BIOGAS SEPTIC TANK as green energy .pptx

Biogas is a gaseous renewable energy source[1] produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste. Biogas is produced by anaerobic digestion with anaerobic organisms or methanogens inside an anaerobic digester, biodigester or a bioreacto The gas composition is primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulfide (H2S), moisture and siloxanes. The methane can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used in fuel cells and for heating purpose, such as in cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat

1. BIOGAS SEPTIC TANK Eng. Faisal Gozoli Eisab Phone: [phone] Email: [email protected]

2. هادمات للمواد العضويه

3. Design of Rural Household Digester

4. The principles of design & construction Multi-function: The digester must have functions of production and distribution of biogas, making fertilizer, sanitation, protection of ecological environment and so forth. Economy: Adopting local construction materials according to the local situation and controlling the materials required and the cost of construction. The digester should be convenient to operate it’s multi-functions with optimum efficiency. Safety: The technical process must be reliable and stable. The structure of the digester and the attachment must be safe.

5. BIOGAS SEPTIC TANKS Design parameters  

6. Composition and properties of domestic sewage

7. Source Flow rate (l/cap/d) Pollution load rate γ (g/cap/d) BOD 5 COD Cr SS N P Night soil Toilets 40-60 13-15 18-25 20-25 5-7 0.4-0.6 Sewage Kitchen 30-40 15-20 50-70 20-25 4-5 0.6-0.8 Bath 40-60 9-15 Laundry 30-40 Wash 20-30 Other 10-20 Total 170-250 40-50 70-95 40-50 9-12 1-1.4

8. Average content of pollutants in untreated domestic sewage (1) (Unit: mg/L except precipitable solids) Constituent Concentration High Med. Low Total Solids 1200 720 350 Total dissolved solids 850 500 250 Fixed 525 300 145 Volatile 325 200 105 Total suspended solids 350 220 100 Fixed 75 55 20 Volatile 275 165 80 Precipitable solids (ml/l) 20 10 5 BOD 5 (20 ℃) 400 220 110 Total organic carbon (TOC) 290 160 80 COD 1000 500 250 Total nitrogen (calculated in N) 85 40 20

9. Q wg = 0.37A + 0.49B + 1.04C   Q wg = theoretic methane prod. From 1 g of organic matter (l/g); A= carbohydrates content in 1 g org. Matter of domestic sewage (g/g); B= protein content in 1 gram organic matter of domestic sewage (g/g); C= lipid content in 1 gram organic matter of domestic sewage (g/g);

10. Determining flow rate of domestic sewage Flow rate is calculated based on the water consumption of residents surveyed. Firstly take the maximum of monthly average water consumption as daily domestic sewage discharging rate per capita, then it is multiplied by n (the people number served by the designed system in future) and the simultaneity coefficient k 1 , which is estimated as follows:        n  50,        k 1 =1 200 > n > 50, k 1 =0.95 500 > n  200, k 1 =0.90  

11. Determining flow rate of domestic sewage Flow rate of excrement in domestic sewage for water-flushing toilet can be estimated as 30 L/capita/day, if there is no data available. Flow rate of excrement for the public toilets should be determined based on the number of site, maximum number of user and capacity of flushing devices.

12. Quality of domestic sewage Generally the quality of domestic sewage is expressed as pollutant production rate (g/cap/d). It is estimated as follows (g/cap/d) :    BOD 5 30-60 COD Cr 50-80 SS 40-70   In domestic sewage, the production rate of excrement is counted as 1-1.5 kg/cap/d, which contains (g/cap/d) : BOD 5 13-18 COD Cr 25-40 SS 20-25

13. Three types of Biogas Septic Tanks

14. 3.2.1 Type I – for purposes of both decontaminating excrement and biogas recovery It’s suitable to the undeveloped towns while with a high environmental capacity and being subject to infectious intestinal diseases to treats domestic sewage with high concentration. Adopting multi-stage digesters with baffles as the process and operated at HRT as 8-40 days. Usually the effluent is used as fertilizer and the discharge is controlled according to the ova of schistosome and ascarid .

15. 3.2.2 Type II – for purposes of sanitation, removing part of pollutants and biogas recovery (2) The effluent is discharged into environment or applied for agricultural irrigation. Its quality should be controlled according to national or local standard.

16. 3.2.3 Type III – for purpose of meeting the national integrated wastewater discharge standard (1) It’s suitable to medium scale cities where there is no centralized wastewater treatment plant, or the suburb of big cities where is not covered by the municipal drainage system. It mainly treats domestic sewage from residential or public buildings. The process consists of several units, i.e., desilting , sedimentation, anaerobic filter and facultative filtration or contact aeration tank. When design and construct, the quality of structure must be controlled similar to that of municipal buildings. Usually the cost is high

17. 3.2.3 Type III – for purpose of meeting the national integrated wastewater discharge standard (2) The effluent quality should be controlled according to national sanitary standard for excrement decontamination as well as national discharge standard

18. Biogas system for decontamination of domestic sewage

19. Process flow for sewage treatment from the combined discharge system Sewage Desilting Baffle digestion Anaerobic filter Filtration Biogas Discharge Sludge

20. Our applications in Sudan

21. BioCon in Sudan

22. Thank you