Potential Impact Categories Research Articles

Environmental life cycle assessment of biogas production from marine macroalgal feedstock for the substitution of energy crops

The central objective of this paper is to evaluate the production of biogas by the substitution of energy crops with marine macroalgae: mixture of brown (20%) and red algae (80%) as feedstock in an industrial scale biogas plant. This plant operates with the co-digestion of maize (27%), grass (54%), rye (8%) and chicken manure (11) and produces 500 kWh energy. In order to assess environmental friendliness, a life cycle assessment was performed by using the software Simapro. Potential environmental impact categories under investigation were global warming, acidification, eutrophication and land transformation potential.Our results determine the affirmative impact of the codigestion of algae with chicken manure on the emission reductions: 52%, 83%, 41% and 8% lower global warming, acidification, eutrophication and land transformation potentials, respectively per 1 MJ of energy generation, moreover, 84% and 6% lower acidification and land transformation potentials per kg of feedstock.

Water and carbon footprint of selected dairy products: A case study in Catalonia

This study assesses the LCA-based Water Footprint (WF) and Carbon Footprint (CF) of various types of yoghurts in the Spanish dairy plant of La Fageda. Primary data have been used to allocate impacts to the core processing stages. . The total amount of water consumption and greenhouse gas emissions for the production of 1 kg of yoghurt in La Fageda plant are 204 L H2O and 1.94 kg CO2eq respectively. The results indicated that raw milk and milk-based ingredients are the main contributors to all impact categories examined; their contribution to CO2eq ranged from 80 to 96%. Energy consumption and packaging materials have significant contribution to freshwater ecotoxicity, acidification and global warming potential (GWP) impact categories ranging from 30 to 99% when raw milk is excluded from the analysis. In terms of the direct impacts of the plant, Cleaning in Place (CIP) and cleaning operations are responsible for 70% of the water requirements, while refrigerators, pasteurisation and packaging account for 70% of the energy consumption in the facility. The water and carbon footprint varies depending on the production process and the region. The sensitivity analysis illustrates that high precipitation and application of different techniques for raw milk production increases the contribution of the direct impacts of the plant from 2% to 15% in terms of water use.

Innovation strategies in a fruit growers association impacts assessment by using combined LCA and s-LCA methodologies

In the challenging world of territorial transformations within the agriculture, there is an increasing need for an integrated methodological framework of assessment that is able to reconcile the demand for solutions that are both economically sustainable and contribute to environmental and social improvement.This study aims to assess the introduction of innovation into agro-food systems by combining an environmental life cycle (LCA) assessment and a social life cycle assessment (s-LCA) to support the decision making process of a fruit growers co-op for the adoption of mulching and covering in raspberry farming. LCA and s-LCA have been applied independently under specific consistency requirements, selecting two scenarios to compare the impact with (1) and without (2) the innovation and then combined within a cause-effect chain. The interactions between the environment and socioeconomic components were considered within a nested frameset of business and territorial features. The total emissions from raspberry production in Scenario 1, according to the Global Warming Potential (GWP) Impact Category amounted to 2.2840kg of CO2 eq. In Scenario 2, the impact of production was associated with a GWP of 0.1682kg of CO2 eq. Social repercussions analysis from Scenario 1 compared to Scenario 2 indicate more satisfaction for working conditions and the management of climate risks. The mulching and covering, implemented within a given framework of farm activity, created conditions for the preservation of a model in which raspberry production contributes to landscape protection, the business sustainability of farms and the creation of employment. The combined use of the two methods contributes to the development of a strategy planning due to its ability to deliver, as well as specific analysis at a functional level, a wider framework for assessing the consistency of the impacts related to innovation in raspberry production.

Environmental impact assessment of centralized municipal wastewater management in Thailand

Urbanization and industrial development intensify water utilization and wastewater generation. The efficiency of wastewater treatment systems varies and depends on system design and wastewater condition. The research aims to examine seven existing centralized municipal wastewater treatment plants (WWTPs) in Bangkok to discover which system configuration yields the best environmental and economic performance. The degree of environmental impact and operational costs from different system designs were investigated to help select future wastewater treatment systems. Life cycle assessment (LCA) has been conducted to evaluate environmental impacts from centralized municipal wastewater treatment systems. Life cycle impact assessment method based on endpoint modeling (LIME) was applied, with three major potential environmental impact categories including eutrophication, global warming, and acidification. All seven centralized municipal WWTPs in Bangkok were investigated as case studies. The system configurations are classified into five types of activated sludge (AS) systems. The contribution of impacts from individual processes in each type of AS system was analyzed. The methodology covered major on-site and off-site operational processes excluding construction and maintenance phases. Average annual data were calculated to develop an inventory dataset. JEMAI-Pro software was utilized in this study to analyze the life cycle impact of the systems. The level of environmental impact from a WWTP depends on the configuration of the AS system. The highest potential environmental impact from a municipal WWTP is eutrophication, which is obviously affected by ammonium and phosphorous discharges into water bodies. The vertical loop reactor activated sludge (VLRAS) system yielded the best treatment performance among the five AS sub-systems. The consumption of electricity used to operate the system contributed significantly to global warming potential and correlated considerably with operating costs. Comparing among three system sizes, the large-scale WWTP revealed inefficient electricity consumption, whereas the medium plant provided better performance in chemical use and operating costs. Centralized municipal WWTPs with capacities ranging from 10 to 350 × 103 m3/day were evaluated with respect to environmental performance and costs during the operating phase. Among all case studies, a medium-scale WWTP with a VLRAS system offered the best operating performance in terms of low environmental impact, resource consumption, and cost. To enhance WWTP management, it is vital to improve the efficiency of electricity consumption in primary and secondary treatment processes and increase wastewater collection efficiency to maximize the plant operating capacity and minimize overall environmental impacts.

Comparison Study of Environmental Impacts between Mid (CML) and End Point (Eco 95) Methods for Babel Lead Acid Battery Production Processes

In this research, quantitative analysis, comparison of the environmental impacts for Iraqi Babel Lead acid battery (capacity of 135 Amps/hr) throughout the production processes is conducted for 2012 year, according to the ISO (14040-14043) series of standards. Two impact assessment methods employed are; Centre of Environmental Studies (CML–midpoint) and (Eco 95-endpoint). Chain Management Life Cycle Analysis [CMLCA] software is used to process and generate the collected data. In CML (mid-point) method four potential environmental impact categories are; [Global Warming Potential (GWP), Acidification, Eutrophication, and Human toxicity], while Eco 95 (endpoint) method evaluates six categories of environmental impact are; [Global Warming Potential (GWP), Acidification, Eutrophication, Heavy metals, Summer, and Winter Smog]. Results generated according to CML method reveal that formation process as the highest contributor to GWP by (26%), Eco 95 declared contribution to the GWP of the same process by (4%). Through CML (mid-point) the assembly process is identified as having the most significant impact on acidification by (50%), while Eco 95 method quantify acidification for the same process by (4%). Human toxicity is allocated by (60%) contribution in the assembly process by CML method, whereas the same process is identified as the most hazardous process of (93%) contribution heavy metals impact is, and winter smog (3%) according to Eco 95 method. Formation process is the highest contributor to Eutrophication according CML method, while Eutiphication is not of concern, according to (Eco 95) for this process. It is concluded that the environmental impacts of Babel battery spread over the production processes and every process have certain environmental impact category (nerveless the quantifying method). Therefore, it is recommended using both methods to expose all the environmental categories, and to control the environmental aspects of the company, also it is recommended to use new technologies for battery production that have less impact on the environment.

Comparative impact assessment study of various hydrogen production methods in terms of emissions

A comparative environmental impact assessment is performed for different hydrogen production methods. The methods are characterised on the basis of different energy sources such as renewables and fossil fuel. Steam methane reforming (SMR) of natural gas is studied and is categorized under the fossil fuel based hydrogen production. Renewable based hydrogen production includes electrolysis using sodium chlorine cycle. Electrolytic hydrogen production is also compared using membrane cell, diaphragm cell and mercury cell. Wind and solar energy is utilized for electricity generation which is in turn used in electrolytic hydrogen production. The present study uses life cycle assessment (LCA), which is an analytical tool to identify and quantify environmentally critical phases during the life cycle of a system or a product and/or to evaluate and decrease the overall environmental impact of the system or product. The LCA results of the hydrogen production processes indicate that SMR of natural gas has the highest environmental impacts in terms of abiotic depletion, global warming potential, greenhouse gases and other impact categories. The abiotic depletion for SMR is found to be 0.131 kg Sb eq. which is the highest among all methods. The second highest abiotic depletion value is electrolysis using mercury cell which is 0.00786 kg Sb eq. However, thermodynamic results suggest-that SMR is the most efficient method of hydrogen production because the amount of hydrogen energy produced as output in the system is larger than any other method.

DEALING WITH LCA MODELING FOR THE END OF LIFE OF MECHATRONIC PRODUCTS

This paper discusses end-of-life (EoL) modeling issues in Life Cycle Assessment (LCA), through the application to a domestic cooker hood. Two EoL approaches are applied and discussed, namely the avoided burden and the one recommended by the Product Environmental Footprint (PEF) Guide, presently under testing. While no case studies on PEF application have been published yet, to the best of our knowledge, the scientific community is questioning the robustness and relevance of some methodological aspects, especially the EoL formula. The objective of the work is to provide a case study for supporting the scientific discussion on EoL modeling by: applying the avoided burden approach to the cooker hood EoL; testing the PEF EoL approach on a cooker hood component, the aluminum filter, and compare the results with those obtained from the avoided burden approach; evaluating how both the approaches affect the allocation of burdens/credits associated to recycling. The Global Warming Potential (GWP) and the Abiotic Depletion Potential (ADP) impact categories are investigated. The study points out that the PEF EoL approach delivers higher environmental impacts than the avoided burden one, due to a reduced contribution from the avoided impacts. Overall, the application of the PEF EoL approach is more complex, due to the additional and often not available information needed, such as the recycled content of the materials and the disposal treatments that are avoided when recycled materials are used in the product. Also the structure of the LCA datasets may limit the application of the PEF EoL.

Carbon Footprint of Cassava Starch Production in North-Eastern Thailand

Carbon footprint was calculated for cassava starch product in Thailand. Objective of this study was to evaluate and compare the global warming impacts of cassava starch production in 3 factories located in North-Eastern Thailand. The system boundary was defined from cradle to factory gate, starting from cassava cultivation and harvesting until cassava starch production by using life cycle assessment (LCA) methodology based on ISO 14040 series. The selected functional unit was 1,000kg of dry native starch, excluding packaging. Input and output data were analyzed and results were shown in terms of global warming potential (GWP) impact categories. The average greenhouse gases (GHGs) emission value based on LCA methodology of 3 factories was 594 kgCO2e per one ton of dry native starch. The results indicated that the cultivation and harvesting procedure was the major source emitting GHGs, around 40-59% of the total, if the factory used the biogas from wastewater treatment plant. Based on this result, the estimated total GHGs emission of cassava starch production in Thailand in the year 2013 was a total of approximately 10,500 million tons of CO2e.

Quantifying carbon sequestration on sheep grazing land in Australia for life cycle assessment studies

The sheep industry has played an important role in Australia’s development and economy over the 220 years since European settlement and remains an important land use in Australia, occupying an estimated 85 million ha of continental land mass. Historically, deforestation was carried out in many sheep-rearing regions to promote pasture growth but this has not occurred within recent decades and many wool producers have invested in planting trees as well as preserving patches of remnant vegetation. Although the limitations of single environmental impact studies are recognised, this paper focuses on the contribution of carbon sequestration in trees and shrubs on sheep farms to the global warming potential impact category in life cycle assessment of wool. The analysis represents three major wool-producing zones of Australia. Based on default regional yields as applied in Australia’s National Inventory model, FullCAM, CO2 removals in planted exotic pines and mixed native species were estimated to be 5.0 and 3.0 t CO2 ha–1 year–1, respectively, for the Northern Tablelands of New South Wales in the ‘high-rainfall zone’ and 1.4 t CO2 ha–1 year–1 for mixed native species in the ‘sheep-wheat zone’ of Western Australia. Applying modified factors allowing for the higher measured growth rates in regions with rainfall >300 mm, gave values for native species reforestation of 4.4 and 2.0 t CO2 ha–1 year–1 for New South Wales and Western Australia, respectively. Sequestration was estimated to be 0.07 t CO2 ha–1 year–1 over 100 years for chenopod shrublands of the ‘pastoral zone’ of South Australia but this low rate is significant because of the extent of regeneration. Sequestration of soil organic carbon in improved permanent pastures in the New South Wales Northern Tablelands was evaluated to be highly uncertain but potentially significant over large areas of management. Improved data and consistent methodologies are needed for quantification of these benefits in life cycle assessment studies for wool and sheep meat, and additional impact categories, such as biodiversity, need to be included if the public and private benefits provided by good management of vegetation resources on farms are to be more fully recognised.

A framework for deciding on the inclusion of emerging impacts in life cycle impact assessment

As technology progresses, so does the concern about the potential health impacts on humans and biodiversity that go in hand with technological development. Emerging new impacts that are characteristic of the anthropocene require more attention in current life cycle assessment (LCA), a framework in which many relevant impact assessment models are still missing. More attention, more data and more concern require the LCA community to intervene and to start or increase the modelling efforts to accommodate new impacts in LCA. To date the process of inclusion of new impacts in LCA has not yet been formalised. To deal with this process, a framework is here proposed and tested through the analysis of three emerging impact categories, noise, ecological light pollution (ELP) and radio-frequency electromagnetic fields (RF-EMF). We show that any development must start from a careful study of the theories and investigations from other specialist fields of science than the field of LCA. The gathering of such information is fundamental to assess the maturity of the impacts, their importance and the quality of the evidence that is available. In addition, this information has to be bridged to the computational structure of LCA, to check whether the physical properties of new impacts may be adjusted to the basics of LCA. We discuss the three new potential impact categories as a paradigm for action for any new development in LCA.

From “farm to fork” strawberry system: Current realities and potential innovative scenarios from life cycle assessment of non-renewable energy use and green house gas emissions

In this study, we analysed the environmental profile of the strawberry industry in Northern Italy. The analysis was conducted using two scenarios as reference systems: strawberry crops grown in unheated plastic tunnels using currently existing cultivation techniques, post-harvest management practices and consumption patterns (scenario 1) and the same strawberry cultivation chain in which some of the materials used were replaced with bio-based materials (scenario 2). In numerous studies, biodegradable polymers have been shown to be environmentally friendly, thus potentially reducing environmental impacts. These materials can be recycled into carbon dioxide and water through composting. Many materials, such as Mater-BI® and PLA®, are also derived from renewable resources. The methodology chosen for the environmental analysis was a life cycle assessment (LCA) based on a consequential approach developed to assess a product's overall environmental impact from the production system to its usage and disposal. In the field stage, a traditional mulching film (non-biodegradable) could be replaced with a biodegradable product. This change would result in waste production of 0kg/ha for the bio-based product compared to 260kg/ha of waste for polyethylene (PE). In the post-harvest stage, the issue addressed was the use and disposal of packaging materials. The innovative scenario evaluated herein pertains to the use of new packaging materials that increase the shelf life of strawberries, thereby decreasing product losses while increasing waste management efficiency at the level of a distribution platform and/or sales outlet. In the event of product deterioration or non-sale of the product, the packaging and its contents could be collected together as organic waste without any additional processes because the packaging is compostable according to EN13432. Scenario 2 would achieve reductions of 20% in the global warming potential and non-renewable energy impact categories.

Life cycle assessment of a food waste composting system: environmental impact hotspots

Abstract A life cycle assessment (LCA) approach was used to identify the processes and stages in organic waste composting that have the largest environmental impacts. The LCA included impacts associated with the collection of feedstock, production and distribution of compost, and its use as a replacement for peat for soil conditioning. The use phase of the compost product has not been included in previous LCA studies in the United States. Nine LCA impact categories were analyzed (global warming potential, ozone depletion, smog, acidification, eutrophication, carcinogens, non-carcinogens, respiratory effects, and ecotoxicity) using TRACI 2 methodology. The functional unit was defined as the collection, processing, transportation, and application of one tonne of compost that meets USEPA composting standards. The compost was produced at the Organics Material Processing and Education Center (OMPEC) at The Pennsylvania State University. The data used in the assessment was collected from seven composting windrows over thirteen consecutive months (December 2010–January 2012). Given the wide range of decomposition emission factors reported in the literature for methane (CH 4 ), nitrous oxide (N 2 O) and ammonia (NH 3 ), three emission scenarios were calculated: average, minimum, and maximum emission scenarios. Carbon dioxide (CO 2 ) emissions from the compost were considered biogenic and not included in the assessment. For all scenarios, compost processing was the stage with the largest environmental impact, with decomposition emissions contributing the most to global warming potential, acidification and eutrophication impact categories under the average and maximum emissions scenarios. To account for the avoided environmental impacts of peat mining and transport, these values were subtracted from the composting life cycle. The avoided impacts from peat replacement were higher than the impacts from composting for all categories, illustrating that using compost instead of peat results in net environmental gains. This study highlights the importance of minimizing life cycle impacts associated with CH 4 , N 2 O and NH 3 emissions during the decomposition process and the need for more consensus in the literature on emission values from composting processing.

Life cycle assessment of pyrolysis–gasification as an emerging municipal solid waste treatment technology

Waste-to-energy technologies are considered as one of the key waste treatment technologies due to their energy and heat recovery efficiencies from the waste. A number of research studies were accomplished to understand the potential environmental burdens from emerging waste treatment technologies such as pyrolysis–gasification (PG). The aim of this study was to examine the PG of municipal solid waste (MSW) treatment process through a life cycle assessment (LCA) method. The study also includes a comparative LCA model of PG and incineration to identify the potential environmental burdens from the existing (incineration) and emerging (PG) waste treatment technologies. This study focused on ten environmental impact categories under two different scenarios, namely: (a) LCA model of PG and (b) comparative LCA model of PG and incineration. The scenario (a) showed that PG had significant environmental burdens in the aquatic eco-toxicity and the global warming potential impact categories. The comparative scenario (b) of PG and incineration of MSW showed that PG had comparatively lower potential environmental burdens in acidification, eutrophication, and aquatic eco-toxicity. Both LCA models showed that the environmental burdens were mainly caused by the volume of the thermal gas (emissions) produced from these two technologies and the final residue to disposal. Therefore, the results indicate that the efficiency and environmental burdens of the emerging technologies are dependent on the emissions and the production of final residue to the landfill.

Environmental assessment of urban water cycle on Mediterranean conditions by LCA approach

Urban water authorities in many countries are struggling to satisfy the increasing demand for both potable and non-potable water whilst also improving the environmental profile of the urban water system. The main goal of this study is to use the Life Cycle Assessment methodology to carry out an environmental analysis of every stage of the urban water cycle in Tarragona, a Mediterranean city of Spain (scenario I). These stages are: water abstraction, potable water treatment, intermediate pumping, distribution network, sewage collection and wastewater treatment. This study also proposes possible scenarios for improving the environmental performance reducing the high level of water stress resulting from increasing demand and limited resources: using reclaimed water (scenario II) and using desalination plants and reclaimed water to supply water during a drought (scenario III). Inventory analysis was performed using local operation data. In the current situation (scenario I) the main environmental impacts on urban water cycle were caused by 35.2% of distribution network, 20.5% of collection pumping and 13.8% of wastewater treatment plant for the Global Warming Potential impact category because these stages have high energy consumption. In Reclaimed water (scenario II), no significant improvement in indicators is observed, because the addition of environmental loads introduced by the tertiary treatment, except for the reduction in freshwater consumption due to the net water saving. In the drought scenario (scenario III), all impact categories have been increased from Scenario II e.g. 18% in Photochemical Oxidation, 21% in Eutrophication Potential, 30% Ozone Depletion Potential and Ecotoxicity Potential, 36% in Depletion of Abiotic Resources and Cumulative Energy Demand, 38% in Global Warming Potential and 42% in Acidification Potential.

Life cycle assessment of biofuel production from brown seaweed in Nordic conditions

The use of algae for biofuel production is expected to play an important role in securing energy supply in the next decades. A consequential life cycle assessment (LCA) and an energy analysis of seaweed-based biofuel production were carried out in Nordic conditions to document and improve the sustainability of the process. Two scenarios were analyzed for the brown seaweed (Laminaria digitata), namely, biogas production (scenario 1) and bioethanol+biogas production (scenario 2). Potential environmental impact categories under investigation were Global Warming, Acidification and Terrestrial Eutrophication. The production of seaweed was identified to be the most energy intensive step. Scenario 1 showed better performance compared to scenario 2 for all impact categories, partly because of the energy intensive bioethanol separation process and the consequently lower overall efficiency of the system. For improved environmental performance, focus should be on optimization of seaweed production, bioethanol distillation, and management of digestate on land.

Environmental assessment of energy production based on long term commercial willow plantations in Sweden

The present paper analyzed the environmental assessment of short rotation willow plantations in Sweden based on the standard framework of Life Cycle Assessment (LCA) from the International Standards Organisation. The analysis is focused on two alternative management regimes for willow plantations dedicated to biomass production for energy purposes. The data used included the averages of a large sample of commercial plantations. One of the scenarios is carried out under nitrogen based fertilized conditions and the other under non-fertilized management with total biomass yields (dry weight) of 140t/ha and 86t/ha over a 21 and 22-year life time respectively. The environmental profile was analyzed in terms of the potentials for abiotic depletion, acidification, eutrophication, global warming, ozone layer depletion, photochemical oxidant formation, human toxicity, fresh water aquatic ecotoxicity, marine aquatic ecotoxicity and terrestrial ecotoxicity. In addition, an energy analysis was performed using the cumulative energy demand method (CED). The application of nitrogen based fertilizers allows an increase in the biomass yield per ha of up to 40% although the contributions to almost all impact categories, particularly the eutrophication potential and toxicity potential impact categories are also considerably higher. Conversely, due to the higher biomass yields achieved with fertilization of these willow plantations, that regime presents a better overall environmental profile in terms of energy yield and global warming potential.

Home composting as an alternative treatment option for organic household waste in Denmark: An environmental assessment using life cycle assessment-modelling

An environmental assessment of the management of organic household waste (OHW) was performed from a life cycle perspective by means of the waste-life cycle assessment (LCA) model EASEWASTE. The focus was on home composting of OHW in Denmark and six different home composting units (with different input and different mixing frequencies) were modelled. In addition, incineration and landfilling was modelled as alternatives to home composting. The most important processes contributing to the environmental impact of home composting were identified as greenhouse gas (GHG) emissions (load) and the avoided emissions in relation to the substitution of fertiliser and peat when compost was used in hobby gardening (saving). The replacement of fertiliser and peat was also identified as one of the most sensible parameters, which could potentially have a significant environmental benefit. Many of the impact categories (especially human toxicity via water (HTw) and soil (HTs)) were affected by the heavy metal contents of the incoming OHW. The concentrations of heavy metals in the compost were below the threshold values for compost used on land and were thus not considered to constitute a problem. The GHG emissions were, on the other hand, dependent on the management of the composting units. The frequently mixed composting units had the highest GHG emissions. The environmental profiles of the home composting scenarios were in the order of −2 to 16 milli person equivalents (mPE) Mg −1 wet waste (ww) for the non-toxic categories and −0.9 to 28 mPE Mg −1 ww for the toxic categories. Home composting performed better than or as good as incineration and landfilling in several of the potential impact categories. One exception was the global warming (GW) category, in which incineration performed better due to the substitution of heat and electricity based on fossil fuels.

LCA of environmental and socio-economic impacts related to wood energy production in alpine conditions: Valle di Fiemme (Italy)

An extended Life Cycle Assessment (LCA) is performed for evaluating the impacts of a woody biomass supply chain for heating plants in the alpine region. Three main aspects of sustainability are assessed: greenhouse gas emissions, represented by global warming potential (GWP) impact category, costs and direct employment potential. We investigate a whole tree system (innovative logging system) where the harvest of logging residues is integrated into the harvest of conventional wood products. The case study is performed in Valle di Fiemme in Trentino region (North Italy) and includes theoretical and practical elements. The system boundary is the alpine forest fuel system, from logging operations at the forest stand to combustion of woody biofuels at the heating plant. The functional unit is 1 m 3 solid over bark of woody biomass, delivered to the district heating plant in Cavalese (Trento). The relative sustainability of traditional and innovative systems is compared and energy use is estimated. Results show that the overall GWP and costs are about 13 kg CO 2equivalent and 42 euro per functional unit respectively for the innovative system. Along the product supply chain, chipping contributes the greatest share of GWP and energy use, while extraction by yarder has the highest financial costs. The GWP is reduced by 2.3 ton CO 2equivalent when bioenergy substitutes fuel oil and 1.7 ton CO 2equivalent when it substitutes natural gas. The sensitivity analysis illustrates that variations in fuel consumption and hourly rates of costs have a great influence on chipping operation and extraction by cable yarder concerning GWP and financial analysis, respectively. This is confirmed by sensitivity analysis. Better technologies, the use of biofuels along the product supply chain and more efficient systems might reduce these impacts. Replacing the traditional system with the innovative one reduces emissions and costs. A low energy input ratio is required for harvesting logging residues. The direct employment potential is a conflicting aspect and needs further investigations.

Ökobilanz der Biogaserzeugung auf dem Unteren Lindenhof der Universität Hohenheim

Significant contributions to anthropogenic greenhouse gas emissions are caused by agricultural activities. An effective way to reduce agricultural emissions is the implementation of liquid manure to produce biogas, whereby the greenhouse gas emissions from manure storage are avoided. Additionally, renewable energy in terms of heat and electricity is generated in combined heat and power plants which substitute fossil power plants. The objective of this study was to assess the environmental impacts of biogas production at a research plant of the University of Hohenheim. A model was designed to evaluate the biogas production systems according to their environmental impact using Gabi 4.3 software. Besides global warming potential other impact categories have been used to evaluate the systems effects in the field of eutrophication and acidification. The results show that environmental benefits can be obtained with regard to the emission of greenhouse gases when comparing electricity production from biogas.

Comparison of allocation approaches in soybean biodiesel life cycle assessment

<title/>This work shows the influence of using different allocation approaches when modelling the inventory analysis in a soybean biodiesel life cycle assessment (LCA). Results obtained using mass, energy and economic based allocations are compared, focusing on the following aspects: normalised potential environmental impact (PEI) categories, total PEI and relative contributions to the total PEI from each life cycle stage and environmental impact category. Similar results are obtained either using economic and energy based allocations. However, different results are obtained when mass based allocation is used when compared with the other two. This study also illustrates that using different allocation approaches in biodiesel LCA may influence the final conclusions, especially in comparative assertions, emphasising the need to perform a sensitivity analysis in the LCA interpretation step.