Ammongas CO2 Separation
Ammongas has developed an amine based system for removal of CO2 in biogas etc. which is based on a proven, high-quality, cost efficient stripper-absorber concept.
The system has its special advantage by working pressure less. Hereby reducing investment costs and power consumption. The system is remarkably effective and is able to upgrade a biogas into a >99 % pure methane gas, with a methane loss to the atmosphere below 0,1%. As an energy source for the system, heat is needed. Excess heat can be reused as 75 °C (or higher) water to e.g. central heating, pasteurization or heating of biogas reactors etc.
Description of the plant
An Ammongas Biogas Upgrading plant consists roughly of four plant sections. Namely the upgrade CO2 separation section, compression section, drying/filtration section and finally the gas quality measurement.
The main section, upgrade, deals with the removal of CO2 from the raw biogas, thereby upgrading it to Biomethane. It comprises of a CO2 absorber column where the CO2 is captured and absorbed in an Amine solution. A reboiler is continuously adding heat energy to the stripper in which the CO2 is stripped from the saturated absorbent (Amine) and thereby regenerating the solvent.
In the reflux system steam and CO2 are separated. The condensed steam is returned to the system as water, resulting in an equilibrium of liquid in the plant and thus eliminating the water consumption.
Biogas upgrading with Ammongas
The main advantages of using Ammongas’ stripper-absorber technology are:
|· Pressure less system||· Very efficient solvent|
|· Methane slip below 0,1%||· Removes 99% of H2S in addition to CO2|
|· No water consumption||· Heat is used to strip CO2 from solvent|
|· Modular system means flexible installation||· Delivers recuperated heat at 85°C and 45°C|
|· Low electric consumption, below 0,1kWh/m3 raw gas as only CH4 is compressed||· Pure CO2 can be used in other applications|
When comparing the Ammongas upgrading plant with other technologies, another crucial advantage comes from the fact that the gas compression follows the upgrading section, thereby only the biomethane is pressurized. This gives a reduction in compressor size by up to 50% compared to other technologies thus reducing the hardware price and electrical consumption considerably.
Behind the numbers
Ammongas biogas upgrading plants are based on the well-known amine gas sweetening principle, which is a proven technology from the oil & gas industry.
There are two factors greatly contributing to the success of Ammongas plants: They use heat, from any heat source, to strip the CO2 from the solvent and they run with a pressureless system for absorption of CO2 and H2S. This results in a plant with low maintenance costs and low energy consumption.
Ammongas upgrading plants can recover a large fraction of the energy used and deliver this back as heat, at a temperature higher than 85°C. The recovered heat can be used in the biogas plant to give a low total energy consumption.