Energy crops Flashcards
What does it need to be ‘successful’? - from historical to designer crops
What were / are drivers of increasing importance of any specific alt. crop?
Why did we come from basic nutrients to medication?
Regulatory hurdles?
Conflicts of interest /
Who owns which rights?
Will we see a higher diversity of plants being used in the near future?
How much area would the world need to cover its energy needs from plants only?
Miscanthus: 0.6 Gha
Global land area is 15 Gha, Agriculturallyused land is 4,8 Gha and crops 1 Gha
Why did the US plan to grow several Mio ha Miscanthus or other energy crops by 2030?
The US government wanted to replace 30% of its 2005 oil consumption by fuel from renewable sources ‚within the next decades‘ (200 of 650 billion [Milliarden] Liters).
The US government wanted to replace 30% of its 2005 oil consumption by fuel from renewable sources ‚within the next decades‘ (200 of 650 billion (Milliarden) Liters).
If 20% would come from ethanol that is produced from maize, 30 Mio ha agricultural land would be needed. This is 25% of the current US cropland and more than what is currently planted with maize/corn.
If Miscanthus, switchgrass or ‚low input high diversity‘ (LIHD) grasslands could be used, demand on cropland were much lower
Miscanthus biomass yield currently 2.5 x higher than that of maize
Miscanthus can currently produce harvestable yields of 30 t/ha, switchgrass 10-20 t/ha, LIHD 4 t/ha (Heaton et al. 2008). All at minimal agricultural input (fertilizer, crop protection).
Energy from biomass in CH
‚Flurholz‘ and greens along roads, but also remainders of wood, dung, slurry etc. can be cut down and fermented to biogas…
Advantage of biomass vs. Other renew- ables: can be stored, can be converted to fuels (in addition to electricity, heat)
Total, additional sustainable potential‘ for Switzerland: Electricity for ca. 5000 additional households – only a small fraction of current total Swiss energy consumption
Biofuel/-mass/-energy crops of the ‚first‘, ‚second‘ and ‚third‘ generation
First generation: Regular agricultural crops
Second generation: Plants that can be grown as crops but that have no use as a human food resource
Third generation: Plants that have to be cultivated completely different
Classical agricultural crops for biomass supply (first generation)
Maize / corn (starch – sugars – ethanol)
Sugar cane (whole plant – sugars – ethanol)
Rapeseed / canola (seeds – fat, lipid – diesel)
Forestry products (wood – thermal energy)
Ethanol in Brazil
Ethanol produced from sugar cane domestically
Flexfuel cars sold since 2003
All cars can use up to 20% ethanol; lots take 100%
50% share in the car fuel market (US: 10%) ca. 2015
Produced on 1% of arable land in Brazil
Since the early 2020s: Also Brazil moves more and
more to electricity-powered cars
Non-food crops for biomass supply - second generation
Miscanthus / C4-grasses (lignocellulose; thermal energy; ethanol)
Species mixtures / pastures / LIHD (lignocellulose / biogas)
Low Input High Diversity
Short-rotation coppice wood (poplar, salix; thermal energy)
-> Common feature: Dynamic distribution of resources between shoot and root; perennial
Non-food crops, novel cultivation, conversion pipelines as biomass supply - third generation
Algae (terpenes, lipids - butanol)
Your favourite designer crop
-> still a lot of research to be done; potential use of oceans and freshwater area (2/3 of globe)
Miscanthus (Chinaschilf, Elefantengras)
Origin: China, Japan, East Asia
Most interesting species: Miscanthus giganteus, triploid bastard of M. sinensis and M. sacchariflorus
Perennial C4-species with rhizomes
Can yield up to 60 t/ha with limited
fertilizer / pesticide input
Dissemination: A single plant came from Japan to Europe in the 1920s (Denmark, Aksel Olsen) and was distributed from there on.
First use: horticultural
Products of miscanthus
Straw
Wood chips
- burning (thermal energy)
- Ethanol from Ligno-Cellulose (cell wall material
- Fibres as basic material for insulation, fibre boards
Young shoots can be used as food
Biology of miscanthus
Perennial plant that can produce stable yields for > 20 years
Safe habitat for a lot of insects and mammals (perennial)
C4-plant: high efficiency of conversion light – biochem. energy
Rhizomatous plant: Transfer of nutrients to rhizomes in winter
Production requirements of miscanthus
Planting at a density of 1 plant / m2 (higher density: less yield)
Soil requirements: light soil with pH 5-7 (in heavy soils, more resources are put into the rhizome; low harvest index)
Water: 600 – 800 mm rain/year
Fertilization up to 50 kg N/ha*a from year 2 on (no fertilization in
year 1; otherwise too little rhizome storage before winter)
Altitude below 700 m a.s.l. (winter frosts)
Diseases: No pest problems known yet
Harvest: February to early April (plant water content below 20%), when all nutrients have been transferred to rhizomes
Harvested yield: around 20 t/ha in Europe (10-40); 30 t/ha in US (up to 60 t/ha reported by Heaton et al. 2008)
Total areas planted: 500 ha in CH, several 1000 ha in UK, US, F, D
Other 2nd generation generation plant biomass systems
Short-rotation coppice
(Kurzumtriebs-Plan- tagen) of willow, salix, poplar; a lot of trials in Scan- dinavia; harvested every 2-4 years with choppers
Other perennial grasses such as switchgrass or low input high diversity LIHD systems of US prairies
Ways to get energy from plant biomass systems
- Thermal conversion (burning of e.g. pellets)
- Ethanol from lignocellulose (chemical, enzymatical or microbiological conversion of cellulose to sugars and to ethanol CHOOH that can be used as a fuel)
- Generation of ‘Biogas’ (decomposition of several compounds to methane CH4 that can be used as a fuel)
