marelli.pdf · 2015. 3. 29. · hydrothermal conversion biogas bioethanol crude oil off-shore...
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www.jrc.ec.europa.eu
Sustainability of advanced biofuels
Luisa Marelli
European Commission, Joint Research Centre,
Institute of Energy and Transport (IET) (Ispra,
VA, Italy)
Energy and Climate Challenges
The RED 2020 targets:� decrease energy consumption by 20%
� increase the share of renewables to 20%
(10% renewable energy in transport)
Energy and climate package post-2020� 40% GHG reduction in 2030
� Calls for a range of alternative fuels for 2030, with special focus on 2G
and 3G biofuels
� Wide coordination for large scale deployment of alternative fuels
� Stable policy framework to attract investments
NEW Energy Union – Sustainable Low-carbon economy � Alternative fuels and clean vehicles
� Road transport and Renewable Energy package
� Achieve the 40% GHG reduction target
Why promote advanced biofuels?
329 March 2015
Rural Development (Pillar II of EU CAP)• Rural economies benefit from sustainable utilisation of biomass
• Key RD measures in CAP: “Facilitating the supply and use of
renewable sources of energy, of byproducts, wastes, residues and
other non-food raw material for purposes of the bio-economy”
• RD policy to enable rural areas to benefit from RE technology,
including advanced biofuels
Diversification of sources for transport fuels� EU transport sector mainly dependent on fossil fuels
� A critical challenge: 80% reduction in GHG emissions in 40 years (Energy
Roadmap 2050)
� Biofuels are one of the few options to reduce GHG emissions in
transport
4
• Concerns on environmental impacts of 1G biofuels (food-based) calls for
fast transition to 2G and 3G biofuels
• High supply chain GHG emissions savings can be achieved
Notes:
OD = Open storage of digestate;
CD = Closed storage of digestate;
OGC = Off-gas combusted;
OGV = Off-gas vented;
References:
[1] JRC EUR 26696 EN, 2014;
[2] Well-to-Wheels v.4a, 2014.
Why promote advanced biofuels?
529 March 2015
1. Biofuels 1. Biofuels 1. Biofuels 1. Biofuels from wastes and residuesfrom wastes and residuesfrom wastes and residuesfrom wastes and residues
Biofuels from wastes and residues:
• Abundant, relatively cheap and widespread
• No competition with food or land
• Wastes have no or low iLUC
• Valorization of waste streams
Mobilization of wastes and residues is essential but the impacts (environmental/economic) of
increased removal should be carefully assessed
Materials and methodsMaterials and methodsMaterials and methodsMaterials and methods
Four materials:
1. Cereal straws
2. Cattle/Pig slurry and manures
3. Logging residues
4. Pruning residues
629 March 2015
Potential effects:
1. Non – Bioenergy uses (baseline)
2. Removal effects
3. Displacement effects
Environmental impacts:
1. Total GHG balance
2. Soil Organic Carbon
3. Nutrient pools
4. Soil health and productivity
5. Direct N2O, CH4 emissions
6. Pests, diseases and odours
7. Biodiversity
8. Water
Straw
� Harvestable straw: ∼50% of ABG residues
� 25-30% of straw in EU available for bioenergy (Kretchmer et al, 2012)
� The share varies significantly due to site-specific conditions and different
management practices applied
7
Straw Left on the field
• Increased soil erosion• Decrease of SOC and nutrients• Yield reduction• Increased use of mineral fertilizers• Decreased N2O emissions• Negative impacts on water and biodiversity
Current use(non-bioenergy)
• Animal bedding
• Mushroom production• Mulching• Fodder• Industry
Potential effects
Replacement withalternative materials and
impacts associated to their production and use.
Removal for bioenergy
Displacementto bioenergy
Effect on SOC and nutrients
� RED and FQD method for default GHG emissions does not include SOC emissions
� Largest impact on C and N pools
� Experimental studies - removal has a limited impact on SOC (low removal rates, limited duration of experiments, substantial input of other organic matter – roots, stubble)
� Larger impact on soil microbial biomass than on total SOC -important for maintaining good soil physical properties and soil fertility → early warning
� Modelling studies – predict larger impact of straw removal on SOC
829 March 2015
SOC emissions (CO2/MJEt)� Based on modelling data for Europe (Lugato et al (2014)
AR_RES scenario - 50% removal of AGR in comparison to straw incorporation)
9
� High variability due to site-specific characteristics
Quantitative example: Influence of removal effectsQuantitative example: Influence of removal effectsQuantitative example: Influence of removal effectsQuantitative example: Influence of removal effects
Impacts on global temperature change
a) Continuous production of 1 MJ of fuel each year : 73% mitigation of straw ethanol by the end of the century
b) sustained production of 1 MJ of fuel for 20 years only: 83% mitigation of straw ethanol by the end of the century
• Dynamic emission profiles in time • Use of instantaneous climate emission metric (surface
temperature response), as opposed to cumulative GWP metric
Forest logging residues
1129 March 2015
• High supply-chain GHG savings, but this indicator is not an accurate measure of climate mitigation effects of a policy
• Biogenic-CO2 emissions from biomass not considered
• Impact of other climate forcers is also important
Global temperature change (WMGHG)
1229 March 2015
2014 2025 2050 2075 2100-0.5
0.0
2.0
4.0
6.0 [x 10-15]
2% yr-1
2.7% yr-1
11.5% yr-1
20% yr-1
40% yr-1
Coal Fuel Oil NG Bioenergy (Branches) Bioenergy (2.7%) Bioenergy (20%) Range decay (2% - 40%)
S
urfa
ce T
empe
ratu
re R
espo
nse
(ins
tant
aneo
us)
[K]
Years
(a)[x 10-15]
2014 2025 2050 2075 2100-0.25
0.0
0.5
1.0
1.5
2.0
2% yr -12.7% yr -1
11.5% yr -1
20% yr -1
40% yr-1
Coal Fuel Oil NG Bioenergy (Branches) Bioenergy (2.7%) Bioenergy (20%) Range decay (2% - 40%)
(b)
Sur
face
Tem
pera
ture
Res
pons
e (i
nsta
ntan
eous
) [K
]Years
a) Continuous production of 1 MJ of heat each year
b) Sustained production of 1 MJ of heat for 20 years – then residues left to decompose
1329 March 2015
Impact of other climate forcers
1429 March 2015
Livestock manuresLivestock manuresLivestock manuresLivestock manures
Solid manure
and liquid slurry
Direct field application as
fertilizers
Current uses
Potential effects of bioenergy use
• GHG savings from avoided emissions (raw manure storage)
• Contribution to the domestic energy supply (replacement of other sources of energy)
• (Potential) Effect on SOC
• Increase N fertilizer potential (short-term) may lead to potential decreased use of mineral fertilizers
• Negative impacts on groundwater
• Decrease odours
• Increase veterinary safety
Anaerobic digestion and digestate
application as fertilizer
Bioenergy Use
Livestock manures
• Management of raw manures and slurries is responsible for large
GHG and other pollutants' emissions (mainly: CH4, N2O and
NH3) (baseline)
• Anaerobic digestion and collection of biogas can avoid most of
such emissions (emission credits) without impacting the function
of organic fertilizer (covered by residual digestate).
• However, potential impacts associated with lower organic matter
supply to the soil could reduce these advantages.
• Also, technological options for biogas plants can have a
significant influence on the final results achieved (leakages and
losses of methane). Especially for energy crops (that have no
credits). Best practices should be promoted to avoid these
emissions.
1529 March 2015
Influence of technological choices
1629 March 2015
Source:
JRC EUR 26696 EN
JG5
Snímka 16
JG5 There are other important potential emissions from biogas plants:
1) Flaring and venting2) accidental leakages3) Upgrading slip streams of methaneGIUNTOLI Jacopo (JRC-PETTEN); 17. 3. 2015
1729 March 2015
Co-digestion of multiple substrates (maize silage and wet manure)
Off-gas vented Off-gas combusted
1829 March 2015
(Baselines =
left on soil
except
prunings)
Total GHG Total GHG Total GHG Total GHG
emissions emissions emissions emissions
compared to compared to compared to compared to
fossil fuelsfossil fuelsfossil fuelsfossil fuels
SOCSOCSOCSOCNutrientsNutrientsNutrientsNutrients
PoolPoolPoolPool
Soil health Soil health Soil health Soil health / / / /
fertilityfertilityfertilityfertilityNNNN2222O, O, O, O, CHCHCHCH4444
Pests, Pests, Pests, Pests,
diseases, diseases, diseases, diseases,
odoursodoursodoursodours
BioBioBioBio----
diversitydiversitydiversitydiversityWaterWaterWaterWater
DisplacemeDisplacemeDisplacemeDisplaceme
nt effectsnt effectsnt effectsnt effects
StrawStrawStrawStraw ☺☺☺ ��� ��� ��� ☺☺ ☺☺ �� � ��
Pruning Pruning Pruning Pruning
residuesresiduesresiduesresidues☺☺☺ ��� ��� ��� ☺ ☺☺ �� �� �
ManureManureManureManure ☺☺☺ ��� ☺ ☺☺ ☺☺☺ ☺☺☺ �� ��No alternative
use
Forest Forest Forest Forest
residuesresiduesresiduesresidues
Short term:
���� �� �� � ☺☺ ��� �
No alternative
use Long-term:
☺☺☺
Qualitative assessment
UCO and Tallows
• UCO (used cooking oil) and waste-grade tallows (animal fats)
produce fuels with higher GHG savings compared to 1st
generation biofuels.
• Some waste tallow already used for heat in rendering factories;
if redirected into biodiesel, its most likely replaced by fossil fuels
• UCO collection volumes in EU can improve. Non-EU sourced
materials available but can have higher transport emissions
• Some non-waste tallows are used for cosmetics, animal feeds
etc; if redirected into biodiesel, most likely replaced by palm oil
• Concerns exist re: non-waste material fraudulently sold as
waste biofuel, lowering GHG savings. Feedstock certification
helps
1929 March 2015
ALGAE biofuels: Macroalgae
2029 March 2015
� Over 10,000 species in intertidal zones ("cast seaweeds") and sub-tidal zones (submerged "kelp")
� Range in size: 10 cm - 60 m (aquatic plants)
Ma
cro
alg
ae
Anaerobic digestion
Fermentation
Hydrothermal conversion
Biogas
Bioethanol
Crude oil
Off-shore cultivation
On-shore cultivation
Wild stocks
• Sunlight
• Water(seawater,wastewater)
• Fertilizers
� Cultivation: key questions about yield and composition of biomass, resource supplies, site selection, sustainability issues for aquatic systems
� Wild harvest: impacts on the biodiversity of flora and fauna
ALGAE biofuels: Microalgae
2129 March 2015
� Over 30,000 species in various marine and freshwater habitats � Range in size: 2 - 20 µm (unicellular, lack of roots, stems and leaves)
� Benefits potentials: use of non-food crops lands (low iLUC), higher oil yields (60 m3 ∙ ha-1) than other crops (e.g. soybean (0.45 m3 ∙ ha-1)
� Cultivation: key questions about different designs, high demands of resource supply (CO2, fertilizers, water), influence of water types on biomass yield
Cultivation in open ponds (ORP)
Cultivation in photobioreactor (PBR)
• Sunlight
• Water(freshwater,seawater,wastewater)
• Fertilizers
• CO2 Mic
roa
lga
e
Lipids extraction and
conversion
Fermentation
Anaerobic digestion
Hydrothermal conversion
Biodiesel
Bioethanol
Biogas
Pyrolysis oil, jet fuel
2229 March 2015
ALGAE biofuels: Microalgae biodiesel
� Low estimates of energy returns, biogas (from residual biomass) is a key parameter for electricity/heat production for on-site use and nutrients recovery
� Significant uncertainties on key parameters/technologies, lack of operational data
Biodiesel
Cultivation
Harvesting-dewatering,
drying
Lipids extraction
Transesterification
Glycerol
Algal biomass
Coproduct management
Coproduct managementAnaerobic digestion
Digestate
Coproduct management
Biogas
Combustion
Electricity
Heat
Water
CONCLUSIONS
29/03/2015 23
• Biofuels are one of the few options to reduce GHG emissions in
transport
• Advanced biofuels may offer advantages with respect to first-
generation, but sustainability and market mediated effects
(competition with other sectors, displacement from existing uses, etc.)
have to be considered.
• Net GHG savings in the long-term for all the analysed residues
• Other impacts present medium to high risks, especially biodiversity
and decrease of SOC
• Additional impacts usually worse than fossil (eutrophication, PM etc…)
• Further long-term research needed
IS BIOENERGY FROM IS BIOENERGY FROM IS BIOENERGY FROM IS BIOENERGY FROM RESIDUES AND WASTES RESIDUES AND WASTES RESIDUES AND WASTES RESIDUES AND WASTES REALLY AND REALLY AND REALLY AND REALLY AND
ALWAYS SUSTAINABLE?ALWAYS SUSTAINABLE?ALWAYS SUSTAINABLE?ALWAYS SUSTAINABLE?
2429 March 2015
Precautionary approachPrecautionary approachPrecautionary approachPrecautionary approach
• The word "residue" is not automatically synonym with "sustainable"
• GHG reductions may come at the expenses of other impacts
• Mitigation measures and techniques can often be found and arranged
• But first we need to be aware of the issues
• Choices that cause trade-offs in impacts should be made knowingly and not out
of ignorance.
Straw: Environmental impactsSOC Impact −−−− Removal of C contained in the residues, increasing risks for runoff and soil erosion, accelerating SOC
mineralization under the bare soil surface because of alterations in soil temperature and moisture regimes;Larger impact on soil microbial biomass.
Mitigation Removal rates determined on a site-specific basis;Conservation tillage, adequate crop rotation, cover crops, cropping intensification;Application of alternative soil improvers, use of biochar or by-product of fermentation;Adequate monitoring regime
Nutrients Impact −−−− Larger removal of N; removal of P and K are also significant
Mitigation Replacement with mineral fertilizersApplication of fermentation by-product
Nutrient loss Impact +
−−−−−−−−
Incorporation of straw and mineral fertilisers can cause higher N application due to initial N nitrogen immobilisation, fertilisation is planned not considering fertilisation value of straw;Increased runoff and leaching;Initial immobilization of N by microbial decomposition of straw and slow release offers a possibility to improve N efficiency
Mitigation Management practices that reduce nutrient loss (e.g. adequate rate, timing and method of fertiliser application, use of cover crops, nitrification inhibitors, precision farming, reduced tillage)
Yields Impact −−−− Due to nutrient removal, higher water and temperature stress (highly variable)
Mitigation Replacement of nutrients removed;Straw management practices defined on site-specific characteristics
Pest/Diseases
Impact + Removal with the straw (usually small impact)
Mitigation
Water Impact −−−−−−−−
Additional input of mineral fertilisersIncrease of sediment and nutrient delivery in nearby waters
Mitigation Management practices that reduce soil erosion and nutrient loss;Appropriate drainage system;Riparian buffer strips and infiltration belts
Biodiversity Impact −−−− Species depending on agricultural habitats, e.g. farmland birds; species living in soil due to lower input of fresh organic matter; water ecosystems due to increased inflow of sediments and nutrients
Mitigation Use of cover crops to provide alternative habitat;Implementation of management practices that reduce soil erosion and nutrient loss
25
Straw: Displacement effect
Use Alternative
Soil improver Manure, mineral fertilisers, green manure and cover crops
Animal bedding Woodchips, shavings and sawdust, waste shredded paper, paper crumb, and lime ash, high-yielding grasses, plastic mattresses
Animal fodder supplement Hay, silage, commercial feed, out grazing
Mushroom production (growth substrate) Compost, sawdust, other lingo-cellulosic material
Frost prevention in horticulture Limited commercial alternatives, plastic sheeting is used, but still requires some straw
Strawberries (preventing damage to fruit) Matting or plastic sheeting
Compost industry Wood chip, other plant fibre with low N content
Traditional building materials Alternatives include all common building materials
Energy Other biomass feedstock depending on boiler structure / other biofuel feedstock
2629 March 2015 Kretchmer et al. (2012)
Forest logging residues: impacts and mitigation
27
Impact
category Potential risks / benefits Mitigation measures
Soil organic
carbon
= A reduction of SOC associated with whole-tree harvesting was predicted by various
modelling studies (Wall, 2012). However, meta-analyses of field studies have not
substantiated such results. Only a small percentage of the experimental data
analysed indicated a decrease in SOC when removing logging residues (Johnson
and Curtis, 2001; Nave et al., 2010; Wall, 2012). However, the actual effects on
SOC may become evident in the very long-term.
= Stump removal is responsible for soil disruption at depths reaching 1 m (Moffat et
al., 2011). This could favour soil mixing and mineralisation.
Nutrients
pool1
- More than half of total tree N stock is contained in logging residues for spruce and
pine. Of this amount, about half is contained in needles and it is released faster than
the N in branches. Thus, removing residues may impact mostly the quantity of
available N rather than total N soil stock (Tuomasjukka et al., 2014).However, N
depletion is considered more critical in areas of low atmospheric deposition and in
low-fertility soils (Wall, 2012).
- Experimental results consistently indicate decreases in calcium, potassium,
magnesium and phosphorus when residues are removed (Wall, 2012).
- Increase of the acidity of soil is also recorded (Wall, 2012).
- Therefore, soils with low fertility and smaller nutrient pools are more subject to
suffer from the removal of residues and nutrients (Fritsche et al., 2014).
- Stumps contain a small fraction of macronutrients, but coarse roots are responsible
for significant inputs of nitrogen and potassium to the soil (Moffat et al., 2011).
• Leaving foliage and needles,as well as bark, on the forest floor could largely mitigate the
losses of nutrients and growth losses associated with the removal of logging residues (Egnell ,
2011; Lattimore et al., 2009; Tuomasjukka et al., 2014).
• Mitigation of soil acidification via liming could be considered, but negative effects on tree
growth have been reported when applying lime on forest soils (Saarsalmi et al., 2011).
• Re-application of combustion ashes could also return some macronutrients to the soil, but the
eventual positive effects of ash application on tree growth are still uncertain. Data even
suggests decreased growth when ashes are recirculated on nitrogen-poor soils (IEA, 2014).
• Nitrogen is almost completely lost during combustion, so it is not present in ashes and will
need to be supplied via synthetic or organic fertilisers. Experimental data have shown
increased growth rates in fertilised forests, but guidelines in some countries still advise against
synthetic forest fertilisation (Fritsche et al., 2014; Stupak et al., 2007).
• Avoid extraction on rocky, dry and poor soils (Lamers et al., 2013; Wall, 2012)
Soil health
and
productivity
= Many studies have shown results that are not statistically different when comparing
trees grown on sites where residues are either collected or left on floor.
+ Some studies have shown smaller diameters for trees grown in areas where residues
were regularly removed. This has been linked to the initial soil nutrients capital and
the relative fraction of nitrogen removed with the residues (Holub et al., 2013; IEA,
2014; Thiffault et al., 2011).
• Measures to compensate for nutrients losses may actually have negative consequences on
forest growth (see above). These measures should thus be assessed on a case-by-case basis by
developing site-specific nutrient management regimes (Lamers et al., 2013).
• A combination of ash recirculation and urea supply has shown increased volume production of
almost 45% compared to the control study (Saarsalmi et al., 2012).
• Negative impacts of residues accumulation have also been reported. An abundant bed of
residues may delay the stand establishment by as long as one year (Hakkila, 2004) and
excessive, long-term accumulation of residues on the forest floor could limit productivity