28 waste feedstocks – a comprehensive
overview of what is sustainable, affordable, reliable, available – is
this the most comprehensive survey ever?
In the UK, a comprehensive 28-feedstock assessment,
commissioned by the UK Department for Transport from E4Tech, presents
evidence on feedstock supply potentials and prices, the maturity and
costs of different biofuel production options, direct GHG emissions of
different chains, plus competing markets and indirect substitution
effects for each feedstock. It also looks at recent policy developments
and the effectiveness of multiple counting.
The study then proposes and applies a framework to
facilitate the transparent assessment of feedstock sustainability and
risks on a common basis, and determine which merit additional policy
support.
Feedstocks include:
Bio-fraction of municipal solid waste
Bio-fraction of commercial & industrial waste
Straw
Animal manure
Sewage sludge
Palm oil mill effluent
Empty palm fruit bunches
Tall oil pitch
Crude Glycerine
Bagasse
Grape marcs
Wine Lees
Nut shells
Husks
Cobs
Bark, branches and leaves
Sawmill co-products
Black and brown liquor
Used Cooking Oil
Animal fats (Categories I and II)
Non-food cellulosic material
Short rotation coppice
Short rotation forestry
Small round-wood
Micro-algae
Macro-algae
Renewable non-bio liquids & gases
Waste carbon gases
Biofuel uptake within Europe has stalled in recent years due to the
policy uncertainty surrounding Indirect Land Use Change (ILUC). Proposed
changes to the Renewable Energy Directive (RED) have gone through
rounds of Commission, Parliament and Council amendments since October
2012 – with ILUC factors, caps on food-based biofuels, multiple counting
and sub-targets for advanced biofuels all under intense debate.
The 28 or so feedstocks within the Annex IX lists are proposed to
count double (or quadruple) towards national renewable transport
targets, and/or count towards a 2020 sub-target for biofuels from novel
conversion technologies using these resources. This feedstock list
started with the RED and the Commission’s communication on practical
implementation, taking onboard criteria and classifications of wastes
and resides drawn up by the Renewable Fuels Regulators Club in 2010. In
their 2012 proposals, the Commission added feedstocks they considered to
be low ILUC risk, but since then several other feedstocks have been
added, removed or reinserted, but with no transparent rationale or
underlying analysis. The process and criteria by which future feedstocks
will be added to the list are also still unclear.
Sustainability of Annex IX feedstocks
In this study, we have collected information regarding the basic
characteristics, supply potentials, technology compatibility, economics
and sustainability for each of the 28 feedstocks within the Annex IX
lists. The analysis is based on the best evidence publicly available
that could be gathered within the short duration of the study, and we
have highlighted where the available evidence is most uncertain and the
additional information needs. For a more detailed picture, or a regional
focus, market analyses for individual feedstocks will be required. Our
synthesized findings are as follows:
1. Availability: Feedstock supply data for today and
2020 was collected (in million tonnes/yr and PJ/yr of biofuel
equivalent) for the UK, EU and globally. MSW and C&I wastes, straw,
manures, forestry and renewable electricity typically have the largest
supply potentials. Other feedstocks have more modest potentials, whereas
wine residues, tall oil pitch, crude glycerine resources are the most
limited. Energy crops, short rotation forestry and algae will also be in
short supply by 2020, but have longer-term potential.
2. Technology: There are numerous conversion
technologies capable of transforming the Annex IX feedstocks into
biofuel. Many routes are still at pilot scale, whilst those in
demonstration, and hence potentially able to contribute meaningful
biofuel volumes by 2020 include lignocellulosic ethanol and butanol,
pyrolysis oil upgrading, gasification routes to alcohols, bio-Synthetic
Natural Gas, Fischer-Tropsch diesel & jet, plus renewable
electrolysis. Some technologies are commercially available, but are only
compatible with a few of the Annex IX feedstocks, such as biomethane
from anaerobic digestion (e.g. for MSW, C&I wastes), FAME biodiesel
and Hydrotreated Vegetable Oil (e.g. for UCO, animal fats and
micro-algae).
3. Economics: Wastes with a gate fee have a negative
price, and those energy dense feedstocks (like tall oil pitch, crude
glycerine, UCO and animal fats) have the highest positive prices – along
with algae and renewable electricity. Delivered biofuel production
costs have also been calculated in the study for 30 selected supply
chains.
4. Competition: Competing uses vary widely, as do
the likely substitute resources and price impacts if the Annex IX
feedstock was to be diverted to biofuels. Generally, feedstocks that are
disposed of (e.g. MSW, C&I wastes, UCO, waste carbon gases) or left
uncollected (e.g.
straw, cobs, forest residues, small round-wood) can be collected
sustainably up to certain limits. Manure and sludge spread to land can
be treated via anaerobic digestion first before returning the digestate
to land. Diverting a feedstock out of heat & power or industrial
uses will have an impact through the carbon intensity of the replacement
resource (i.e. high risks if replaced with fossil fuels vs. low risks
if sustainable biomass used instead). Diverting straw and wood from
animal bedding will likely rely on additional sustainable supplies of
straw and wood to be found, whereas animal feed if diverted will need
more roughage or carbohydrate crops produced from land (a potential ILUC
risk). Some industries have minimal feedstock flexibility, such as the
spirits industry (grape marcs and wine lees), paper & panel board
(forestry) and high-value chemicals (e.g. glycerine). For those
feedstocks specifically grown for biofuels, current competing uses are
relatively unimportant, but the land they are grown on is important – in
particular, energy crops grown on agricultural land could cause ILUC,
if mitigation measures are not implemented. In general, those feedstocks
with minimal expansion potential and high competition levels are likely
to suffer price increases if diverted to biofuels.
GHG savings: Most Annex IX biofuel routes are able
to achieve GHG savings above 80%. Routes using MSW, C&I waste,
bagasse, wine lees, algae and waste carbon gases are more likely to fall
into the 60-80% bracket, due to cultivation emissions, chemical or
energy inputs, and transport distances. GHG emissions have been combined
with the relative economics to give an indicative cost of GHG saving
(in Åí/tCO2e) versus a fossil comparator.
Rationale for considering feedstocks for additional policy support
Based on the gathered information, the study developed a framework to
determine feedstocks for which additional regulatory support could be
justified (note that this does not specify the support mechanism). The
following hierarchy of questions are illustrated as a flow diagram that
can be followed to determine if a feedstock meets all the criteria to be
eligible for support:
1. What is it classified as: a waste or processing
residue (non-land using), or alternatively, an agricultural/forestry
residue, co-product or product (land using)?
2. If land using, what type of land does it come
from? Has the use of high biodiversity, high carbon stock or peat land
been avoided? (meeting current RED is a minimum requirement)
3. What are the key competing uses, and potential
substitute resources? Would diversion to biofuels result in a high risk
of unacceptable carbon, cost, environmental or social impacts – such as
the knock-on use of more fossil fuels or land? (These risks can be
volume and location dependent). Alternatively, for new non-food crops,
is there a risk of competition with food via ILUC?
4. Are the lifecycle GHG emissions savings of
producing biofuel from the feedstock high enough (versus a suitable
fossil comparator) to be supported? At least 60% will be required under
the RED, but a higher threshold could be chosen by policymakers.
5. Would use of the feedstock for biofuels be
economically viable without support, and hence likely to be deployed? Or
would deployment only occur with support, due to the lack of commercial
readiness of the conversion technology, infrastructure investments
required or other reasons?
Applying these criteria across the whole of the Annex IX list leads to the following conclusions.
1. Several feedstocks have a significant uncollected
resource that could be diverted from current disposal, produced without
indirect impacts, or sustainably extracted with limited competition.
MSW, C&I wastes, manures, forest residues, small round-wood, algae
and renewable electrolysis are likely to need further support to be
economically viable or help commercialize conversion technologies. UCO
may not require additional support, depending on infrastructure
investments to access domestic supplies.
2. Some feedstocks face higher levels of
competition, and hence only a smaller unused fraction of the total
supply is likely to be at low risk of causing indirect impacts. This
includes straw, cobs, sewage sludge, bagasse, empty palm fruit bunches
and waste carbon gases. For other feedstocks, such as animal fats, nut
shells, husks, sawdust & cutter shavings, tall oil pitch, brown
& black liquor, support should only be provided if the industries
involved can show replacement of the missing energy demands with low
carbon, sustainable alternatives – otherwise there is a risk of
increased fossil fuel use offsetting any GHG savings.
3. Energy crops and short rotation forestry have
longer-term potential (post 2020), but will require strict enforcement
of ILUC mitigation measures to ensure the land grown on avoids food
competition as well as being low risk (e.g. protecting carbon stocks).
4. A few feedstocks should probably not be supported
for biofuel production, as they have multiple competing uses with high
risks of detrimental indirect impacts – these include crude glycerine,
grape marcs and wine lees. Until more information is available for
Bacteria, the risks of its inclusion likely outweigh the benefits, as it
could cover a broad range of processes (and feedstocks).
There is significant potential for biofuel production using low ILUC
risk feedstocks, as many of the feedstocks in the Annex IX lists meet
the criteria listed above – or could do so where only uncollected
fractions are considered or when fossil fuel substitution can be
avoided. However, most of the novel technologies that convert these
feedstocks to biofuels still need to be commercialized, and only a few
of the routes are currently economically competitive (compared to fossil
transport fuels or conventional food-based biofuels) – despite the
attractive GHG savings on offer.
The complete study can be downloaded here.
The 28-feedstock annex is here.
Source: Biofuels Digest Author: Jim Lane