Recently, a lot of work has been done within the European project Grass2Grit to achieve our objective: reusing grass juice by concentrating the salts in this juice into brine, which can be used as road salt.
The Grass2Grit project aims to ensure that roadside grass is sustainably processed and reused. The grass is washed and pressed into traffic signs. Grass juice is released during this process. This juice contains, in addition to humic acids and water, also salts. To close the natural cycle, the G2G project also aims to reuse the grass juice. This is done by desalinating the water, so the desalinated water can be used to wash the grass and the salt can be concentrated to a road salt solution.
To achieve this goal, the first steps have been taken in the laboratories of the University of Twente. Here the result was that the maximum concentration of salts from the grass was 8%.
Water Future has been commissioned to scale up this process to pilot level. Scaling up is important because only then can sufficient brine be produced to actually scatter roads. Initially, various experiments will be conducted on the road.
A number of pilot experiments have been carried out. This showed that the concentration was initially limited to 4%. This was not good enough to turn it into a business case. It was therefore decided to improve the system by implementing more power capacity. After that, the first experiments with a representative saline solution showed that a concentration of 8% could be achieved!
We have succeeded in producing 100 liters of brine with a concentration of 6.5% salts from 1000 liters of grass juice. In addition, we were able to obtain 900 liters of desalinated grass juice from the same 1000 liters, which can be reused to rinse the grass. This is achieved within 8 hours. If necessary, it can still be concentrated to 8% in a second process step.
We can safely conclude that the upscaling to pilot level has been successfully achieved with this. We are looking forward to taking the next steps within this innovative project
Read more about this project on Grass2Grit.com