1. Plant sizing PPRE Oldenburg University biogas compact course April 26 – 28, 2011

2. Parameters I

3. Parameters II

4. Plant lay out Digester volume Gas storage volume Compensation volume

5. Size 1: min sub fee; min fee Minimum daily substrate feeding: min sub fee1 = min gas prod1 / spec gas prod. min sub fee1 = 1.00 / 0.040 = 25 [kg dung day] 25 [kg dung / day] requires (1:1 dung to water ratio) equal amount of water. min fee1 = 50 [ltr / day]

6. Size 1: dig vol; max fee; max gas prod Min feeding : max HRT. dig vol1 = HRTmax x min fee1. dig vol1 = 60 x 50 = 3,000 [ltr] Max feeding : min HRT. max fee1 = dig vol / HRTmin max fee1 = 3,000 / 40 = 75 [ltr/day] Then, max sub fee = 37.5 [kg/day] max gas prod1 = max sub fee1 x spec gas prod. max gas prod1 = 37.5 x 0.040 = 1.5 [m3 biogas/day]

7. Size 1: gas stor vol; main dimensions gas storage volume set on 60% of maximum daily gas production gas stor vol1 = 0.6 x 1.5 = 0.9 [m3] main dimensions of plant size 1: –Digester volume:3,00 m 3 –Gas storage volume:0.90 m 3 –Total plant volume:3.90 m 3

8. Size 2: min fee, min gas prod; max fee Range of plant sizes: –min sub fee2 = max sub fee1. max fee2 = 37.5 [kg dung/day]. –min gas prod2 = max gas prod1 min gas prod2 = 37.5 x 0.040 = 1.5 [m3 biogas/day] dig vol2 = HRTmax x min fee2. dig vol2 = 60 x 75 = 4,500 [ltr] max fee2 = dig vol2 / HRTmin max fee1 = 4,500 / 40 = 112,5 [ltr/day] max sub fee2 = 56.25 [kg dung/day]

9. Size 2: max gas prod; gas stor vol, main dim max gas prod2 = max sub fee2 x spec gas prod. max gas prod2 = 56.25 x 0.040 = 2.25 [m3 biogas/day] gas storage volume gas stor vol2 = 0.6 x 2.25 = 1.35 [m3] main dimensions –Digester volume:4,50 m3 –Gas storage volume:1.35 m3 –Total plant volume:5.85 m3 Etc …:

10. Size range: