The potential of optimized process design to advance LCA performance of algae production systems
Boxtel, A.J.B. van; Perez-Lopez, P. ; Breitmayer, E. ; Slegers, P.M. - \ 2015
Applied Energy 154 (2015). - ISSN 0306-2619 - p. 1122 - 1127.
life-cycle assessment - biodiesel production - microalgae
Environmental impact is an essential aspect for the introduction of algae production systems. As information of large scale algae production is hardly available, process simulation is the only way to evaluate environmental sustainability in an early phase of process design. Simulation results allow the evaluation of production and design scenarios, and reveal the potential to improve the Life Cycle Performance of algae production systems. In this work, we discuss how choices in the process design of algae production systems (cultivation, biorefinery and the supply chain) advance LCA-results
Effect of feed-related farm characteristics on relative values of genetic traits in dairy cows to reduce greenhouse gas emissions along the chain
Middelaar, C.E. van; Berentsen, P.B.M. ; Dijkstra, J. ; Arendonk, J.A.M. van; Boer, I.J.M. de - \ 2015
Journal of Dairy Science 98 (2015)7. - ISSN 0022-0302 - p. 4889 - 4903.
life-cycle assessment - genomic selection - economic values - milk-production - methane - cattle - mitigation - impact - level - model
Breeding has the potential to reduce greenhouse gas (GHG) emissions from dairy farming. Evaluating the effect of a 1-unit change (i.e., 1 genetic standard deviation improvement) in genetic traits on GHG emissions along the chain provides insight into the relative importance of genetic traits to reduce GHG emissions. Relative GHG values of genetic traits, however, might depend on feed-related farm characteristics. The objective of this study was to evaluate the effect of feed-related farm characteristics on GHG values by comparing the values of milk yield and longevity for an efficient farm and a less efficient farm. The less efficient farm did not apply precision feeding and had lower feed production per hectare than the efficient farm. Greenhouse gas values of milk yield and longevity were calculated by using a whole-farm model and 2 different optimization methods. Method 1 optimized farm management before and after a change in genetic trait by maximizing labor income; the effect on GHG emissions (i.e., from production of farm inputs up to the farm gate) was considered a side effect. Method 2 optimized farm management after a change in genetic trait by minimizing GHG emissions per kilogram of milk while maintaining labor income and milk production at least at the level before the change in trait; the effect on labor income was considered a side effect. Based on maximizing labor income (method 1), GHG values of milk yield and longevity were, respectively, 279 and 143 kg of CO2 equivalents (CO2e)/unit change per cow per year on the less efficient farm, and 247 and 210 kg of CO2e/unit change per cow per year on the efficient farm. Based on minimizing GHG emissions (method 2), GHG values of milk yield and longevity were, respectively, 538 and 563 kg of CO2e/unit change per cow per year on the less efficient farm, and 453 and 441 kg of CO2e/unit change per cow per year on the efficient farm. Sensitivity analysis showed that, for both methods, the absolute effect of a change in genetic trait depends on model inputs, including prices and emission factors. Substantial changes in relative importance between traits due to a change in model inputs occurred only in case of maximizing labor income. We concluded that assumptions regarding feed-related farm characteristics affect the absolute level of GHG values, as well as the relative importance of traits to reduce emissions when using a method based on maximizing labor income. This is because optimizing farm management based on maximizing labor income does not give any incentive for lowering GHG emissions. When using a method based on minimizing GHG emissions, feedrelated farm characteristics affected the absolute level of the GHG values, but the relative importance of the traits scarcely changed: at each level of efficiency, milk yield and longevity were equally important. Key words: breeding, milk yield, longevity, economic value.
Strategies for improving water use efficiency in livestock feed production in rain-fed systems
Kebebe, E.G. ; Oosting, S.J. ; Haileslassie, A. ; Duncan, A.J. ; Boer, I.J.M. de - \ 2015
Animal 9 (2015)05. - ISSN 1751-7311 - p. 908 - 916.
sub-saharan africa - life-cycle assessment - agriculture - management - ethiopia - adoption - intensification - farmers - trials - straw
Livestock production is a major consumer of fresh water, and the influence of livestock production on global fresh water resources is increasing because of the growing demand for livestock products. Increasing water use efficiency of livestock production, therefore, can contribute to the overall water use efficiency of agriculture. Previous studies have reported significant variation in livestock water productivity (LWP) within and among farming systems. Underlying causes of this variation in LWP require further investigation. The objective of this paper was to identify the factors that explain the variation in LWP within and among farming systems in Ethiopia. We quantified LWP for various farms in mixed-crop livestock systems and explored the effect of household demographic characteristics and farm assets on LWP using ANOVA and multilevel mixed-effect linear regression. We focused on water used to cultivate feeds on privately owned agricultural lands. There was a difference in LWP among farming systems and wealth categories. Better-off households followed by medium households had the highest LWP, whereas poor households had the lowest LWP. The variation in LWP among wealth categories could be explained by the differences in the ownership of livestock and availability of family labor. Regression results showed that the age of the household head, the size of the livestock holding and availability of family labor affected LWP positively. The results suggest that water use efficiency could be improved by alleviating resource constraints such as access to farm labor and livestock assets, oxen in particular.
Social sustainability of cod and haddock fisheries in the northeast Atlantic: what issues are important?
Veldhuizen, L.J.L. ; Berentsen, P. ; Bokkers, E.A.M. ; Boer, I.J.M. de - \ 2015
Journal of Cleaner Production 94 (2015). - ISSN 0959-6526 - p. 76 - 85.
life-cycle assessment - environmental impacts - production systems - fish - categories - indicators - products - welfare - stress - salmon
Research on the sustainability of capture fisheries has focused more on environmental and economic sustainability than on social sustainability. To assess social sustainability, first relevant and important social sustainability issues need to be identified. The objective of this study was to identify relevant social sustainability issues for cod and haddock fisheries in the northeast Atlantic and to determine the importance of these issues based on stakeholder input. A heterogeneous group of stakeholders was invited to take part in two consecutive surveys on social sustainability issues. The first survey (n=41) resulted in a long list of 27 relevant social sustainability issues, including six issues that were not identified in previous studies and that address aspects of fish welfare, employees' training and education opportunities, and employees' time off from work. The second survey (n=51) resulted in a ranking of the social sustainability issues in order of importance. The most important issues are worker safety, product freshness and companies' salary levels. In general, social sustainability issues concerning working conditions, employees' job fulfilment and fish welfare are seen as more important than other social sustainability issues. A main discussion point concerns the relation between the importance of a social sustainability issue on the one hand and the type of need that the issue relates to and the state of the issue on the other hand. From the study it can be concluded that the relative importance of social sustainability issues differs per stakeholder group depending on the relation between the stakeholder group and each particular issue. This demonstrates the importance of consulting different stakeholder groups in future studies on social sustainability in order to get a balanced view on the importance of social sustainability issues. Results on the relevance and importance of social sustainability issues for cod and haddock fisheries in the northeast Atlantic enable the fishing industry and policy-makers to direct improvement efforts towards the more important issues. ©
Sustainability of milk production in the Netherlands - A comparison between raw organic, pasteurised organic and conventional milk
Asselt, E.D. van; Capuano, E. ; Fels-Klerx, H.J. van der - \ 2015
International Dairy Journal 47 (2015). - ISSN 0958-6946 - p. 19 - 26.
life-cycle assessment - environmental impacts - production systems - dairy farms - tool - metaanalysis - agriculture - consumption - indicators - quality
Consumer preferences are changing, resulting in an increased demand for both organic milk and raw milk due to their perceived higher nutritional value and positive contribution to animal welfare. To compare the advantages and disadvantages of these products with conventional pasteurised milk, a sustainability assessment was performed incorporating social, environmental and economic factors. The assessment showed that raw organic milk gave the highest overall sustainability score. This is due to, for example, a high score for animal welfare and a high score for the environmental factors due to the omission of the pasteurisation step compared with conventional milk. The latter may pose human health risks due to the possible presence of pathogens in raw milk. As the approach followed is transparent, it allows policy makers to discuss the outcome of the sustainability assessment both with stakeholders and the general public, which will facilitate the decision making process.
Resource-efficient supply chains: a research framework, literature review and research agenda
Matopoulos, A. ; Barros, A.C. ; Vorst, J.G.A.J. van der - \ 2015
Supply Chain Management : an International Journal 20 (2015)2. - ISSN 1359-8546 - p. 218 - 236.
greenhouse-gas emissions - life-cycle assessment - food-production systems - carbon footprint - land-use - environmental assessment - conceptual-framework - manufacturing firms - energy efficiency - complexity theory
Purpose – The study aims to define a research agenda for creating resource-efficient supply chains (RESCs) by identifying and analysing their key characteristics as well as future research opportunities. Design/methodology/approach – We follow a systematic review method to analyse the literature and to understand RESC, taking a substantive theory approach. Our approach is grounded in a specific domain, the agri-food sector, because it is an intensive user of an extensive range of resources. Findings – The review shows that works of literature has looked at the use of resources primarily from the environmental impact perspective. There is a need to explore whether or not and how logistics/supply chain decisions will affect the overall configuration of future food supply chains in an era of resource scarcity and depletion and what the trade-offs will be. Research imitations/implications – The paper proposes an agenda for future research in the area of RESC. The framework proposed along with the key characteristics identified for RESC can be applied to other sectors. Practical implications – Our research should facilitate further understanding of the implications and trade-offs of supply chain decisions taken on the use of resources by supply chain managers. Originality/value – The paper explores the interaction between supply chains and natural resources and defines the key characteristics of RESC. Keywords Systematic literature review, Logistics and supply chain design decisions, Natural resource-based view, Resource scarcity, Resource-efficiency, Sustainable supply chains
Cell disruption for microalgae biorefineries
Günerken, E. ; Hondt, E. d'; Eppink, M.H.M. ; Garcia-Gonzalez, L. ; Elst, K. ; Wijffels, R.H. - \ 2015
Biotechnology Advances 33 (2015)2. - ISSN 0734-9750 - p. 243 - 260.
microwave-assisted extraction - fluidized-bed adsorption - electric-field treatment - synechocystis pcc 6803 - life-cycle assessment - chlorella-vulgaris - lipid extraction - microbial-cells - saccharomyces-cerevisiae - biodiesel production
Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies.
Analysis of sustainability metrics and application to the catalytic production of higher alcohols from ethanol
Patel, A.D. ; Telalovic, S. ; Bitter, J.H. ; Worrell, E. ; Patel, M.K. - \ 2015
Catalysis today 239 (2015). - ISSN 0920-5861 - p. 56 - 79.
life-cycle assessment - nanofiber-supported platinum - solid-base catalysts - guerbet reaction - ghg emissions - hydroxyapatite - condensation - hydrogenation - 1-butanol - energy
Use of sustainability metrics can help channel chemical research toward important long-term societal goals. For effective outcomes, it is important to understand the strengths and weaknesses of the sustainability assessment methods that can be applied in the chemical process development chain. In this paper we report the results from application of sustainability metrics in parallel with findings from laboratory research for production of higher alcohols from ethanol by application of the Guerbet reaction. 2-Ethyl-1-hexanol is used as an exemplary compound for the targeted higher alcohols. The accuracy of early-stage sustainability metrics using laboratory data is evaluated by comparing the results with metrics based on detailed process simulation models, techno-economic analysis and life cycle assessment. The analysis has provided insights on pitfalls to avoid and effective application of early-stage metrics considering the dynamic nature of information available from laboratory research. Anticipation of the process configuration was found to be particularly important for effective application of early-stage metrics. The results from catalysis research for 2-ethyl-1-hexanol highlight the potential opportunities for higher chain Guerbet alcohols from biobased ethanol. The comparison of this biobased route with conventional fossil based process shows the challenges for such a process from an economic and environmental perspective.
The way forward in biochar research: targeting trade-offs between the potential wins
Jeffery, S.L. ; Bezemer, T.M. ; Cornelissen, G. ; Kuyper, T.W. ; Lehmann, J. ; Mommer, L. ; Sohi, S.P. ; Voorde, T.F.J. van de; Wardle, D.A. ; Groeningen, J.W. van - \ 2015
Global change biology Bioenergy 7 (2015)1. - ISSN 1757-1693 - p. 1 - 13.
life-cycle assessment - soil organic-matter - black carbon - climate-change - conservation agriculture - sustainable agriculture - pyrolysis temperature - anaerobic-digestion - chemical-properties - nitrogen dynamics
Biochar application to soil is currently widely advocated for a variety of reasons related to sustainability. Typically, soil amelioration with biochar is presented as a multiple-‘win’ strategy, although it is also associated with potential risks such as environmental contamination. The most often claimed benefits of biochar (i.e. the ‘wins’) include (i) carbon sequestration; (ii) soil fertility enhancement; (iii) biofuel/bioenergy production; (iv) pollutant immobilization; and (v) waste disposal. However, the vast majority of studies ignore possible trade-offs between them. For example, there is an obvious trade-off between maximizing biofuel production and maximizing biochar production. Also, relatively little attention has been paid to mechanisms, as opposed to systems impacts, behind observed biochar effects, often leaving open the question as to whether they reflect truly unique properties of biochar as opposed to being simply the short-term consequences of a fertilization or liming effect. Here, we provide an outline for the future of soil biochar research. We first identify possible trade-offs between the potential benefits. Second, to be able to better understand and quantify these trade-offs, we propose guidelines for robust experimental design and selection of appropriate controls that allow both mechanistic and systems assessment of biochar effects and trade-offs between the wins. Third, we offer a conceptual framework to guide future experiments and suggest guidelines for the standardized reporting of biochar experiments to allow effective between-site comparisons to quantify trade-offs. Such a mechanistic and systems framework is required to allow effective comparisons between experiments, across scales and locations, to guide policy and recommendations concerning biochar application to soil.
Multiple data sets and modelling choices in a comparative LCA of disposable beverage cups
Harst, E.J.M. van der; Potting, J. ; Kroeze, C. - \ 2014
Science of the Total Environment 494-495 (2014). - ISSN 0048-9697 - p. 129 - 143.
life-cycle assessment - global warming contributions - environmental assessment - greenhouse gases - paper - system - pulp - management - impacts - options
This study used multiple data sets and modelling choices in an environmental life cycle assessment (LCA) to compare typical disposable beverage cups made from polystyrene (PS), polylactic acid (PLA; bioplastic) and paper lined with bioplastic (biopaper). Incineration and recycling were considered as waste processing options, and for the PLA and biopaper cup also composting and anaerobic digestion. Multiple data sets and modelling choices were systematically used to calculate average results and the spread in results for each disposable cup in eleven impact categories. The LCA results of all combinations of data sets and modelling choices consistently identify three processes that dominate the environmental impact: (1) production of the cup's basic material (PS, PLA, biopaper), (2) cup manufacturing, and (3) waste processing. The large spread in results for impact categories strongly overlaps among the cups, however, and therefore does not allow a preference for one type of cup material. Comparison of the individual waste treatment options suggests some cautious preferences. The average waste treatment results indicate that recycling is the preferred option for PLA cups, followed by anaerobic digestion and incineration. Recycling is slightly preferred over incineration for the biopaper cups. There is no preferred waste treatment option for the PS cups. Taking into account the spread in waste treatment results for all cups, however, none of these preferences for waste processing options can be justified. The only exception is composting, which is least preferred for both PLA and biopaper cups. Our study illustrates that using multiple data sets and modelling choices can lead to considerable spread in LCA results. This makes comparing products more complex, but the outcomes more robust.
Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe
Blaas, H. ; Kroeze, C. - \ 2014
Science of the Total Environment 496 (2014). - ISSN 0048-9697 - p. 45 - 53.
life-cycle assessment - biodiesel - microalgal
Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed. To this end, scenarios for the year 2050 are analysed, assuming that in the 27 countries of the European Union fossil diesel will be replaced by biodiesel from algae. Estimates are made for the required fertiliser inputs to algae parks, and how this may increase concentrations of nitrogen and phosphorus in coastal waters, potentially leading to eutrophication. The Global NEWS (Nutrient Export from WaterSheds) model has been used to estimate the transport of nitrogen and phosphorus to the European coastal waters. The results indicate that the amount of nitrogen and phosphorus in the coastal waters may increase considerably in the future as a result of large-scale production of algae for the production of biodiesel, even in scenarios assuming effective waste water treatment and recycling of waste water in algae production. To ensure sustainable production of biodiesel from micro-algae, it is important to develop cultivation systems with low nutrient losses to the environment.
Sustainability of meat production beyond carbon footprint: a synthesis of case studies from grazing systems in Uruguay
Picasso, V.D. ; Modernel Hristoff, P.D. ; Becona, G. ; Salvo, L. ; Gutierrez, L. ; Astigarraga, L. - \ 2014
Meat Science 98 (2014)3. - ISSN 0309-1740 - p. 346 - 354.
life-cycle assessment - impact assessment - sequestration - emissions - climate - grasslands - balance
Livestock production has been challenged as a large contributor to climate change, and carbon footprint has become a widely used measure of cattle environmental impact. This analysis of fifteen beef grazing systems in Uruguay quantifies the range of variation of carbon footprint, and the trade-offs with other relevant environmental variables, using a partial life cycle assessment (LCA) methodology. Using carbon footprint as the primary environmental indicator has several limitations: different metrics (GWP vs. GTP) may lead to different conclusions, carbon sequestration from soils may drastically affect the results, and systems with lower carbon footprint may have higher energy use, soil erosion, nutrient imbalance, pesticide ecotoxicity, and impact on biodiversity. A multidimensional assessment of sustainability of meat production is therefore needed to inform decision makers. There is great potential to improve grazing livestock systems productivity while reducing carbon footprint and other environmental impacts, and conserving biodiversity.
A model-based combinatorial optimisation approach for energy-efficient processing of microalgae
Slegers, P.M. ; Koetzier, B.J. ; Fasaei, F. ; Wijffels, R.H. ; Straten, G. van; Boxtel, A.J.B. van - \ 2014
Algal Research 5 (2014). - ISSN 2211-9264 - p. 140 - 157.
response-surface methodology - life-cycle assessment - biodiesel production - algal biomass - process integration - transesterification - oil - flocculation - biorefinery - extraction
The analyses of algae biorefinery performance are commonly based on fixed performance data for each processing step. In this work, we demonstrate a model-based combinatorial approach to derive the design-specific upstream energy consumption and biodiesel yield in the production of biodiesel from microalgae. Process models based on mass and energy balances and conversion relationships are presented for several possible process units in the algae processing train. They allow incorporating the effects of throughput capacity and process conditions, which is not possible in the data-based approach. Therefore, the effect of choices in the design on the overall performance can be quantified. The process models are organised in a superstructure to evaluate all combinations of routings. First, this is done for selected fixed design conditions, which is followed by optimisation of the process conditions for each route by maximising the net energy ratio (NER), based on upstream energy consumption and biodiesel yield. A scenario based on current energy production and state-of-the art techniques for algae processing is considered. The optimised process conditions yield NER values which are up to about 30% higher than those for fixed process conditions. In addition, the approach allows a quantitative bottleneck analysis for each process route. The model-based approach proves to be a versatile tool to guide the design of efficient microalgae processing systems.
Comparison of environmental performance for different waste management scenarios in East Africa: The case of Kampala City, Uganda
Oyoo, R. ; Leemans, R. ; Mol, A.P.J. - \ 2014
Habitat International 44 (2014). - ISSN 0197-3975 - p. 349 - 357.
life-cycle assessment - greenhouse-gas emissions - organic household waste - cities - home - systems - china - water
Poor waste flows management in East African cities has become an environmental and public health concerns to the city authorities and the general public. We assessed the environmental impacts of waste recycling in Kampala City, for four designed waste management scenarios, namely: (1) Scenario S1 representing the current status quo, (2) Scenario S2 maximizing landfill, (3) Scenario S3 combining composting, resource recovery, landfill and sewerage, and (4) Scenario S4 integrating anaerobic digestion, resource recovery, landfill and sewerage. These scenarios are quantitatively assessed for environmental impacts of global warming, acidification, nutrient enrichment, photochemical ozone formation, water pollution and resource conservation. Sensitivity analyses are performed on the robustness for the ranking of the scenarios. Scenario S4 integrating anaerobic digestion, resource recovery, landfill and sewerage performs best for all environmental impact categories. Sensitivity analysis shows that this assessment result is robust. Therefore, integrating waste recycling into the formal waste management system for Kampala would considerably reduce the environmental impacts of waste flows. Also, considering the similarities in municipal solid waste compositions, sanitation systems and settlement patterns among the large cities in East Africa, assimilating waste recycling into the formal waste management systems for these cities would results in minimal environmental impacts for their waste flows.
The impact of the rebound effect of the use of first generation biofuels in the EU on greenhouse gas emissions: A critical review
Smeets, E.M.W. ; Tabeau, A.A. ; Berkum, S. van; Moorad, J. ; Meijl, J.C.M. van; Woltjer, G.B. - \ 2014
Renewable and Sustainable Energy Reviews 38 (2014). - ISSN 1364-0321 - p. 393 - 403.
life-cycle assessment - energy - policy - price
An important objective of the mandated blending of biofuel in conventional gasoline and diesel in the EU is reducing greenhouse gas (GHG) emissions. An important assumption thereby is that biofuels replace the production and consumption of oil. However, recent literature challenges this assumption, because an increased use of biofuels will lower oil prices and therefore result in increase crude oil consumption. This so-called rebound effect offsets the expected GHG emission saving effects of using biofuels. A review of eight studies, mainly on current and future US biofuel policies, provides insights in the current state of research into this topic, showing a wide range of values of the rebound effect of biofuel use, depending among others on the biofuel policy, the applied method and the model parameter assumptions. Generally, estimated rebound effects are negative in the country where biofuel use is being promoted (i.e. the use of 1 unit of biofuel reduces oil consumption by less than 1 unit; units on energy basis). The rebound effects in other countries are always positive (biofuel use reduces oil consumption by less than 1 unit so the total fuel consumption is increasing). The net global rebound effect is usually positive, which means that GHG emissions savings are not achieved as much as usually is assumed, or emissions may even increase. Own estimations with the global MAGNET computable general equilibrium model indicate a global rebound effect of the 10% biofuel blend mandate in the EU in the year 2020 of 22–30% (i.e. the use of 1 unit of biofuel reduces global oil consumption by 0.78–0.70 units). This means that GHG emissions will not be reduced as much as usually is assumed, or may even increase. These results show that rebound effects can significantly lower the effectiveness of biofuel policies in reducing GHG emissions.
Methods to determine the relative value of genetic traits in dairy cows to reduce greenhouse gas emissions along the chain
Middelaar, C.E. van; Berentsen, P.B.M. ; Dijkstra, J. ; Arendonk, J.A.M. van; Boer, I.J.M. de - \ 2014
Journal of Dairy Science 97 (2014)8. - ISSN 0022-0302 - p. 5191 - 5205.
enteric methane emissions - life-cycle assessment - land-use change - economic values - milk-production - grazing behavior - farm-level - model - cattle - rumen
Current decisions on breeding in dairy farming are mainly based on economic values of heritable traits, as earning an income is a primary objective of farmers. Recent literature, however, shows that breeding also has potential to reduce greenhouse gas (GHG) emissions. The objective of this paper was to compare 2 methods to determine GHG values of genetic traits. Method 1 calculates GHG values using the current strategy (i.e., maximizing labor income), whereas method 2 is based on minimizing GHG per kilogram of milk and shows what can be achieved if the breeding results are fully directed at minimizing GHG emissions. A whole-farm optimization model was used to determine results before and after 1 genetic standard deviation improvement (i.e., unit change) of milk yield and longevity. The objective function of the model differed between method 1 and 2. Method 1 maximizes labor income; method 2 minimizes GHG emissions per kilogram of milk while maintaining labor income and total milk production at least at the level before the change in trait. Results show that the full potential of the traits to reduce GHG emissions given the boundaries that were set for income and milk production (453 and 441 kg of CO2 equivalents/unit change per cow per year for milk yield and longevity, respectively) is about twice as high as the reduction based on maximizing labor income (247 and 210 kg of CO2 equivalents/unit change per cow per year for milk yield and longevity, respectively). The GHG value of milk yield is higher than that of longevity, especially when the focus is on maximizing labor income. Based on a sensitivity analysis, it was shown that including emissions from land use change and using different methods for handling the interaction between milk and meat production can change results, generally in favor of milk yield. Results can be used by breeding organizations that want to include GHG values in their breeding goal. To verify GHG values, the effect of prices and emissions factors should be considered, as well as the potential effect of variation between farm types.
Opportunities for small-scale biorefinery for production of sugar and ethanol in the Netherlands
Kolfschoten, R.C. ; Bruins, M.E. ; Sanders, J.P.M. - \ 2014
Biofuels Bioproducts and Biorefining 8 (2014)4. - ISSN 1932-104X - p. 475 - 486.
life-cycle assessment - regional biomass chains - pulsed electric-fields - cooling crystallization - bioethanol production - raw juice - beet - chemicals - food - intensification
Developments such as the Common Agricultural Policy reform, growth of the bio-based economy, increasing energy prices, increasing sustainability demands, and expected growth of global sugar demand change the environment in which the sugar producing industry operates. In order to remain competitive and profi t from this, the traditional large-scale sugar producing industry can adapt. The aim of this study was to address sustainability and energy issues of the traditional sugar production process and to provide opportunities for improving the process and value chain. The methodological approach included evaluating function and resource usage of the unit operations. More sustainable alternative unit operations and processes were identifi ed and studied. The results indicate that the current sugar production and by-product valorization focuses on centralized processing and has been individually optimized per sector and industry based on relatively inexpensive transportation and energy without a focus as such on the bio-based economy. For incorporation of the opportunities, a process for targeting new bio-based markets and supplementing large-scale sugar production was designed. It was found that small-scale biorefi neries as an alternative and/or supplementation of the traditional large-scale process have the ability to increase the overall sustainability of sugarbeet processing, for example reduce energy usage and carbon footprint, by reducing transportation movements. Moreover, it provides opportunities for leaving out certain unit operations and using less capital-intensive technologies. With a holistic approach throughout the value chain, the introduction of small-scale biorefineries can help meet the challenges of the sugar producing industry, while simultaneously benefitting people, planet, and profit.
Modeling food logistics networks with emission considerations: the case of an international beef supply chain
Soysal, M. ; Bloemhof, J.M. ; Vorst, J.G.A.J. van der - \ 2014
International Journal of Production Economics 152 (2014). - ISSN 0925-5273 - p. 57 - 70.
life-cycle assessment - operations management - programming approach - green logistics - design - sustainability - challenges - inventory - quality - systems
Intrinsic characteristics of food products and processes along with growing sustainability concerns lead to the need for decision support tools that can integrate economic considerations with quality preservation and environmental protection in food supply chains. In this study, we develop a multi-objective linear programming (MOLP) model for a generic beef logistics network problem. The objectives of the model are (i) minimizing total logistics cost and (ii) minimizing total amount of greenhouse gas emissions from transportation operations. The model is solved with the ee-constraint method. This study breaks away from the literature on logistics network models by simultaneously considering transportation emissions (affected by road structure, vehicle and fuel types, weight loads of vehicles, traveled distances), return hauls and product perishability in a MOLP model. We present computational results and analysis based on an application of the model on a real-life international beef logistics chain operating in Nova Andradina, Mato Grosso do Sul, Brazil and exporting beef to the European Union. Trade-off relationships between multiple objectives are observed by the derived Pareto frontier that presents the cost of being sustainable from the point of reducing transportation emissions. The results from the pie chart analysis indicate the importance of distances between actors in terms of environmental impact. Moreover, sensitivity analysis on practically important parameters shows that export ports' capacities put pressure on the logistics system; decreasing fuel efficiency due to the bad infrastructure has negative effects on cost and emissions; and green tax incentives result in economic and environmental improvement.
Benchmarking the economic, environmental and societal performance of Dutch dairy farms aiming at internal recycling of nutrients
Dolman, M.A. ; Sonneveld, M.P.W. ; Mollenhorst, H. ; Boer, I.J.M. de - \ 2014
Journal of Cleaner Production 73 (2014). - ISSN 0959-6526 - p. 245 - 252.
life-cycle assessment - data envelopment analysis - sustainability - agriculture - netherlands - indicators - nitrogen - systems - land
Several dairy farms in the Netherlands aim at reducing their environmental impact by improving the internal nutrient cycle (INC) at farm level. Practices to improve nutrient cycling at these INC farms, however, might not only reduce the environmental impact on-farm, but alter also the off-farm environmental impact associated with supply chain processes (production and transport) related to inputs entering the farm, such as purchased feed or fertilizer or the economic or societal performance of these farms. We compared, therefore, a set of sustainability indicators of nine INC farms with a group of benchmark farms, comparable in terms of farm size, intensity and site-specific circumstances. This benchmark group was composed using statistical matching to exclude the effect of these characteristics on economic, environmental and societal performance. Economic indicators used were: farm income per unpaid annual working unit and the costs to revenues ratio. Environmental indicators used were derived from a cradle-to-farm-gate life cycle assessment: land occupation (LO), non-renewable energy use (NREU), global warming potential (GWP), acidification potential (AP) and eutrophication potential (EP), expressed per kg fat-and-protein-corrected milk (FPCM). In addition, we quantified the soil content of organic carbon and phosphorus, and the soil nitrogen supply. Societal indicators used were: payments for agri-environmental measures, grazing hours and penalties for aberrant milk composition. Results showed that INC farms had a lower non-renewable energy use per kg FPCM, higher soil organic carbon content and received higher annual payments for agri-environmental measures, whereas economic and other environmental, societal indicators did not differed. Furthermore, we demonstrated the need for a sound benchmark to assess the effect of INC-farming on the economic, environmental and societal performance. Statistical matching enabled us to define, for each INC farm, a benchmark group with similar farm characteristics, which are known to affect sustainability indicators. Observed differences in sustainability indicators between both farm groups, therefore, truly resulted from aiming at internal nutrient cycling, and not from differences in other farm characteristics.
Energy use and greenhouse gas emissions in organic and conventional farming systems in the Netherlands
Bos, J.F.F.P. ; Haan, J.J. de; Sukkel, W. ; Schils, R.L.M. - \ 2014
NJAS Wageningen Journal of Life Sciences 68 (2014). - ISSN 1573-5214 - p. 61 - 70.
life-cycle assessment - southern germany - dairy - agriculture - efficiency - biodiversity - balances - impacts - model - milk
Organic agriculture is often considered to contribute to reducing energy use and greenhouse gas (GHG) emissions, also on a per unit product basis. For energy, this is supported by a large number of studies, but the body of evidence for GHGs is smaller. Dutch agriculture is characterized by relatively intensive land use in both organic and conventional farming, which may affect their performance in terms of energy use and GHG emissions. This paper presents results of a model study on energy use and GHG emissions in Dutch organic and conventional farming systems. Energy use per unit milk in organic dairy is approximately 25% lower than in conventional dairy, while GHG emissions are 5-10% lower. Contrary to dairy farming, energy use and GHG emissions in organic crop production are higher than in conventional crop production. Energy use in organic arable farming is 10-30% and in organic vegetable farming 40-50% higher than in their respective conventional counterparts. GHG emissions in organic arable and vegetable farming are 0-15% and 35-40% higher, respectively. Our results correspond with other studies for dairy farming, but not for crop production. The most likely cause for higher energy use and GHG emissions in Dutch organic crop production is its high intensity level, which is expressed in crop rotations with a large share of high-value crops, relatively high fertiliser inputs and frequent field operations related to weeding