Greenhouse gas reporting for biofuels: A comparison between the RED,RTFO and PAS2050 methodologies

Biofuels have been identified as a potential short-term solution for reducing greenhouse gas (GHG) emissions from road transport. Currently, ‘1st generation’ biofuels are produced from food crops, but there are concerns with the indirect effects of utilising edible crops for fuel. There is increased interest in producing ‘2nd generation’ biofuels from woody crops and straw, as these can be grown on lower grade land or do not compete directly with food. In order to ensure that biofuels actually deliver emission savings, the overall GHG balance of producing them must be calculated accurately, and compared with conventional fossil fuels. The GHG balance can vary significantly however, depending on biomass type, the production processes, the indirect effects, and also by the method by which the GHG emission balance is calculated. Currently, in the UK, there are three main GHG methodologies that potentially affect biofuel producers. Each has a different approach to measure GHG emissions from biofuel production, and each provides a different result, causing difficulties for policy makers. This study performs a partial life cycle assessment for bioethanol production from wheat grain and wheat straw to demonstrate the variability of the results between methodologies.     

Indirect fuel use change (IFUC) and the lifecycle environmental impact of biofuel policies

A common assumption in lifecycle assessment (LCA) based estimates of greenhouse gas (GHG) benefits (or costs) of renewable fuel such as biofuel is that it simply replaces an energy-equivalent amount of fossil fuel and that total fuel consumption remains unchanged. However, the adoption of renewable fuels will affect the price of fuel and therefore affect total fuel consumption which, may increase or decrease depending on the policy regime and market conditions. Using a representative two-region model of the global oil market in which, one region implements a domestic biofuel mandate and the other does not, we show that the net change in global fuel consumption due to the policy, which we term indirect fuel use change (IFUC), can have a significant impact on the net GHG emissions associated with biofuel. If LCA-based regulations are designed to account for indirect emissions such as indirect land use change, then we argue that IFUC emissions cannot be ignored. Our work also shows how different policies can affect the environmental impact from adopting a given clean technology differently.     

Greenhouse gas balances of transportation biofuels,electricity and heat generation in Finland—Dealing with the uncertainties

One way to reduce greenhouse gas emissions from the transportation sector is to replace fossil fuels by biofuels. However, production of biofuels also generates greenhouse gas emissions. Energy and greenhouse gas balances of transportation biofuels suitable for large-scale production in Finland have been assessed in this paper. In addition, the use of raw materials in electricity and/or heat production has been considered. The overall auxiliary energy input per energy content of fuel in biofuel production was 3–5-fold compared to that of fossil fuels. The results indicated that greenhouse gas emissions from the production and use of barley-based ethanol or biodiesel from turnip rape are very probably higher compared to fossil fuels. Second generation biofuels produced using forestry residues or reed canary grass as raw materials seem to be more favourable in reducing greenhouse gas emissions. However, the use of raw materials in electricity and/or heat production is even more favourable. Significant uncertainties are involved in the results mainly due to the uncertainty of N₂O emissions from fertilisation and emissions from the production of the electricity consumed or replaced.     

Biofuel market and carbon modeling to analyse French biofuel policy

In order to comply with European Union objectives, France has set up an ambitious biofuel plan. This plan is evaluated on the basis of two criteria: tax exemption on fossil fuels and greenhouse gases (GHG) emission savings. An economic marginal analysis and a life cycle assessment (LCA) are provided using a coupling procedure between a partial agro-industrial equilibrium model and an oil refining optimization model. Thus, we determine the minimum tax exemption needed to place on the market a targeted quantity of biofuel by deducting the biofuel long-run marginal revenue of refiners from the agro-industrial marginal cost of biofuel production. With a clear view of the refiner's economic choices, total pollutant emissions along the biofuel production chains are quantified and used to feed an LCA. The French biofuel plan is evaluated for 2008, 2010 and 2012 using prospective scenarios. Results suggest that biofuel competitiveness depends on crude oil prices and demand for petroleum products and consequently these parameters should be taken into account by authorities to modulate biofuel tax exemption. LCA results show that biofuel production and use, from “seed to wheel”, would facilitate the French Government's compliance with its “Plan Climat” objectives by reducing up to 5% GHG emissions in the French road transport sector by 2010.     

A prospective study of bioenergy use in Mexico

Bioenergy is one of the renewable energy sources that can readily replace fossil fuels, while helping to reduce greenhouse gas emissions and promoting sustainable rural development. This paper analyses the feasibility of future scenarios based on moderate and high use of biofuels in the transportation and electricity generation sectors with the aim of determining their possible impact on the Mexican energy system. Similarly, it evaluates the efficient use of biofuels in the residential sector, particularly in the rural sub-sector. In this context, three scenarios are built within a time frame that goes from 2005 to 2030. In the base scenario, fossil fuels are assumed as the dominant source of energy, whereas in the two alternative scenarios moderate and high biofuel penetration diffusion curves are constructed and discussed on the basis of their technical and economical feasibility. Simulation results indicate that the use of ethanol, biodiesel and electricity obtained from primary biomass may account for 16.17% of the total energy consumed in the high scenario for all selected sectors. CO₂ emissions reduction—including the emissions saved from the reduction in the non-sustainable use of fuelwood in the rural residential sector—is equivalent to 87.44 million tons of CO₂ and would account for 17.84% of the CO₂ emitted by electricity supply and transportation sectors when the base case and the high scenario are compared by 2030.     

Is it environmentally advantageous to use vegetable oil directly as biofuel instead of converting it to biodiesel?

The oil price instability and the measures taken to reduce the increase in greenhouse gas emissions are the main factors promoting the development and use of environmentally friendly energies. From an energy efficiency point of view, biofuels constitute a renewable energy source and its use helps to reduce energy dependency on fossil fuels. The most used biofuels for transport worldwide are biodiesel (BD) and bioethanol. However, there are other options such as straight vegetable oil (SVO).SVO can be small-scale produced in local cooperatives through pressing, filtering and conditioning processes which are much simpler than the ones required for BD production. In this study a comparative life cycle assessment (LCA) of two biofuels obtained from Spanish rapeseed, namely small-scale SVO and large-scale BD, is performed. The LCA methodology allows the two biofuels’ production and their rate of consumption in a vehicle (a truck) to be compared. In this manner, it is possible to assess which is environmentally advantageous: to use SVO directly as biofuel or to convert it to BD. Moreover, LCA is used in the study to calculate the energy return on investment index (EROI) and an energy conversion ratio to evaluate which biofuel is more energy efficient.The obtained results show the environmental benefits of using SVO instead of BD by analyzing representative impact categories defined by the CML and EDIP methods. A sensitivity analysis has also been conducted. EROI indexes for SVO and BD production show a clear preference for SVO as compared to BD.     

Assessing the value of pulp mill biomass savings in a climate change conscious economy

Pulp mills use significant amounts of biofuels, both internal and purchased. Biofuels could contribute to reach greenhouse gas emission targets at competitive costs. Implementing process integration measures at a pulp mill in order to achieve pulp production with less use of energy (biofuels) has not only on-site consequences but also off-site consequences, such as substitution of fossil fuels elsewhere by the saved pulp mill biofuels, and less on-site electric power generation. In this paper a method, a linking model, is suggested to analyse pulp mill biofuel saving measures when carbon dioxide (CO₂) external costs are internalised. The linking model is based on equilibrium economics and links information from CO₂ constrained energy market future scenarios with process integration measures. Pulp mill economics and marginal energy market CO₂ response are identified. In an applied study, four process integration measures at a Swedish pulp mill were analysed using five energy market future scenarios emanating from a Nordic energy model. The investigated investment alternatives for biofuel savings all result in positive net annual savings, irrespectively of the scenario used. However, CO₂ emissions may increase or decrease depending on the future development of the Nordic energy market.     

Development of biofuels for the UK automotive market

The UK transport sector has the fastest rate of growth in terms of primary (and end-use) energy consumption, and is currently responsible for 30% of UK CO₂ emissions. Biofuels could significantly reduce the emissions from the road-transport sector if they were widely adopted. They have been shown to reduce carbon emissions, and may help to increase energy security. There are many different types of biofuels, which are produced from various crops and via different processes. Biofuels can be classified broadly as biodiesel and bioethanol, and then subdivided into conventional or advanced fuels. Such biofuels are assessed in terms of indigenous UK production potential, and whether they are able to meet the domestic take-up targets set by the British Government for the road-transport sector. The various types of biofuels currently available are examined, together with potential future conversion-technologies. In-vehicle performance of these biofuels is then compared with conventional fuels, and their potential carbon savings evaluated. Finally, the main drivers and barriers to the use of biofuels in the road transport sector are discussed.     

Energy and environmental balance of biogas for dual-fuel mobile applications

Considerable research is currently being devoted to seeking alternative fuels to comply with transportation needs while reducing the environmental impact of this sector. Within the transport activity sector, on road vehicles and agricultural machinery require around 2 Mtoe energy in France. The anaerobic digestion of farm waste could roughly cover these needs. This paper aims to study the environmental and energy interest of this short power supply path. An ideal biogas production system has been built up from the average characteristics of current rural biogas plants in France. Pollutant emissions, energy demands and production are assessed for various scenarios in order to produce methane for dual fuel engines. Life cycle assessment (LCA) is used to evaluate the environmental impact of dual fuel agricultural machines, compared to diesel engines. The energy balance is always in disfavour of biogas fuel, whereas LCA energy indicators indicate a benefit for biogas production. This gap is related to the way in which the input of biomass energy is handled: in conventional biofuel LCA, this energy is not taken into account. A carbon balance is then presented to discuss the impact of biogas on climate change. Dual fuel engines were found to be interesting for their small impact. We also show, however, how the biogenic carbon assumption and the choice of allocation for the avoided methane emissions of anaerobic digestion are crucial in quantifying CO₂ savings. Other environmental issues of biogas fuel were examined. Results indicate that are management and green electricity are the key points for a sustainable biogas fuel. It is concluded that biofuel environmental damage is reduced if energy needs during biofuel production are covered by the production process itself. As agricultural equipment is used during the biofuel production process, this implies that a high substitution rate should be used for this equipment.     

Leveling the playing field of transportation fuels: Accounting for indirect emissions of natural gas

Natural gas transportation fuels are credited in prior studies with greenhouse gas emissions savings relative to petroleum-based fuels and relative to the total emissions of biofuels. These analyses, however, overlook a source of potentially large indirect emissions from natural gas transportation fuels, namely the emissions from incremental coal-fired generation caused by price-induced substitutions away from natural-gas-fired electricity generation. Because coal-fired generation emits substantially more greenhouse gases and criteria air pollutants than natural-gas-fired generation, this indirect coal-use change effect diminishes potential emissions savings from natural gas transportation fuels. Estimates from a parameterized multi-market model suggest the indirect coal-use change effect rivals in magnitude the indirect land-use change effect of biofuels and renders natural gas fuels as carbon intensive as petroleum fuels.     

Stimulating the use of biofuels in the European Union: Implications for climate change policy

The substitution of fossil fuels with biofuels has been proposed in the European Union (EU) as part of a strategy to mitigate greenhouse gas emissions from road transport, increase security of energy supply and support development of rural communities. In this paper, we focus on one of these purported benefits, the reduction in greenhouse gas emissions. The costs of subsidising the price difference between European bioethanol and petrol, and biodiesel and diesel, per tonne of CO₂ emissions saved are estimated. Without including the benefits from increased security of energy supply and employment generation in rural areas, the current costs of implementing European domestic biofuel targets are high compared with other available CO₂ mitigation strategies. The policy instrument of foregoing some or all of the excise duty and other taxes now applicable to transport fuels in EU15 on domestically produced biofuels, as well as the potential to import low-cost alternatives, for example, from Brazil, are addressed in this context.     

Large-scale open pond algae biomass yield analysis in India: a case study

Global warming, depletion of fossil fuel and increasing demand for energy have led to the substantial interest in developing alternate energy sources, especially biodiesel. First generation biofuels produced from food crops and oil seeds are limited to achieve targets for biodiesel production. Second generation biofuel produced from non-food feed stock such as microalgae provides various potential advantages for biofuel production when compared with first generation biofuels. This paper investigates the possible use of microalgae for biofuel production on the selected potential sites in the country. Algal biomass and oil yield for the selected sites are predicted using the analytical method.     

Lifecycle economic analysis of biofuels: Accounting for economic substitution in policy assessment

This paper develops a lifecycle economic analysis (LCEA) model that integrates endogenous input substitution into the standard lifecycle analysis (LCA) of biofuel that typically assumes fixed-proportions production. We use the LCEA model to examine impacts of a pure carbon tax and a revenue-neutral tax-subsidy policy on lifecycle greenhouse gas emissions from cellulosic ethanol using forest residues as feedstock in Washington State. In a model allowing for input substitution in the cellulosic ethanol feedstock, conversion, and transportation process, we consider energy source substitution (woody biomass for coal in the cellulosic ethanol conversion plant and biodiesel for diesel in feedstock production and feedstock and ethanol transportation) as well as substitution of capital and labor for energy in all stages of the lifecycle. We find that ignoring endogenous input substitution by using standard LCA leads to substantial underestimation of the impact of carbon tax policies on carbon emissions. Both tax policies can substantially reduce carbon emissions by inducing substitution among inputs. The revenue-neutral tax-subsidy policy reduces emissions more effectively than the carbon tax policy for carbon tax rates currently in place throughout most of the world. It stimulates substitution of woody biomass for coal and biodiesel for diesel at much lower tax rates when accompanied by corresponding subsidies for reduced emissions from renewable sources.     

Trading greenhouse gas emission benefits from biofuel use in US transportation: Challenges and opportunities

Replacing petroleum fuels with biofuels such as ethanol and biodiesel has been shown to reduce greenhouse gas (GHG) emissions. These GHG benefits can potentially be traded in the fledgling carbon markets, and methodologies for quantifying and trading are still being developed. We review the main challenges in developing such carbon trading frameworks and outline a proposed framework for the US, the main features of which include, lifecycle assessment of GHG benefits, a combination of project-specific and standard performance measures, and assigning GHG property rights to biofuel producers. At carbon prices of 10 $ t⁻¹, estimated monetary benefits from such trading can be 4.5 M$ hm⁻³ and 17 M$ hm⁻³ of corn ethanol and cellulosic ethanol respectively.     

Biofuel production and implications for land use,food production and environment in India

There is a large interest in biofuels in India as a substitute to petroleum-based fuels, with a purpose of enhancing energy security and promoting rural development. India has announced an ambitious target of substituting 20% of fossil fuel consumption by biodiesel and bioethanol by 2017. India has announced a national biofuel policy and launched a large program to promote biofuel production, particularly on wastelands: its implications need to be studied intensively considering the fact that India is a large developing country with high population density and large rural population depending upon land for their livelihood. Another factor is that Indian economy is experiencing high growth rate, which may lead to enhanced demand for food, livestock products, timber, paper, etc., with implications for land use. Studies have shown that area under agriculture and forest has nearly stabilized over the past 2–3 decades. This paper presents an assessment of the implications of projected large-scale biofuel production on land available for food production, water, biodiversity, rural development and GHG emissions. The assessment will be largely focused on first generation biofuel crops, since the Indian program is currently dominated by these crops. Technological and policy options required for promoting sustainable biofuel production will be discussed.     

LCA of domestic and centralized biomass combustion: The case of Lombardy (Italy)

This paper analyzes and compares the environmental impacts of biomass combustion in small appliances such as domestic open fireplaces and stoves, and in two types of centralized combined heat and power plants, feeding district heating networks. The analysis is carried out following a Life Cycle Assessment (LCA) approach. The expected savings of GHG (greenhouse gases) emissions due to the substitution of fossil fuels with biomass are quantified, as well as emissions of toxic pollutants and substances responsible for acidification and ozone formation.The LCA results show net savings of GHG emissions when using biomass instead of conventional fuels, varying from 0.08 to 1.08 t of CO₂ eq. per t of dry biomass in the different scenarios. Avoided GHG emissions thanks to biomass combustion in Lombardy are 1.32 Mt year^?1(1.5% of total regional GHG emissions). For the other impact categories, the use of biomass in district heating systems can again cause a consistent reduction of impacts, whereas biomass combustion in residential devices shows higher impacts than fossil fuels with a particular concern for PAH, VOC and particulate matter emissions. For example, in Lombardy, PM10 emissions from domestic devices are about 8100 t year^?1, corresponding to almost one third of the total particulate emissions in 2005.     

Addressing uncertainty in life-cycle carbon intensity in a national low-carbon fuel standard

Policies formulated to reduce greenhouse gas (GHG) emissions, such as a low-carbon fuel standard, frequently rely on life-cycle assessment (LCA) to estimate emissions, but LCA results are often highly uncertain. This study develops life-cycle models that quantitatively and qualitatively describe the uncertainty and variability in GHG emissions for both fossil fuels and ethanol and examines mechanisms to reduce those uncertainties in the policy process. Uncertainty regarding emissions from gasoline is non-negligible, with an estimated 90% confidence interval ranging from 84 to 100 g CO₂e/MJ. Emissions from biofuels have greater uncertainty. The widths of the 90% confidence intervals for corn and switchgrass ethanol are estimated to be on the order of 100 g CO₂e/MJ, and removing emissions from indirect land use change still leaves significant remaining uncertainty. Though an opt-in policy mechanism can reduce some uncertainty by incentivizing producers to self-report fuel production parameters, some important parameters, such as land use change emissions and nitrogen volatilization, cannot be accurately measured and self-reported. Low-carbon fuel policies should explicitly acknowledge, quantify, and incorporate uncertainty in life cycle emissions in order to more effectively achieve emissions reductions. Two complementary ways to incorporate this uncertainty in low carbon fuel policy design are presented.     

A multi-actor multi-criteria framework to assess the stakeholder support for different biofuel options: The case of Belgium

The multi-actor multi-criteria analysis (MAMCA) is a methodology to evaluate different policy measures, whereby different stakeholders’ opinions are explicitly taken into account. In this paper, the framework is used to assess several biofuel options for Belgium that can contribute to the binding target of 10% renewable fuels in transport by 2020, issued by the Renewable Energy Directive (RED). Four biofuel options (biodiesel, ethanol, biogas and synthetic biodiesel (also referred to as “biomass-to-liquid” or BTL)) together with a reference fossil fuel option, are evaluated on the aims and objectives of the different stakeholders involved in the biofuel supply chain (feedstock producers, biofuel producers, fuel distributors, end users, vehicle manufacturers, government, NGOs and North–South organizations). Overall, the MAMCA provided insights in the stakeholder’s position and possible implementation problems for every biofuel option. As such, it helps decision makers in establishing a supportive policy framework to facilitate implementation and to ensure market success, once they have decided on which biofuel option (or combination of options) to implement.     

Cost-effectiveness analysis of algae energy production in the EU

Today’s society relies heavily on fossil fuels as a main energy source. Global energy demand increase, energy security and climate change are the main drivers of the transition towards alternative energy sources. This paper analyses algal biodiesel production for the EU road transportation and compares it to the fossil fuels and 1st generation biofuels. A cost-effectiveness analysis was used to aggregate private and external costs and derive the social cost of each fuel. The following externalities were internalized: emissions (GHG and non-GHG), food prices impact, pesticides/fertilizers use and security of supply. Currently the social cost of producing algal biodiesel at 52.3 € GJ⁻¹ is higher than rapeseed biodiesel (36.0 € GJ⁻¹) and fossil fuels (15.8 € GJ⁻¹). Biotechnology development, high crude oil prices and high carbon value are the key features of the scenario where algal biodiesel outcompetes all other fuels. A substantial investment into the biotechnology sector and comprehensive environmental research and policy are required to make that scenario a reality.