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Biogas Upgrading

Upgrading of biogas in a class of its own with Ammongas

Advantages of an Ammongas upgrading plant?

Designed to your needs

We use our experience and expertise to tailor the plant to your specific needs.

No pre-treatment

Expensive pre-treatment of biogas is not necessary with an upgrading plant from Ammongas.

Large savings

An upgrading process with pressure saves a lot of costs in the building phase and less expenses in maintenance.

A long life

The parts in an upgrading plant from Ammongas are robust and of high quality, which ensures a long life.

About the process

1. The raw biogas enters the absorber column

The raw biogas enters the absorber column without any pre-cleaning directly from the gas storage. The biogas is washed with a watered-down amine solution, where the CO₂ (and other acidic gases such as H₂S) are absorbed into the amine solution. This process is pressureless, eliminating the need to compress the heavy CO₂, and the methane is only compressed to the needed pressure. When the gas leaves the absorber column, the biogas has been upgraded to biomethane. After upgrading, the gas is polished in an active carbon filter before being compressed to the needed pressure for the gas grid. The gas is then dried and cooled before the final injection to the gas grid.

2. Pumped to desorber column

After the amine solution has absorbed the CO₂ from the biogas, it is pumped into the desorber column (stripper column). The amine solution is heated, typically by the boiler which supplies heat to the biogas plant. By heating the amine solution CO₂, H₂S, and steam will leave the desorber column. The amine is then pumped back to the absorber column and is ready to absorb CO₂ and H₂S again. In this way, the amine solution is used in a closed circuit, and the amine consumption is minimal.

3. Heat recuperation

The heat from the boiler, which leaves the desorber column along with the CO₂ and steam, can be recuperated. Typically, it is possible to recuperate 30-40% of the added heat at about 80-90°C, depending on the feed temperature. Likewise, it is possible to recuperate the middle temperature from the amine cooling at 50-60°C – typically 40-50% is recuperated at this point. If recuperation from the compressors is added, it is possible to achieve >90% heat recuperation with an amine-based upgrading plant by Ammongas.