Germany-headed biogas plant manufacturer Weltec Biopower GmbH (WELTEC) has announced the rebranding of its Kumac slurry and digestate treatment technology to "WELTEC BLUE WATER in response to international market requirements.
The name WELTEC BLUE WATER thus reflects the growing global demand on the one hand and refers to the largest output of water on the other.
In several process steps, the output materials are converted fully automatically into compost, fertilizer, animal bedding, biogas substrate, and, depending on the input material, up to approximately 60 percent dischargeable water.
Tried and tested technology
In recent years, 17 WELTEC BLUE WATER plants have been put into operation worldwide. The first plant in Germany has been in operation since March 2024.
Plants are currently under construction and at an advanced stage of project development in Europe, Asia, and the United States, while the first references in Japan and Spain for the easily scalable systems are nearing completion.
Water conservation
The technology is proving to be interesting for farms in processing regions where there is a high supply of liquid manure or water shortages – such as in Denmark and Spain.
In Europe, investments are supported by the European Agricultural Fund for Rural Development (FEADER).
According to the company, its WELTEC BLUE WATER technology is also suitable for separating nitrogen and returning the water to the biogas process to dilute the source materials.
A high proportion of nitrogen-rich input materials such as poultry manure for the production of biogas is possible with the system.
No thermal energy required
WELTEC BLUE WATER separates the solids from the water in a multi-stage process. The distribution of the separated materials can vary depending on the dry matter content of the input material.
Compared to other systems, the technology requires no thermal energy and converts the solids into high-quality fertilizer.
At the beginning of the process, additives are mixed into the source materials to increase efficiency. This flocculates the finest components and makes them easier to separate.
At the same time, certain substances are better separated from each other and odour emissions are minimized. The fermentation residue is then dewatered in a belt press.
The separated liquid from the belt press is aerated in a flotation tank – this causes particles and suspended matter to settle at the bottom of the tank.
This sludge is added back into the process. In the final step, up to 99 percent of the dissolved salts and nutrients are separated using a multi-stage reverse osmosis process.
The nutrient concentrate can be applied as an easily transportable liquid fertilizer. After treatment in the ion exchanger, dischargeable water remains that can be used or returned to the water cycle.
This means that up to 60 percent storage capacity for fermentation residues can be saved and no tanks need to be built for this purpose.
The solid material with a dry matter content of around 30 percent is used or sold by users as fertilizer, compost, animal bedding, or as a substrate for biogas production.
The system is modularly scalable and can be used from an input of 50,000 tonnes per year or more.