Publications

The full fact sheet is currently only available in Swedish. Below is a translated excerpt.

In the spring of 2023, two new EU regulations, FuelEU Maritime and ReFuelEU Aviation, were adopted, aiming to steer the maritime and aviation sectors towards the EU’s climate targets for 2030 and 2050. These regulations are an important part of the EU’s transition plan “Fit for 55” and aim to reduce the climate impact of shipping and aviation.

The regulations (European Parliament and Council 2023a, European Parliament and Council 2023b) aim to increase the demand for and use of renewable and low-carbon fuels in maritime and aviation, while ensuring that these sectors operate efficiently without distortions in the internal market. Fuel producers should be confident in a future high demand for large-scale production of sustainable fuels for shipping and aviation. The new rules for maritime transport will apply from January 1, 2025, with the exception of two articles [1] that take effect on August 31, 2024. For aviation, the new rules came into force on January 1, 2024, with the exception of five articles [2] that will be applied starting January 1, 2025.

Read or download the fact sheet in its entirety as a PDF (in Swedish).

[1] on the establishment and amendments of monitoring plans for ships.

[2] on the shares of sustainable aviation fuel available at certain airports within the EU, refueling requirements, the obligation to facilitate access to sustainable aviation fuels, as well as reporting obligations for aircraft operators and aviation fuel suppliers.

The full text is available in Swedish.

All renewable fuels, in large quantities, are needed to achieve a fossil-independent vehicle fleet. However, to fully benefit from a fossil-independent vehicle fleet, it is not enough for usage to increase – domestic production must also keep up. Beyond reducing climate impact, renewable fuels bring with them a range of positive societal effects that could help meet Sweden’s environmental goals and strengthen the social and economic sustainability of regions. Examples of these include improved air quality, reduced noise, increased employment, enhanced energy security, and strengthened competitiveness on a national level. This particularly applies to biofuels. However, the current focus on climate impact has resulted in the majority of the biofuels used in Sweden, or the raw materials used for biofuel production, being imported. This leads us to miss out on the positive societal effects.

In efforts to reduce greenhouse gas emissions and transition to a fossil-free transport sector, the demand for renewable fuels in the world is likely to increase significantly in the coming years. From a global perspective, Sweden is rich in natural resources suitable for biofuel production. We also have favorable conditions for renewable electricity production and a growing industry for battery manufacturing. Therefore, increased domestic production of biofuels, renewable electricity, and electric vehicle batteries is desirable. Reasons for this include better opportunities for traceability and control over environmental impact, and reduced dependence on imported raw materials and fuels, hereby strengthening Swedens crisis preparedness. Given our abundance of biobased natural resources, Sweden should therefore be a net exporter of biofuels and/or the raw materials from which biofuels are produced, but currently we are far from being that. Close to 90 percent of biofuel consumption in Sweden consists of biofuels that are imported or biofuels produced from imported raw materials. [1] At the same time, it should be emphasized that some of the biofuels produced in Sweden today are exported.

Production and use of renewable fuels enhance competitiveness

Using national resources such as raw materials, established industry and expertise to produce, utilise and scale up renewable fuels contribute to national growth in the form of development and employment [2]. The production and use of renewable fuels also have a connection to enhanced competitiveness, knowledge, and innovation – through links to innovative environments, research, and innovation – and thus have an impact on employment.

Domestic production of renewable fuels contributes to the expansion of existing socio-technical systems, the creation of new systems [3, 4], and as a consequence, stimulates employment and economic activity along the entire value chain from raw material to usage. For biofuels, there is a particularly strong connection to local resources. However, the positive socio-economic effects decrease if a significant portion of the raw materials for biofuel production is imported.

Table 1 presents a compilation of the effects on employment and stimulation of regional growth for different value chains of biofuel production [5]. The compilation is based on a literature review of a significant number of national and international studies focusing on Sweden and Europe. As can be seen in Table 1, the results of the compilation point to an indicative figure of generated full-time positions (Full Time Equivalents, FTE) per TWh of produced biofuel, which seems to vary somewhat between the reviewed biofuels. For biogas, Energigas Sverige has estimated the total employment effect to be approximately 1 job per GWh [6]. A regional study for biogas also shows estimates that align with the results in Table 1 [7].

Tabell 1. Indicative results regarding employment and regional net productions for fuel production. The table is a synthesis conducted by Mossberg et al. (2019) [5] based on several different studies [3, 4].

Based on Table 1, the stimulation of regional growth from domestic production of biofuels can be estimated at an indicative figure of approximately 1 million SEK per GWh of fuel. Although there is a wide range of data in Table 1, it can be concluded that biofuel production in Sweden is likely to yield socio-economic benefits and is likely to increase further if the raw materials are of Swedish origin.

For employment related to renewable electricity production, the picture is more complex. Currently, there are many different production technologies where some are associated with relatively high employment and others significantly lower (such as hydropower, for example). However, it can generally be stated that renewable energy technologies have the potential to create higher employment than fossil alternatives, including electricity production. Studies show that the effects are greater for bio-based value chains than other value chains for electricity production such as solar and wind power [8]. Worth noting is that in a situation of low unemployment, this job creation does not provide any particular socio-economic added value (aside from any regional policy aspects). In a situation of labor shortage, the effects can even be negative for the overall economy [9]. The national strategy for sustainable regional growth and attractiveness also highlights innovation and entrepreneurship, skills supply, and international cooperation as priority areas for regional development and employment [10].”

The use of locally available raw materials increases innovation capacity

In terms of strengthening regional/national innovation capacity, renewable fuels linked to regionally/nationally available raw materials, such as local biomass, should have an advantage. In the long term, fuel value chains that connect to existing industry and innovation areas can be advantageous as they provide the opportunity to scale up already established structures. However,  established industries are often passive when it comes to renewal and investing in radically new value chains, making the regional context and collaboration in the actor network especially important [11, 12]. The ability to innovate is also influenced by the number of industries and the concentration of workplaces. Metropolitan regions and larger regions generally have both higher industry diversification and lower workplace concentration [1].

Internationalization of companies is also important for renewal, which can be expressed as the proportion of employees in international/multinational companies [1]. Another important aspect of societal development is providing conditions for a vibrant rural economy, with opportunities for entrepreneurship, employment, housing, and welfare. Here, the opportunity for jobs in rural areas related to some part of the value chain for renewable fuels is a clear synergy. Such a connection often relates to the use of local raw materials and is therefore particularly prominent for bio-based value chains. For example, small-scale upgrading close to the the location of the raw material can have a positive effect on the number of jobs in rural areas. Furthermore, the utilization of by-products that were previously unused provides conditions for increased profitability throughout the value chain. The production of renewable fuels also increases diversity and provides more potential income sources for local businesses, strengthening their redundancy  [3]. Production of biofuels, especially through the utilization of by- and waste products from agriculture and forestry, thus strengthens the possibility for a competitive forestry and agricultural sector nationwide. Increased biofuel production on agricultural land in rural areas also has the advantage that production ensures that the land is cultivated and creates more jobs, compared to leaving land fallow. Previous studies have shown that domestic agricultural-based raw materials can contribute to between 4 and 10 TWh of biofuels per year without negative side effects regarding indirectly changed land use [13].

Continue reading the full report (in Swedish) in the PDF version. It includes a literature review that summarizes what is found in a selection of studies regarding the socio-economic benefits of renewable fuel production.

The full compilation is currently only available in Swedish. Below is a translated excerpt.

The biofuel-producing industry often points out that their decisions and willingness to invest are heavily influenced by uncertain policy measures, legislation, guidelines, etc. In recent years, a number of studies have investigated theese issues. The studies point out that clear and long-term political conditions for transition are of importance, and that uncertainty in these aspects affects both industry, financiers and other market participants.

In order to achieve the goals for the transport sector, access to sustainable renewable fuels needs to increase, and the production conditions in Sweden are good. Both current producers and new stakeholders in the fuel industry have plans to greatly expand the production of renewable fuels over the next ten years. [1]  However, without policy measures pushing for development, there is a significant risk that the plans will not be realized. The government’s assignment to the so-called bioeconomy investigation (Bioekonomiutredningen) therefore included analyzing measures that promote efficient production of liquid biofuels based on domestic raw materials in Sweden, including proposals for long-term production support.

Within the industry, however, it is also often highlighted that a high degree of uncertainty and frequent changes in the scope and design of the policy measures hinder development. Sweden and the EU have had been measures promoting the development of renewable fuels since the beginning of the 2000s, and in 2008 the first fuel directive was introduced with targets for use and with clear sustainability criteria. However, the design of policy instruments has changed over time and they are often decided for short periods of time. As an example, the reduction obligation was introduced in 2018, as a long-term policy instrument designed to apply until 2030. It is now being changed drastically after only five years. Uncertainty increases the risk with investments and can affect development, both directly through reduced willingness to invest on the part of companies, and indirectly through uncertainty among consumers on the vehicle market and worse conditions on the capital market. The example above also shows that it is not enough to design a policy instrument that is long-term, but that there also needs to be broad political agreement around it.

To what extent and how does political uncertainty and instability in policy measures affect willingness to invest and the development of renewable fuels? As a first step in clarifying the state of knowledge regarding this, f3 has summarized how it is raised in a few examples from the literature. Here are some conclusions:

• In the litterature, it is unanimously emphasized that political uncertainty, short-term policy measures, and frequent changes to policy measures contribute to making investments in industry, and, thus the development of renewable fuels, more difficult.
• Uncertain policy measures aimed directly at promotion of renewable fuels is not only what effects investments and decision-making. There is also an effect from uncertainty about permit processes, policy measures designed for other sectors that affect the demand for biofuels and bio rawmaterials, and from targets and ambitions for climate policy in large, both in Sweden and internationally.
• To a large extent, the studied litterature bases its conclusions on interviews, surveys and workshops with industry representatives and other stakeholders. In these, political uncertainty is consistently highlighted as a central barrier to the industry’s transition. The conclusion is also established in general policy research around barriers and driving forces.
• Few have studied the issue from an empirical perspective, specifically for renewable fuels. From a comparative study of developments in the US and within the EU, however, there are indications that higher uncertainty also has an impact on actual investments over time.

Several of the studies also highlight examples of knowledge gaps in the field, and it is clear that the issue can be approached from several different perspectives and with different research methods.

In the overview made by f3, a summary of the outcome of a selection of current and central investigations and research studies concerning the importance of political uncertainty for the development of renewable fuel production is presented. The overview takes its point of departure from the so-called bioeconomy investigation (Bioekonomiutredningen), whose first interim report was published in spring 2023.

Read or download the overview in its entirety as a PDF (in Swedish).

The full compilation is currently only available in Swedish.

In Sweden, renewable fuels are produced that are used for low blend in fossil fuel and diesel as well as high blend or pure biofuels. Here, the status of existing and planned facilities for the production of different types of renewable fuels within the country’s borders is compiled.

The compilation includes both biofuels and electrofuels. It is based on future production capacity as announced in July 2023, in terms of concrete facilities. Capacity as part of more overall targets is not included. The production is presented based on the maximum capacity of each plant and not based on historical or expected actual production. Finally, the compilation is based on the production of fuel that could be used for the transport sector (with current fuel markets) – the actual use of the fuel is not specified, neither with respect to which sector, nor whether it is within Sweden or abroad.

Currently, the total maximum production capacity is about 10 TWh, which corresponds to roughly half of the biofuel use in Sweden’s domestic transport. [1] However, actual production is normally lower. This is explained by difficulties to maintain optimal economic and technical operating conditions for all plants. If all planned facilities were to be realized, this corresponds to a fivefold increase in the existing production capacity until about 2030 (see Table 1 in PDF). To avoid double-counting, intermediate products are not included, as these are used as raw materials for the production of one of the final fuels.

Based on the compilation of total production, the following more comprehensive reflections can be made:

• The planned increase in production of liquid fuel from biomass is very large. Most of it can be linked to former oil refineries, but there are also plans for new biorefineries with different techniques for liquefaction. In these, the share of other biofuels than diesel, e.g. jet fuel and biogasoline, is generally expected to increase.
• There are significant plans for the production of electrofuels, so far mainly aimed at the production of methanol for ships and aviation fuels.
• For the production of gaseous fuels, current plans involve a strong shift from CBG to LBG.
• Only a small part of planned facilities (e.g. SkyFuelH2 and SCA Östrand) can be linked to the use of gasification technology, and planned facilities for the production of gaseous fuels through gasification are completely absent.

The more detailed compilation is divided into two chapters: liquid and gaseous fuels. Plant data is based on Bioenergitidningen’s compilation Biodrivmedel i Norden 2022 [2] (Biofuels in the Nordics 2022), but has been supplemented and updated based on publicly available data. The information relating to industry stakeholders that are member so of f3 has been confirmed directly with those companies.

The full compilation is available the PDF.

The factsheet is currently only available in Swedish.

Vätgas, H₂, är en flexibel energibärare med många möjliga tillämpningar och en av dem är som drivmedel i fordon. Vätgas kan tillverkas av vatten, fossila bränslen eller biomassa. Vid dess användning, till exempel i en bränslecell eller genom förbränning, bildas inte koldioxid utan istället vatten. Användning av vätgas som drivmedel kan därmed bidra till att reducera växthusgasutsläpp och utsläpp av partiklar från transporter. Likt användningen av el i batterifordon beror vätgasens klimatpåverkan till stor del på hur den tillverkas.

Användning

Vätgas, H₂, används idag främst framställning av ammoniak samt för oljeraffinering. Framöver väntas en rad nya tillämpningar av vätgas. De tydligaste exemplen med potentiellt stora volymer är som industriråvara, till exempel för stålproduktion, som energilager, som drivmedel och som råvara för framställning av andra drivmedel. Vätgas är exempelvis en central komponent vid tillverkning av HVO (eng. hydrogenated vegetable oil) och elektrobränslen.

Det finns idag två modeller av vätgasbilar på den svenska marknaden, Hyundai Ix35 och Toyota Mirai. Dessa bilar använder sig av bränsleceller för att konvertera den kemiska energin i vätgasen till elektricitet för att sedan driva en elmotor av samma sort som finns i elbilar. Sådana bränsleceller kan nå nära den dubbla verkningsgraden som vissa förbränningsmotorer.

Bränslecellstekniken är speciellt attraktiv som ett alternativ till rena batterifordon för tillämpningar som kräver längre räckvidd och tung last, eller där den relativt korta tanktiden är en betydande fördel. Bränsleceller i lastbilar och bussar kan därför vara de marknader som växer fram först. I synnerhet har tunga lastbilar med bränsleceller väckt stort intresse. Toyota, Hyundai och Daimler tillsammans med Volvo Lastvagnar hör till aktörer som satsar på området. I Göteborg rullar vätgasdrivna sopbilar från Scania.

I Sverige finns i dagsläget fem vätgastankstationer: Arlanda, Göteborg, Sandviken, Umeå och Mariestad. Fram till 2023 har danska Everfuel planer för ytterligare femton stationer varav tio tillsammans med OKQ8. Även andra aktörer har planer i olika skeenden, till exempel REH₂, Orange Gas och Hynion.

Vätgas kan bli ett alternativ inom flyget och sjöfarten eftersom drivmedlets energidensitet är av yttersta vikt i flygplan och fartyg (då i flytande form eller kemiskt bunden, se nedan). Här har till exempel Airbus presenterat tre koncept för vätgasflygplan under samlingsnamnet ZEROe.

Produktion

Enligt IEA, International Energy Agency, tillverkades ungefär 117 miljoner ton vätgas under 2018. 98 procent av denna vätgas producerades från fossila energikällor, främst från naturgas (s.k. grå vätgas) i Europa och USA och främst från kol (s.k. svart eller brun vätgas) i Kina.

Tillverkningen resulterar i stora direkta utsläpp av koldioxid (CO₂) per producerad mängd vätgas; runt 10 kg CO₂/kg H₂ med naturgas och 19 kg CO₂/kg H₂ med kol. Dessa utsläpp är i huvudsak koncentrerade till stora anläggningar, vilket skulle kunna underlätta avskiljning och geologisk lagring av koldioxiden, CCS (carbon capture and storage). På grund av otillräckliga ekonomiska incitament tillämpas dock inte CCS i någon större utsträckning idag. Vätgas tillverkad från fossila källor med CCS kallas ibland blå vätgas.

Vätgas kan tillverkas via en process som kallas elektrolys, där vatten spjälkas till vätgas med hjälp av elektricitet. Biprodukter från elektrolys av vatten är syrgas (O₂) samt värme. Om elektriciteten som tillförs processen har genererats från fossilfria energikällor kan vätgas produceras med mycket låga utsläpp av växthusgaser. Detta kallas grön vätgas. Om elektriciteten däremot produceras via förbränning av fossila bränslen är vattenelektrolys oattraktivt från ett växthusgasperspektiv på grund av de stora omvandlingsförlusterna. Som jämförelse blir växthusgasutsläppen lägre om vätgasen i så fall produceras direkt från fossila bränslen, utan att de fossila bränslena först förbränts för att producera elektricitet.
Idag finns det finns flera etablerade vattenelektrolystekniker, och alternativa tekniker befinner sig i olika utvecklingsstadier. Den globala installerade kapaciteten är endast runt 100–200 MW (baserat på ingående eleffekt), men stora tillskott väntas inom de kommande åren. I EU:s vätgasstrategi finns ett mål på 40 GW installerad vattenelektrolyseffekt till 2030.

Vätgas kan också tillverkas från biomassa, även om det generellt inte tillämpas industriellt idag. De två mest lovande produktionsvägarna är förgasning av lignocellulosa eller massaindustrins svartlut samt reformering av biometan. Den senare teknologin är mycket lik produktionen av vätgas från naturgas.

Lagring

Vätgas är den lättaste av alla molekyler: vid rumstemperatur och atmosfäriskt tryck upptar ett kg vätgas cirka 11 m³. För att praktiskt kunna använda vätgas som drivmedel måste dess energidensitet ökas så att den kan lagras i ett fordon. Det kan ske genom kompression eller förvätskning, där den senare tekniken leder till en högre energidensitet. Båda teknikerna är energikrävande, särskilt förvätskningsprocessen som kräver omkring 30 procent av vätgasens energiinnehåll.[1] I dagens vätgasfordon lagras vätgasen som komprimerad gas vid ett mycket högt tryck: 350 bar i lastbilar och 700 bar i personbilar.

Tekniker för att kemiskt omvandla vätgasen till olika mer hanterbara substanser för lagring undersöks också. Att lagra vätgas i ammoniak, metanol, metan eller så kallade flytande organiska vätgasbärare (eng. liquid organic hydrogen carriers, LOHCs), kan komma att bli relevant i vissa tillämpningar i framtiden, till exempel som drivmedel inom sjöfarten eller flyget.

Potential och hinder

Vätgas är attraktivt för användning inom många olika tillämpningar, varav drivmedel är en. För tillfället utvecklas användning av vätgas främst inom industrisektorn. Potentialen för ett mer samhällsövergripande genombrott avgörs både av tillgången på vätgas, möjligheterna till lagring och transport av vätgas, samt den politiska inriktningen.

Användningen av vätgas i bränslecellsfordon begränsas idag av höga kostnader för bränslecellen och vätgastanken såväl som för själva vätgasen. Utbyggnaden av infrastruktur för vätgastankning är också en kritisk faktor samt den närliggande konkurrenssituationen med batterifordon, i synnerhet för lättare fordon. Komplicerade och oförutsägbara tillståndsprocesser ses också som ett betydande hinder för vätgasen. Det finns även ett behov av att informera och utbilda om säkerhetsaspekter, framför allt utanför industrin.

[1] I förvätskningsanläggningar med dagens bästa tillgängliga teknik går det åt ungefär 10 kWh el/kg vätgas som förvätskas (lägre värmevärde H₂=33 kWh/kg H₂ -> 10/33=0.3).

Electric Road Systems (ERS) allow vehicles to charge whilst driving, with electricity provided from the road infrastructure either in the roadside area or within the road construction. There are three major concepts of ERS: conductive overhead lines/catenary technology, conductive rails, and wireless induction technologies. Currently, several ERS technologies are in different stages of demonstration, in Sweden as well as abroad.

The ERS concept builds upon five subsystems: electricity supply (including transmission and distribution), the road itself, a power transfer system, a road operation system, and the vehicles. The systems include control components for these corresponding services. For instance, the power transfer system consists of equipment that detects the vehicle, transfers power from the road, and controls safe activation and operation of a power receiver in the vehicle. The electric road operation subsystem controls the energy management of the overall system and identifies vehicles to handle access and lane control. The vehicle subsystem converts the power from the power transfer subsystem into either propulsion of the vehicle or to energy storage.

Applications of ERS technologies are tested at several locations around the world, from test sites in Italy, France, Israel and Japan, through inductive charging of city buses in South Korea, to fully operating demonstrations on regional roads and highways in Sweden and Germany. To this date, no long-term tests have been performed but the ERS concept development is progressing, with some examples given for the three major concepts below.

ERS technology concepts

• Conductive overhead lines/catenary technology

This concept builds on the same idea as the railway, with roadside support masts to hold contact cables about 5 meters above the road. Trucks or buses with pantographs mounted on the roof will be able to connect to the overhead lines and charge conductively while driving. The difference from trolley buses is that vehicles can connect to the lines while in motion and likewise disconnect if for instance having to change lanes. Passenger vehicles will not be able to use such a system. Conductive overhead lines have no direct impact on the road construction, but the need for extra infrastructure, such as the support masts, visually impacts the landscape.

The first electric road opened on a road with regular traffic was built for the catenary ERS concept. It was successfully implemented during 2016-2020 along 2 km of the E16 road close to Sandviken, Sweden, and demonstrated the use of power lines above the road to electrify heavy-duty vehicles. In Germany, conductive overhead lines placed above a 10 km stretch of the autobahn A5 between Darmstadt and Frankfurt were implemented in 2019 as part of a three-stage project called ELISA. Currently, the project is in phase two, testing the eHighway system regarding vehicles and infrastructure.

• Conductive rails

Conductive rails can be installed in the road surface, bolted upon the surface, or installed at the side of the road. An electric current collector or pick-up mounted under the vehicle will either attach itself to the rail construction or slide along the contact material, conductively transferring energy to the vehicle. This technology can be used for heavy-duty trucks, distribution trucks as well as passenger vehicles. Compared to the catenary concept, conductive rails will not visually impact the landscape.

Two demonstration projects on regular roads in Sweden are using the conductive rail concepts; eRoadArlanda and EVolutionRoad. In the first, 2 km of conductive rail were installed in the road surface between a logistics terminal and the Arlanda airport freight terminal. In the second, an electric road with a ground-level feeding system is being tested for a city bus in Lund. The concept can be used both for trucks, buses and passenger vehicles. There re also other technology concepts being tested in Sweden and abroad, e.g. by Alstom and Honda.

• Wireless induction

For this technology concept, copper coils are installed underneath a surface layer of asphalt. An electric current is magnetically induced between the copper coils in the road and a receiver in the vehicle. Wireless induction is totally embedded within the road construction, with the visible impact being electrical distribution boxes/boards that are regularly placed along the roadside. Because of the embedded copper coils, regular road maintenance and operations such as snow ploughing, or preventive anti-icing will not be affected by or harm the technology itself.

Wireless induction is currently tested in Visby, Sweden, where the installation of a 1.6 km long electric road was finished in December of 2020 for the purposes of a demonstration project called SmartRoad Gotland. This electric road can be used both by trucks and cars.

ERS adaptation

The impact on the road infrastructure and roadside areas from the implementation of ERS varies between concepts. The catenary concept is not expected to affect the road surface, whereas the rail and inductive technologies will affect the road structure during the installation procedure and the roads service life, for example when the road needs resurfacing. However, the catenary concept may influence maintenance operations by complicating verge maintenance and snow ploughing activities. The embedded inductive technology will probably not affect winter operations. It is crucial to recognize that implementation of ERS may affect not only road users, but also road maintenance operators, emergency personnel, energy grid suppliers, road authorities and vehicle manufacturers.

ERS potential

ERS technology is not intended to be installed on all roads or along the whole road stretch, but rather work as a range extender between charging points. Vehicles using the ERS therefore need to be able to drive outside the electrified road network. This can be achieved either by using a rechargeable battery or a hybrid solution where the vehicle uses some other kind of fuel or energy carrier. The combination of battery and vehicle size along with availability of additional charging possibilities determines the driving range outside the ERS.

Focus for ERS has so far been on the heavy goods transport sector, but in-ground installed ERS could be an alternative suitable for passenger cars as well. It could also potentially offer stationary charging of distribution trucks while loading or unloading goods at depot.

When it comes to costs of the ERS, the installation costs vary between concepts and assessments remain uncertain until a large-scale implementation has been performed. Estimates range between 1.7 and 3.1 Million EUR/km, including costs for installation, infrastructure, connection with the electricity grid, etc. The high costs for the system could become a potential barrier towards a large-scale implementation of ERS.

Another difficulty associated with ERS technologies concerns standardization. There are many interfaces of the system where standards are needed but not always applied. The interface between vehicles and infrastructure is one and the payment system another. Some standards have already been agreed upon at a European level while decisions on others remain.

Electrofuels is a way to produce renewable energy carriers from renewable electricity that can be used in segments of the transport sector where direct electrification is more challenging to implement. Some electrofuels can be used directly in vehicles, ships and airplanes today, without further demands on distribution and tank infrastructure. The biggest challenges connected to electrofuels are associated with low energy efficiency and high costs for production.

This fact sheet is currently only available in Swedish.

Recent articles and statements in the media [1, 2] raise concerns over the climate effects of using forest biomass for bioenergy. As some statements seem to reflect misconceptions about forest bioenergy, IEA Bioenergy here provides a brief overview of key facts about the use of forest biomass for climate change mitigation. [3]

This fact sheet reproduces a text developed by Göran Berndes, Annette Cowie, Luc Pelkmans and members of IEA Bioenergy Task 45, the IEA Bioenergy Technology Collaboration Programme (TCP). f3 publishes the text as a whole with permission from IEA Bioenergy.

The IEA Bioenergy TCP is organised under the auspices of the International Energy Agency (IEA) but is functionally and legally autonomous. Views, findings and publications of the IEA Bioenergy TCP do not necessarily represent the views or policies of the IEA Secretariat or its individual member countries.

In summary

Energy from woody biomass can contribute to climate change mitigation, as a renewable fuel. It should be used efficiently, and when harvested from forests, it must come from sustainably managed forests, where carbon stocks are maintained or enhanced on a regional or national basis. Forest bioenergy can support rapid transformation of the energy sector. Furthermore, bioenergy linked with carbon capture and storage (BECCS) is one of the options that can deliver negative emissions, likely to be required to meet the temperature targets of the Paris Agreement. Forest management that maintains or increases carbon stocks, while also producing timber, fibre and energy, contributes to climate change mitigation by storing carbon on land and replacing carbon-intensive materials and fossil fuels.

1. Forest bioenergy is not by definition carbon neutral; emissions in the supply chain and impacts on forest carbon stock must be included.

Bioenergy is sometimes said to be “carbon neutral” in the sense that the carbon that is released during combustion (biogenic carbon emissions) has previously been sequestered from the atmosphere and will be sequestered again as the plants regrow.

But “carbon neutrality” is an unhelpful term because it is ambiguous and used differently in different contexts. As is further elaborated below, biogenic carbon needs to be considered in assessments in order to fully reflect how bioenergy will affect atmospheric GHG concentrations. If extraction of biomass for energy leads to a decline in the forest carbon stock or carbon sink strength, this needs to be accounted for. Furthermore, assessments need to consider all emissions associated with the production, processing, transport and use of bioenergy. Finally, the bioenergy scenario should be compared with a counterfactual scenario, in which energy is provided by another source, to quantify the net effect on GHG emissions.

2. Forest biomass is not treated as carbon neutral in national greenhouse gas inventories.

The treatment of bioenergy in greenhouse gas inventories has been criticized for containing a loophole because bioenergy is “counted as carbon neutral”. This is incorrect. Under the agreed approach for preparation of national greenhouse gas inventories, countries report harvest of forests for any purpose, including bioenergy, as a CO2 emission in the land use sector. [4] CO2 emissions from combustion of biomass for energy are not counted in the energy sector to avoid double counting with the land use sector. Thus, there is no accounting error that requires correction, or emission that is overlooked in reporting, and bioenergy is not assumed to be carbon neutral: if bioenergy leads to a reduction (or slower growth) in forest carbon stock this is reflected in national inventories. [5] Fuel use in the supply chain is counted in the energy sector of the country where the fuel is consumed, as for all other traded materials including energy carriers.

Where biomass for bioenergy is traded, the importing country reports no emissions, while the exporting country reports the emissions in the land sector. This convention could be criticised as supporting “outsourcing” of emissions by the importing country. This issue applies also to off-shore manufacturing. For instance, a large share of emissions associated with production of goods consumed in Europe is reported by China, where manufacturing occurs. [6] The case of biomass imports for bioenergy is an example where policymakers have recognized and taken action to address this challenge. [7] The EU RED II requires that forest biomass is sourced only from locations where legislation at national/subnational level, or management systems at the forest sourcing area, ensure that forests are regenerated and that carbon stocks and sink levels in the forest are maintained or strengthened over the long term. [8] Specifically concerning EU pellet importation from the United States, data show that forest carbon stocks in the south-eastern United States (SE US) where biomass is sourced, are steadily increasing, [9 ] and biomass harvests for wood pellets represent only a small fraction of harvest removals from forests in the SE US. [10]

3. Climate effects of using woody biomass cannot be determined at stand level; assessments need to be made at the landscape (estate) level.

A forest estate is generally managed as a series of stands of different ages, harvested at different times, to produce a constant supply of wood products. When considered at stand level, much of the carbon that has been sequestered into the stand as the trees grow is abruptly lost from the stand at the time of harvest, and is not fully sequestered again until the stand has reached harvest age. Stand-level assessments that start the accounting when the stand is harvested will, therefore, show upfront emissions and a delay before forest bioenergy contributes to net reductions in atmospheric CO2, particularly in long-rotation forests.

However, across the whole forest estate (landscape), i.e., at the scale that forests are managed, carbon losses in harvested stands are balanced by carbon gains (growth) in other stands, so the carbon stock of production forests is roughly stable. The magnitude of the carbon stocks in forest landscapes depends on biophysical factors such as soil and climate conditions, historic and current management regimes, and events such as storms, fires and insect outbreaks. To quantify the climate effects of harvesting woody biomass for energy and other products, the effect of this harvesting on the development of carbon stocks at the landscape level needs to be determined.

Landscape-scale assessment can provide a more complete representation of the dynamics of forest systems, as it integrates the effects of all changes in forest management and harvesting that take place in response to – experienced or anticipated – bioenergy demand. The landscape approach therefore helps to identify how total forest carbon stocks are affected by specific changes in forest management. For instance, if a new management regime with more residues and/or trees extracted, or a shorter rotation length, leads to a long-term decline in the carbon stock and carbon sink capacity of the forest estate, this would reduce the climate benefit. On the other hand, an increase in demand for bioenergy and other forest products could also incentivise changes in forest management (e.g., improved site preparation, use of nurse trees, advanced genetics, measures to reduce risks for forest fires or pests/diseases) that enhance forest sink strength and carbon stocks.

4. Forest biomass is a renewable energy source if forest productivity is maintained.

Forest biomass is renewable if it is harvested from forests that are managed such that there is no loss of productive capacity – i.e., so that growth rate and therefore capacity to sequester carbon are maintained over successive rotations. Sustainable forest management is key to maintaining healthy and productive forests. Biomass derived from deforestation should not be recognized as renewable.

5. The climate change effect of using biomass for energy cannot be determined by comparing GHG emissions at the point of combustion.

It is sometimes stated that CO2 stack emissions per MWh inevitably increase when biomass replaces coal. However, at the point of combustion, wood and coal have similar CO2 emission factors, as the ratio of heating values between the two fuels is similar to the ratio of carbon content. Furthermore, biomass fuel characteristics (moisture content, grindability, heating value) affect the energy efficiency of co-firing systems. In large coal power plants, there can be a derating of a few percent, as there is more flue gas generated per GJ of fuel, which leaves the stack at a temperature above the ambient temperature resulting in so-called stack losses. However, when the co-firing ratio is low (<10%) there is usually no significant efficiency penalty. Fuel type (both coal and biomass) also matters. For low rank coal, biomass co-firing (especially torrefied biomass) can increase the boiler efficiency and net power plant efficiency. The outcome also depends on modifications made when power plants are adapted to using biomass (e.g., investments in steam turbine upgrades and internal waste heat utilization to dry biomass fuel).

More importantly, comparing emissions at the point of combustion does not show the effect on atmospheric GHG concentrations of switching from fossil fuels to biomass. There is a fundamental difference between fossil fuels and biomass: burning fossil fuels releases carbon that has been locked up in the ground for millions of years, while burning biomass emits carbon that is part of the biogenic carbon cycle. In other words, fossil fuel use increases the total amount of carbon in the biosphere-atmosphere system, while bioenergy systems operate within this system; if the forest carbon stock is constant there is no net transfer of carbon to the atmosphere.

Instead of comparing GHG emissions at the point of combustion, the biogenic carbon flows and fossil GHG emissions associated with the complete life cycle of the bioenergy system need to be compared with the GHG emissions in a realistic reference situation (counterfactual scenario) where energy sources other than bioenergy are used. Also, indirect impacts (positive or negative) on land use, wood products and fossil fuel use need to be considered.

6. Long-distance transport does not negate the climate benefits of woody biomass as a renewable energy source.

Fossil energy used in the biomass supply chain is generally small compared to the energy content of the bioenergy product, even when transported internationally. For example, the fossil fuel use related to cultivation and processing of wood pellets corresponds to between 2.5 and 15 g CO2/MJ. [11] Transporting pellets between North America and Europe increases supply chain emissions by up to 5 g CO2/MJ [12] (for comparison: the life cycle GHG emissions of hard coal (supply & combustion) is around 112 g CO2/MJ). Thus, long-distance transport does not negate the climate benefits of forest-based bioenergy; these supply chains still offer substantial climate benefit when sourced from sustainable biomass.

7. Switching from coal to woody biomass reduces atmospheric CO2 over time scales relevant to climate stabilisation.

Some articles point to the fact that forest-based bioenergy systems can cause a short-term increase in emissions, although delivering mitigation in the longer term, and claim that bioenergy is not compatible with climate change goals if it has a payback period of more than a decade, due to the urgent need to address climate change.

First, there remains disagreement about the appropriate methodological approach for calculating payback time. Stand-level assessments are in our view not appropriate since they represent the assessed system as a strict sequence of events (e.g., site preparation, planting or natural regeneration, thinning and other silvicultural operations, final felling) that in reality occur simultaneously0 across the forest landscape (see point 3). The outcome for stand-level assessments will vary dramatically for the same system, depending on which starting point is chosen (time of replanting or time of harvest). Moreover, defining a realistic counterfactual for the calculation of payback times is critical, but challenging, considering the dynamics of forestry systems. Some studies use unrealistic assumptions for counterfactuals, e.g. assuming that forests planted for commercial use are left unharvested when there is no demand for bioenergy, and ignoring that most forest biomass used for bioenergy is a by-product of high value timber.

Second, the relationship between net emissions, global warming and climate stabilisation is complex. The IPCC 1.5 report [13] shows many alternative trajectories towards stabilization temperatures of 1.5 and 2°C. The IPCC emphasizes the need for transformation of all the major sectors of society to achieve net zero CO2 emissions, and finds a requirement for carbon dioxide removal in many scenarios. The IPCC’s assessment of current scientific understanding does not conclude that individual measures towards achieving transformation need to meet specific “payback periods”.

The most important climate change mitigation measure is to transform energy and transport systems so that we can leave fossil carbon in the ground. Using bioenergy now, in conjunction with other renewables, is an important measure to achieve this. Biomass is a storable, dispatchable energy source that can support the rapid expansion of intermittent renewables, providing grid stability and balancing. In the longer term, biomass is likely to be primarily used in applications where the substitution of carbon-based fuels is particularly difficult, such as in aviation and long-distance marine transportation. Biomass may also be increasingly used in applications that deliver net negative GHG emissions. For the mid – to longer term, the IPCC 1.5 report found most scenarios that deliver climate stabilisation at 1.5 or 2°C require substantial deployment of negative emissions technologies. Bioenergy linked with carbon capture and storage (BECCS) is one of the major available options for achieving negative emissions. The further transformation of existing power systems will depend on how biobased and other technologies develop to meet future demands, including the development of technologies for providing negative emissions that are not based on biomass.

Concern about near-term emissions is not a strong argument for stopping investments that contribute to net emissions reduction beyond 2030, be it the scaling-up of battery manufacturing to support electrification of car fleets, the development of rail infrastructure, or the development of biomass supply systems and innovation to provide biobased products displacing fossil fuels, cement and other GHG-intensive products. We assert that it is critical to focus on the global emissions trajectory required to achieve climate stabilization, acknowledging possible trade-offs between short- and long-term emissions reduction objectives. A strong focus on short-term carbon balances may result in decisions that make long-term climate objectives more difficult to meet.

8. Sustainability governance is required to ensure that woody biomass used for energy makes a positive contribution to addressing climate change and other societal goals.

Scientific studies have shown that forest-based bioenergy can make a substantial contribution to climate stabilisation. Sustainability governance is needed to support achievement of this potential and minimise the risk of negative outcomes. Many countries have rigorous forest management regulations requiring implementation of sustainable forest management practices. [14] Sustainable forest management, such as defined by FSC- or PEFC-endorsed schemes, is used to manage hundreds of millions of hectares of forest worldwide, and these practices should be deployed more broadly. Sustainability requirements have been developed to govern the eligibility of forest biomass for renewable energy in several countries as well as under the updated European Renewable Energy Directive. Regulations governing eligibility for bioenergy subsidies in the Netherlands, for example, stipulate that natural forests cannot be converted, that biodiversity and forest vitality are at least maintained, that forests must be regrown, and that forest carbon stock must be maintained or increased in the long term. To secure sustainability compliance and oversight throughout the chain, all economic operators are supervised by public authorities and the certification schemes involved.

9. Managed forests can provide greater climate benefits than conservation forests.

The cessation of harvesting from forests, to allow them to sequester carbon, has been proposed as a climate change mitigation option that also can provide other benefits such as biodiversity protection. There are indeed many good reasons for protecting natural forests. With respect to climate, the IPCC has pointed out that forests managed for producing sawn timber, bioenergy and other wood products can make a greater contribution to climate change mitigation than forests managed for conservation alone. This is for three reasons. First, the sink strength diminishes as conservation forests approach maturity; production forests maintained in an actively growing state have high sink strength. Second, wood products displace GHG-intensive materials and fossil fuels. Third, carbon in forests is vulnerable to loss through natural events such as insect infestations or wildfires, as recently seen in many parts of the world including Australia and north America. Managing forests can help to increase the total amount of carbon sequestered in the forest and wood products carbon pools, reduce the risk of loss of sequestered forest carbon, and reduce fossil fuel use.

10. Managed forests produce wood for multiple products, not just bioenergy.

The picture, which is often presented, that whole forest stands are cut for bioenergy alone, is misleading. Forest biomass for bioenergy is typically obtained from forests managed for multiple purposes, including production of pulp and saw logs, and provision of other ecosystem services (e.g., air quality improvement, water purification, soil stabilization, biodiversity conservation). Bioenergy systems are components in value chains or processes that aim to produce forest products such as sawnwood, paper and chemicals. Stems that meet quality requirements are used to produce high value products such as sawnwood and wood panels, displacing carbon-intensive building materials such as concrete, steel and aluminium, while residues from forestry operations (tops, branches, thinnings, wood that is unsuitable for lumber) and wood processing residues are used for bioenergy. (e.g. [15]). When bioenergy from forest biomass displaces fossil fuels, this adds to the climate benefits of managed forestry.

Footnotes

1. For example: BBC News 23.02.2017 “Most energy schemes are a ‘disaster’ for climate change”; EASAC press release 10.09.2019 “EASAC’s Environmental Experts call for international action to restrict climate-damaging forest bioenergy schemes”; The Guardian 16.12.2019 “Converting coal plants to biomass could fuel climate crisis, scientists warn”; EASAC press release 26.08.2020 “Emissions Trading System: Stop Perverse Climate Impact of Biomass by Radically Reforming CO2 Accounting Rules”
2. For example: Brack, D., 2017. Woody biomass for power and heat: Impacts on the global climate. Environment, Energy and Resources Department, Chatham House.; Searchinger, T.D., Beringer, T., Holtsmark, B., Kammen, D.M., Lambin, E.F., Lucht, W., Raven, P. and van Ypersele, J.P., 2018. Europe’s renewable energy directive poised to harm global forests. Nature communications, 9(1), pp.1-4.; Sterman, J.D., et al., 2018. Does replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy. Environmental Research Letters, 13(1), p.015007.; Norton, M.et al., 2019. Serious mismatches continue between science and policy in forest bioenergy. GCB Bioenergy, 11(11), pp.1256-1263.
3. IEA Bioenergy, 2020. The use of forest biomass for climate change mitigation: dispelling some misconceptions. https://www.ieabioenergy.com/wp-content/uploads/2020/08/The-use-of-biomass-for-climate-change-mitigation-dispelling-some-misconceptions-August-2020-Rev1.pdf
4. UNFCCC reporting sectors Agriculture, Forestry and Other Land Use (AFOLU), formerly Land use, Land-use change and Forestry (LULUCF) sector.
5. However, there is incomplete coverage under the Kyoto Protocol because only some countries account for their GHG emissions in the second (2013- 2020) commitment period. Under the Paris Agreement, commencing 2020, all parties will include the land sector in their national accounting.
6. E.g. Chen, Q., Löschel, A., Pei, J., Peters, G.P., Xue, J. and Zhao, Z., 2019. Processing trade, foreign outsourcing and carbon emissions in China. Structural Change and Economic Dynamics, 49, pp.1-12.
7. see EU Renewable Energy Directive II, L 328/97 (point 102), ‘… harvesting in forests is carried out in a sustainable manner in forests where regeneration is ensured …’
8. EU Renewable Energy Directive II, L 328/131-132, Article 29, par. 6-9
9. Woodall, C. et al. (2015). The U.S. Forest Carbon Accounting Framework: Stocks and Stock Change, 1990-2016. USDA Forest Service, Newtown Square, PA. https://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs154.pdf [November 28, 2019].
10. Dale, V. et al. (2017). Status and prospects for renewable energy using wood pellets from the southeastern United States. GCB Bioenergy (2017)
11. or up to 25 g CO2/MJ when fossil fuel is used for drying, which is uncommon in modern pellet plants.
12. J. Giuntoli, A. Agostini, R. Edwards, L. Marelli, 2015. Solid and gaseous bioenergy pathways: input values and GHG emissions. JRC Report EUR 27215 EN.; Jonker, J.G.G., Junginger, M. and Faaij, A., 2014. Carbon payback period and carbon offset parity point of wood pellet production in the South-eastern United States. Global Change Biology Bioenergy, 6(4), pp.371-389.
13. IPCC, 2018: Summary for Policymakers. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. World Meteorological Organization, Geneva, Switzerland, 32 pp. https://www.ipcc.ch/sr15/chapter/spm/
14. For example, the Montréal Process (https://www.montrealprocess.org/) countries contain 90% of the world’s temperate and boreal forests and produce 49% of the world’s roundwood.
15. Enviva’s website identifies that 17% of feedstock is mill residues, with the remainder being forest biomass. This forest biomass is not high-value timber, but rather a mix of thinnings, limbs and low-quality stems, consistent with the biomass sources identified by Matthews et al. (2018) as having low risk, and leading to low GHG emissions.

Lignocellulosic biomass can be converted into fuels and chemicals using thermochemical or biochemical process pathways. Thermochemical technologies apply heat and chemical processes in order to produce bioenergy from biomass. There are four main thermochemical conversion processes: direct combustion, gasification, pyrolysis and liquefaction. Direct combustion produces heat while the three latter can produce various types of energy carriers that can be converted into fuels.

Direct combustion

Direct combustion is the burning of biomass in open air, or, in the presence of excess air, converting the chemical energy stored in biomass into heat, mechanical power or electricity. Direct combustion is carried out using stoves, furnaces, steam turbines, or boilers at a temperature range starting at 800°C. All types of biomass can be burned, but in practice, direct combustion is only performed for biomass that has low moisture content (less than 50%). Biomass containing higher levels of moisture needs to be dried prior to combustion, or it may be better suited to biochemical conversion.

Gasification

Gasification is the partial oxidation of biomass at high temperatures (over 700°C) in the presence of a gasification agent, which can be steam, oxygen, air or a combination of these. The resulting gas mixture is called syngas or producer gas, and can be used in various processes to produce liquid fuels such as methanol, ethanol and Fischer-Tropsch diesel, and gaseous fuels, such as hydrogen and methane.

Syngas is comprised mainly of hydrogen and carbon monoxide, but could also contain methane, carbon dioxide, light hydrocarbons (e.g. ethane and propane) and heavy hydrocarbons (e.g. tars). Undesirable gases, such as hydrogen sulfide may also be present. The composition of the syngas depends on the type of biomass, the gasifier, the gasification agent, and on the temperature used in the process. Generally, when the biomass has high content of carbon and oxygen, the syngas produced via gasification is rich in carbon monoxide and carbon dioxide.

The most common biomass feedstocks used in the gasification process to produce biofuels are different kinds of wood, forestry wastes and agricultural residues. The heat for the high temperature gasification process can be supplied either directly by oxidation of part of the biomass in the gasifier, or indirectly by transferring energy to the gasifier externally.

Pyrolysis

Pyrolysis is the thermal decomposition of biomass to liquid, solid and gaseous fractions at high temperatures in the absence of oxygen in order to avoid significant levels of combustion. The liquid fraction is called bio-oil or bio-crude; a dark brown, viscous liquid with a high density, composed by a mixture of oxygen-containing organic compounds. Due to its high oxygen content, bio-oil is not suitable for direct use as a drop-in transportation fuel. However, it can be easily transported and stored, and after upgrading it has the potential to substitute crude oil, which makes it the most interesting product of pyrolysis. The solid fraction obtained from pyrolysis is called biochar, i.e. charcoal made from biomass, and the gasous fraction is syngas. The relative proportions of these fractions depend on the type of reactor employed and the feedstock used. It is controlled by varying the temperature, the heating rate and the residence time of the material in the reactor.

Depending on the heating rate employed, there are three main types of pyrolysis processes: slow, fast and flash pyrolysis. Slow pyrolysis has been used for thousands of years for the production of solid fuel. It is a decomposition process at relatively low temperatures (up to 500°C) and low heating rates (below 10°C/min), which takes several hours to complete, and results in solid biochar as the main product.

Fast pyrolysis is currently the most widely used process. It occurs at controlled temperature of around 500°C employing relatively high heating rates and only takes a few seconds to complete. The key product from fast pyrolysis is bio-oil (60-75%). In addition, biochar (15-25%) and syngas (10-20%) are also produced.

When heating rates and reaction temperatures are even higher, and the reaction time is shorter than that of fast pyrolysis, the process can be described as flash pyrolysis. Flash pyrolysis can result in a high yield of bio-oil and high conversion efficiencies (up to 70-75%).

Liquefaction

Hydrothermal liquefaction is the conversion of biomass to bio-oil in the presence of water, with or without a catalyst. During hydrothermal liquefaction, large compounds in the biomass are broken down into unstable shorter molecules that in turn reattach to each other and form bio-oil. In contrast to pyrolysis and gasification, the liquefaction process does not require the use of dry biomass, which reduces the cost of drying. The resulting bio-oil has lower oxygen content than the bio-oil obtained from pyrolysis, and therefore, it requires less upgrading prior to utilization as a transportation fuel.

Lignocellulosic biomass can be converted into fuels and chemicals using thermochemical or biochemical process pathways. Biochemical processes involve biocatalysts. They can be enzymes that degrade biomass to a mixture of sugars, which can be fermented by microorganisms to produce a wide range of valuable compounds such as fuels, organic acids, alcohols, etc. When the aim is to produce liquid and gaseous biofuels, mainly two biochemical conversion processes are used: fermentation for ethanol production and anaerobic digestion for biogas production.

Fermentation process for ethanol

A typical process to convert biomass to ethanol consists of four main steps: pretreatment, enzymatic hydrolysis, fermentation, and product recovery (Figure 1).

Pretreatment

Lignocellulose is a very resistant material. It consists of an intertwined network of cellulose (30-50%), hemicellulose (20-30%) and lignin (20-30%) that provides strength and resistance to the plant structure. Converting lignocellulose to sugar molecules requires pretreatment to open its structure and make it easier to break down the cellulose fibers consisting of glucose linked together in long chains. The pretreatment step can separate the cellulose from hemicellulose and lignin.

Several pretreatment methods, including biological, physical, and chemical pretreatments, have been studied. In a biomass-to-ethanol process at commercial scale, steam pretreatment has so far been the main choice. During steam pretreatment high-pressure steam is used to increase the temperature of the biomass to 160-240°C for a certain time, after which the pressure is released causing most of the hemicellulose and part of the lignin to solubilize. The cellulose remains undissolved but becomes more available for the enzymes.

Enzymatic hydrolysis

During enzymatic hydrolysis, the cellulose fibers and hemicellulose which were not degraded in the pretreatment are decomposed into simple sugar molecules. Cellulases, a mixture of several types of enzymes acting in synergy, are used to attack the bonds between glucose molecules in different regions of the cellulose. As hemicellulose mainly consists of other types of sugars than glucose, and has a different structure compared to cellulose, its hydrolysis requires different enzymes (hemicellulases). In the end of the enzymatic hydrolysis a solution that is rich in various kinds of sugars is obtained and can be fermented.

Fermentation

The sugars produced can be fermented to ethanol by yeast or bacteria. Due to it generally being recognized as safe, robust, and presenting high ethanol tolerance, ordinary baker’s yeast (Saccharomyces cerevisiae) is the most preferred microorganism. But ordinary baker’s yeast can only ferment sugars that contain six carbon atoms, such as glucose. To convert sugars from hemicellulose containing five carbons (e.g. xylose and arabinose), the yeast needs to be genetically modified or replaced with other microorganisms, e.g. bacteria. Enzymatic hydrolysis and fermentation can be carried out in two main configurations: consecutively, known as separate hydrolysis and fermentation, or at the same time in one vessel, known as simultaneous saccharification and fermentation (see Figure 1).

Product recovery

To obtain a high-purity product that can be used for fuel production, ethanol needs to be recovered from the fermentation by distillation and dehydration. Residues from distillation are separated into solids and liquids. The solid residue, which is rich in lignin, can either be burnt to produce steam, heat, and electricity, or converted to various coproducts. The liquid residue is sent to an anaerobic digestion plant to produce biogas. Ethanol obtained by this process is blended with gasoline at different ratios (E5-E85) or can even be used as a pure ethanol fuel (E100).

Anaerobic digestion for biogas production

Anaerobic digestion (AD) is the microbial decomposition of biomass into biogas without the presence of oxygen. Biogas is mainly composed of 55-65% methane and 35-45% carbon dioxide, but it can also contain small amounts of e.g. nitrogen, hydrogen, oxygen, hydrogen sulfide, and ammonia. The composition of the resulting biogas depends on the type of biomass used.

It is possible to break down biomass by means of AD without pretreatment. However, higher biogas yields can be achieved in shorter time if pretreatment is applied. The four main steps of AD are hydrolysis, acidogenesis, acetogenesis, and methanogenesis (Figure 2). In each step, different groups of microorganisms are used.

In the hydrolysis step, large macromolecules such as carbohydrates, lipids and proteins are broken down by enzymes to smaller compounds, such as simple sugars, amino acids, fatty acids. These are further degraded in the acidogenesis to organic acids and alcohols, which are in turn converted to acetate, as well as to carbon dioxide and hydrogen in the acetogenesis. In the final step, methanogenesis, biogas, i.e. a mixture of methane and carbon dioxide, is produced by two different types of bacteria. One converts acetate and the other type utilizes carbon dioxide and hydrogen to produce biogas.

Biogas obtained from AD can be burnt and the energy released can be used for heating purposes. Alternatively, after removal of carbon dioxide, biogas can be compressed the same way as natural gas and used as a vehicle fuel.

The fact sheet is currently only available in Swedish.

Jet A1, också benämnt som flygfotogen eller jetbränsle, är det drivmedel som används i flygplan och helikoptrar drivna med jetmotorer. När biobaserade bränslen blandas i flygbränsle brukar det kallas biojet. Det är i dagsläget bränsle från fyra olika biobaserade produktionsvägar som är certifierat som tillsats (upp till 50%) i konventionell Jet A1 enligt standarden för flygbränsle: hydrerade estrar och fettsyror (HEFA), Alcohol-to-Jet (AtJ), Fischer-Tropsch (FT) och direktfermentering av socker (DSHC).

För att ge biojet bra klimatprestanda är det viktigt att vätgasproduktionen som processteg görs hållbar. I svenska bioflygbränsleprojekt är det främst tre av de biobaserade produktionsvägarna som är intressanta att utveckla, HEFA, AtJ och FT, vilka presenteras närmare i detta faktablad. Längs värdekedjan för respektive teknik finns olika faktorer som påverkar status för bioflygbränslena, och därmed också hur de kan bidra till luftfartssektorns klimatmål.

De fyra produktionsvägarna för biobaserade drop in-bränslen certifierade för inblandning i flygbränsle enligt standard ASTM 7566-18. Med inblandning av dessa kallas flygbränslet för Biojet.

HEFA – hydrerade estrar och fettsyror

Hydrerade (vätebehandlade) estrar och fettsyror, HEFA, produceras ur vegetabiliska och animaliska oljor och fetter, också avfallsoljor som använd matolja. Råvaran vätebehandlats för att reducera syreinnehåll och konvertera fetter och oljor till kolväten. En förbehandling krävs för att använda förorenade råvaror.

HEFA är ASTM-certifierad för en inblandning i flygbränsle på upp till 50%.

HEFA-processen är den enda produktionsprocess som idag har kommersiell produktion av bioflygbränsle. Eftersom tillverkningsprocessen till stor del är densamma som för HVO (hydrerad vegetabilisk olja) som finns på marknaden för vägtransporter, kan anläggningar ha en flexibel produktmix, dvs fördelning mellan olika produkter (t ex mellan flygbränsle, andra fordonsbränslen och kemikalier). Men det betyder också att en konkurrenssituation om vissa råvaror kan uppstå mellan drivmedelsproduktion för flyget respektive vägtransporter. En ökad efterfrågan på vegetabiliska oljor kan orsaka tryck på ändrad markanvändning i vissa fall. Lignocellulosaråvaror har mycket högre tillgänglighet och lägre indirekta miljöeffekter men kan med dagens teknik inte användas för HEFA-produktion.

Investeringskostnader har i exempel beräknats ligga kring 8 000 SEK/årston för storskaliga anläggningar vilket ger ett uppskattat lägsta försäljningspris för HEFA på i storleksordningen 8-12 SEK/l beroende på råvara. [1, 2] De relativt låga produktionskostnaderna är delvis beroende av synergier med annan kolväteproduktion. Andra uppskattningar av produktionskostnader är högre, t ex 15-17 SEK/l för använd matolja som råvara. [3]

Omvandlingsprocessen från biomassa till bioflygbränsle har vätgas som viktigaste insatsvara i tillägg till olja/fett-råvaran. Tillverkat av förnybara och hållbara råvaror kan bioflygbränsle med HEFA minska utsläppen av växthusgaser med 70-80% jämfört med konventionellt jetbränsle. [2, 3]

AtJ – Alcohol to Jet

Alcohol to Jet (AtJ) innebär att biojetbränsle framställs katalytiskt ur någon av alkoholerna butanol eller etanol. Dessa alkoholer kan ha framställts ur många olika biogena råvaror och en mängd olika biologiska processer. Det innebär att det finns många varianter av AtJ som produktionsväg.

För s k första generationens etanol används främst socker från sockerrör och stärkelse från sädesslag som råvara. Men användningen av grödor för drivmedelsproduktion är omdebatterad och EU har satt ett tak för den. För att bredda råvarubasen har teknik för att producera såväl etanol som butanol från lignocellulosa, t ex trä och halm, tagits fram. Restströmmar från befintlig industri kan också vara ett viktigt komplement till råvarubasen.

Att omvandla biomassa till AtJ-baserat bioflygbränsle kan ske med låg miljöpåverkan. Den övergripande miljöprestandan är en kombination av val och metod för insamling av råvara och den specifika produktionsvägen. I allmänhet betraktas rest- och biprodukter från skogsbruk och jordbruk samt biogena avfall som de viktigaste framtida råvarorna. De är enligt reglerna för växthusgasberäkning som tillämpas i förnybarhetsdirektivet [4, 5] associerade med låga utsläpp av klimatpåverkande gaser. Jämfört med fossila bränslen ger bioflygbränsle producerat från någon av dessa råvaror enligt AtJ en signifikant växthusgasreduktion. I typfallet är minskningen större än 80%. [2]

Som process är AtJ relativt mogen och ett flertal aktörer bedriver aktivt utvecklingsarbete. Tekniken är dock ännu inte demonstrerad i kommersiell storskalig produktion. Detta innebär att den ekonomiska prestandan för AtJ-processen är osäker. [6] Det är dock tydligt att produktionsekonomin skiljer sig beroende på vilken råvara som används. Priser på 25-35 SEK/l har t ex angivits för de första anläggningarna som producerar AtJ-bränsle från lignocellulosa. Med mogen teknik förväntas de sjunka till 15-25 SEK/l. [2, 7, 8]

ASTM-certifiering som tillåter upp till 50% inblandning i fossilt jetbränsle finns för produktion både via butanol och etanol.

FT – Fischer Tropsch

Fischer Tropsch (FT) är en serie kemiska reaktioner som kan användas för att uppgradera syntesgas (H2 och CO) till vätskeformiga bränslen. Råvaran för framställning av syntesgasen kan vara av både fossilt ursprung eller biomassa och avgör alltså om slutprodukten är bioflygbränsle. Det finns i dagsläget ingen storskalig produktion av flygbränsle från biomassa baserat på FT-teknik, men snarlik teknik, baserad på fossila råvaror, har sedan länge använts för kommersiell produktion av flygbränsle. Två kommersiella produktionsanläggningar är 2019 under uppförande i USA med planerad start 2020.

Det är inte möjligt att producera enbart bioflygbränsle i en FT-process, men 50-70% av produkten kan bli bioflygbränsle med förnybar diesel som den viktigaste andra produkten. Effektiviteten beror mycket på processkonfiguration och råvara men typiskt kan 35-50% av energin i råvaran bli till drivmedel. Dessutom bildas en stor mängd värme som kan vara värdefull om produktionen integreras med andra processer eller i ett fjärrvärmenät.

Det är svårt att generalisera produktionskostnader för FT-baserade bioflygbränslen. Skälet är att de i hög grad beror på lokalisering, råvaruval, anläggningens storlek och vald produktmix. Generellt präglas kostnadsprofilen av höga investeringskostnader men låga råvarukostnader jämfört med de flesta andra produktionstekniker. För FT-baserade bioflygbränslen anges ofta produktionskostnader i ett intervall om 10-20 SEK/l. [2, 3, 8, 9] Kostnader i den lägre delen av intervallet kan sannolikt nås för kommande anläggningar som byggs integrerade med befintlig industri, exempelvis svensk skogsindustri.

Att omvandla biomassa till FT-baserat bioflygbränsle har potential att göras med mycket liten miljöpåverkan från själva omvandlingsprocessen eftersom få ytterligare insatsvaror används och endast lite avfall bildas. Det innebär att så länge hållbart producerade och insamlade råvaror används, kan totalt sett god miljöprestanda nås med denna produktionsväg. Med de regler för växthusgasberäkning som tillämpas i förnybarhetsdirektivet [4, 5] är dessa associerade med låga klimatgasutsläpp och ger växthusgasreduktion för producerat bioflygbränsle med >90% jämfört med fossila bränslen. [7]

The fact sheet is at this point only available in Swedish.

Förhållanden mellan markanvändning och biodrivmedel diskuteras i många sammanhang. Att uppta mark för biodrivmedelsproduktion kan potentiellt leda till att matproduktion flyttar till andra platser, och att ny odlingsmark behöver tas i anspråk. Detta kan påverka både livsmedelspriser och utsläpp av växthusgaser. Men vad säger den senaste forskningen?

Vad är ILUC?

I debatten används ofta uttrycken direkt och indirekt förändrad markanvändning. De brukar förkortas DLUC (eng. Direct Land Use Change) och ILUC (eng. Indirect Land Use Change).

DLUC innebär att mark byter användning, från exempelvis skog till åkermark, för att möjliggöra odling av grödor till biodrivmedel. Det är viktigt att ta med i beräkning av klimatprestanda för biodrivmedel från länder där det sker avskogning. DLUC kan beräknas via mätningar av mängden kol i mark och biomassa innan och efter den ändrade markanvändningen, eller via modeller. Även om det finns stora osäkerheter i bedömningen finns en direkt koppling mellan grödan och den ändrade markanvändningen.

Samband mellan efterfrågan på grödor och direkta och indirekta effekter på markanvändning.

ILUC är ett mer komplicerat begrepp, grundat i ekonomiska resonemang. Om vi inom EU upptar stora arealer för odling av grödor till biodrivmedel, kan det bli en påverkan på livsmedelspriserna. Vår matproduktion kan då flyttas till andra områden inom EU, eller till andra delar av världen där maten är billigare att producera. Det kan leda till att ny odlingsmark tas i anspråk, mark som tidigare kanske varit i träda, skog eller extensiv betesmark. Det behöver inte vara negativt; om mark i träda som inte används kommer i bruk, kan vi producera mat och biodrivmedel och samtidigt binda in mer kol i marken.

Högre livsmedelspriser kan innebära att bönderna ser möjlighet till investeringar i jordbruket och kan intensifiera sin odling, vilket ofta är klimatsmart. Högre livsmedelspriser kan även påverka konsumtionsmönster. ILUC-teorin uttrycks alltså i flera steg och är svår att härleda till biodrivmedel då det finns många andra faktorer som påverkar bönders och konsumenters val. ILUC brukar därför uppskattas med hjälp av ekonomiska jämviktsmodeller.

Hur stor klimatpåverkan ger ILUC?

Det finns en stor mängd litteratur som försöker uppskatta ILUC. Resultaten varierar mycket och beror på val av modelleringsverktyg, systemgränser, indata och så vidare. Spannet varierar mellan -75 och 55 g koldioxidekvivalenter (CO₂-ekv) per megajoule (MJ) biodrivmedel enligt senaste IPCC-rapporten om markanvändning. Det kan jämföras med utsläpp från ett fossilt bränsle på ca 94 g CO₂-ekv per MJ. Ofta får grödbaserade drivmedel högre ILUC än lignocellulosabaserade drivmedel. Notera att ILUC i vissa fall kan bli negativt, det vill säga en besparing av utsläpp. Det kan hända i de fall där biprodukter ersätter andra mer resurskrävande produkter, till exempel när drank ersätter soja.

Bör vi ta hänsyn till ILUC?

På grund av de stora osäkerheterna gällande metoder för att uppskatta ILUC, rekommenderar de flesta handböcker i livscykelanalys att inte inkludera ILUC i klimatberäkningar av enskilda produkter.

I ett globalt perspektiv går det att ifrågasätta relevansen av ILUC. När en ändring i markanvändning sker, räknas den som DLUC för den gröda som odlas på platsen. Att samma markanvändning sedan även ska bokföras som ILUC för en annan gröda blir en dubbelräkning. ILUC är alltså ett högst teoretiskt sätt att beräkna markanvändning, i verkligheten finns bara DLUC.

Men att beräkna ILUC kan vara relevant i vissa sammanhang, till exempel inom explorativ forskning, där effekterna på markanvändning vid införande av en policy undersöks. Vissa forskare, som Timothy D Searchinger, anser även att all markanvändning som inte producerar enligt sin maxkapacitet, leder till ILUC-effekter och bör tas med i utvärdering av markanvändning.

Oavsett diskussionen, är det extremt viktigt att värna om mark som en resurs både i Sverige och internationellt. Vi måste upprätthålla god markhälsa och minska skövling av värdefull skog. I störst möjliga mån bör bioenergi integreras i existerande system, utan att äventyra produktion av livsmedel. Det bör emellertid nämnas att biodrivmedelsgrödor utgör ett fåtal procent av den globala jordbruksmarken; vi behöver också fokusera på övriga drivkrafter till ändrad markanvändning, till exempel den globalt ökande köttkonsumtionen.

Hur hanteras ILUC i lagstiftningen?

Det är mycket svårt att lagstifta bort indirekta effekter som kan ske på andra sidan jordklotet. Men att ignorera att all markanvändning idag sammanlänkas genom ett globalt nät av förflyttningar av grödor, livsmedel och biodrivmedel är inte heller en framkomlig väg.

I EU har frågan om ILUC diskuterats länge. I det senaste direktivet om förnybar energi (2018:2001) har ILUC-risk för jordbruksråvaror delats upp i två nivåer, låg och hög. Lågrisk-ILUC tillskrivs grödor där man undviker omflyttningseffekter av foder- och livsmedelsgrödor, grödor producerade genom förbättrade jordbruksmetoder samt grödor från områden som tidigare inte användes för odling av grödor. Grödor som inte återfinns i dessa kategorier anses vara högrisk-ILUC; dessa får inte räknas in i EU:s ramverk efter 2030.