1. Site-adapted energy crops for biogas
production cultivated under non-irrigated
conditions in the Comunidad Valenciana
(Spain)
ainia
Paz Gómez
29.08.2011 Vienna, Austria

2. Analysis
Content
• Introduction and aim
• Methods
• Results and Discussion
• Conclusions

3. Introduction and aim

4. Introduction and aim
Introduction
• Climate change and rural development (Castilla la Mancha & Com. Valenciana)
• High number of pigs farms in inland villages of CV. But lack of co-substrates
• High percentage of non-irrigated land (<700 mm of annual pluviometry)
• Soil conditions of arable land: low organic matter, high percentage of carbonates,
loam soils
Aim of the study
• To evaluate different site-adapted energy crops for biogas production which
were cultivated under non-irrigated conditions
• Cultivation of energy crops
• Batch test
• Estimation of methane potential per surface unit

5. Methods

6. Analysis
Methods
Cultivation
• Crops VARIETIES. Triticale (cv.
Bondadoso), Barley (cv. Oralia; cv. Unia),
Oat (var. Prevision), Mixture of ryegrass
(45% cv. Trinova; 40% cv. Braulio) and
clover (8% cv. Paradana; 7% cv. Laser).
• Location: CASTELLON
• Weather & Soil CONDITIONS
• Thermal integral
• Annual pluviometry
• Soil conditions
• HARVEST TIME considering TS for ensiling
and max. biogas potential awaited in
relation to maturity scale (BBCH scale)
• ENSILING at pilot scale (MONITORING OF
TS, VS)

7. Analysis
Methods
Batch tests
• VDI Standard 4630
• Inoculum from agricultural biogas
plant
• Digester volume: 2L
• Incubator at 38ºC ± 2ºC
• Biogas production: counter 1 mL
resolution
• Gas analysis. Measurement range
CH4 and CO2 sensors: 0-100%

8. Results and Discussion

9. Results
Cultivation
After harvesting After ensiling
Crop Mat. TS1 VS1 Crop TS2 VS2
Stage (%) (TS%) yield (%) (TS%)
(BBCH) (t/ha)
Triticale 77-83 32.44 93.49 21.25 20.50 88.90
Oats 71-81 27.13 93.65 23.20 17.90 80.70
Barley 77-83 48.40 95.77 15.50 23.19 80.92
(1) (1) (1) (2) (2)
R&C 59-60 30.92 93.75 6.00 25.10 79.30
1: Barley (cv. Oralia); 2: Mixture of Oralia and Unia varieties (ensiled together) .
Mean values (not available standard deviation)

10. Results
Biogas Potential Test
CH4 (%)
700
58%
600
58%
500 54%
Biogas [NL/kg VS]
400 58%
300
200
100
0
0 10 20 30 40 50 60
Time (days)
Triticale (cv. Bondadoso)
Oats (cv. Prevision)
Barley (cv. Oralia; cv. Unia)
Mixture ryegrass (cv. Trinova; cv. Braulio) and clover (cv. Paradana; cv. Laser)

11. Results & Discussion
Estimation biogas potential per surface unit
Methane
(Nm3/kg seeds (Nm3/L
(Nm3/tVS) (Nm3/ha)
sown) rainwater)
Triticale 353 1,368 9 1.1
Oats 314 1,051 7 n.a.
Barley 280 814 6 0.6
Mixture R&C 221 264 2 0.2
Discussion
• Maximum methane potential per hectare estimated between 264-1,368 Nm3CH4/ha
• Triticale shows best results for methane potential per hectare, per kilogram of
seeds sown or per liter of rainwater. Most suitable under those cultivation conditions.
• Methane potential per hectare of TRITICALE tested under DRY conditions was
20% LOWER than under WET conditions (1,700 Nm3/ha; FNR, 2010)
• Barley and Oat showed “similar” results of biogas potential per unit of volatile solids.
Nevertheless, methane potential per hectare was HIGHER for OATS.

12. Conclusions

13. Conclusions
• Under non-irrigated conditions triticale and oats showed the best estimated
results of maximum methane potential per unit of surface (both over
1,000 Nm3 CH4/ha).
• Barley showed a good biodegradability and a better maximum slope of
accumulated biogas production than oats. Nevertheless, methane potential
per volatile solid unit was higher for oats. Therefore, at bigger scale should be
analyzed in detail which is the most suitable crop for biogas production
considering crop yield per hectare of each specific area, total solids after
ensiling as well as volatile solids.
• The mixture of ryegrass and clover, with a potential per surface unit of 264
Nm3CH4/ha seemed to be an inappropriate alternative for the studied areas
with low pluviometry. But it´s needed further research in order to evaluate its
suitability for biogas production as a rotation crop in those areas.
This research was carried out with funding from The Spanish Ministry of
Environment and Agriculture (Ministerio de Medio Ambiente, Rural y Marino),
under the Project ENERAL. http://eneral.info/

14. Thank you for your attention!
pgomez@ainia.es ainia