Think Biorefinery

A modern, state-of-the-art ethanol plant is more than just a distillery, writes Rob Vierhout. It's a biorefinery, he says, highlighting several technologies and innovations that turn a kernel of grain into a panoply of high-value products.
By Robert Vierhout | May 14, 2014

From time to time I go to the plants of ePURE members to get up to speed on the latest developments in the sector I defend and represent. Recently I went to see what I consider a state-of-the-art production facility in Belgium. The 300,000 cubic meter (77.8 MMgy) plant runs two-thirds on wheat and one-third on the juice from sugar beets (molasses or sugar juice).

The plant has a number of characteristics and coproducts that make it very special.

The most remarkable element is the way this plant is generating its energy. Unlike most of the U.S. and European Union ethanol plants, it produces about 90 percent of its energy needs itself, in this case, by burning the bran (hard outer layer) of cereal. It is similar to what Brazilian plants do with the bagasse left over from processing sugar cane. Even though a biomass boiler comes with a high capital expenditure it has the big advantage that greenhouse gas emissions savings go up significantly. In the long run it is also increases the operating margin, as the price of energy remains an important cost factor in Europe.

Originally, bran was used to generate steam (energy) only. A recent technology investment at the plant now makes it possible to separate bran into digestible and nondigestible parts. The digestible part, which is now used as an animal feed, is being replaced by shredded waste wood. This reduces costs even further and increases revenues.

With this new separation technology in place, the plant is now able to produce three streams of feed and food. First, there is the fiber-rich bran. Then we have the well-known wheat yeast concentrate with high-protein content. Both are widely used as ruminant feed. And finally, gluten is produced out of the nonsoluble protein after milling the branless wheat. It is very popular in the fish feed market and the food industry.

But innovation does not stop there. The company wants to go a step further in the bran separation process. The bran that is used as an animal feed still contains some traces of starch. Taking starch out of the bran could increase ethanol yield even further.

Another recent innovation is a treatment of the ashes from the biomass boiler. In the early days it was simply waste, but now it is being sold as an organic fertilizer. Remarkably the plant is also a net producer of electricity. The excess electricity generated is sold to the grid as green electricity and also delivers extra revenues.

The latest innovation being studied is the extraction of wheat germ oil, which has a high nutritional value and favourable characteristics for human health. The final coproduct that comes out of this plant is CO2, which is captured and sold for the production of carbonated soft drinks. Considering this impressive list of coproducts and knowing their economic value, one could almost joke that ethanol is, in fact, the coproduct.

It’s clear a modern, state-of-the-art ethanol distillery is much more than just a plant producing alcohol. From a simple kernel of grain we can make a panoply of high-value products. It’s actually a biorefinery. Depending on the raw material used, an impressive list of products can be produced, making ethanol plants the most innovative industrial installations we have.

What other industry makes so much out of an agricultural crop while hardly producing any waste? It is time we start promoting the biorefinery concept.

Author: Robert Vierhout
Secretary-general, ePURE
Vierhout@epure.org