which is equivalent to 1 275 tonnes of CO2 avoided. Apart from the environmental benefits, the measures also save Syral Haussimont € 150 000 per year.

In Champagne-Ardenne where the plant is located, the Regional Council, together with Ademe, devoted a part of the Regional Climate Environment Fund (FREC) to encourage and support efforts by companies to control energy and improve sustainability.