Gerfried Jungmeier

Towards a standard methodology for greenhouse gas balances of bioenergy systems in comparison with fossil energy systems

In this paper, which was prepared as part of IEA Bioenergy Task XV (“Greenhouse Gas Balances of Bioenergy Systems”), we outline a standard methodology for comparing the greenhouse gas balances of bioenergy systems with those of fossil energy systems. Emphasis is on a careful definition of system boundaries. The following issues are dealt with in detail: time interval analysed and changes of carbon stocks; reference energy systems; energy inputs required to produce, process and transport fuels; mass and energy losses along the entire fuel chain; energy embodied in facility infrastructure; distribution systems; cogeneration systems; by-products; waste wood and other biomass waste for energy; reference land use; and other environmental issues. For each of these areas recommendations are given on how analyses of greenhouse gas balances should be performed. In some cases we also point out alternative ways of doing the greenhouse gas accounting. Finally, the paper gives some recommendations on how bioenergy systems should be optimized from a greenhouse-gas-emissions point of view.

Allocation in lca of wood-based products experiences of cost action E9 part i. methodology

Goal and BackgroundThe treatment of allocation in the descriptive LCA of wood-based products has been discussed for a long time and different solutions have been presented. In general, it is accepted that the influence of different allocation procedures on the results of LCA of wood-based products can be very significant. This paper is a result of the Cost Action E9 ’Life cycle assessment of forestry and forest products’ and represents the experience of involved Cost E9 delegates.ObjectiveWood is a renewable material that can be used for wood products and energy production. Consistent methodological procedures are needed in order to correctly address the twofold nature of wood as a material and fuel, the multi-functional wood processing generating large quantities of co-products, and reuse or recycling of paper and wood. Ten different processes in LCAs of wood-based products are identified, where allocation questions can occur: forestry, sawmill, wood industry, pulp and paper industry, particle board industry, recycling of paper, recycling of wood-based boards, recycling of waste wood, combined heat and power production, landfill.MethodologyFollowing ISO 14 041 a step-wise procedure for system boundary setting and allocation are outlined. As a first priority allocation should be avoided by system expansion, thus adding additional functions to the functional unit. Alternatively, the avoided-burden approach can be followed by subtracting substituted functions of wood that are additionally provided. If allocation cannot be avoided, some allocations methods from case studies are described.ConclusionsThe following conclusions for allocation in LCA of wood-based products are given. 1) Avoid allocation by expansion of system boundaries by combining material and energy aspects of wood, meaning a combination of LCA of wood products and of energy from wood with a functional unit for products and energy. 2) Substitute energy from wood with conventional energy in the LCA of wood products to get the func-tional unit of the wood product only, but identify the criteria for the substituted energy. 3) Substitution of wooden products with non-wooden products in LCA of bioenergy is not advis able, because the substitution criteria can be too complex. 4) If avoiding allocation is not possible, the reasons should be documented. 5) Different allocation procedures must be analysed and documented. In many cases, it seems necessary to make a sensitivity analysis of different allocation options for different environmental effects. It can also be useful to get the acceptance of the chosen allocation procedure by external experts. 6) Different allocation factors, e.g. mass or economic value, are allowed within the same LCA. 7) For allocation of forestry processes it is necessary to describe the main function of the forest where the raw material is taken out. In some cases different types or functions of forests must be considered and described. 8) Regarding the experiences from the examples, the following most practical allocation for some specific processes are identified: forestry: mass or volume; sawmill: mass or volume and proceeds; wood industry: mass and proceeds.

Allocation in LCA of wood-based products experiences of cost action E9

Goal and BackgroundThe treatment of allocation in the descriptive LCA of wood-based products has been discussed for a long time and different solutions have been presented. In general, it is accepted that the influence of different allocation procedures on the results of LCA of wood-based products can be very significant. This paper is a result of the Cost Action E9 ‘Life cycle assessment of forestry and forest products’ and represents the experience of involved Cost E9 delegates.ObjectiveWood is a renewable material that can be used for wood products and energy production. Consistent methodological procedures are needed in order to correctly address the twofold nature of wood as a material and fuel, the multi-functional wood processing generating large quantities of co-products, and reuse or recycling of paper and wood. Ten different processes in LCAs of wood-based products are identified, where allocation questions can occur: forestry, sawmill, wood industry, pulp and paper industry, particle board industry, recycling of paper, recycling of wood-based boards, recycling of waste wood, combined heat and power production, landfill.MethodologyFollowing ISO 14 041 a step-wise procedure for system boundary setting and allocation are outlined. As a first priority allocation should be avoided by system expansion, thus adding additional functions to the functional unit. Alternatively, the avoided-burden approach can be followed by subtracting substituted functions of wood that are additionally provided. If allocation cannot be avoided, some allocations methods from case studies are described.ConclusionsThe following conclusions for allocation in LCA of wood-based products are given. 1) Avoid allocation by expansion of system boundaries by combining material and energy aspects of wood, meaning a combination of LCA of wood products and of energy from wood with a functional unit for products and energy. 2) Substitute energy from wood with conventional energy in the LCA of wood products to get the functional unit of the wood product only, but identify the criteria for the substituted energy. 3) Substitution of wooden products with non-wooden products in LCA of bioenergy is not advisable, because the substitution criteria can be too complex. 4) If avoiding allocation is not possible, the reasons should be documented. 5) Different allocation procedures must be analysed and documented. In many cases, it seems necessary to make a sensitivity analysis of different allocation options for different environmental effects. It can also be useful to get the acceptance of the chosen allocation procedure by external experts. 6) Different allocation factors, e.g. mass or economic value, are allowed within the same LCA. 7) For allocation of forestry processes it is necessary to describe the main function of the forest where the raw material is taken out. In some cases different types or functions of forests must be considered and described. 8) Regarding the experiences from the examples, the following most practical allocation for some specific processes are identified: forestry: mass or volume; sawmill: mass or volume and proceeds; wood industry: mass and proceeds.

Biorefinery Concepts in Comparison to Petrochemical Refineries

Biorefinery, the sustainable processing of biomass into a spectrum of marketable products and energy, is compared to petrochemical refineries. The economic value of biomass refining as well as a universal classification system will be discussed. Examples of conventional and advanced biorefineries including oleochemical, lignocellulosic feedstock, next generation hydrocarbon, and green biorefinery will be presented. Special emphasis is given to the comparison of biorefinery concepts with petrochemical refineries in relation to the different platform molecules currently used in petrochemical refineries. To better assess the different biorefinery concepts the Biorefinery Complexity Index will be introduced. The ambition of this index is to create a tool for industry, decision-makers, and investors to better judge potential and risks of the different biorefinery concepts on short, medium, and long term.

Energy aspects in LCA of forest products - guidelines from Cost Action E9

Intention and Background.This paper outlines guidelines for the treatment of energy in LCAs of forest products. The paper is a result of the Cost Action E 9 ‘Life cycle assessment of forestry and forest products’ and reflects the experience of Cost E9 delegates, contributing to Working Group ‘End of life — recycling, disposal and energy generation’.ObjectivesAfter overviewing different aspects of energy in LCA of forest products, the most important aspects are identified: 1) energy and carbon balance, 2) energy generation, 3) energy substitution and 4) comparison with other waste management options. For these aspects, guidelines are developed and examples are given to demonstrate the practical application of recommended guidelines.ConclusionsBeside the proper treatment of the above mentioned aspects, the following conclusions for the LCA practitioners are given: 1) Draw attention to losses of potential energy in carbon flows. 2) Compared to heating value of biomass the auxiliary energy need is low (<10%). 3) The substitution rate (bioenergy for fossil fuel) might be lower than 100%, depending on technical systems available. 4) A high substitution rate might be an optimisation criterion for LCA. 5) A sensitivity analysis of different substitution criteria should be made. 6) Compare energy generation to other waste management options. 7) Use of bioenergy might be ‘CO2-neutral’, but not ‘CO2-free’. 8) Most important benefit of bioenergy is greenhouse gas reduction by substituting fossil energy.

Solving the multifunctionality dilemma in biorefineries with a novel hybrid mass–energy allocation method

Processing biomass into multifunctional products can contribute to food, feed, and energy security while also mitigating climate change. However, biorefinery products nevertheless impact the environment, and this influence needs to be properly assessed to minimize the burden. Life cycle assessment (LCA) is often used to calculate environmental footprints of products, but distributing the burdens among the different biorefinery products is a challenge. A particular complexity arises when the outputs are a combination of energy carrying no mass, and mass carrying no energy, where neither an allocation based on mass nor on energy would be appropriate. A novel hybrid mass–energy (HMEN) allocation scheme for dealing with multifunctionality problems in biorefineries was developed and applied to five biorefinery concepts. The results were compared to results of other allocation methods in LCA. The reductions in energy use and GHG emissions from using the biorefinerys biofuels were also quantified. HMEN fairly distributed impacts among biorefinery products and did not change the order of the products in terms of the level of the pollution caused. The allocation factors for HMEN fell between mass and economic allocation factors and were comparable to energy allocation factors. Where the mass or the energy allocation failed to attribute burdens, HMEN addressed this shortcoming by assigning impacts to nonmass or to nonenergy products. Under the partitioning methods and regardless of the feedstock used, bioethanol reduced GHG by 72–98% relative to gasoline. The GHG savings were 196% under the substitution method, but no GHG savings occurred for sugar beet bioethanol under the surplus method. Bioethanol from cellulosic crops had lower energy use and GHG emissions than from sugar beet, regardless of the allocation method used. HMEN solves multifunctional problems in biorefineries and can be applied to other complex refinery systems. LCA practitioners are encouraged to further test this method in other case studies.

Chapter 1 – Bioeconomy Strategies

Facing a shortage of petrochemicals in the long term, biomass is expected to be the main future feedstock for chemicals, including liquid transportation fuels. Currently, biomass is mainly used for food, feed, and material purposes; only a small fraction is used in energy conversion (ie, heating/cooling, power, or transport fuels). The “bioeconomy” has been referred to as the set of economic activities that relate to the invention, development, production and use of biological products and processes. The transition from an economy based on fossil raw materials to a bioeconomy, obtaining its raw materials from renewable biological resources requires concerted efforts by international institutions, national governments, and industry sectors, and prompts for the development of bioeconomy policy strategies. However, there is still little understanding on how current markets will transition towards a national and essentially global bioeconomy. This joint analysis brings together expertise from three IEA Bioenergy subtasks: Task 34 on Pyrolysis, Task 40 on International Trade and Markets, and Task 42 on Biorefineries. The underlying hypothesis is that bioeconomy market developments can benefit from lessons learned and developments observed in bioenergy markets. The question is not only how the bioeconomy can be developed, but also how it can be developed sustainably in terms of economic and environmental concerns. The strength of bringing three IEA Bioenergy subtasks into this analysis is found in each task’s area of expertise. Tasks 34 and 42 identify the types of biorefineries that are expected to be implemented and the types of feedstock that may be used. Task 40 provides complementary work including a historical analysis of the developments of biopower and biofuel markets, integration opportunities into existing supply chains, and the conditions that would need to be created and enhanced to achieve a biomass supply system supporting a global bioeconomy.

Key issues in life cycle assessment of electric vehicles — Findings in the International Energy Agency (IEA) on Hybrid and Electric Vehicles (HEV)

Electric vehicles have the potential to substitute for conventional vehicles and to contribute to the sustainable development of the transportation sector worldwide, e.g. reduction of greenhouse gas and particle emissions. There is an international consensus that the improvement of the sustainability of electric vehicles can only be analysed on the basis of life cycle assessment (LCA) including the production, operation and the end of life of the vehicles. Based on LCA activities in the 17 member countries, the International Energy Agency (IEA) Implementing Agreement on Hybrid and Electric Vehicles (IA-HEV) works in a Task on the LCA of electric vehicles. In this Task 19 “Life Cycle Assessment of Electric Vehicles - From raw material resources to waste management of vehicles with an electric drivetrain” the key issues of applying LCA to EVs&HEVs are identified and applied in various case studies. The following seven categories of key issues were identified, analysed and applied in “best practice” applications: 1) General issues, 2) Life cycle modelling, 3) Vehicle cycle (production - use - end of life), 4) Fuel cycle (electricity production), 5) Inventory analyses, 6) Impact assessment and 7) Reference system. For these seven key issues the main relevant factors were identified, reviewed and verified in international “best practice” applications.