Sustainable Feedstocks for Advanced Biofuels and Intermediate Bioenergy Carriers Production in Europe
Biomass is the oldest source of fuel energy. However, using biomass for the production of transport fuels is a relatively new application with a significant increase during the last 10 to 15 years. Biofuels can substitute fossil derived transport fuels, with the advantage of providing carbon from a renewable source.
In broad terms, the various types of biomass feedstocks potentially available for bioenergy production can be categorized as follows :
Wastes and Residues
On the basis of the feedstock used in production, biofuels and intermediate bioenergy carriers may be referred to as:
Conventional (first-generation) biofuels are produced from food crops (sugar, starch, oil), such as palm, rapeseed, soy, beets and cereals (corn, wheat, etc).
Advanced (second-generation and third-generation) biofuels - as defined by the European Commission - are produced from feedstock that "do not compete directly with food and feed crops, such as wastes and agricultural residues (i.e. wheat straw, municipal waste), non-food crops (i.e. miscanthus and short rotation coppice) and algae.” At the moment only about 2 % of biofuel production are covered by advanced biofuels [Bacovsky et al. 2012].
Following global concerns about the impacts of using food crops for production of bioenergy, the EC has introduced measures to encourage a more diverse range of feedstocks to be used in future. Measures include restricting state aid for conventional biofuels, a proposed cap of 7 % (of transport energy use) on biofuels from "food crops", and double counting of biofuels produced from certain wastes and residues. Hence, the future expansion of biofuels (for road freight, air transport, shipping, and other uses) will require the commercial deployment of innovative conversion technologies that may be more complex and costly than conventional production methods.
This page contains general information and links on a range of sustainable feedstocks that could be used for producing advanced biofuels and intermediate bioenergy carriers. These include :
- Energy crops grown on marginal land - that do not compete directly with food crops for land or cause indirect Land Use Change
- Wastes and residues - agricultural, forestry, food, MSW, and other organic wastes and residues
- Novel feedstocks - such as aquatic plants, macroalage (seaweed), microalgae and other microbial biomass
The term advanced biofuels typically refers to biofuels produced from lignocellulosic (LC) biomass (i.e. any non-food 'woody' parts of plants that humans cannot digest). This covers a range of plant molecules/biomass containing cellulose and hemicelluose with varying amounts of lignin, chain length, and degrees of polymerization. Some cellulosic materials are relatively easy to breakdown into substrates that can be used to create fuel molecules. For example, citrus peel may be converted to plant sugars. For more complex cellulosic materials containing greater amounts of lignin (e.g. hardwood) the production route to liquid biofuels requires pretreatment and may be more challenging and costly.
Availability of biomass for advanced bioenergy production
In Europe, proposals have been introduced to limit the amount of bioenergy feedstock that can be grown on land suitable for food-crop production. Hence future expansion of bioenergy production is dependent on cultivation of energy crops on marginal land, and mobilisation of waste streams (for example, from agriculture, forestry, bioindustry and domestic refuse collection). The actual amount of sustainable feedstock available depends on various factors:
- the potential amount of 'marginal' land types that may theoretically be available for energy crops
- the total amount of organic wastes and residues that are theoretically available across Europe
- competition for land for other uses such as, housing, conservation, animal grazing, recreation, etc
- the percentage of marginal land that it is feasible to exploit for biomass production for economic, logistic and enviromental reasons (relating to water, soil carbon, fertiliser inputs, biodiversity, etc)
- competing demand for biomass from bioenergy and bioproducts
Such issues have been the subject of a range of projects and studies on biomass availability in Europe.
Deliverable D8.2 "Vision for 1 billion dry tonnes lignocellulosic biomass as a contribution to biobased economy by 2030 in Europe" from the S2Biom project states that "Recent studies and work in S2Biom provide robust scientific evidence that at least 1 billion tonnes of lignocellulosic biomass will exist in Europe on an annual basis across the various supply sectors (agriculture, forestry, biowastes and dedicated perennial crops)...The recently published studies of biomass assessments for 2020-2030 identify four primary sources that could provide additional biomass and support growth of bio-based industries, namely: agricultural residues, forest biomass, wastes and non-food crops...The recent S2Biom estimates for the 2030 base potential (which includes the sustainability criteria as stated within the Renewable Energy Directive I) amount to 1,093 million tonnes of dry lignocellulosic biomass per year"(2016).
Total lignocellulosic biomass potential (in ,000 dry tonnes per year; Source: s2biom D8.2 Vision for 1 billion tonnes biomass 2030)
Current feedstock production
Elbersen et al. (2012) estimate that there are approximately 5.5 million hectares of agricultural land on which bioenergy cropping takes place. This amounts to 3.2 % of the total cropping area (and around 1 % of the utilised agricultural area) in the EU-27. Practically all of this land is used for biofuel cropping, mostly oil crops (82 % of the land used for biomass production), which are processed into biodiesel. The rest is used for the production of ethanol crops (11 %), biogas (7 %), and perennials which go mostly into electricity and heat generation (1 %).
There are plenty of studies on biomass potentials. In the IEA Bioenergy ExCo Report of 2009 an enormous variation in the results of worldwide biomass potential assessment according to different studies is stated. In the same report a technical biomass potential of 1500 EJ/year is mentioned; speaking about a sustainable biomass potential the authors claim 200 – 500 EJ/year by 2050. In the so called “sustainability scenario” of Elbersen et al. (2012) the potential for 2030 is 353 Mtoe compared to the current 314 Mtoe, with the overall waste potential declining. Only a rise for agricultural residues and for secondary and tertiary forestry residues (e.g. saw dust, black liquor) is to be expected. On the other hand the authors of "Waste – Europe’s untapped resource" state that if all waste and residues were converted only to biofuels in the EU, 16% of road transport fuel could be provided in 2030 (technical potential of sustainably available feedstock from waste).
Other recent assessments of biomass potential include Global Bioenergy Supply and Demand Projections: A working paper for REMap 2030 published by IRENA in September, 2014.
An EEA report published in 2013 EU bioenergy potential from a resource efficiency perspective provides an overview on the use of biomass feedstocks in Europe, and discusses some of the issues surrounding expansion of energy crop production.
Globally, projects - such as the Landscape Biomass Project Iowa State University - look at how to balance needs for food, feed, fuel and energy, by integrating advanced biofuels technologies and novel energy crops.
The links at the end of this page provide more detailed information on the various types of sustainable feedstocks for production of advanced biofuels.
Plant breeding and biomass yield
The amount of biomass required to replace a significant proportion of the fossil fuel used in transport runs into millions of tonnes. Hence, a crucial question is that of biomass yield. Higher yields obviously enable a similar amount of biofuel to be replaced using less land. However, land use efficiency may also be improved by selecting an overall production chain that can use a high yielding biomass crop.
Competition for biomass
Competition for biomass is a key issue in the debate on bioenergy. Biomass is used as food, materials (e.g. bioplastics, wood, textiles etc.) and for energetic use – all these applications require (biomass) resources. Factors influencing competition are raw material prices, prices of end products, policy, availability of land for feedstock or technological constraints. This brings along the following challenges for bioenergy deployment:
- Competition between sectors of the Bioeconomy could deter investors (too many options and none with an established market)
- Competition between sectors of the Bioeconomy could trigger a “supply bubble” (rising feedstock prices at stable or decreasing demand)
- Feedstock producers need to be reassured that additional costs deriving from mobilizing agricultural/forestry residues will generate stabile income and long-term benefits
- Lack of coherent national Bioeconomy development plans does not allow allocating resources according to needs, while the biomass markets are still rather volatile
- Resources for research and development funding are also affected by competition
An accurate planning, coordination, implementation and control of biomass disposability is essential for successful bioenergy production. The overall economic, environmental and energy cost of collection, handling, processing and transport needs to be assessed. Other factors include :
- The specific properties of biomass: low energy density, which often requires drying and densification; seasonal availability causing long storage and therefore high costs and problematic storage requiring further pre-treatment (e.g. pelletizing, torrefication) to lower transportation costs.
- Limited supply because of a lack of available and appropriately mechanized equipment and limited access to conversion structure and markets.
- At local level, planning issues, traffic movements and industrial development policies need to be taken into account. Generally, it is a benefit to develop a biofuel plant close to the point of feedstock production. However this has to be balanced against economies of scale of the biofuel production facility.
A Life Cycle Analysis for any proposed use of biomass needs to be applied taking into account the total cost and energy balance from the source of the feedstock to its end use.The Sustainability section of this website discusses land availability, food vs fuel, iLUC and related topics in more detail.
Fuel quality directive and renewable energy directive (P8_TA-PROV(2015)0100 Fuel quality directive and renewable energy directive II; European Parliament legislative resolution of 28 April 2015 on the Council position at first reading with a view to the adoption of a directive of the European Parliament and of the Council amending Directive 98/70/EC relating to the quality of petrol and diesel fuels and amending Directive 2009/28/EC on the promotion of the use of energy from renewable sources (10710/2/2014 – C8-0004/2015 – 2012/0288(COD))).
Setting up international biobased commodity trade chains
Netherlands Enterprise Agency (2014)
Sustainable Biomass Production and Use - Lessons Learned from the Netherlands Programe on Sustainable Biomass (NPSB) 2009-2013
Netherlands Enterprise Agency (2014)
Space for Energy Crops - Assessing the potential contribution to Europe's energy future
Produced by IEEP for European Environmental Bureau, Birdlife International and Transport & Environment (2014)
Prospects for Agricultural Markets and Income in the EU 2013-2023
EC Agriculture and Rural Development (2014)
Status of Advanced Biofuels Demonstration Facilities in 2012. IEA Report Task 39.
Bacovsky et al. (2013)
Mobilising Cereal Straw in the EU to Feed Advanced Biofuel Production
Institute for European Environmental Policy IEEP (Report produced for Novozymes, 2012)
Smart Use of Residues - Exploring the factors affecting the sustainable extraction rate of agricultural residues for advanced biofuels
WWF-World Wide Fund For Nature (with support from Novozymes and EU, 2012)
Atlas of EU biomass potentials Deliverable 3.3: Spatially detailed and quantified overview of EU biomass potential taking into account the main criteria determining biomass availability from different sources
Elbersen et al. (2012)
Sustainable Production of Second-generation Biofuels. IEA Information Paper
Eisentraut, A. (2010)
Bioenergy – a Sustainable and Reliable Energy Source – Main Report
IEA Bioenergy: ExCo: 2009:06
Toward a classification approach for biorefinery systems. Biofuels Bioproducts & Biorefining
Cherubini et al. (2009)