Refining sugar beet into sugar costs energy. Lots of energy: several megawatts per hour. That is why Raffinerie Tirlemontoise is pushing hard for efficiency. With a brand new centrally controlled boiler room, it increased its energy efficiency from 85 to 98 per cent in one fell swoop.
Making sugar is evaporating water
Washing sugar beets, peeling them, cutting them into pieces, then extracting them with hot water so that the sugars dissolve into sugar juice, and then concentrating and crystallizing this juice.
This is how the Tiense Sugar Refinery has been making sugar for 190 years. The principles have remained the same, but the scale has grown. And the technology has improved.
“A sugar factory is a water factory,” says Benny Holemans, project manager Energy & Sustainability. “Sugar beet contains 14 to 18 per cent sugar depending on the season. The rest is dry matter, but mostly water. And we need to evaporate that water. That costs a lot of energy.”
The Raffinerie Tirlemontoise is working hard to use this energy as efficiently as possible. In 2023, the company built a new diffusion tower with higher efficiency and lower energy consumption than the old extraction systems. The juice is thickened with steam in the evaporators and cooking pans.
The entire evaporation installation is balanced and all condensate flows and heat surpluses are utilized to the maximum. An industrial heat pump extracts energy from a portion of low-calorific steam that was not reused.
From energy producer to battery for the grid
Despite all these efforts, energy remains a challenge. “We need to go green. For our planet, but also to control our costs. Currently, we produce 14 to 15 megawatts, mainly with gas. We ourselves consume about 13 megawatts of that, the rest we put on the grid. That is getting more expensive. Doing nothing would cost us tens of millions of euros over the next 15 years.”
“We also generate biomethane from beet waste, though it still falls far short of meeting our energy demand. So we need to electrify. But then comes the problem: we produce sugar from September to March, along with the beet harvest. These are precisely the dark months, when there is little solar energy available. So we had to take another efficiency leap.”
Additional challenge: a mix of energy sources. “Right now, we are an energy producer. With electrification, we are becoming an energy consumer. We want to consume as cheaply as possible, so the solution had to be flexible. During our production months, there is sometimes too little electricity, but sometimes too much, for example when there is too much wind. Then we are paid to use that energy. That way, we even become a battery for the grid.”
State-of-the-art gas, electricity and hydrogen boiler room
Scattered around the site were 3 boiler rooms, one of which was still running on coal until recently. Callens, Callensvyncke and Siemens built one central boiler room in eight months. “We worked with a small project group full of specialists, and it paid off.”
“We’ve been a fixture here since 1995,” adds Stein Monserez, Vertical Manager Food & Beverage at Siemens. “We know each other inside out; as a result, there are very short lines of communication.”
About Raffinerie Tirlemontoise
Raffinerie Tirlemontoise has been producing sugar since 1836. The company is the market leader in Belgium, with around 600 employees spread across six sites in Belgium and the Netherlands. The Tienen plant covers 17 hectares.
