LIFE CYCLE ANALYSIS OF BRASSICA CARINATA FOR ELECTRICITY AND HEAT IN SPAIN.

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1 LIFE CYCLE ANALYSIS OF BRASSICA CARINATA FOR ELECTRICITY AND HEAT IN SPAIN. Carmen Lago Rodríguez; Israel Herrera Orozco; Rosa Sáez Angulo; Yolanda Lechón Pérez Centro de Investigaciones, Medio Ambientales y Tecnológicas (CIEMAT). Av Complutense Madrid carmen.lago@ciemat.es ABSTRACT: Increased use of biomass for electricity and heat generation is one of the tools for Spain to comply with the Kyoto protocol as well as to reduce the dependence on imported energy and to increase the security of energy supply. However the use of biomass has some associated environmental impacts which largely depend on which energy crop is considered and the particular conditions in which the production of biomass is made in each country. The objective of this work is to present preliminary results on environmental impacts of Brasssica carianta as an energy crop in Spain. This study is being carried out in the framework of a higher scope project -Development, demonstration and evaluation of the feasibility of energy production in Spain through biomass from energy crops- which is a coordinated effort of enterprises, universities and R&D institutions to achieve the commercial deployment of energy crops in Spain, according to the objectives of the current policy in renewable energies. In this study, detailed data of agricultural field operations, crop storage, and preparation and transport of biomass were collected and analysed. Data from several locations in Spain were used. The methodology selected to assess the environmental impacts of this crop is the Life Cycle Assessment (LCA) which provides results of energy use and environmental emissions as well as the associated impacts. The environmental impacts categories assessed are: Energy consumption, global warming, acidification, eutrophication, toxicity and ecotoxicity. Results will show the processes accounting for the majority of the impacts and will provide insight into the sensible points in which improvement measures can be undertaken. Keywords: Brassica carinata; Energy crops; Life Cycle Analysis; Bioenergy 1 INTRODUCTION On cultivos, Crops for energy production is a national singular and strategic project, launched by the Spanish Ministry of Science and Education. Into this framework the LCA of Brassica carinata has been assessed. The evaluation of the energy crops sustainability have been carried out by evaluating the energetic and environmental life cycle analysis of the considered energy crops. Brassica carinata has several desirable agronomic characteristics, such as resistance to a wide range of diseases and pests, which makes it a suitable candidate for semiarid regions. The document is structured in four parts, the first part, provide the aims and approach of the study. The LCA of Brassica carinata (the second part) describes the main characteristics involved in the LCA methodology, goal and scope definition determine what and how in the study. Furthermore, in this second part, life cycle inventory methodology describes the steps to obtain the main data in order to calculate environmental loads for each scenario. Finally, in the case of Life cycle impact assessment, the problem oriented methodology has been chosen, and EDIP method [1] was used to obtain the characterisation factors for impact categories selected. Results discussion and conclusions are presented in items three and four respectively. 2 AIMS AND APPROACH The main objective of the paper is to present preliminary results on environmental impacts of Brasssica carinata as an energy crop in Spain. As a consequence of the special characteristic of this specie, its production may serve for the support of the energy crops systems in Spain. The approach employed in the analysis of the agricultural activity is mostly based on Harmonisation of Environmental Life Cycle Assessments for Agriculture [2]. On the other hand, the analysis of power generation is based on LCA guideline: State of LCA in Denmark [3]. Local conditions have been analyzed for acidification, and eutrophication categories. Primary data of the crops were obtained from farmers located in Navarra and Soria, two different Spanish provinces.

2 3 LCA OF BRASSICA CARINATA FOR ENERGY 3.1 Goal and Scope Definition The goal of this study is to carry out an environmental evaluation of three different scenarios to produce biomass for heat and power production from Brassica carinata crop. 3.2 Function and functional Unit The function of the evaluated system is to generate biomass as source of renewable energy [4]. The functional unit considered was 1 kg of produced biomass (dry mass), ready to be used for energy production. 3.3 System description The main characteristics of the considered scenarios are detailed in Table 1. The analysed energy crop system includes the agricultural production steps and transport process for the biomass to the energy production plant [5]. The production processes of different agricultural inputs are also taken into account, such as: fuel production, transportation and use; fertiliser production, transportation and application; tractor and agricultural tools and transport process [6]. Table I: Main characteristics of assessed scenarios Unit Yield main production Kg/ha Moisture at harvest % Seed application Kg/ha 6,7 7 7,9 N fertilisation Kg/ha NPK fertilisation Kg/ha ,5 Fuel consumption l/ha Region Navarra Navarra Soria Date 05/06 06/07 06/07 The analysed energy crop systems include the agricultural production subsystems and the transport to the power energy plant: field preparation, fertilisation, field work, biomass collection and biomass transport. Figure 1: System boundaries of the process preparation includes chiselling, ploughing a rolling labours. Seeder and harvesting labours comprehend field work. Fertilisation includes not only the production and transportation, but also, application labour. Finally, biomass collection involves different labour for each studied scenarios. For scenarios carry out in Navarra, the bales were formed and loaded with the same tractor and farming implements. However, the same step for Soria was developed with different tractor and utensils. 3.4 Geographical and temporal burdens The studied regions ware Navarra and Soria (Spain) and the period studied was Life Cycle Inventory Analysis Methodology used in the LCI phase was mainly based on Life Cycle Inventories of Agricultural production Systems [7] Agricultural infrastructure and operation The inventory take into account resource use and the emission levels during the production, maintenance and disposal of agricultural machinery. Impacts incurred during operation (e.g. emissions from fuel consumption and tyre abrasion) are taken into account as direct emissions for each analysed labour. The amount of machinery (AM) needed for a specific process was calculated using the following formula (1): AM [ kg/ WU] = time[ h / WU] Weight[ kg]* Lifetimeh [ ] Table 2: Main aspects for scenario 1 Energy and raw material Agricultural Work Process FIELD PREPARATION Emissions Air emissions from combustion Data on materials, energy use and emissions from tractors and agricultural process production were obtained from Ecoinvent database (V.2) [8]. Fuel Working materials FERTILISATION FIELD WORK Soil emissions from tyre Heat Waste About to the maintenance of the tractors and agricultural utensils, specific parameters were considered for each scenario [9, 10]. Biomass transport

3 Table 3: Main aspects for scenario 2 Tractor Weight (kg) Powe r (KW) Utensils Type Weigh t (kg) O- T (h/ha) Fuel (l/ha) preparation Chiselling ,80 14 preparation Ploughing ,67 17,33 Work Seeder ,63 16,25 preparation Fertilisation Fertilisation Work Biomass Collection Rolling 600 0,71 7, spreader spreader Harvestin g Loading Bales , ,25 6, ,70 2, ,74 9,79 Operatio Weight (kg) Tractor Power (KW) Utensils Type Weight (kg) O- T (h/ha ) Fuel (l/ha) preparation Chiselling ,67 17,42 preparation Ploughing ,40 7,00 Work Seeder ,63 16,38 preparation Rolling 600 0,71 7,81 Fertilisation Fertilisation spreader spreader ,25 6, ,25 6,50 preparation Harvesting 660 1,00 26,00 Biomass Collection Loading Bales ,30 33,80

4 Table 4: Main aspects for scenario 3 Tractor Weight Power (kg) (KW) preparation preparation Fertilisatio n Fertilisatio n Fuel consumption and emissions associated. Fuel consumption for each labour in the field operation has been obtained by reported requirement (data reported for the different partners in the project). Emission from fuel combustion were estimated according to formula 2: WG[g/WU]=FC[kg fuel /WU]*EF[g WG /kg fuel ] ( 2) Where WG is the waste gases emitted (gfu -1 ), FC is fuel consumption of the different vehicles (kgfuel FU -1 ) and EF is the emission factor of each gas Production of fertiliser The fertiliser inventory used takes into account the use of resources for all production stages ranging from extraction of raw materials to the production of the intermediates and the final product Production of seeds In order to introduce the production process of seed, Rape seed IP, at regional storehouse process was included. This data are contained in Ecoinvent Database [EI v.2] Biomass collection Utensils Type Weigh t (kg) Biomass collection stage was modelled in order to include all labours reported in the three assessed scenarios. In this case, the use of machinery and the emissions by fuel consumption and tyre abrasion were accounting as direct emissions, according to the described methodology Diffuse emissions and others emissions O- T (h/ha) Fuel (l/ha) Chiselling ,28 27 Ploughin g ,9 28 spreader ,18 3 spreader 600 0,18 3 Work Seeder ,24 7 preparation Work Biomass Collection Rolling ,18 5 Harvestin g 720 1,00 10 Loading Bales ,78 14,58 Diffuse emissions by volatilisation of the ammonia were calculated. In case of N fertiliser type, a contribution of 2% to volatilisation from the fertiliser application (according to N content) was considered. For NPK fertilisers type, NH 3 emissions were assumed as 4% of fertiliser application (N content). In the case of N 2 O, the emissions were calculated on the basis of the available nitrogen. The factor of 1,25%, of N lost as N 2 O was used. However, are not taken into account N 2 O emissions induced by ammonia. Finally, NOx emissions were estimated from the emissions of N 2 O by the formula 3. NOx = 0,21*N 2 O (3) Considering the type of fertilisers applied in studied crops, it is assumed that there is not conversion from N 2 O to NOx, thus correction of the N 2 O emission is not required. 3.6 Life cycle impact assessment (LCIA) According to ISO 14044:2006 [11], the mandatory elements in LCIA include: (i) selection of the impact categories, (ii) indicators of category and (iii) models of characterization. In order to assess the impacts, SimaPro [12] was used for the evaluation of life cycle of the systems and the characterization factors was obtained from a midpoint methodology [1]. Four global impacts categories were assessed: Fossil energy consumption, global warming (GWP), human toxicity on air (HTA) and Ecotoxicity Water Cronic (ETWC). On the other hand, categories for Spanish conditions (acidification (ACD) and eutrophication (EUT) were selected in order to evaluate the site-specific impacts 4 RESULTS AND DISSCUSION The results are presented in two groups: Energy consumption in studied scenarios Environmental loads with potential to generate impacts. 4.1Fossil Energy consumption Total fossil energy used has been inventoried for each scenario. Energy has been considered as all the energy from fuels involved in the overall processes chain. Fossil energy consumption is given in Table 2 and Figure 2 respectively:

5 Table 5: Contribution to fossil energy by life cycle E. Fossil (MJeq/k preparation 1,9E-01 4,8E-01 4,7E-01 Fertilisation 4,0E+00 6,5E+00 5,8E+00 Work 2,6E-01 7,8E-02 1,7E-01 Biomass Collection 3,6E-01 2,7E-01 2,1E-01 Biomass transport 1,1E-01 1,1E-01 1,1E-01 Total 4,9E+00 7,4E+00 6,7E+00 The inventory of green house gases emissions has been carried out accounting CO 2, N 2 O and CH 4 in the whole life cycle. Figure 2: Fossil Energy consumption by stages Along the whole life cycle, the fertilisation step supposes more than 80% of contribution for fossil energy consumption. Greenhouse Emissions (kgco2 0,80 0,70 0,60 0,50 0,40 0,30 0, Contribution to the Global Warming Potential 0,10 0,00 Information about global warming contribution is showed in the Table 6 and Figure 3. Table 6: Contribution to Global warming potential preparation 1,8 2,8 3,2 Fertilisation 91,5 94,6 93,2 Work 2,6 0,6 1,4 Biomass Collection 3,0 1,3 1,3 Biomass transport 1,1 0,7 0,8 CO2 N2O CH4 Figure 4: Global Warming contribution by pollutant The highest contribution to global warning potential comes from N 2 O emissions in all studied systems. 4.4 Contribution to the Acidification The overall values to acidification are described in the Table 7 and Figure 5: Table 7: Contribution to acidification impact by step GWP (kgco2eq/kg) 1,2 1 0,8 0,6 0,4 0,2 preparation 2,4 3,7 2,4 Fertilisation 90,4 93,9 95,3 Work 3,4 0,8 1,0 Biomass Collection 2,7 0,9 0,7 Biomass transport 1,1 0,7 0,5 0 Figure 3: Contribution to the Global Warming Potential Fertilisation contributes to global warning impact mainly through the fertiliser production process. Labours and direct emissions represent less than 5% in the contribution of this impact category. 4.3 Contribution to GWP by greenhouse emissions

6 0 1,4E-03 1,2E-03 1,0E-03 preparation 5,6 9,6 14,9 Fertilisation 66,2 75,8 65,0 Work 7,6 1,6 5,6 Biomass Collection 15,9 9,7 9,3 Biomass transport 4,7 3,3 5,2 0,18 0,16 Eutrophication (m2/kg) 8,0E-04 6,0E-04 4,0E-04 2,0E-04 0,0E+00 Figure 6: Contribution of to eutrophication by stages Eutrophication shows similar results than acidification. s production and volatilisation of NH 3 contribute largely to these impact categories. 0,14 0, Contribution to Human Toxicity Acidification (M2/kg) 0,1 0,08 0,06 0,04 0,02 Contribution for toxicity impact in the whole life cycle of the studied scenarios, are reported in the Table 9 and Figure 7. Figure 5: Contribution to acidification by stages Fertilisation process is responsible of practically the preparation 2,7 4,2 2,9 Fertilisation 87,5 91,4 93,1 Work 5,2 2,4 2,4 Biomass Collection 3,1 1,1 0,9 Biomass transport 1,5 0,9 0,7 overall impact to acidification, between 90 to 95% of total in the three scenarios analysed. No sé si el resto es debido al consume de combustible de las labores agrícolas o hay otros procesos implicados. 4.5 Contribution to the Eutrophication The distribution of eutrophicants elements emissions in the life cycle of analysed systems is described in the next table Table 9: Contribution to toxicity for the life cycle Although fertilisation shows the highest contribution to human toxicity, the others stages have also a clear contribution, mainly by emissions from agricultural machinery uses. Human Toxicity Air (M3/kg) 5,0E+03 4,0E+03 3,0E+03 2,0E+03 1,0E+03 0,0E+00 Figure 7: Contribution to toxicity by process steps 4.6 Contribution to Ecotoxicity Table 10 and Figure 8 give data about emissions distribution in the different stages for ecotoxicity. Table 10: Ecotoxicity contribution by stages Table 8: Contribution to eutrophication impact

7 Ecotoxicity in water (M3/kg Figure 8: Contribution to ecotoxicity In the case of ecotoxicity, scenario 2 shows the same tendency than toxicity category, contrary than scenarios 1 and Interpretations of results According to the obtained data, fossil energy consumption, global warming potential, toxicity and ecotoxicity show the higher values for scenario 2. Scenario 1 shows the lowest value for global warming potential. That shows the relation between consumption of fuels and fertiliser and that impact category. preparation 4,0 6,6 8,1 Fertilisation 79,2 86,2 80,8 Work 5,6 1,2 3,1 Biomass Collection 4,5 1,6 2,5 Biomass transport 6,7 4,4 5,5 between fertilisers types shows NPK fertiliser as the main responsible of these impacts. The agriculture labours show low contribution to impacts in the most of the categories. However, for human toxicity, this tendency is broken, having a relevant roll mainly due to the emissions from machinery use. Promotion of Brassica carinata like energy crops, should be accompanied by previous selection of varieties with low requirements of inorganic fertilisers, due to their high energy requirements have very important contribution to all the impact categories. The use of NPK fertiliser in scenario 3, associated with more volatilisation processes, shows the evidence for the relation between fertiliser application and acidification and eutrophication categories. 5 CONCLUSSIONS Energy balance shows the fertilising step as the higher contribution for energy fossil consumption. For the studied systems, this contribution is higher than 80% for the three scenarios. According to the environmental performance of the analyzed systems, the greatest environmental impacts are associated with the fertilisation processes. Among these processes, is the fertiliser production stage which presents the highest impact. In the case of Global Warming Potential category, N 2 O emissions related to the fertilisation phase have the highest load to greenhouse effect. The highest values for acidification and eutrophication are clearly linked to NH3 volatilization process. The comparison 6 REFERENCES [1] Hauschild M. Potting J Spatial differentiation in LCA impact assessment The EDIP2003 Methodology. Environmental news No 80, Denmark, 195. [2] Ausdley et al Harmonization of environmental Life Cycle Assessment for Agriculture. Final report. European Commission s Concerted Action AIR3-CT [3] Danish Ministry of the Environment LCA guideline: State of LCA in Denmark 2003 Introduction to the Danish methodology and consensus Project [4] Weidema B. Wenzel H. Petersen C. Hansen C The product, Functional Unit and reference Flows in LCA. Environmental news No 80, Denmark, 47 [5] European Biomass Association AEBIOM position paper on the Biomass Action Plan: 10 [6] Gagnon l. Bélanger C. Uchiyama Y LCA of electricity generation options: The status of research in year Energy Policy 30, [7] Nemececk T et al Life cycle inventories of Swiss and Europen Agriculture production systems. Final Report. V.2 Nº 15. Swiss centre for Life Cycle

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