In the Netherlands there is a total quantity of 1 million tons of roadside grass which must be mowed at least twice a year to keep the roadside banks safe. The released cuttings remain, decay and emit methane, or are collected and taken away mainly to fermentation plants. The Fine Biofuels project, that recently has been finalized, looked into possibilities to blend roadside grass with the fine fraction from the shreds to make an energy pellet from it, but had to conclude it is not possible. However, making energy pellets from roadside grass or fine fraction does have potential.
Biomass streams (wood chips and shreds) that are released during grubbing and pruning projects contain a lot of sand and small organic particles. This fine fraction is not sieved now, but is supplied to the various bioenergy plants together with high-quality biomass. However, this fraction has little or no combustion value and sometimes even cause a fire hazard.
Improved energy efficiency
The aim of the Fine Biofuels project was to realize one efficient application for two low-value biomass streams: the fine fraction from woody biomass and roadside grass. As a result, energy efficiency in bioenergy plants would be improved. However, these goals can only be achieved on a local scale by fitting in and optimizing the correct reprocessing and screening technologies in combination with the Yilkins Drying Solution in the existing biomass operation of Hooijer Renkum B.V.
Converting into a valuable product
Yilkins Drying Solutions has developed technology for the small-scale efficient production of pellets from low-value, locally available biomass streams. The YDS technology has the ability, after screening through a three-fraction sieve, to remove this fine fraction from non-woody parts such as sand, to dry it homogeneously and then to compact it into wood or fuel pellets – also known as white pellets – of high quality with a market value of 140 to 160 Euro/ tons. This allows residual flows with a negative value to be converted into a valuable product with market demand.
Based on the amount of woody biomass available in the Netherlands (around 1,500,000 tons per year), the repeat potential of the present project is around 90 times and the primary fossil energy displacement can rise to around 10-11 PJ per year.
Over the next 5 years, Yilkins expects to sell a total of 20 YDS installations in the Netherlands and around 50 worldwide. In the Dutch context this amounts to approximately 2 PJ/ year.
Click here for the final report (Dutch only).