Blog

15-06-2020

Behind the scenes at our biorefinery in Ghent

People associate Alco Bio Fuel mainly with bioethanol, the green fuel that we mix in petrol in Belgium to meet the European environmental targets. However, three other products are made at the biorefinery in Ghent port. Plant manager Pablo Vercruysse: “We let nothing go to waste in our production process. Sustainability is ingrained in our DNA”.

The sky above Ghent port is steel blue. On a sunny winter afternoon, plant manager Pablo Vercruysse opens the gates of Alco Bio Fuel. He holds a PhD in microbiology and joined ABF mid-2007. The biorefinery was still under construction at the time: “We work with mainly fermentation and distillation processes here. So my knowledge of microorganisms came in handy”.  Since 2016 he has been the manager of the entire plant, which processes some 1900 tonnes of maize per hour into bioethanol, protein-rich animal feed, green CO2 and maize oil. To put that figure in perspective: that’s about three large lorries of maize per hour, in a refinery that operates 24/7, 350 days a year. “If you smell attentively, you will recognize the typical smell of fermentation that also hangs over breweries,” says Vercruysse as he crosses the company grounds to reach two large, metal silos. He points up: “This is where everything starts. This is our storage buffer for raw materials.” At any other location the high cylinders would look impressive, but here they are literally in the shadow of the concrete silos of the neighbouring Eurosilo. They deliver some 600,000 tonnes of maize to their ‘neighbour’ Alco Bio Fuel every year via a practical and convenient transport trench.

Speaking of a convenient location…

Pablo Vercruysse: “Our location is logistically perfect, as a matter of fact. We make large volumes of products with limited profit margins, so keeping our transport costs under control is vital. The cheapest logistics solution is still over water. Large Panamax ships can moor in the port of Ghent. They unload their maize at the quay of Eurosilo, with which we have good relations because their principal shareholder, Vanden Avenne, is also one of our shareholders. At the same time, we are a stone’s throw away from Oiltanking Ghent, where we store our bioethanol which is shipped to petrochemical companies in North-West Europe – largely by boat once again. Not only are such efficient transport routes economical; they are also vital in sustainability terms.”

What did you taken into account when designing the factory?

PV: “”Apart from the purchase price of raw materials, our biggest cost is energy. Energy efficiency was consequently an important consideration. We have a cogeneration unit in operation, which supplies steam for our industrial processes. The entire layout of the plant takes into account the different cold and heat flows. As a player in the renewable energy sector, we want to produce in an extremely energy-efficient manner, as this has an impact on the sustainability of our end products”.

Do you make only bioethanol from maize?

PV: “We make some 26 million litres of bioethanol a year, which can rightly be called our main product. But a number of interesting by-products we simply would not want to go to waste are created during the production process. To begin with, we grind the maize from a coarse grain to maize meal, and use water to make a sticky batter. We then boil it and let it cool down again before adding yeast. All these preparatory steps together take no more than an hour. The real work, the fermentation process, starts in the brewing tank – we have four of them in use, with a capacity of three million litres each”.

So you brew beer as well?

PV: “That’s right: we brew a strong beer, and then distil bioethanol from it later. We use the same yeast for fermentation as breweries do, and the chemical process is identical: micro-organisms convert sugars into alcohol and green CO2. We have a different approach, however. Brewers are concerned about the taste of their beer, so they give fermentation the necessary time – usually one to a few weeks. For us, things can move far quicker: we brew an 18° ‘beer’ — almost as strong as gin – in less than 60 hours. I just wouldn’t recommend tasting it (laughs). Since 2016, have been capturing the CO2. that is released during the fermentation process as well. An installation in the centre of our company premises purifies it to food quality. This is how we arrive at our first by-product: we produce 100,000 tonnes of food quality CO2 every year.”

Could you please elaborate on that concept of ‘food quality CO2?

PV: “CO2 has various application possibilities. For instance, you can use it to heat garden greenhouses or as a preservative in food packaging, but also as dry ice or to make bubbles in soft drinks. Needless to say, the highest quality standards are applied in the food and beverage industry. Alco Bio Fuel has set up a joint venture with industrial gas supplier Messer Benelux and IJsfabriek Strombeek: Green CO2. We produce food quality CO2 in liquid form which is practical for transport.”

Can the bioethanol you produce be pumped as such?

PV: “You are getting a little ahead of yourself (laughs). After 60 hours, we convey the beer from the brewing tanks to the distillation unit, which is recognizable from its four high towers – the highest on our site. Those distillation columns look rather ordinary from the outside, but they have an ingenious, stepped structure inside for maximum liquid and vapour exchange. Distillation is ultimately nothing more than a chemical separation process based on the fact that water and alcohol have different boiling points. We collect the bioethanol from our distiller for a short period in two tanks on the company premises for quality control purposes. It then goes through an underground pipeline to two enormous tanks near Oiltanking Ghent. They in turn see to the transport to the petrochemical companies, who mix our bioethanol in petrol to make various blends from it: E 5, E10, E85, etc. Most drivers of a petrol carl in Belgium have been fuelling with E10 since the beginning of 2017.

Are by-products also obtained during the distillation process?

PV: “Once the water and alcohol have been extracted from the beer, maize residues remain. These are rich in proteins, so we want to use them to good effect, in line with our sustainable philosophy. We spin dry the moist pulp to turn it into dried animal feed: DDGS or Dried Distillers’ Grains with Solubles, which we then store again at Eurosilo: 160,000 tonnes a year nonetheless. We also make maize oil from a part of the maize residue. If you add it to chicken feed, you will get eggs with nice yellow yolks. We currently produce ca. 5000 tonnes of maize oil annually. As you can see, we do not let anything go to waste. That would go against the grain of our DNA.”

How long does the entire production process take?

PV: “Maize grains we take out of our silos at 8 o’clock on Monday morning are in the brewing tank an hour later. We start getting CO2 as of Monday afternoon, and by Wednesday evening we have ethanol – taking a few buffer moments into account. The feed and maize oil will follow in the course of Thursday. So we process maize completely into useful products in a good three days”.