Biogas treatment system allows purify biogas up to bio-methane condition (complete analog of natural gas with methane concentration in the range of 90-97%). After treatment biogas can be used as vehicle fuel or to be fed in to the general natural gas grid.
 |
 |
3D model of biogas treatment unit
250 m3/h capacity
|
Biogas treatment unit 500 m3/h capacity
|
| Characteristics |
Model 1
|
Model 2
|
Model 3 |
Model 4 |
| Efficiency m3/hour |
250 |
500 |
1000 |
2000 |
| Electricity consumption kW/hour |
72 |
145 |
290 |
580 |
| Water consumption per day |
6 |
12 |
24 |
48 |
Composition
| Equipment |
Model 1
|
Model 2
|
Model 3 |
Model 4 |
| Gas separation column
|
1
|
1 |
1 |
1 |
| Purification column
|
1
|
1 |
1 |
1 |
| Methane regeneration column
|
1
|
1 |
1 |
1 |
| Bio filtration column |
1
|
1 |
1 |
1 |
| Columns recirculation pump
|
1
|
1 |
1 |
1 |
| Compressor
|
1
|
2 |
2 |
2 |
| Transport pump
|
1
|
1 |
1 |
1 |
| Biogas compressor
|
1
|
1 |
1 |
1 |
| Drying unit
|
1
|
1 |
1 |
1 |
Description
One of the most efficient systems of anaerobic digestion biogas treatment is regeneration system. The working principle for that system includes two technological processes CO2, H2S and moisture removal. Inlet biogas is initially compressed to operational pressure 8-10 bar. Then biogas directed to purification column and purified with cooled water under pressure. Water is supplied from cooling system from the top of the column in the reverse direction to the biogas flow. In that way СO2 and H2S admixtures are removed in purification column thanks to their solubility in water if to be compared to methane. Column is filled with special material in order to secure good throughput capacity and heat conductivity.
The purification process is most efficient when water has low and constant temperature. For that purpose cooling system is included into the technological process. Water that is used for biogas purification contains dissolved methane and other gases that is why it is compressed to 2 bars and directed to methane regeneration column. Gas is extracted from the water and supplied to the inlet of the treatment system for purification and recirculation.
Methane losses can be controlled by adjustment of pressure in the regeneration column. Methane regeneration from the water is performed in 3 ways:
1. recuperated gas saturated with CO2, H2S and CH4 is directed to big purification circle with second compression at inlet compressor.
2. Gas extracted from the bottom of the column also directed to initial compression stage.
3. Recalculated water is directed to gas separation column for CO2 and H2S removal by air. Air and water form gas separation column is directed to bio filtration column which is filled with plastic balls that areused as bacteria carrier. As a result of intensive mixing bacteria removes remnants of H2S and CO2. Microorginizm removed from the balls come out as sludge.
Gas drying system is installed after the purification columns which consist of a drying module, carbon filter. This system removes water remnants from a purified gas. Drying unit is self-cleaning and completely controlled by electronic system. For optimum process control levels of CO2, CH4, H2O, H2S and Wobbe-index are constantly fixed by electronic system, the results are displayed at system monitor.
The advantage of this system is low cost for biogas treatment due to usage of water as a main purification element.
Scheme of biogas treatment system
рус 
Biogas plants
Biogas treatment system
Print version