PROGRESS TOWARDS THE RESOURCE REVOLUTION
Christian Ludwig and Sonia Valdivia (Eds.) 2019
PROGRESS TOWARDS THE RESOURCE REVOLUTION
Christian Ludwig Sonia Valdivia
A World Resources Forum Production Printed by Paul Scherrer Institute Villigen PSI – March 2019
PROGRESS TOWARDS THE RESOURCE REVOLUTION Printed by Paul Scherrer Institute (PSI)
Editors Prof. Dr. Christian Ludwig, PSI and Ecole Polytechnique Fédéral de Lausanne (EPFL) Prof. Dr. Sonia Valdivia, World Resources Forum (WRF) Program Manager
Scientific Advisor Dr. Cecilia Matasci, World Resources Forum (WRF) Scientific Officer
Editorial Management Jordan Prieto, EPFL
Citation Ludwig, Chr., Valdivia, S., Progress towards the Resource Revolution, World Resources Forum, Villigen PSI and St. Gallen, Switzerland, 2019
Available from Paul Scherrer Institute ENE-LBK-CPM 5232 Villigen PSI, Switzerland Phone +41 56 310 21 11 www.psi.ch
ISBN 978-3-9521409-8-7
Part 2 – Methods, Indicators, and Design for Resource Efficiency and Sufficiency
15. Methodology for the Life Cycle Assessment of Clay Masonry from Energy and Water Consumption Sergio Alfonso Ballén Zamora *, Liliana Medina Campos *, Luz Amparo Hinestrosa Ayala, Adriana Cubides Pérez, James Ortega Morales, Adriana Marcela Serrano, Oscar Mauricio García Abstract Considering the clay masonry production, energy and water’s resources consumption has a high relevance, mainly at raw extraction materials, and transformation phases, highlighting the environmental impacts ensued by these types of activities. Life Cycle Assessment Methodology (SIMAPro v8) applied to evaluate the environmental impact, and water and energy consumption, at “cradle to gate” for a Non- structural masonry unit (1) Clay hollow brick No. 5, revealed a highest energy consumption (55%) at Benefit & Transformation phase, followed by drying & baking consuming 45% from total energy required. Green water (known as collected rainwater) is highlighted as low as resource consumption, requiring a total of 0,3696 kg H2O (rainwater)/unit. Raw material´s extraction activities result as an impact evaluation greatest generator; Mixing, Crushing and Molding are the second energy demanding and impacting activities. Baking activity is the third activity that can cause impact, mainly due by Eutrophication, Acidification, Photochemical oxidation, Global Warming Potential and Human toxicity. Considering the Colombia´s commitments to achieve a 20% reduction of emissions by 2030, results are demonstrating even higher environmental impact related to the change in land usage, in order to extract construction materials. This alarming situation requires an urgent environmental intervention, and tougher rules for construction companies, which help to prevent and mitigate the environment degradation. Keywords: Life Cycle Assessment, Cradle to Gate, Energy Consumption, Water Consumption, Water Stress, Emissions, Impact Analysis, Impact Categories, Clay Masonry.
Introduction The building sector contributes directly to 6.4% of emissions (IPCC 2014). The production of construction materials such as clay mason is not specifically referred by the IPCC, however, it is related to the increase of the emissions by 2.7% (Ibidem), due to mining extraction. The water consumption for a specific product (production process) reported by the clay masonry industry water, will be evaluated based on the ISO 14046 methodology (ISO 2014). However, elementary flows —to determine the impact on the water demand— will be evaluated as an indirect water footprint for an organization (Hoekstra 2003). Considering a global water requirement (scenario projected to 2050), for the productive sector of 4000 km3 (WWAP 2015), the blue water footprint evaluated for the industrial sector in Colombia (CTA et al. 2015), is 65.4 million m3/y, which does not consider precisely the masonry industry. Studies on hollow clay brick energy consumption for production are not common in Latin America; Mexico study (Chargoy 2009) referring specifically this common building product is highlighted. Peru and Colombia are unique, they are the only Latin American countries that still use coal as energy a main source of energy in the masonry industry (CAEM et al. 2015). This is done mainly to run the kiln and drying the final product. Other sources as firewood, sawdust, agricultural waste, coal, gas, tires, or used oil are used as well. Peru reports water consumption values only for the clay and sand mixture [between 0.36 - 1.45 kg H2O/brick] (reference King Kong from Peru), it depends if it is handmade (lower value) or mechanized (COSUDE); Argentina (Herrera 2014), refers to water for artisanal brick, as "a resource that enters from nature to the system", establishing a value of 2 kg H2O/brick; Mexico refers a volume of drinking water of 2.5 kg H2O/clay hollow block unit (Chargoy 2009).
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Methodology The study was developed using information provided by Arcillas de Colombia, a masonry building manufacturer (Figure 15-1), identifying, for clay hollow brick No 5 information (Table 15-1) the study roadmap (Figure 15-2), the processes (Figure 15-3) specifically raw materials, energy and water inputs and outputs in a first local inventory (Colombia) focused in referred product. Inventory allowed to define study at “cradle to gate� phase based on ISO 14040 (ISO/TC 207) and Functional Unit Technical Datasheet based on software SIMAPro v8 data requirement (Table 15-2).
Figure 15-1: Arcillas de Colombia Location (Cogua, Cundinamarca, Colombia); source: authors.
Figure 15-2 : Project Roadmap; source: authors.
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Table 15-1: Clay Hollow Brick No. 5 Features; source: authors.
Figure 15-3: Clay Hollow Brick No. 5 – Colombia Process Inventory; source: authors.
Table 15-2: Functional Unit Technical Datasheet; source: authors.
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SIMAPro v8 as main tool, Ecoinvent version 3.0 as database, Cumulative Energy Demand V1.08 (CED) for energy demand, Water Stress Index (WSI) – AWARE WULCA for water demand and CML impact methodology -IA baseline V3.01 for environmental impact categories were used.
Results and Discussion Greater energy flow and demand is concentrated at the clay extraction (mining) and its demand for fossil fuels such as diesel and oil. Highest energy consumption was (55%) at Benefit & Transformation phase, followed by cooking & drying consuming 45% from total energy required (Figure 15-4). The first clay extraction and second processing stages are linked to non-renewable energies of nuclear origin; on the other hand, the drying stage of the block is almost entirely committed to non-renewable energies of fossil origin due to the use of coal dryer. In our case, hydropower is the main source of national energy, so the results must be carefully interpreted.) It is worth noting that this evaluation is made based on the European energy matrix, where the supply of renewable energy systems varied and allow these results. The highest impact flow related to the demand for water resources (Figure 15-5), also comes from the open clay extraction stage (84.8%) and secondly the clay processing (15.2%). Producer collects and use green water (rainwater) at production phase with a total of 0.3696 kg H2O (rain)/unit, this value is comparatively less than that referred for Mexico (Chargoy 2009) of 2.5 kg H2O (potable)/unit. The water supply must be highlighted, considering no water flow deviation or affectation, evidenced in a low demand established by SIMAPro v8. Considering that there is no comparison information for the extractive phase for the present study, the resulting generated by the software should be assumed as initially approximated to the reality of consumption in a mining extraction process, the weight of the resulting SIMAPro v8 for the demand for energy and water resources for the extractive phase must be considered significant.
Figure 15-4: Energy Demand; source: authors.
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Figure 15-5: Water Demand; source: authors.
The global warming analysis shows a significant flow of impacts in the clay extraction stage (82%), clay processing (12.7%,) and the masonry blocks firing (4.7%). As in the previous figures and analyzes, a large portion of the responsibility for the impacts lied in the use of diesel as the main source of fuel, oil (in addition to heavy crude oil,)electricity, and natural gas and its residues. Producer emissions report for 2012 (CAEM et al. 2015), must be considered, with values of 16.89 t CO2/y, associated with diesel fuel is used for backhoe loaders, forklifts, loaders and trucks, vehicles used at process plant, representing in 213,76 t CO2eq of emissions by mobile sources. The reference study does not include information about consumption by mobile or fixed sources during the extraction phase; and that emissions are not discriminated by a specific product, but by total products. Considering that Clay Hollow Brick No. 5 represents 10.5% of the production, an emission for this product of 22.44 t CO2eq can be estimated. SIMAPro v8, establishes a value of 21.35 kg CO2/unit as emission, a value that compares to the one reported in Mexico (Chargoy 2009), of 1,179 kg CO2, the value referred to in the present study is higher representative. Comparing the results with Mexico (Chargoy 2009), the NOx value (among which NO2 refers), is 0.0014 kg/unit NOx, a value that contrasts with the 1.62 kg/unit NO2, and that considering the value of 0 for the NO2 referred in 2012 (CAEM et al. 2015), an uncertainty is generated in the analysis. Greatest impacts as Global Warming Potential, acidification, photochemical oxidation and human toxicity, correspond to the extractive phase (Figure 15-6), highlighting that, in the baking phase, the acidification, photochemical oxidation and Global warming potential impacts are the following in relevance. In general, the clay extraction stage shows the biggest impacts in almost all the categories, being clay transforming the subsequent. The baking phase has notable impacts, as photochemical oxidation, acidification and especially eutrophication, due to the use of coal which produces emissions of CO2, CH4, N2O, CO, SOx, NOx, among others. The drying stage of the blocks has an almost totally related impact in the category of depletion of abiotic resources related to the use of fossil fuels and electricity as main source of power.
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Figure 15-6: Environmental Impacts Categories; source: authors.
Conclusions Mining (clay extraction) represents the highest levels of consumption of energy and water, causing other impacts activities. Mixing, crushing, and molding are the activities second for high energy demand and impact. In third place comes the baking activity. The most relevant categories are: Eutrophication, Acidification, Photochemical oxidation, Global Warming and Human toxicity. This study provides arguments to enhance mining activities and public production policies formulation, that would accomplish 20% emissions reduction by 2030.
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ISBN 978-3-9521409-8-7