sugar cane waste transformed into energy

Sugar production on the Indian Ocean island may have been divided by three in 20 years, but the exploitation of cane today makes it possible to produce green and renewable electricity. Jérôme Jaen is general manager for agro-industry in Mauritius.

Faced with the regular decline in production and turnover, the sugar industry has had to reinvent itself on Mauritius. The arduous jobs of collecting cane in the fields in summer, in the heat and humidity, no longer attract young people and mechanization has its limits.

Jérôme Jaen has lived in Mauritius for 15 years. He is today general director for agro-industry and energy at Omnicane, one of the major sugar players on the island. He explains that to continue to exist, the sugar industry had to diversify, particularly in the production of electricity, thanks to bagasse, the solid residue of sugar cane.

“We have energy plants with very high efficiencies, which allow us to produce a much greater quantity of energy with the same quantity of cane. It is burned in a boiler, which will produce steam, resulting in a turbine and produce electricity.”

Until a few years ago, whether in Brazil, South Africa or India, sugar factories sought to barely be self-sufficient in energy. Today, the Omnicane power plant alone produces nearly 20% of the electricity consumed by the whole of Mauritius, with a high efficiency of 100 kw/hour per tonne of sugar cane. Especially since the resource is already present in the factory. In peak season, it consumes 30m3 of sugar cane per hour.

Spine

Until now, in winter, since the sugar cane season only lasts six months a year, starting in July, the power plant used coal, an environmentally unfriendly fossil fuel, to make up for the lack of bagasse. But this practice is changing, assures the Frenchman :

“Today, with all the environmental issues, we are in the process of replacing coal with biomass, mainly wood, part of which will be local, and part imported. Knowing that the Mauritian State is committed to eliminate coal by 2030, and our objective is rather 2028.”

Sugar exports today represent barely 2% of Mauritius’ GDP, after having reached their peak in the 19th century. The sector suffers in particular from foreign competition. The prices guaranteed by the European Union for Mauritian sugar have been abolished over time.

Production costs have also increased significantly. Result : Mauritius today produces around 250,000 tonnes of sugar each year, or barely 1% of world production, but the country ranks 8th for refined sugar production.

“Historically, recalls Jérôme Jaen, it was the main economy of Mauritius, and over time its share in the overall economy declined quite a bit, but it was the backbone of the Mauritian economy for a long time. It has declined, but it is an economy that has a very large multiplier effect. If you look at all the derivative products, electricity, transport, all the added values ​​generated, it still has a significant weight in the economy, and it still employs quite a few people.”

40,000 hectares of land are still planted with sugar cane on Mauritius. The Omnicane company also recycles the liquid residue of sugar cane, molasses, by distillation, to obtain alcohol, ethanol for the pharmaceutical industry, or liquid fertilizers for agriculture. Even the CO2 produced by the fermentation process is recovered. It is reused in the soft drink industry.

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The Omnicane sugar factory on Mauritius

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