From sugar refinery to biorefinery clusters

Published: 12-11-2015, | Member: Suiker Unie

In three of its most modern refineries, Suiker Unie processes its side material streams into biofuel and innovative biobased products. Two examples are the healthy sweetener arabinose and sugar beet pulp-based microfibers for use in liquid detergents. Suiker Unie’s biorefineries can also process side material streams from other agro-food companies.

Every year from September to January, Suiker Unie processes 6.5 billion kilos of sugar beet. Traditionally, white sugar was their main product. However, sugar production leaves a large part of the beet unused. Suiker Unie has come up with solutions for all of its waste streams, from soil tare to beet pulp. There is currently great interest in upcycling waste streams as the foundation of a biobased economy.

Sustainability underlies all Suiker Unie’s activities, according to Frank van Noord, the company’s R&D director. He stresses the importance of Suiker Unie’s form of enterprise: “We’re a co-op. Our farmers are our company’s owners and therefore get a fair share of the profit. The entire production chain is important for us, from sustainable farming practices to upcycling waste streams. In that respect, Suiker Unie is one of the pioneers in Europe.”

Biobased economy
The sugar industry uses and produces massive streams. It takes five truckloads of sugar beets to produce one truckload of sugar. Besides sugar, beets also contain pulp and a great deal of water. Beet pulp has traditionally been used as cattle feed. Since the 1980s, the tens of thousands of kilos of soil tare have been rinsed off, collected and used for paving and dike reinforcement.

Five years ago, Suiker Unie changed direction in terms of upcycling organic waste streams. The company built modern biomass digesters at three locations: two in The Netherlands and one in Germany. These digesters produce more than 30 million cubic meters of biogas which is fed into the natural gas grid. This makes Suiker Unie one of the largest producers of biogas in The Netherlands. The biogas is also used to produce biomethanol.

Suiker Unie sees many opportunities and is working with various partners on innovative products. Van Noord talks about one of them. “We’re cascade the sugar beet further and further into it’s components. Take our research program into extracting arabinose from pulp, for instance. This special sugar has health benefits compared to other sugars, like glucose.”

Another innovation Suiker Unie is working on is the conversion of pulp to microfibers for use in liquid laundry detergents. “Liquid laundry detergents contain microplastics to give them a thicker consistency. Those microplastics cannot be filtered out by waste water treatment plants, so they stay in the environment where they are a growing problem. At the Cosun research lab’s we’ve found that we’re able to isolate particles with the same properties from beet pulp. Those organic microfibers are a good, biodegradable alternative additive to liquid detergents,” Van Noord says.

New clusters
At the Dinteloord plant, Suiker Unie is pioneering a special collaboration with several greenhouse growers and farmers in an effort to create as many closed circles as possible. The Tuinbouw Ontwikkelings Maatschappij (TOM; horticultural development company) upcycles the processing water from the sugar production to irrigation water for their greenhouses. The sugar refinery supplies its residual heat to the greenhouses while the organic waste that remains after harvesting greenhouse tomatoes and field crops is digested in the sugar plant’s biomass digester. The resulting biogas is pumped into the public gas grid while the carbon dioxide is piped back into the greenhouses for use as a CO2 fertilizer.

Suiker Unie expects new business clusters to spring up around the sugar plants and the biomass digesters in the future. As Van Noord puts it, “We see clear analogies with the oil industry. Biorefineries are going to provide raw materials for chemical products, for new plant-based proteins, for fibers and for bioplastics. That is exactly how Suiker Unie is going to contribute to the circular economy.”

Suiker Unie