the contribution of biogas plants to nutrient management planning
DESCRIPTION
The contribution of biogas plants to nutrient management planning. Adviser Torkild Birkmose, DAAS, Denmark. Photo: Torben Skøtt, BioPress. Biogas. Biogas rests on tree legs. Energy. Agriculture. Environment. Agricultural advantages. Improved fertilizer value of nitrogen - PowerPoint PPT PresentationTRANSCRIPT
Dansk LandbrugsrådgivningLandscentret
The contribution of biogas plants to nutrient management planning
Adviser Torkild Birkmose,
DAAS, Denmark
Ph
oto
: T
orb
en
Sk
øtt
, B
ioP
res
s
Dansk LandbrugsrådgivningLandscentret
Biogas rests on tree legs
Biogas
Energy EnvironmentAgriculture
Dansk LandbrugsrådgivningLandscentret
Agricultural advantages
• Improved fertilizer value of nitrogen
• Balanced P and K-balance in slurry
• Homogeneous and light fluid
• Full declaration of nutrients
• Free from germs and seeds
• Reduced costs for transportation of slurry
Dansk LandbrugsrådgivningLandscentret
Environmental advantages
• Reduced nitrate leaching
• Reduced odour problems
• Reduced green house gas emission
• Controlled recycling of organic waste
Dansk LandbrugsrådgivningLandscentret
Mixing and digesting slurry change the characteristic of the slurry
DM,
%
N-tot,
kg/t
NH4-N,
kg/t
P,
kg/t
K,
kg/t
pH NH4-N, %
Digested slurry
Pig slurry
Cattle slurry
4,8
5,0
7,5
4,4
4,8
3,9
3,5
2,9
2,4
1,0
1,1
0,9
2,3
2,3
3,5
7,6
7,1
6,9
81
74
61
Dansk LandbrugsrådgivningLandscentret
Fertilizer value
Dansk LandbrugsrådgivningLandscentret
Ammonia evaporation in spring barley
0
10
20
30
40
50
2002 2003
NH
3-lo
ss, %
of
spre
ad N
H4-
N
Untreated pig slurry Digested pig slurry
Dansk LandbrugsrådgivningLandscentret
Improved fertilizer effect of nitrogen- trials in winter wheat
0 20 40 60 80 100
Cattle slurry, injected
Pig slurry, injected
Digested slurry, injected
Cattle slurry, trailing hoses
Pig slurry, trailing hoses
Digested slurry, trailing hoses
N-utilization, % (fertilizer equivalent)
Dansk LandbrugsrådgivningLandscentret
Fertilizer plan for nitrogen for 1 ha grass
250250N-requirement, kg
170170N in slurry, kg total
6040N-utilization, %
10268N- in slurry, utilized, kg
34
17
-
-
Saved, kg
Saved, £
148182Mineral fertilizer
Digested slurryCattle slurryPer hectare
Dansk LandbrugsrådgivningLandscentret
Digestion reduces risk of spreading diseases
Dansk LandbrugsrådgivningLandscentret
Digested slurry is low on germs
<5<5<5<5<5
1,300,000140,000690,000
9,000,00062,000
Mar. 18May 13July 15Sept. 9Nov. 11
AfterBeforeDate
Test results from Ribe Biogas,bacteria per ml. slurry (1998)
Lo
g10
ger
ms
per
ml.
slu
rry
Time, weeks
Slurry tank, 6-8°C Mesofile biogas, 35°CThermofile biogas, 53°C
10
6
5
3
Dansk LandbrugsrådgivningLandscentret
Digestion reduces odour
Dansk LandbrugsrådgivningLandscentret
Reduction of odour compounds in the biogas reactor
0
1
2
3
4
5
6
7
8
0 5 10 15 20
Days
Odour
units
Dansk LandbrugsrådgivningLandscentret
Concentration of VFA in slurry
0
200
400
600
800
1000
Iso-butanoicacid
Butanoic acid Iso-valericacid
Valeric acid
mg
per
litr
e s
lurr
y
Untreated slurry Digested slurry
Dansk LandbrugsrådgivningLandscentret
Carcass chamber for collecting air samples
Dansk LandbrugsrådgivningLandscentret
Odour concentration in air samples after spreading
0
200
400
600
800
1000
1200
20 minutes 260 minutes
Od
ou
r u
nit
s p
er
m3 o
f air
Untreated slurry Digested slurry