At a large biomethane plant in northern Germany, the digestate undergo extensive treatment. Odour emissions occur during the storage of the digestate and the treatment process. The aim was to remove ammonia, but also other odour-forming components. The operator entrusted the experts from the Jacobi Group with the implementation of a filter system to prevent odours.
The Challenge
Large quantities of digestate are produced by biogas plants. Digestate typically accounts for between 85% and 95% of the total amount of biomass introduced into a biogas plant. The main purpose of digestate treatment at biogas or biomethane plants is to separate the solid and liquid components for further use or environmentally friendly disposal. The process steps are:
- Separation of the solid and liquid phases
- Drying and evaporation
- Storage
Various odour-causing substances can arise during these processes. These include:
Sulphurous compounds
- Hydrogen sulphide (H₂S)
- Mercaptans (thiols, e.g. methanethiol, dimethyl sulphide)
Nitrogenous Compounds
- Ammonia (NH₃)
- Amines (e.g. Trimethylamine)
Volatile Organic Compounds (VOCs)
- Ketones and Aldehydes (e.g. Acetone, Butanal)
- Carboxylic Acids (e.g. Butyric Acid, Acetic Acid)
Since the odour threshold of these substances is sometimes very low, even the smallest concentrations are enough to cause intolerable odour emissions. The operator was already familiar with the Jacobi Group from a previous project for biogas desulfurization (H₂S removal) and has now turned to us again with the request for an odour control filter concept.
The Solution
The Result
The result is to the full satisfaction of the plant operator. There are no more odour emissions from the digestate treatment of this large biomethane plant. With the selected filter solution, we are making a decisive contribution to environmental protection and occupational safety.
The activated carbons AddSorb VB1-BG and EcoSorb BS can safely bind and concentrate the odour-causing substances. As soon as the activated carbon is saturated, the complete mobile filters are replaced by new mobile filters that are already pre-filled with the selected activated carbon. Our comprehensive service means that the plant operator has no handling of activated carbon on site.
The saturated activated carbon is disposed off in an environmentally friendly manner or sustainably recycled in our modern reactivation plant so that it can be reused. In this high-temperature process, all adsorbed substances are desorbed and completely incinerated. Complex flue gas treatment ensures compliance with emission limits.
With our mobile filters, which we have already prepared for immediate use by pre-filling them with activated carbon, we were able to offer an effective solution while at the same time meeting the customer’s requirements.
For more information on our services for biogas you can visit our page here. Alternatively if you have a treatment requirement you would like to discuss with our team of experts, you can get in touch with them via our contact page.