Figure 1.
![Acquisition of biogas in the years 2011–2016 [9]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f4783f1392090d6977e/j_acee-2019-029_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=ASIA6AP2G7AKGO7TCLZT%2F20260125%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260125T224845Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEGQaDGV1LWNlbnRyYWwtMSJHMEUCIQCK4Usy%2BC2kU4n7swansMuiubPNu7XyAKF4vpdPrkiEbAIgP0FNmyA6eeyoKXU5MApSnYKY1Oczlz%2FzqFjZUkOl56EqvAUILRACGgw5NjMxMzQyODk5NDAiDDgBKUVZQIUYum6MViqZBRxZRSaKJbIeLP8ygph2cIzEZI706RQ7Tn1NLkP2JQ0Uk%2BBcnKKrxM5KRD50SD6kf6bP1ewibNVaJP7CR7zBs6GXRdwIgsn7Rhd0P7l6QmLupS8yD698mP3HWV99llViZGSjD8ZSbUL%2BliXiUg6eIL4vIYOgTYhsZHcXSjkYe%2FRp5gfV9Y4XSYQYyLPH770droTv5kukep1l18xQEbhtTZLZ6GPWGChCULpr156JOJ%2FCZRivMyL3czbeBQyf0jQYW61Hf%2BZpDpI0z48qxP9Y8Josq3tdCkUlB6s0XkFZLd0XDhJm2gfcqBm2RaF4lOjGDMbcJumP7AuchjJ8Vw9J8XnCBUExqjRnf%2BJgtdQehvwySjs5tAg%2FwCkXF9H9zwZyFjvkSYhur1omZffdD%2BZD85f4oyruMR5lrhNWcjkJSfYW2Vd13vfkbJOIBe5dLSztzrtSUZIgqwnbCYnqhz%2BNGsUl0nt7dB9LEn3U%2B17i09CmcbpvzrEPOaUu10aM2ZLq5oTdLeHa3DIeueM6H2Gdn3Q6H%2Fif%2BcHS3DGazM8kdL09DqjanshHMFkz7bf6yeHyPhwmiG89gpJbSKGI31wJfxx0XQEAhZ30%2FDaIcQGWfvnex4QkEaJXA3WGyL%2FX%2BouSz2gzI1SS1MfLtT%2BxVaSE8rpH7J4lDjeQ1T0RhopQHoN2ia4BwdpMRGUToVmtMuEK4YCzx%2B3d5caQ3wlfJiI1MJDus23zV3770vA1djO1ya%2B8x%2FIccNSW%2BNI3Oe6SYd0LduUq%2FlGirdSsEDOh4GaMTUExjnG2KrTQU%2BAOglC7BYBLaAgg%2B9ZCjHzv%2FXstSXVVOAmEqVv0%2FQ9tvDEEmpMt634JZsAbu1oXMjpxavL23V%2FeyDeehU3oR6Y%2FMKbe2csGOrEBZ8ycnan2u16%2BtnFYIZhWt4yfjzmhpXWTAuMn3A9ChL%2FlW%2BdomwlzJctABVQPhkjLcv%2B%2FoK5XTIDLo1MbtVE97i51c2lIogrXtMRii5vSdIS9K2kXnpn%2F7movA8%2BV25aZntkMfnAcjP7I3mKGA1LGuBcyyBWne1Q4KrssuWkQptd0wIU33HfkqaRmX7b1vLWGYxMCPDBJ%2B0RHWIC0WdwFClsDMZ6IfSjgV9dwI7XAtl7E&X-Amz-Signature=2a1fa6602f6e57cbe14ebdef259c71c88c6f29c1e0766170a5af73e684e52434&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 2.
Comparison of the composition of individual types of gases_ Own study based on [21]
| Parameter | Biogas from treatment plant | Biomethane | Natural gas |
|---|---|---|---|
| Methane | 66.42% | 97% | 93 – 98% |
| Carbon dioxide | 33.0% | 2.3% | 3% |
| Nitrogen | <3% | <2% | <1% |
| Oxygen | <1% | <1% | 0.2% |
| Hydrogen sulphide | 1.59 mg/m3 | <1 mg/m3 | 7.0 mg/m3 |
| Siloxanes | 5.9 mg/m3 | - | - |
| Heat of combustion | 26.45 MJ/m3 | 31 MJ/m3 | 30–34 MJ/m3 |
| Wobbe number | 28.27 MJ/m3 | 39 MJ/m3 | 37.5–45 MJ/m3 |
Chemical composition of biogas at selected treatment plants in Poland [7, 8, 12, 15]
| Treatment plant | CH4
| CO2
| O2
| N2
| H2S |
|---|---|---|---|---|---|
| Object 1 | 62.3 | 36.4 | 0.4 | 0.6 | 384 |
| Object 2 | 63.6 | 35.2 | 0.1 | 0.8 | 25.3 |
| Object 3 | 62.6 | 35.4 | 0.3 | 0.4 | 15.1 |
| Object 4 | 59.8 | 36.9 | 0.1 | 2.1 | 62.1 |
| Object 5 | 61.5 | 38.2 | 0.02 | 0.15 | 19.4 |
| Object 6 | 64.4 | 34.3 | 0.2 | 0.5 | 147 |
Emissions of selected engine fuel pollutants [24]
| Lp. | Fuel type | CO [g/km] | HF | NOx
| CO2
|
|---|---|---|---|---|---|
| 1 | Diesel | 0.20 | 0.40 | 9.73 | 0.100 |
| 2 | Naturalgas | 0.40 | 0.60 | 1.10 | 0.022 |
| 3 | Biomethane | 0.08 | 0.35 | 5.40 | 0.015 |
Technologies of biogas treatment and purification [6]
| Technology | Conditions of the process | Content of methane after the process % | Methane loss % |
|---|---|---|---|
| Water scrubber (physical absorption) | Pressure absorption of CO2 In water | 98 | 1÷2 |
| Organic scrubber (physical absorption) | Pressure absorption of CO2 in the organic solvent | <96 | 2÷4 |
| Pressure adsorption (PSA) | Absorption of CO2 under pressure on activated carbon | >96 | 3÷10 |
| Chemical absorption | Chemical reaction of CO2 with the solution of amines : non-pressure process, high temperature | 99÷99.4 | <0.1 |
| Cryogenic separation | Compression and cooling in several stages: CO2 separated in liquid form | 95 ÷ 98 | 0.5 |
| Membrane separation | Permeation of gas molecules under pressure | >95 | 2 |
Selected biogas parameters after the purification process [10]
| No | Parameter | Unit | Result |
|---|---|---|---|
| 1. | Methane (CH4) | % | 66.42 |
| 2. | Carbon dioxide (CO2) | % | 33.0 |
| 3. | Hydrogen (H2) | % | 0.01 |
| 4. | Hydrogen sulfide (H2S) | ppm | 15 |
| 5. | Oxide (O2) | % | not found |
| 6. | Heat of combustion | MJ/m3 | 26.45 |
| 7. | Calorific value | MJ/m3 | 23.78 |
| 8. | Wobbe number | MJ/m3 | 28.27 |
Balance sheet of the produced biogas and the method of its use_ Own study based on [10]
| Year 2017 | The volume of produced biogas [m3] | The volume of biogas used to generate electricity [m3] | The amount of produced electricity [kWh] | Surplus of biogas [m3] |
|---|---|---|---|---|
| January | 149360.0 | 112750.2 | 243117.6 | 36609.8 |
| February | 149422.0 | 100493.0 | 216688.0 | 48929.0 |
| March | 159233.0 | 105714.6 | 227947.0 | 53518.4 |
| April | 156868.0 | 111400.8 | 240208.0 | 45467.2 |
| May | 150001.0 | 113688.1 | 245140.0 | 36312.9 |
| June | 138283.0 | 107784.3 | 232410.0 | 30498.7 |
| July | 137858.0 | 80782.5 | 174187.2 | 57075.5 |
| August | 129037.0 | 102972.3 | 222034.0 | 26064.7 |
| September | 122893.0 | 94832.2 | 204482.0 | 28060.8 |
| October | 134820.0 | 107126.7 | 230992.0 | 27693.3 |
| November | 146462.0 | 107869.5 | 232593.6 | 38592.5 |
| December | 161615.0 | 115133.2 | 248256.0 | 46481.8 |
| Total | 1735852.0 | 1260547.4 | 2718055.4 | 475304.6 |
Average concentrations of pollutants in the sewage inflowing and treated at the sewage treatment plant in 2017 [10]
| Parameter | Raw sewage | Required values | Treated sewage [mg/l] |
|---|---|---|---|
| BZT5 | 414 | 15 | 4.23 |
| ChZT | 1042 | 125 | 43.1 |
| POG | 7.32 | 1 | 0.32 |
| NCał | 63.8 | 10 | 8.41 |
| Total suspension | 448 | 35 | 13 |
| Ether extract | 170 | 50 | 14.8 |
| Petroleum substances | 1.2 | 15 | 0.067 |
Annual volume of carbon dioxide emissions for selected types of motor vehicles [23]
| Type of vehicle | Annual emission of CO2
| Percentage change in emission | |||
|---|---|---|---|---|---|
| petrol/diesel | Natural gas | Biomethane | Natural gas vs. petrol / diesel | Biomethane vs.petrol / diesel | |
| Truck up to 3.5 t (petrol) | 1.70 | 1.39 | 0.20 | -18 | -88 |
| Truck up to 3.5 t (diesel) | 1.31 | 1.39 | 0.20 | +6 | -85 |
| Truck 3.5 to 12 tons (diesel) | 18.7 | 20.43 | 4.91 | +13 | -73 |
| Truck 12 to 26 tons (diesel) | 48.21 | 55.94 | 10.61 | +16 | -78 |
| Bus (diesel) | 57.53 | 60.96 | 10.10 | +15 | -82 |