 |
| |||||||||||||||||||||||||||||||||||||||||||||
Design calculation
|
Sizing factors |
Example |
|
Daily substrate input, Sd |
= 115 l/d |
|
Retention time, RT |
= 70 days |
|
Daily gas production, G |
= 2.5 m³/d |
|
Storage capacity,Cs |
= 60% |
|
Digester volume, Vd |
= 8 m³ |
|
Gasholder volume, Vg |
= 1.5 m³ |
Calculating formulae after Sasse, 1984
1. Vg = Cs · G
2. ha = design-dependent
3. Vg= r · p · h
4. rg = 
5. rd = r + 0.03
6. Vd1 = p · d2 · p
· h
7. Vd2 = R3 · p · 2/3
8. R =
9. Vd3 = R2 · p · H/3
10. H =
R/5
11. Vd3 = R3 · p · 1/15
12. Vd2 : Vd3 = 10 : 1
13. Vd(2+3) = 1.1
Vd2
14. Vd(2+3) = Vd - Vd1
15. hd = hg
16. hdk = hd + structurally
dependent free board (0.1 . . . 0.2 m)
Fig.
10.1: Conceptual drawing of a floating-drum biogas plant
Vd = Vdl +Vd2 +Vd3
= digester volume
Vg = gasholder
volume
Index g = gas holder
Index d = digester
|
Sample calculation |
Results |
|
1. Vg = 0.6 · 2.5 |
= 1.5 m³ |
|
hg = (specified) |
= 0.7 m |
|
4. r = |
= 0.82 m |
|
5. r = 0.85 (chosen) |
|
|
6. Vdl = 0.852 ·3.14 · 0.7 |
= 1.58 m³ |
|
14. Vd (2+3) = 8.45 - 1.58 |
= 6.87 m³ |
|
8+ 14. R = |
= 1.45 m |
Fig.
10.2: Constructional drawing of a floating-drum plant. Vd = 6.4 m³, Vg =
1.8 m³. Material requirements: Excavation 16.0 m³, Foundation 1.6
m³, Masonry 1.1 m³, Rendered area 18.0 m², Sheet steel 5.7
m². (Source: OEKOTOP, Sasse) 
Fig.
10.3: Constructional drawing of a water-jacket plant. Vd = 6.0 m³, Vg = 1.8
m³. Material requirements: Excavation 16.0 m³, Foundation 1.6 m³,
Masonry 1.6 m³, Rendered area 21 m², Sheet steel 5.7 m². (Source:
OEKOTOP, Sasse) 
Fig.
10.4: Constructional drawing of a cylindrical floating-drum plant for
quarrystone masonry. Vd = 9.4 m³, Vg = 2.5 m³. Material requirements:
Excavation 21.0 m³, Foundation 1.0 m³, Masonry 5.4 m³, Rendered
area 27.3 m², Sheet steel 6.4 m². (Source: OEKOTOP, KVIC)
10.1.2 Fixed dome plants
Design calculation
|
Sizing factors |
Example |
Sample calculation |
|
Daily substrate input, Sd |
= 115 l/d |
R = (0.76 · 8)1/3= 1.85 m |
|
Retention time,RT |
= 70 days |
r = 0.52 R= 0.96 m |
|
Daily gas production, G |
= 2.5 m³/d |
h = 0.40 R= 0.72 m |
|
Storage capacity, Cs |
= 60% |
p = 0.62 R= 1.14 m |
|
Digester volume, Vd |
= 8 m³ |
|
|
Gasholder volume, Vg=G·Cs |
= 1.5 m³ |
|
|
Vd : Vg |
= 5.3 : 1 | |
Tab. 10.1:
Calculating parameters for fixed-dome biogas plant (Source: Sasse
1984.OEKOTOP)
|
Vg : Vd |
1:5 |
1:6 |
1:8 |
|
R |
(0.76 · Vd)1/3 |
(0.74 · Vd)1/3 |
(0.72 · Vd)1/3 |
|
r |
0.52 R |
0.49 R |
0.45 R |
|
h |
0.40 R |
0.37 R |
0.32 R |
|
p |
0.62 R |
0.59 R |
0.50 R |
Fig.
10.5: Conceptual drawing of fixed-dome biogas plant. Vg gasholder volume, Vd
digester volume. (Source: OEKOTOP, Sasse) 
Fig.
10.6: Constructional drawing of a fixed-dome plant. Vd = 8 m³, V = 1.5
m³. Material requirements: Excavation 25 m³, Foundation 2.2 m³,
Masonry 2.0 m³, Rendered area 22.0 m², Sealed area 7.0 m².
(Source: OEKOTOP, Sasse, BEP Tanzania)
10.1.3 Earth pit with
plastic-sheet gasholder
Fig.
10.7: Constructional drawing of an earth-pit biogas plant with plastic-sheet
gasholder. Vd = 11 m³, Vg = 2.2 m³. Material requirements: Excavation
16 m, Rendered area 28 m², Sheeted area 10 m² (Source: OEKOTOP)
10.1.4 Estimating the
earth-pressure and hydraulic forces
Fig.
10.8: Schematic diagram of earth-pressure and water-pressure forces
In-depth forces, h (e, w)
pW = wW · hw
pW = hydrostatic
pressure at depth hw (m) wW = specific weight of water
= 1000 kp/m³ pW =
1000 · h (kp/m²)
pE = wE · ce · he
pE =
active earth pressure, i.e. force of pressure of dry, previously loose but now
compact column of earth on a solid vertical wall
wE = specific weight of dry
backfill earth
= 1800 . . . 2 100 kp/m³
he = height of earth column
(m)
ce = coefficient of earth pressure for the earth column in question
=
0.3 . . . 0.4 (-)
pE = (600 . . . 700) · h
(kp/m² )
Force acting on a surface
P(E, W) = p · A (kp = (kp/m²) · m²)
Note: The above formulae are simplified and intended only for purposes of rough estimation.
dp = FL + Ztot
dp = pressure drop (N/m²)
FL =
friction losses in the gas pipe (N/m²)
Ztot = sum total of friction
losses from valves, fittings, etc. (N/m²)
dp = cp l/D · D/2 v2
+ (cfl D/2 · v2 + . . . + cfn ·
D/2 · v2)
(approximation formula)
cp =
coefficient of pipe friction (-)
l = length of pipe section (m)
D = pipe
diameter(m)
g = density of biogas (1.2 kg/m³)
v = velocity of gas in
the pipe (m/s)
cf = friction coefficients of valve, fittings, etc.
Q = v
· A
Q = gas flow (m³/s)
v = velocity
of gas in the pipe (m/s)
A = p r2 = cross-sectional area of pipe
The coefficient of pipe friction (cp = non. dimensional) is a
function of:
- the pipe material and internal surface roughness
- pipe
diameter
- flow parameter (Reynolds number)
For pipe diameters in the 1/2" . . . 1" range, the coefficients
of friction read:
PVC tubes approx. 0.03
steel pipes approx. 0.04
Some individual friction-loss factors (cf; nondimensional)
|
elbow |
0.5 |
valve 3.0 |
|
constriction |
0.02-0.1 |
water trap 3 - 5 |
|
branch |
0.8-2.0 | |
10.2.2
Calculating gas parameters
Temperature-dependent change of volume and density
D = DN · P · TN / (PN · T)
V =
VN · PN · T / (P
· TN)
where:
D = density of biogas (g/l)
DN = density under
s.t.p. conditions (0 °C, 1013 mbar)
V = volume of biogas (m³)
VN
= volume of biogas under s.t.p. conditions
P = absolute pressure of biogas
(mbar)
PN = pressure under s.t.p. conditions (1013 mbar)
T = absolute
temperature of biogas (measured in ºKelvin = ºC + 273)
TN=
temperature under s.t.p. conditions (0 0ºC = 273 °K)
Table 10.2: Atmospheric
pressure as a function of elevation (Source: Recknagel/Sprenger, 1982)
|
Elevation (km) |
0 |
0.5 |
1.0 |
2 |
3 |
4 |
6 |
8 |
|
Atm.pressure (mbar) |
1013 |
955 |
899 |
795 |
701 |
616 |
472 |
365 |
Fig.
10.9: Nomogram for correcting gas pressures/temperatures (Source: OEKOTOP)
Determining the calorific value
Fig.
10.10: Nomogram for finding the net calorific value of biogas as a function of
temperature, pressure and moisture content. T gas temperature (°C), F
relative dampness of biogas (%), Hu, N net calorific value (n.c.v.) of biogas
under s.t.p. conditions (0 °C, 1013 mbar), Hu, T net calorific value
(n.c.v.) at gas temperature, P gas pressure (mbar), Hu, T, P net calorific value
(n.c.v.) at gas temperature and pressure, PW partial pressure of water vapor,
Hu, T, PF net calorific value (n.c.v.) of biogas at gas temperature, corrected
to reflect the water-vapor fraction (Source: OEKOTOP)
Using the nomogram
1. Quadrant I: Determine the net calorific value under standard conditions as a function of the CH4-fraction of the biogas
2. Quadrant II: Determine the net calorific value for a given gas temperature
3. Quadrant III: Determine the net calorific value as a function of absolute gas pressure (P)
4. Quadrant IV: Interim calculation for determining the partial water-vapor pressure as a function of gas temperature and relative dampness. This yields the gas pressure (PF) = absolute pressure (P) - partial pressure of water vapor (PW); PF = P - PW. The expanded calorific value determination with account for the moisture content occurs via quadrant III.
Sample calculation
|
Given: | |
|
Biogas |
55 vol. % CH4 |
|
Gas temperature |
T = 40 °C |
|
Gas dampness |
F = 100% |
|
Gas pressure |
P = 1030 mbar |
|
Results: | |
|
|
Hu, N |
= f (CH4-vol. 70) |
Quadrant I |
| |
= 5.5 kWh/m³ |
|
|
Hu,T |
= f(T) |
QuadrantII |
| |
= 4.8 kWh/m³ |
|
|
Hu,T,P |
= f(T, P) |
Quadrant III |
| |
= 4.6 kWh/m³ |
|
|
PF |
= f(P, T) |
Quadrant IV |
|
- f(PW) |
Quadrant III |
|
|
|
Hu, T, PF = 4.3 kWh/m³ | |
Table 10.3:
Partial pressure of water vapor, PW, and absolute humidity, GM, at the
saturation point (Source: Recknagel / Sprenger, 1982)
|
T (°C) |
PW (mbar) |
GM (g/m³) |
|
.0 |
6.1 |
4.9 |
|
10 |
12.3 |
9.4 |
|
20 |
23.4 |
17.3 |
|
30 |
42.4 |
30.4 |
|
40 |
73.7 |
51.2 |
|
50 |
123.3 |
83.0 |
|
60 |
199.2 |
130.2 |
|
70 |
311.6 |
198.2 |
|
80 |
473.6 |
293.3 |
|
90 |
701.1 |
423.5 |
|
100 |
1013.3 |
597.7 |
Table 10.5: Conversion of imperial measures (Source: Sasse, 1984)
|
Length |
1 m = 1.094 yrd |
1 yrd = 0.914 m |
| |
1 cm = 0.0328 ft |
1 ft = 30.5 cm |
| |
1 cm = 0.394 inch |
1 inch = 2.54 cm |
|
Area |
1 m² = 10.76 sqft |
1 sqft = 0.092 m² |
| |
1 cm² = 0.155 sq.in |
1 sq.in = 6.452 cm² |
| |
1 ha = 2.47 acre |
1 acre = 0.405 ha |
|
Volume |
1 1 = 0.220 gall. |
1 gall. = 4.55 1 |
| |
1 m³ = 35.32 cbft |
1 cbft = 28.31 |
|
Mass |
1 kg = 2.205 lb |
1 lb = 0.454 kg |
|
Pressure |
1 MN/m² = 2.05 lb/sqft |
1 lb/sqft = 0.488 MN/m² |
| |
1 cm Ws = 205 lb/sqft |
1 lb/sqft = 70.3 cm Ws |
|
Quantity |
1 kcal = 3.969 BTU |
1 BTU = 0.252 kcal |
|
of heat |
1 kWh = 3413.3 BTU |
1000 BTU = 0.293 kcal |
| |
1 kcal/kg = 1799 BTU/lb |
1 BTU/lb = 0.556 kcal/kg |
|
Power |
1 PS = 0.986 HP |
1 HP = 1.014 PS |
| |
1 kpm/s = 7.24 ft.lb/s |
1 ft.lb/s = 0.138 kpm/s |
Table 10.6:
Conversion factors for work, energy and power (Source: Wendehorst,
1978)
Comparison of work units (work = power X time)
| |
kpm |
PSh* |
Ws = J |
kWh |
kcal |
|
1 kpm = |
1 |
3.70 X 10-6 |
9.807 |
2.7 X 10-6 |
2.342 X 10-3 |
|
1 PSh*= |
270 X 103 |
1 |
2.648 X 106 |
0.7355 |
632.4 |
|
1 Ws = J = |
0.102 |
377.7 X 10-9 |
1 |
277.8 X 10-9 |
239 X 10-6 |
|
1 kWh = |
367.1 X 103 |
1.36 |
3.6 X 106 |
1 |
860 |
|
1 kcal = |
426.9 |
1.58 X 10-3 |
4186.8 |
1.163 X 10-3 |
1 |
* PS = 0.986 HP
UNDEFINED PAGEof_v">
Table 10.7: Energy content of
various fuels (Source: Kaltwasser, 1980)
|
Fuel |
Calorific value |
Unit | |
| |
MJ |
kWh | |
|
Plants |
16-19 |
4A- 5.3 |
kg TS |
|
Cow dung |
18-19 |
5.0 - 5.3 |
kg TS |
|
Chicken droppings |
14-16 |
3.9- 4.4 |
kg TS |
|
Diesel, fuel oil, gasoline |
41-45 |
11.4-12.5 |
kg = 1.1 1 |
|
Hard coal (anthracite) |
30-33 |
8.3- 9.2 |
kg |
|
Wood |
14-19 |
3.9- 5.3 |
kg |
|
Producer gas |
5-7 |
1.4 - 1.9 |
Nm³ |
|
Pyrolysis gas |
18-20 |
5.0- 5.6 |
Nm³ |
|
City gas |
18-20 |
5.0- 5.6 |
Nm³ |
|
Propane |
93 |
25.8 |
Nm³ |
|
Natural gas |
33-38 |
9.2-10.6 |
Nm³ |
|
Methane |
36 |
10.0 |
Nm³ |
|
Biogas |
20-25 |
5.6- 6.9 |
Nm³ |
Table 10.8:
Conversion factors for units of pressure (Source: Wendehorst, 1978)
| |
kp/m² |
N/m² |
pa |
cm WG |
mbar |
at |
|
kp/m² |
1 |
10 |
10 |
0.1 |
0.1 |
0.0001 |
|
N/m² |
0.1 |
1 |
1 |
0.01 |
0.01 |
10-5 |
|
pa |
0.1 |
1 |
1 |
0.01 |
0.01 |
10-5 |
|
cm WG |
10 |
100 |
100 |
1 |
1 |
0.001 |
|
mbar |
10 |
100 |
100 |
1 |
1 |
0.001 |
|
at |
104 |
105 |
1000 |
1000 |
1000 |
1 |
Table 10.9:
Table of powers and radicals
|
n |
n2 |
n3 |
n |
n2 |
n3 |
n |
n2 |
n3 |
n |
n2 |
n3 |
|
0.60 |
0.36 |
0.22 |
1.10 |
1.21 |
1.33 |
1.60 |
2.56 |
4.10 |
2.10 |
4.41 |
9.26 |
|
0.65 |
0.42 |
0.27 |
1.15 |
1.32 |
1.53 |
1.65 |
2.72 |
4.49 |
2.15 |
4.62 |
9.94 |
|
0.70 |
0.49 |
0.34 |
1.20 |
1.44 |
1.73 |
1.70 |
2.89 |
4.91 |
2.20 |
4.84 |
10.65 |
|
0.75 |
0.56 |
0.42 |
1.25 |
1.56 |
1.95 |
1.75 |
3.06 |
5.36 |
2.25 |
5.06 |
11.39 |
|
0.80 |
0.64 |
0.51 |
1.30 |
1.69 |
2.20 |
1.80 |
3.24 |
5.83 |
2.30 |
5.29 |
12.17 |
|
0.85 |
0.72 |
0.61 |
1.35 |
1.82 |
2.46 |
1.85 |
3.42 |
6.33 |
2.35 |
5.52 |
12.98 |
|
0.90 |
0.81 |
0.73 |
1.40 |
1.96 |
2.74 |
1.90 |
3.61 |
6.86 |
2.40 |
5.76 |
13.82 |
|
0.95 |
0.90 |
0.86 |
1.45 |
2.10 |
3.05 |
1.95 |
3.80 |
7.41 |
2.45 |
6.00 |
14.71 |
|
1.00 |
1.00 |
1.00 |
1.50 |
2.25 |
3.38 |
2.00 |
4.00 |
8.00 |
2.50 |
6.25 |
15.63 |
|
1.05 |
1.10 |
1.16 |
1.55 |
2.40 |
3.72 |
2.05 |
4.20 |
8.62 |
2.55 |
6.50 |
16.58 |
|
n |
n1/3 |
n |
n1/3 |
n |
n1/3 |
n |
n1/3 |
n |
n1/3 |
n |
n1/3 |
|
0.001 |
0.10 |
0.22 |
0.60 |
1.33 |
1.10 |
4.10 |
1.60 |
9.26 |
2.10 |
17.58 |
2.60 |
|
0.003 |
0.15 |
0.27 |
0.65 |
1.53 |
1.15 |
4.49 |
1.65 |
9.94 |
2.15 |
18.61 |
2.65 |
|
0.008 |
0.20 |
0.34 |
0.70 |
1.73 |
1.20 |
4.91 |
1.70 |
10.65 |
2.20 |
19.68 |
2.70 |
|
0.016 |
0.25 |
0.42 |
0.75 |
1.95 |
1.25 |
5.36 |
1.75 |
11.39 |
2.25 |
20.80 |
2.75 |
|
0.027 |
0.30 |
0.51 |
0.80 |
2.20 |
1.30 |
5.83 |
1.80 |
12.17 |
2.30 |
21.95 |
2.80 |
|
0.043 |
0.35 |
0.61 |
0.85 |
2.46 |
1.35 |
6.33 |
1.85 |
12.98 |
2.35 |
23.15 |
2.85 |
|
0.064 |
0.40 |
0.73 |
0.90 |
2.74 |
1.40 |
6.86 |
1.90 |
13.82 |
2.40 |
24.39 |
2.90 |
|
0.091 |
0.45 |
0.86 |
0.95 |
3.05 |
1.45 |
7.41 |
1.95 |
14.71 |
2.45 |
25.67 |
2.95 |
|
0.125 |
0.50 |
1.00 |
1.00 |
3.38 |
1.50 |
8.00 |
2.00 |
15.63 |
2.50 |
27.0 |
3.00 |
|
0.166 |
0.55 |
1.16 |
1.05 |
3.72 |
1.55 |
8.62 |
2.05 |
16.58 |
2.55 |
28.37 |
3.05 |
Fig.
10.11: Fundamental geometric formulae (Source: Sasse
1984)
Notes on using the data sheet (table 10.10)
The data survey (data sheet, table 10.10) contains fictive, but nonetheless substantially realistic, data on a family-size biogas plant. Those data are reffered to for explaining and calculating the arithmetic models described in chapter 8. Such data must be ascertained separately for each project site.
Notes on the individual data-sheet items
1. In order to keep the calculations uncomplicated, an unrealistically constant annual rate of inflation is assumed. It is possible to account for different inflation rates in the various analytical procedures. For explanatory details beyond those offered in this guide, please refer to Finck/Oelert, chapter C III.
2. Calculatory interest rate, i: assumed rate of interest for evaluating the cash flows (income and expenditure) generated by a biogas plant during its technical service plant. Proceeding on the assumption that the expenditures are all the more burdensome, the earlier they fall due, while income is all the more valuable, the earlier it is earned, all cash flows occuring in connection with the investment are compounded/discounted at an assumed rate for a fixed point in time. Please refer to chapter 8.4 for the calculation procedure.
3. Investment costs (incl. wages):
- planning
- land
aquisition/leasing (as applicable)
- civil works
- building and
structures/digester
- modification of animal housing
- gas
appliances/aggregates
- slurry spreading implements
- assembly and
commissioning
- customs, taxes, duties, fees
- transportation
4. Manpower costs for:
- feeding the plant
- spreading the
digested slurry
5. Maintenance and repair:
- spare parts/materials
- wages
for maintenance/repair work
6. Energy revenues
- market value of replaced energy
-
energy supplied
- production induced with extra energy (market value)
7. Revenues from fertilizer:
- market value of replaced
inorganic fertilizer
- revenues from sales of digested slurry
- higher
cash-crop yields due to fertilizing with digested slurry
8. Time saved (real financial income only) for additional:
-
wage work
- work on the farm (included additional incom)
9. Depreciation (annual for linear depreciation):
=
investment costs / n (technical service life)
In this example, the technical service life of the plant is conservatively estimated at only 10 years.
10. Depreciation and capital-servicing costs (interest on
loans): neither of these two factors is included as a cost factor in the dynamic
models presented in chapter 8, because the cost of investment is equal to the
sum of cash values from depreciation and interest (cf. Brandt, 1982, for
details). In this example, it is assumed that no external capital is needed,
i.e. that the biogas plant is fully financed with internal capital.
Table 10.10: Data sheet for
economic analysis (Source OEKOTOP; Finck/Oelert, Table 1)
|
Project title: |
Location: |
Owner: |
Type of plant/digester volume: | |||||||||
|
Technical service life: |
years |
| | |
| | |
| | |
| |
|
Item Period |
|
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
|
Year | |
19... |
19... |
19... |
19... |
19... |
19... |
19... |
19... |
19... |
19... |
19... |
|
1.1 General inflation rate 1) |
% |
34 |
34 |
34 |
34 |
34 |
34 |
34 |
34 |
34 |
34 |
34 |
|
1.2 Market interest rate, p |
% |
48 |
48 |
48 |
48 |
48 |
48 |
48 |
48 |
48 |
48 |
48 |
|
1.3 Assumed interest rate, i 2) |
% |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
10.4 |
|
2. Investment costs, I 3) |
CU |
1100 | | | | | | | | | | |
|
3.1 Manpower costs 4) |
CU |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- | |
|
3.2 Maintenance and repair 5) |
CU |
- |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
|
spare-parts requirement | | | | | | | | | | | | |
|
4.1 Taxes and levies not linked to profit |
CU |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
|
4.2 Other expenditures |
CU |
- |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
|
5. Total operating costs, |
Co | |
35 |
35 |
35 |
35 |
35 |
35 |
35 |
35 |
35 |
35 |
|
6.1 Energy-related revenues 6) |
CU |
- |
210 |
210 |
210 |
210 |
210 |
210 |
210 |
210 |
210 |
210 |
|
6.2 Revenues from fertilizer 7) |
CU |
- |
250 |
250 |
250 |
250 |
250 |
250 |
250 |
250 |
250 |
250 |
|
6.3 Time saved 8) |
CU |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
|
6.4 Other income |
CU |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
|
6.5 Subsidies |
CU |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
|
7. Total income |
CU |
- |
235 |
235 |
235 |
235 |
235 |
235 |
235 |
235 |
235 |
235 |
|
8. Returns (item 7- item 5) |
CU |
200 |
200 |
200 |
200 |
200 |
200 |
200 |
200 |
200 |
200 |
200 |
|
9. Depreciation 9) |
CU |
110 |
110 |
110 |
110 |
110 |
110 |
110 |
110 |
110 |
110 |
110 |
|
10. Capital servicing costs 10) |
CU |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
|
11. Profit |
CU |
- |
90 |
90 |
90 |
90 |
90 |
90 |
90 |
90 |
90 |
90 |
CU = currency unit; in local currency or DM/US $ (conversion to
DM/US $ rarely advisable due to fluctuating exchange rates)
Table 10.11: Discounting
factors for interest rates of i = 1 -30% and periods of t = 1 - 30 years
|
ti |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
|
1 |
.990 |
.980 |
.971 |
.962 |
.952 |
.943 |
.935 |
.926 |
.917 |
.909 |
.901 |
.893 |
.885 |
.877 |
.870 |
|
2 |
.980 |
.961 |
.943 |
.925 |
.907 |
.890 |
.873 |
.857 |
.842 |
.826 |
.812 |
.797 |
.783 |
.769 |
.756 |
|
3 |
.971 |
.942 |
.915 |
,889 |
.864 |
.840 |
.816 |
.794 |
.772 |
.751 |
.731 |
.712 |
.693 |
.675 |
.658 |
|
4 |
.961 |
.924 |
.888 |
.855 |
.823 |
.792 |
.763 |
.735 |
.708 |
.683 |
.659 |
.636 |
.613 |
.592 |
.572 |
|
5 |
.951 |
.906 |
.863 |
.822 |
.784 |
.747 |
.713 |
.681 |
.650 |
.621 |
.593 |
.567 |
.543 |
.519 |
.497 |
|
6 |
.942 |
.888 |
.837 |
.790 |
.746 |
.705 |
.666 |
.630 |
.596 |
.564 |
.535 |
.507 |
.480 |
.456 |
.432 |
|
7 |
.933 |
.871 |
.813 |
.760 |
.711 |
.665 |
.623 |
.583 |
.547 |
.513 |
.482 |
.452 |
.425 |
.400 |
.376 |
|
8 |
.923 |
.853 |
.789 |
.731 |
.677 |
.627 |
.582 |
.540 |
.502 |
.467 |
.434 |
.404 |
.376 |
.351 |
.327 |
|
9 |
.914 |
.837 |
.766 |
.703 |
.645 |
.592 |
.544 |
.500 |
.460 |
.424 |
.391 |
.361 |
.333 |
.308 |
.284 |
|
10 |
.905 |
.820 |
.744 |
.676 |
.614 |
.558 |
.508 |
.463 |
.422 |
.386 |
.352 |
.322 |
.295 |
.270 |
.247 |
|
11 |
.896 |
.804 |
.722 |
.650 |
.585 |
.527 |
.475 |
.429 |
.388 |
.350 |
.317 |
.287 |
.261 |
.237 |
.215 |
|
12 |
.887 |
.788 |
.701 |
.625 |
.557 |
.497 |
.444 |
.397 |
.356 |
.319 |
.286 |
.257 |
.231 |
.208 |
.187 |
|
13 |
.879 |
.773 |
.681 |
.601 |
.530 |
.469 |
.415 |
.368 |
.326 |
.290 |
.258 |
.229 |
.204 |
.182 |
.163 |
|
14 |
.870 |
.758 |
.661 |
.577 |
.505 |
.442 |
.388 |
.340 |
.299 |
.263 |
.232 |
.205 |
.181 |
.160 |
.141 |
|
15 |
.861 |
.743 |
.642 |
.555 |
.481 |
.417 |
.362 |
.315 |
.275 |
.239 |
.209 |
.183 |
.160 |
.140 |
.123 |
|
16 |
.853 |
.728 |
.623 |
.534 |
.458 |
.394 |
.339 |
.292 |
.252 |
.218 |
.188 |
.163 |
.141 |
.123 |
.107 |
|
17 |
.844 |
.714 |
.605 |
.513 |
.436 |
.371 |
.317 |
.270 |
.231 |
.198 |
.170 |
.146 |
.125 |
.108 |
.093 |
|
18 |
.836 |
.700 |
.587 |
.494 |
.416 |
.350 |
.296 |
.250 |
.212 |
.180 |
.153 |
.130 |
.111 |
.095 |
.081 |
|
19 |
.828 |
.686 |
.570 |
.475 |
.396 |
.331 |
.277 |
.232 |
.194 |
.164 |
.138 |
.116 |
.098 |
.083 |
.070 |
|
20 |
.820 |
.673 |
.554 |
.456 |
.377 |
.312 |
.258 |
.215 |
.178 |
.149 |
.124 |
.104 |
.087 |
.073 |
.061 |
|
21 |
.811 |
.660 |
.538 |
.439 |
.359 |
.294 |
.242 |
.199 |
.164 |
.135 |
.112 |
.093 |
.077 |
.064 |
.053 |
|
22 |
.803 |
.647 |
.522 |
.422 |
.342 |
.278 |
.226 |
.184 |
.150 |
.123 |
.101 |
.083 |
.068 |
.056 |
.046 |
|
23 |
.795 |
.634 |
.507 |
.406 |
.326 |
.262 |
.211 |
.170 |
.138 |
.112 |
.091 |
.074 |
.060 |
.049 |
.040 |
|
24 |
.788 |
.622 |
.492 |
.390 |
.310 |
.247 |
.197 |
.158 |
.126 |
.102 |
.082 |
.066 |
.053 |
.043 |
.035 |
|
25 |
.780 |
.610 |
.478 |
.375 |
.295 |
.233 |
.184 |
.146 |
.116 |
.092 |
.074 |
.059 |
.047 |
.038 |
.030 |
|
26 |
.772 |
.598 |
.464 |
.361 |
.281 |
.220 |
.172 |
.135 |
.106 |
.084 |
.066 |
.053 |
.042 |
.033 |
.026 |
|
27 |
.764 |
.586 |
.450 |
.347 |
.268 |
.207 |
.161 |
.125 |
.098 |
.076 |
.060 |
.047 |
.037 |
.029 |
.023 |
|
28 |
.757 |
.574 |
.437 |
.333 |
.255 |
.196 |
.150 |
.116 |
.090 |
.069 |
.054 |
.042 |
.033 |
.026 |
.020 |
|
29 |
.749 |
.563 |
.424 |
.321 |
.243 |
.185 |
.141 |
.107 |
.082 |
.063 |
.048 |
.037 |
.029 |
.022 |
.017 |
|
30 |
.742 |
.552 |
.412 |
.308 |
.231 |
.174 |
.131 |
.099 |
.075 |
.057 |
.044 |
.033 |
.026 |
.020 |
.015 |
|
ti |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
229 |
30 |
|
1 |
.862 |
.855 |
.847 |
.840 |
.833 |
.826 |
.820 |
.813 |
.806 |
.800 |
.794 |
.787 |
.781 |
.775 |
.769 |
|
2 |
.743 |
.731 |
.718 |
.706 |
.694 |
.683 |
.672 |
.661 |
.650 |
.640 |
.630 |
.620 |
.610 |
.601 |
.592 |
|
3 |
.641 |
.624 |
.609 |
.593 |
.579 |
.564 |
.551 |
.537 |
.524 |
.512 |
.500 |
.488 |
.477 |
.466 |
.455 |
|
4 |
.552 |
.534 |
.516 |
.499 |
.482 |
.467 |
.451 |
.437 |
.423 |
.410 |
.397 |
.384 |
.373 |
.361 |
.350 |
|
5 |
.476 |
.456 |
.437 |
.419 |
.402 |
.386 |
.370 |
.355 |
.341 |
.328 |
.315 |
.303 |
.291 |
.280 |
.269 |
|
6 |
.410 |
.390 |
.370 |
.352 |
.335 |
.319 |
.303 |
.289 |
.275 |
.262 |
.250 |
.238 |
.227 |
.217 |
.207 |
|
7 |
.354 |
.333 |
.314 |
.296 |
.279 |
.263 |
.249 |
.235 |
.222 |
.210 |
.198 |
.188 |
.178 |
.168 |
.159 |
|
8 |
.305 |
.285 |
.266 |
.249 |
.233 |
.218 |
.204 |
.191 |
.179 |
.168 |
.157 |
.148 |
.139 |
.130 |
.123 |
|
9 |
.263 |
.243 |
.225 |
.209 |
.194 |
.180 |
.167 |
.155 |
.144 |
.134 |
.125 |
.116 |
.108 |
.101 |
.094 |
|
10 |
.227 |
.208 |
.191 |
.176 |
.162 |
.149 |
.137 |
.126 |
.116 |
.107 |
.099 |
.092 |
.085 |
.078 |
.073 |
|
11 |
.195 |
.178 |
.162 |
.148 |
.135 |
.123 |
.112 |
.103 |
.094 |
.086 |
.079 |
.072 |
.066 |
.061 |
.056 |
|
12 |
.168 |
.152 |
.137 |
.124 |
.112 |
.102 |
.092 |
.083 |
.076 |
.069 |
.062 |
.057 |
.052 |
.047 |
.043 |
|
13 |
.145 |
.130 |
.116 |
.104 |
.093 |
.084 |
.075 |
.068 |
.061 |
.055 |
.050 |
.045 |
.040 |
.037 |
.033 |
|
14 |
.125 |
.111 |
.099 |
.088 |
.078 |
.069 |
.062 |
.055 |
.049 |
.044 |
.039 |
.035 |
.032 |
.028 |
.025 |
|
15 |
.108 |
.095 |
.084 |
.074 |
.065 |
.057 |
.051 |
.045 |
.040 |
.035 |
.031 |
.028 |
.025 |
.022 |
.020 |
|
16 |
.093 |
.081 |
.071 |
.062 |
.054 |
.047 |
.042 |
.036 |
.032 |
.028 |
.025 |
.022 |
.019 |
.017 |
.015 |
|
17 |
.080 |
.069 |
.060 |
.052 |
.045 |
.039 |
.034 |
.030 |
.026 |
.023 |
.020 |
.017 |
.015 |
.013 |
.012 |
|
18 |
.069 |
.059 |
.051 |
.044 |
.038 |
.032 |
.028 |
.024 |
.021 |
.018 |
.016 |
.014 |
.012 |
.010 |
.009 |
|
19 |
.060 |
.051 |
.043 |
.037 |
.031 |
.027 |
.023 |
.020 |
.017 |
.014 |
.012 |
.011 |
.009 |
.008 |
.007 |
|
20 |
.051 |
.043 |
.037 |
.031 |
.026 |
.022 |
.019 |
.016 |
.014 |
.012 |
.010 |
.008 |
.007 |
.006 |
.005 |
|
21 |
.044 |
.037 |
.031 |
.026 |
.022 |
.018 |
.015 |
.013 |
.011 |
.009 |
.008 |
.007 |
.006 |
.005 |
.004 |
|
22 |
.038 |
.032 |
.026 |
.022 |
.018 |
.015 |
.013 |
.011 |
.009 |
.007 |
.006 |
.005 |
.004 |
.004 |
.003 |
|
23 |
.033 |
.027 |
.022 |
.018 |
.015 |
.012 |
.010 |
.009 |
.007 |
.006 |
.005 |
.004 |
.003 |
.003 |
.002 |
|
24 |
.028 |
.023 |
.019 |
.015 |
.013 |
.010 |
.008 |
.007 |
.006 |
.005 |
.004 |
.003 |
.003 |
.002 |
.002 |
|
25 |
.024 |
.020 |
.016 |
.013 |
.010 |
.009 |
.007 |
.006 |
.005 |
.004 |
.003 |
.003 |
.002 |
.002 |
.001 |
|
26 |
.021 |
.017 |
.014 |
.011 |
.009 |
.007 |
.006 |
.005 |
.004 |
.003 |
.002 |
.002 |
.002 |
.001 |
.001 |
|
27 |
.018 |
.014 |
.011 |
.009 |
.007 |
.006 |
.005 |
.004 |
.003 |
.002 |
.002 |
.002 |
.001 |
.001 |
.001 |
|
28 |
.016 |
.012 |
.010 |
.008 |
.006 |
.005 |
.004 |
.003 |
.002 |
.002 |
.002 |
.001 |
.001 |
.001 |
.001 |
|
29 |
.014 |
.011 |
.008 |
.006 |
.005 |
.004 |
.003 |
.002 |
.002 |
.002 |
.001 |
.001 |
.001 |
.001 |
.000 |
|
30 |
.012 |
.009 |
.007 |
.005 |
.004 |
.003 |
.003 |
.002 |
.002 |
.001 |
.001 |
.001 |
.001 |
.000 |
.000 |
Plant engineering, construction and consultancy services in developing countries
AIT Asian Institute of Technology - Division for Energy Technology, P.O. Box 2754, Bangkok 10501, Thailand
AVARD Association of Voluntary Agencies for Rural Development, c/o Safdarjung Development Area, New Delhi, India
BORDA Bremen Overseas Research and Development Association, Bahnhofsplatz 13, 2800 Bremen, Federal Republic of Germany
Biogas projects: BORDA/UNDARP Poona, India
CEMAT Centro Mesamericano de Estudios sobre Tecnologia Apropiada, A.P.1160, Guatemala-City, Guatemala
GATE/GTZ German Appropriate Technology Exchange/Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ) GmbH, Postfach 5180, 6236 Eschborn, Federal Republic of Germany
GATE/GTZ Biogas Extension Program Projects:
Projecto de
Biogas c/o ENPRA, km 11.5 vieja a Leon, A.P.4772 Managua, Nicaragua
Biogas
Extension Service c/o CAMARTEC, P.O. Box 764, Arusha, Tanzania Projet Biogaz
Cankuzo, D/S 148, Bujumbura, Burundi
CDB/GATE Biogas Team c/o CDB, P.O. Box 407, Wildey St. Michael,
Barbados
Proyeto Biogas PAAC-UMMS-GATE, Casilla 4740, Cochabamba Bolivia
Special Energy Program biogas projects (GTZ-Div.34) GTZ Special Energy Program, P.O. Box 41607, Nairobi, Kenya Projet Special de l'Energie, c/o I.V.E., B.P. 5321 Ouagadougou, Burkina Faso
KVIC Khadi and Village Industries Commission, Gobar Gas Scheme, Ivla Rees, Vila Parle, Bombay 400 056, India
Maya Farms Angona, Rizal, Philippines
OEKOTOP Gesellschaft fur Angepaßte Technologien in Entwicklungsgebieten, Bingerstr. 25a, 1000 Berlin 33, Federal Republic of Germany
Biogas projects (by order of GTZ): Projet Biogaz c/o SODEPRA Ferkessedougou, Cote d'Ivoire Proyecto Biogas Colombo-Aleman c/o CVC, Apto. A2366, Cali, Colombia
RED-Latino Americana de Biogas, Emprater, W3 Norte Q515, Brazilia, Brazil
Equipment producers / suppliers
Elster AG, Postfach 129,6500 Mainz, Federal Republic of
Germany
Products: gasmeters
Kromschroder AG, Postfach 2809,4500 Osnabruck, Federal Republic
of Germany
Products: full range of gas valves
Metallurgica Jackwal Ltd., Rua Braz Cardoso 674, Vila Nova
Canceicao, Sao Paulo, Brazil
Products: lamps, burners, reducing valves
OEKOTOP GmbH, Berlin
Product: portable biogas measuring set
Patel Gas Crafters Ltd., Shree Sai Bazar, Mahatma Gandhi Road,
Bombay 400 054, India
Products: lamps, burners
Saron Vdyog, Shanghai, PR China
Products: gasmeters, lamps,
burners
Service Centre for Development on New Energy, NO. 33 Fugiun
Skeet, Shijiazkuang, PR
China
Products: burners, motors
Shanghai Bioenergy, Shanghai, PR China
Products: gasmeters,
lamps, burners, motors
T.A. Schiller, Postfach 1224, 2072 Bargteheide, Federal Republic
of Germany
Products: lamps, burners, motors
Producers of biogas-fueled engines
Ford AG, Edsel-Ford-Str., 5000 Cologne 71, Federal Republic of
Germany
- Type 2274 E, 15-25 kW, 1500 - 3000 min-1, 4-cylinder, water-cooled,
spark ignition
Henkelhausen, Postfach 9149, 4150 Krefeld 12, Federal Republic
of Germany
- Series GFL 912, 19~0 kW, 1500-2300 min-1, 3-, 4-, 5-,
6-cylinder, air-cooled, spark ignition
- Series GFL 413, 55 - 140 kW, 1500 -
2300 min-1, 5-, 6-, 8-, 10-, 12-cylinder, air-cooled, spark ignition
Kirloska, India, German representative: Schule Co., Postfach
260620, 2000 Hamburg 26,
Federal Republic of Germany
- Series AVG, TVG,
CAG, TAG, 5 - 12 kW, 1200 - 2000 min-1, 1-, 2-cylinder, air-cooled or
water-cooled, dual-fuel
MWM AG, Carl-Benz-Str., 6800 Mannheim, Federal Republic of
Germany
- Series G 227, 18 - 40 kW, 1500 - 2200 min-1, 3-, 4-, 6-cylinder,
water-cooled, spark
ignition
Biotechnical fundamentals and plant engineering
Anaerobic Digestion, Proceedings of the Fourth International
Symposium on Aerobic Digestion, held in Guangzkou, China on 11 -15 November 1985
Baader et al., Biogas in Theorie and Praxis. KTBL Darmstadt 1980
Biogas
Technology Resource Index, Tata Energy Documentation and Information Cenke,
Bombay 1985
BORDA, Biogas Workshop on Community Plants - Input Papers, Bremen
1984
Braun, R, Biogas - Methangarung organischer Abfalle, Vienna/New York
1982
Guidebook on Biogas Development, Energy Resources Development Series,
ESCAP, Bangkok 1980
Hohlfeld, J. et al., Production and Utilization of Biogas
in Rural Areas of Industrialized and Developing countries, GTZ Eschborn 1986
Eggeling, G. et al., Biogas Manual for the Realisation of Biogas Programmes,
BORDA, Bremen 1980
Biogasanlagen in Europa, Neue Energien, Resultate der
Energieforschung der Europaischen Gemeinschaft, TUV Rheinland, Cologne 1985
Sasse, L., The Biogas Plant, GTZ/GATE, Eschborn 1984
Wellinger et al.,
Biogas-Handbuch, Grundlagen, Planung, Betrieb landwrrtschaftlicher Anlagen,
Aarau 1984
Agriculture
Comberg, G. (Ed.), Tierzuchtungslehre, Stuttga~t 1980
Demant,
D., GATE/GTZ, Arbeitspapier zur einheitlichen Versuchsmethodik fur
Faulachlammdungeversuche Eschborn 1987
Memento de l'agronome, Republique
Francaise, Ministere de la Cooperation, 1984
Rehm/Espig, Die Kulturpflanzen
der Tropen und Subtropen, Stuttgart 1976
Williamson, G./Payne, W.J.A., An
Introduction to Animal Husbandry in the Tropics, London/New York 1977
Economic aspects and dissemination/diffusion
Brandt, H., Projektplanung in der kleinbauerlichen Produktion,
Berlin 1982
Finck, H./Oelert, G., A Guide to the Financial Evaluation of
Investment Projects in Energy Supply, GTZ Eschborn 1982
Oelert et al.,
Economic Issues of Renewable Energy Systems - A Guide to Project Planning,
Eschborn
1985
Fig. 1.1: A typical biogas-system configuration
Fig. 2.1:
Biogasplanningmodules
Fig. 3.1: Global 15 °C isotherms for January and
July, indicating the biogas-conducive temperature zone
Fig. 3.2: Integration
of a biogas plant into the agricultural production cycle
Fig. 3.3: Pen with
concrete floor and collecting channel for dung and urine
Fig. 3.4: Stanchion
barn with floating gutter
Fig. 3.5: Cow-cubicle barn with floating gutter
Fig. 3.6: Piggery with group bays (no litter)
Fig. 3.7: Slurry storage
and composting
Fig. 3.8: Flow diagram for integral farming with a biogas
plant
Fig. 3.9: Site plan of the Bouake Ecofarm in Cote d'Ivoire
Fig.
4.1: Balancing the-energy demand with the biogas production
Fig. 5.1:
Three-stage anaerobic fermentation
Fig. 5.2: Gas yield as a function of
temperature and retention time (fT,RT-curves)
Fig. 5.3: The
batch-feed principle vs the continuous-feed principle
Fig. 5.4: The
fermentation channel vs the complete-mixed digester
Fig. 5.5: Slurry flow
for various configurations of feed, discharge and stirring
Fig. 5.6:
Floating-drum plant with internal guide frame
Fig. 5.7: Water-jacket plant
with external guide frame
Fig. 5.8: Cylindrical plant design for quarrystone
masonry construction
Fig. 5.9: Basic function of a fixed-dome biogas plant
Fig. 5.10: Fixed-dome plant with cenkal entry hatch
Fig. 5.11:
Fixed-dome plant with suspended dome
Fig. 5.12: Horizontal balloon-type
biogas plant
Fig. 5.13: Earth-pit plant with plastic-sheet gasholder
Fig. 5.14: Ferrocement biogas plant
Fig. 5.15: Horizontal biogas plant
(KVIC shallow design)
Fig. 5.16: Mixing pit
Fig. 5.17: Mixing pit,
gutter and toilet drain pipe
Fig. 5.18: Inlet and outlet for fixed-dome and
floating-drum plants
Fig. 5.19: Forces acting on a spherical-dome digester
Fig. 5.20: Level line, excavation and foundation
Fig. 5.21: Construction
of a spherical dome from masonry
Fig. 5.22: Construction of a metal
gasholder with internal guide frame
Fig. 5.23: Construction of a fixed-dome
gasholder
Fig. 5.24: Entry hatch of a fixed-dome biogas plant
Fig. 5.25:
Sealing the masonry with paraffin
Fig. 5.26: Separate, mobile, plastic-sheet
gasholder
Fig. 5.27: Gas pipe, valves and fittings of a biogas plant
Fig. 5.28: Gas valves and fittings: U-tube pressure gauge, water trap with
drain valve, U-tube water separator, "gravel pot" flashback arrestor
Fig.
5.29: Ferric-hydrate gas purifier
Fig. 5.30: Schematic drawing of a biogas
burner and its parts
Fig. 5.31: Various types of biogas burners
Fig.
5.32: Schematic drawing of a biogas lamp
Fig. 5.33: Schematic drawing of a
radiant heater
Fig. 5.34: Schematic drawing of an incubator
Fig. 5.35:
Various gas mixers for spark-ignition and diesel engines
Fig. 5.36:
Consumption of diesel and biogas by a 10-kW engine
Fig. 5.37: Energy shares
of an internal-combustion engine
Fig. 5.38: Measuringinstruments for biogas
field tests
Fig. 6.1: Basic principle of organic wastewater treatment
Fig. 6.2: Biogas plant in Ferkessedougou - system OEKOTOP
Fig. 7.1:
Water-seal testing of a digester
Fig. 7.2: Seal testing (water and gas) of a
fixed-dome plant
Fig. 7.3: Gas-seal testing of a metal-gasholder
Fig.
7.4: Pressure testing a gas pipe
Fig. 8.1: Basic elements of an economic
analysis
Fig. 8.2: Costs and benefits of a fixed-dome biogas plant
Fig.
10.1: Conceptual drawing of a floating-drum biogas plant
Fig. 10.2:
Constructional drawing of a floating-drum plant
Fig. 10.3: Constructional
drawing of a waterjacket plant
Fig. 10.4: Constructional drawing of a
cylindrical floating-drum plant for quarrystone masonry
Fig. 10.5:
Conceptual drawing of a fixed-dome biogas plant
Fig. 10.6: Constructional
drawing of a fixed-dome plant
Fig. 10.7: Constructional drawing of an
earth-pit biogas plant with plastic-sheet gasholder
Fig. 10.8: Schematic
diagram of earth-pressure and water-pressure forces
Fig. 10.9: Nomogram for
correcting gas pressures/temperatures
Fig. 10.10: Nomogram for finding the
net calorific value of biogas as a function oftemperature pressure and moisture
content
Fig. 10.11: Fundamental geometric formulae
10.7.2 Tables
Tab. 2.1: Detailed planning guide for biogas plants
Tab.
3.1: Climate zones and their suitability for biogas plants
Tab. 3.2:
Standard liveweight values of animal husbandry and average manure yields (dung +
urine) as percentages of liveweight
Tab. 3.3: TS- and VS-contents of green
plants
Tab. 3.4: Digestion characteristics of animal-husbandry residues
Tab. 3.5: Mean gas yields from various types of agricultural biomass
Tab. 3.6: C/N-ratios of various substrates
Tab. 3.7: Biogas
compatibility of farm types
Tab. 3.8: Survival time of pathogens in biogas
plants
Tab. 3.9: Concentration of nutrients in the digested slurry of
various substrates
Tab. 3.10: Effects of digested slurry on crop yields
Tab. 4.1: Outline for determining biogas demand
Tab. 4.2: Outline for
determining biomass incidence
Tab. 4.3: Simplified gas-yield values for
substrate from cattle and pigs
Tab. 5.1: Basic criteria for acetobacters
(acid forming bacteria) and methanobacters (methaneforming bacteria)
Tab.
5.2: Energy potential of organic compounds
Tab. 5.3: Energetical comparison
of aerobic and anaerobic fermentation
Tab. 5.4: Temperature ranges for
anaerobic fermentation
Tab. 5.5: pH ranges for biomethanation
Tab. 5.6:
Substances with an inhibiting effect on biomethanation
Tab. 5.7: Comparison
of various plant designs
Tab. 5.8: Common substrate mixing ratios
Tab.
5.9: Mortar mixing ratios
Tab. 5.10: Suitability tests for rendering/mortar
sands
Tab. 5.11: Quality ratings for various dome-sealing materials
Tab.
5.12: Properties of plastic sheeting - gasholder suitability ratings
Tab.
5.13: Gas-pipe pressure losses
Tab. 5.14: Composition and properties of
biogas and its constituents under s.t.p. conditions (0 °C, 1013 mbar)
Tab. 5.15: Pointers on flame adjustment
Tab. 5.16: Comparison of various
internationally marketed biogas burners
Tab. 5.17: Biogas consumption for
cooking
Tab. 5.18: Tests for biogas cookers/stoves
Tab. 5.19: Standard
lighting terms and units of measure
Tab. 5.20: Comparison of various biogas
lamps
Tab. 5.21: Artificial brooding requirements, exemplified for a chick
incubator
Tab. 5.22: Technical data of absorption refrigerators
Tab.
5.23: Engine-conversion requirements for various duty and control modes
Tab.
6.1: Some examples of biogas production from agro-industrial residues and
wastewater
Tab. 6.2: Technical data of the Ferkessedougou biogas plant
Tab. 6.3: Slaughterhouse waste quantities
Tab. 7.1: Checklist for the
inspection and acceptance of biogas plants
Tab. 7.2: Checklist for the daily
operation and regular maintenance of biogas plants
Tab. 7.3: Checklist for
troubleshooting in case of insufficient gas production
Tab. 7.4:
Simple-plant malfunctions and remedial measures
Tab. 7.5: Potential repair
situations for simple biogas plants
Tab. 8.1: Comparison of working time
with and without biogas utilization
Tab. 8.2: Investment-cost comparison for
various biogas plants
Tab. 8.3: Schedule of data for calculating the plant
payback period
Tab. 8.4: Schedule of data for net-present-value calculation
Tab. 8.5: Socioeconomic benefits and drawbacks of biogas production and
utilization
Tab. 9.1: Biogas dissemination strategies
Tab. 9.2:
Innovation cycle of biogas dissemination
Tab. 9.3: Catalogue of attributes
for partners in biogas dissemination projects
Tab. 9.4: Institutional
breakdown of biogas-dissemination tasks and activities
Tab. 9.5:
Target-group-oriented biogas training measures
Tab. 10.1: Calculating
parameters for fixed-dome biogas plants
Tab. 10.2: Atmospheric pressure as a
function of elevation
Tab. 10.3: Partial pressure of water vapor and
absolute humidity at the saturation point
Tab. 10.4: SI units of calculation
(selection)
Tab. 10.5: Conversion of imperial measures
Tab. 10.6:
Conversion factors for work, energy and power
Tab. 10.7: Energy content of
various fuels
Tab. 10.8: Conversion factors for units of pressure
Tab.
10.9: Table of powers and radicals
Tab. 10.10: Data sheet for economic
analysis
Tab. 10.11 : Discounting factors for interest rates of i = 1 - 30%
and periods of t = 1- 30 years
10.7.3 Abbreviations
|
A |
area |
|
a |
inflation rate |
|
a |
year (per annum) |
|
at |
atmosphere |
|
B |
biomass |
|
B.D.C. |
bottom dead center |
|
BEP |
GATE/GTZ Biogas Extension Program |
|
BOD |
biochemical oxygen demand |
|
C |
carbon |
|
C |
circumference |
|
CaO |
calcium oxide |
|
cd |
candela (candle power) |
|
ce |
coefficient of earth pressure |
|
cf |
coefficient of friction |
|
CH4 |
methane |
|
cmWG |
cm water gage |
|
C/N |
carbon/nitrogen ratio |
|
CO2 |
carbon dioxide |
|
COD |
chemical oxygen demand |
|
cp |
coefficient of pipe friction |
|
cP |
heat capacity |
|
CS |
crankshaft |
|
Cs |
storage capacity |
|
D |
density of biogas |
|
D |
energy demand |
|
D, d |
pipe diameters |
|
d |
day |
|
d |
stoichiometric air ratio |
|
DN |
density of biogas under normal (s.t.p.) conditions |
|
dp |
pressure drop |
|
Dr |
digestion rate |
|
E |
illuminance |
|
E |
compression ratio |
|
E |
energy |
|
Ee |
energy input |
|
Es |
specific illuminance |
|
F |
luminous flux |
|
F |
relative dampness of biogas |
|
Fe(OH)3 |
ferric hydrate |
|
FL |
friction losses |
|
G |
gas production |
|
gc, max |
max. gas consumption per hour |
|
GM |
moisture content of gas |
|
Gp |
specific gas production |
|
GRP |
glass-reinforced plastic |
|
Gy |
gas yield |
|
H, h |
height |
|
H2 |
hydrogen |
|
he |
height of earth column |
|
hp |
horsepower |
|
hph |
horsepower-hour |
|
H2S |
hydrogen sulfide |
|
I |
luminous intensity |
|
i |
discounting factors/calculatory (assumed) interest rate |
|
Io |
initial investment |
|
J |
joule |
|
K |
potassium |
|
KA |
average capital invested (per time interval) |
|
kcal |
kilocalorie |
|
K2O |
potassium oxide |
|
kWh |
kilowatt hour |
|
L |
latent heat of evaporation |
|
I |
length of pipe |
|
Ld |
digester loading |
|
lrn |
lumen |
|
mbar |
millibar |
|
MgO |
magnesium oxide (magnesia) |
|
mWG |
meter water gage |
|
N |
nitrogen |
|
N |
burner efficiency |
|
N |
Newton |
|
n.c.v. |
net calorific value (in diagrams: n.c.v. = Hu) |
|
NP |
net profit |
|
P |
pressure/gas pressure |
|
P |
phosphorus |
|
p |
market rate of interest |
|
p |
biogas/energy production |
|
pa |
Pascal |
|
PE |
polyethylene |
|
pE |
active earth pressure |
|
PN |
normal pressure |
|
P2O5 |
phosphorus pentoxide |
|
PVC |
polyvinyl chloride |
|
PW |
partial pressure of water vapor |
|
pw |
hydrostatic pressure |
|
Q |
gas flow |
|
QW |
quantity of heated water |
|
R, r |
radius |
|
Re |
luminous efficiency |
|
ROI |
return on investment (profitability) |
|
RT |
retention time |
|
Sd |
daily substrate input |
|
T, t |
temperature |
|
tc, max |
maximum consumption time |
|
T,D.C. |
top dead center |
|
tz, max |
maximum period of zero consumption |
|
TN |
temperature under normal (s.t.p.) conditions |
|
TS |
total solids content |
|
V |
volume |
|
v |
velocity/speed |
|
vc |
maximum gas consumption |
|
Vd |
digester volume |
|
Vg |
gasholder volume |
|
Vh |
compression volume |
|
VN |
volume of biogas under normal (s.t.p.) conditions |
|
Vn |
swept volume |
|
VS |
volatile solids content |
|
Vtot |
total volume of a cylinder |
|
W |
water |
|
W |
watt |
|
Wd |
daily water input |
|
wE |
weight of dry earth |
|
Wl |
water loss (leak testing) |
|
wW |
weight of water |
|
Ztot |
sum total of friction losses |
 |
