The smallest pulping mill on the planet

How can we make better use of green waste streams?

Lignocellulose biomass is the most common organic raw material on earth. It’s the “glue” that gives trees and  plants its strength. Lignin is the reason why fibrous waste streams like grass, wood, straw and reeds are difficult to re-use, because this glue isn’t exactly easily degradable. In the Netherlands we produce 50.000 tonnes of green fibrous waste every year within a radius of 30 km, by mowing roadsides, natural areas, dikes and maintenance of trees along public roads etc. This leads to enormous amounts of material, which we would like to re-use locally as much as possible, for instance as biofuels, new raw material and green chemicals.

The breaking down of Lignin is a tough nut to crack. Take for example paper, something we use on a daily basis. To obtain cellulose for the production of paper the use of several physical and chemical processes is required. Wood fibres are treated with various chemicals, under high pressure & temperature (hot steam, 145 degrees Celsius), are processed mechanically and treated with lots of water. This method is simply not feasible for processing local green waste flows.

The smallest pulping mill: breaking down Lignin with the force of nature

Nature has developed a very effective way to break down lignin, without the necessity of extreme conditions. White rot fungi produce their own chemicals under normal temperature and atmospheric pressure. These fungi are actually like little pulping mills and are capable of pre-treating wood by producing enzymes that break down lignin. The fungus uses the cellulose that is made available for their reproductive phase by producing mushrooms.

In the TKI project Bio-pulping we want to research if the pre-treatment of green waste streams ith white rot fungi can lead to a higher production of bio-energy and if pre-treatment can make it possible to re-use green waste flows as raw materials.

Developing new technology takes cooperation

Bioclear earth and Wageningen University & Research have now tested the bio-pulping concept on laboratory scale. The next step is to translate this concept into a practical and large-scale applicable technology.  To achieve this we cleverly apply techniques that are already developed by the mushroom growing industry.

To make sure that this new technology really meets the demands and possibilities of the market, we have asked several suppliers of biomass, several industry associations and end users to be involved in the project. They provide us with their expertise and offer us the possibilities to test the technique on a larger scale.

Opportunities for bio-pulping

If we are capable of adapting this technique to a large scale, there would be plenty applications for the bio-pulping technique. On laboratory scale we have demonstrated that the pre-treatment leads to a faster digesting of fibres and higher production of biogas. Using the same reactor capacity, the estimated production is found to be 2.5 up to 4.5 times higher. If we only take into account the re-use of grass waste flows we can produce approximately 6 PJ biogas per year -in the Netherlands we use about 300 PJ gas each year to heat our houses- thanks to bio-pulping.

This is 8% of all produced bio-energy in 2016 in the Netherlands.

Not only do we look at the possibilities to use this technique to generate biogas, but also at the possibility to apply it in the production of paper, green chemicals, second generation sugars and cattle feed from straw.

Who are needed for this development?

Would you like to know more about the possibilities of bio-pulping, please contact Jeroen Tideman or Eline Keuning.

Jeroen Tideman
Teammanager Innovation & Technology
Eline Keuning
Consultant biotechnology & innovation