Cement Production Effects on Human health with Respect to Cement Lifecycle Assessment Saeed Morsali Gazi University, Faculty of Applied Science, Department of Environmental Science, Ankara, Turkey;
[email protected] Abstract Increasing climate change challenges due to human activities has made new insight to reduction environmental loads of industrial processes. Not only construction sector uses almost the half of industrial usage energy but also releases a significant amount of waste and pollutant material to the environment. Cement production as the main material in the construction sector is one of the most pollution reason which needs to reduce its impacts on the total environment. From this point of view, human health takes an important role in cement production studies since many of the cement industry has direct and indirect effects on human health, especially in industrial cities. Producing the enormous amount of respiratory organics and inorganics pollutant during the overall cement lifecycle. In this novel study, the affects of cement production have been studied using life cycle assessment tool. Keywords: cement production emissions, cement production effects, human health effected by cement production, Life Cycle Assessment (LCA) of cement. Introduction Climate change is one of the greatest challenges facing humankind today. Human-induced carbon emissions are the major greenhouse gas emissions that drive anthropogenic climate change. Carbon emissions can be generated by fossil fuel combustion, industrial production processes, waste treatment and land use change [1]. Cement is one of the most polluting industries: 5% of the world’s total emission of greenhouse gasses is caused by cement production [2]. Cement production is known to contribute to the greenhouse effect due to the emission of CO2 gas during the clinker manufacturing process [3]. The production of cement is a rather complex process which includes a high amount of raw materials (e.g., limestone, marl, clay, and iron ore), heat, electricity and different fuels (petroleum coke, coal, fuel oil, natural gas or different wastes). Modern cement production pyro-processing involves calcination and sintering processes that generally take place in a rotary kiln. The objective is to create clinker (aggregate alite nodules) from the raw mix (ground limestone mixed with clay or shale). Modern cement industries use both wet and dry rotary kilns
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[4]. Due to this increasing danger of catastrophic global environmental change and other aspects of environmental mismanagement have given rise to concerns about economic development exceeding the Earth's carrying capacity. In order to reduce these effects many international organizations and developed countries have proposed various ideas and initiatives such as green growth, green economy, green transformation, green structural transformation, sustainable transformation, and green industrial policy Green transformation refers to processes within industries and/or companies that lead to reduced environmental change impact [5]. The most important result of the cement production is human health effects in 2012 World Health Organization (WHO) reported that worldwide non-communicable diseases are the leading cause of mortality which accounts for 82 % of deaths and among those non-communicable diseases chronic respiratory diseases, asthma, and chronic obstructive pulmonary diseases accounted for 4 million or 10.7 % deaths [6]. There is a wide variety of research for this industry at different aspect zones. [7], this paper summarizes and reviews the literature on the usage of different types of alternative fuel and their impacts on the cement plant performance. This study suggests alternative fuels to reduce the overall CO2 emission and other air emissions such as NOX, SO2, and dust. [8], this paper presents a study on the utilization of stone coal vanadium slag in preparing cement clinker. The hydrates and hydration mechanism of the cement were analyzed in this study by means of the hydration heat analysis, X-ray diffraction (XRD) and the differential thermal gravity (DTG) analysis. [6], this study was conducted to assess the prevalence and associated factors of chronic respiratory symptoms among cement factory workers in Dejen town, 2015. [9], the objective of this report is the assessment of changes in fractional exhaled nitric oxide (FENO) across the shift which performed among cement production workers and controls. FENO was used as a possible marker of eosinophilic inflammation in the airways. In addition, the relations between personal total dust exposure and FENO changes across the work shift were examined. All the previous studies have the good point to use in cement industry but the aim of this novelty study is a closer look to cement lifecycle using life cycle assessment tools and showing the exact
effects of cement lifecycle on human health, analysis the processes, emissions due to cement cradle to grave period in order to help the decision makers and scientists to focus on the right point of cement pollution causes. 1. METHODOLOGY The analysis of the product life cycle evaluates the interaction between the “product life”, from raw material extraction to final product disposal, and the environment, trying to characterize the impacts imposed to the environment. In an LCA study on a product, process or service, all extractions of resources and emissions from/to the environment are determined, when possible, in quantitative values throughout the life cycle from “cradle to grave”. The LCA analysis has to be based on these data and evaluates the potential impacts on natural resources, environment and human health [10]. In this study for validating the data and analysis, a commercial version of Simapro7.1 is used, since Simapro uses a different kind of methods for analysis the used method for this paper is Eco-Indicator 99 method which has three main impact category; human health, ecosystem quality, and resources. 1.1. Inventory data Inventory data for this study is taken from Simapro database inventory table, for Portland cement production the system model basic materials describes the production of different materials that are used in the life cycle of western Europe energy system. The materials considered are mineralogical materials (sand, gravel, cement, concrete, float glass, mineral wool, lime, limestone, gypsum, clay, barite, bentonite, ceramics, and molecular sieve), inorganic chemicals (chlorine, caustic soda, nitric acid, phosphoric acid, ammonia, iron sulfate, sodium carbonate, hydrofluoric acid, hydrochloric acid, sulfuric acid, secondary sulfur, urea ), organic chemical, metals, plastics, biogenic materials. The inventory tables include resource extraction, refining, and production of bulk intermediate products. These data is taken from Portland cement production from clinker and calcium sulfate. The energy values stem from various publications. 1.2. Cement production process The main process routes for the manufacturing of cement vary with respect to equipment design, a method of operation and fuel consumption [11]. Cement manufacturing process basically includes a quarry, raw meal preparation, preheating of raw meal, kiln, ICSE2017, 15 June 2017
clinker cooling, grinding, storage, and dispatch. Figure 1 shows a basic process flow of cement manufacturing. The basic chemistry of the cement manufacturing process begins with the decomposition of calcium carbonate (CaCO3) at about 900°C to leave calcium oxide (CaO, lime) and liberate CO2; this process is known as calcination. This is followed by the clinkering process in which the calcium oxide reacts at high temperature (typically 1,400°– 1,500° C) with silica, alumina and ferrous oxide to form the silicates, aluminates, and ferrites respectively which forms the clinker. This clinker is then ground together with gypsum and other additives to produce cement. Fuels are required to generate thermal energy during the process of calcination in preheater tower and during the clinkerization process in Kiln [7]. 1.3. System boundaries The systems are divided into subsystems interconnected by flows of materials, energy and environmental discharges. In this study Portland cement production inventory analysis includes extraction, transportation, production stages, land uses for extraction step, only production waste are considered, material production assumed to happen in the nineties even if the material is used in the early twentieth, energy consumption, waterborne and airborne emissions, emissions to the soil, transportation from factory to the markets, raw material production, all these steps are shown in Fig 1. as system boundaries.
Fig 1. System boundary for Portland cement production 1.4. Eco- indicator 99 Eco-Indicator 99 uses three main impact category which every impact includes specific impacts as they are listed below;
Human health; Damage to Human Health: 1- Carcinogens: Carcinogenic affects due to emissions of carcinogenic substances to air, water and soil. 2- Respiratory organics: Respiratory effects resulting from summer smog, due to emissions of organic substances to air, causing respiratory effects. 3- Respiratory inorganics: Respiratory effects resulting from winter smog caused by emissions of dust, sulphur and nitrogen oxides to air. 4- Climate change Damage: resulting from an increase of diseases and death caused by climate change. 5- Radiation Damage: resulting from radioactive radiation. 6- Ozone layer Damage: due to increased UV radiation as a result of emission of ozone depleting substances to air. Ecosystem quality; Damage to Ecosystem Quality, express as the loss of species over a certain area, during a certain time: 1- Ecotoxicity Damage to ecosystem quality: as a result of emission of ecotoxic substances to air, water and soil. Damage is expressed in Potentially Affected Fraction (PAF)*m2 *year/kg emission. 2- Acidification/ Eutrophication Damage to ecosystem quality: as a result of emission of acidifying substances to air. Damage is expressed in Potentially Disappeared Fraction (PDF)* m2 *year/kg emission. 3- Land use: Damage as a result of either conversion of land or occupation of land. Damage is expressed in Potentially Disappeared Fraction (PDF)* m2 *year/ m2 or m2a. Mankind will always extract the best resources first, leaving the lower quality resources for future extraction. The damage of resources will be experienced by future generations, as they will have to use more effort to extract remaining resources. This extra effort is expressed as “surplus energy”. Resources; Damage to Resources, expressed as the surplus energy needed for future extractions of minerals and fossil fuels: 1- Minerals: Surplus energy per kg mineral or ore, as a result of decreasing ore grades. 2- Fossil fuels: Surplus energy per extracted MJ, kg or m3 fossil fuel, as a result of lower quality resources. In weighting step Simapro uses Pt unit to show these impacts. The Pt unit used in eco indicator method defined as a dimensionless value. The value of 1 Pt means one thousandth of the yearly environmental load of one average European inhabitant. In this paper, all the analysis had done for 1 kg Portland cement production.
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Fig 2. Weighting of 1 kg Portland cement production. The figure shows a compared graph between three main impacts category with Pt unit. As Fig 2. shows the most damage occurs in human health category during cement life cycle with a significant difference in comparison with two other categories.
Fig 3. Human health subcategories weighting Fig 3. shows weighting of human health subcategories in the cement life cycle, the used unit for this table is Pt unit as the figure shows respiratory inorganic impact has the highest damage value and climate change damage has the second value.
processes, there are significant emissions to the environment which are listed in Table 1. In the Fig 5. We showed just ten subprocesses with eliminating other processes however for emissions we considered all the processes. No
Substance
Unit
Total
Total of all compartments
Pt
0.05504
1
Particulates
Pt
0.05358
2
Sulfur oxides
Pt
0.000887
3
Sulfur dioxide
Pt
0.000492
4
Nitrogen dioxide
Pt
5.89E-05
5
Nitrogen oxides
Pt
2.11E-05
6
Ammonia
Pt
6.71E-07
Table 1. Emissions with respiratory inorganic effects.
Fig 4. Weighting of two important subcategories per five main processes. Fig 4. Represents respiratory inorganics and climate change subcategories weighting by the five main cement production phases. In Fig 4. It is obtained that cement fabrication has the most negative effects on respiratory inorganics on human health. The second process with high effect is clinker production which effects on climate change category.
Table 1 illustrates emissions from Portland cement life cycle that cause respiratory inorganic effects with Pt unit. For the climate change subcategory which is one of the human health subcategories the same analysis has been done in Table 2. No
Substance
Compartment
Unit
Total of all
Total 0.004988
compartmen ts 1
Carbon
Air
Pt
0.004919
dioxide 2
Methane
Air
Pt
6.54E-05
3
Dinitrogen
Air
Pt
2.72E-06
Air
Pt
1.06E-06
Air
Pt
2.15E-07
Air
Pt
3.84E-08
monoxide 4
Carbon monoxide
5
Methane, tetrafluoro-, FC-14
6
Ethane, hexafluoro-, HFC-116
Fig 5. Tree analysis for cement fabrication Fig 5. Shows tree analysis for cement production, in this figure the shared flow for four different processes has been shown which clinker has the highest flow following with oil energy usage. Furthermore, in clinker stage, six different subprocesses are given that gas energy usage has the highest flow among them. During these ICSE2017, 15 June 2017
7
Propane
Air
Pt
3.43E-08
8
Butane
Air
Pt
2.53E-08
9
Methane,
Air
Pt
-1.9E-07
Table 2. Emissions with climate change effects Table 2. shows the emissions which cause climate change effects, these emissions have negative effects on human health as well.
Carbon dioxide in its gas form is an asphyxiant, which cuts off the oxygen supply for breathing, especially in confined spaces. Exposure to concentrations of 10 percent or more of carbon dioxide can cause death, unconsciousness, or convulsions. Exposure may damage a developing fetus. Exposures to 1-5 % CO2 for short-term periods have been documented to produce symptoms on humans and animals such as dyspnea (shortness of breath), modified breathing, acidosis, tremor, intercostal pain, headaches, visual impairment, lung damage, increased blood pressure, bone degradation, reduced fertility, alterations to urine and blood chemistry as well as erratic behaviour, these levels of CO2 also induce panic attacks, interrupt the processes of metabolic enzymes and disrupt normal cell division processes [12]. Increased temperatures also increase the reproduction rates of microbes and insects, speeding up the rate at which they develop resistance to control measures and drugs (a problem already observed with malaria in Southeast Asia). During the process of oxidation in the atmosphere, this gas forms sulphates or salts that can be transported in the breathable particulate material (PM10) that in presence of humidity forms acids. Later these acids are an important part of the secondary particulate material or finest particulate material (PM2,5). SO2 is a precursor to sulfuric acid, a major constituent of acid rain. It is produced by the combustion of coal, fuel oil, and gasoline, and in the oxidation of naturally occurring sulfur gases, as in volcanic eruptions. Although the magnitudes of the risks of health effects associated in the epidemiology, with respect to SO2 exposures, are relatively small, they represent important impacts on public health due to the number of people potentially affected. The subpopulations that appear to have increased susceptibility to adverse effects from SO2 exposure represent a considerable proportion of the population, with asthmatics and the elderly alone accounting for 8.9% and 14.8% of Canadians, respectively [13]. The exposure to sulphates and the exposure to acids derived from SO2 is extremely risky for people's health because these compounds enter the circulatory system directly through the airways. The SO2 is hygroscopic, when it is in the atmosphere it reacts with humidity and forms sulphuric and sulphurous aerosol acid that is later part of the so-called acid rain. The intensity in the formation of aerosols and the permanence of them in the atmosphere depend on the meteorological conditions and the quantity of catalytic impurities (substances that accelerate the processes) present in the air. But in general, the ICSE2017, 15 June 2017
average time of permanence in the atmosphere is around 3-5 days, so it can be transported to greater distances [14]. Increased levels of nitrogen dioxide can have significant impacts on people with asthma because it can cause more frequent and more intense attacks. Children with asthma and older people with heart disease are most at risk.
2. Results From this novel study, it’s obtained that in Portland cement production from three main impact category the most affected category is human health which affected by released substances to the air, these emissions besides the human health have high effects on climate changes. Respiratory inorganics subcategory is the major problem in cement production. From the all emissions carbon dioxide, nitrogen oxides, sulfur oxides, methane, are the most released emissions to air. Clinker preparation has the highest impact value moreover, energy usage from natural gas in clinker preparation step has the highest impact flow.
3. Conclusion
From this study, in cement life cycle the most important problem is respiratory inorganics effects which cause a different kind of illnesses. The most important reason for this study was to evaluate the exact amount of released material during the cement life cycle in order to take a reasonable decision for reduction these negative effects. With consideration of new technologies, it is quite possible to reduce cement environmental effects by filtering the emissions in clinker or cement fabricates, replacing the old methods or using renewable energies such as solar energy, replacing the cement usage with different material for plastering material.
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for human health, ustralian National University, 2016. [13] Human Health Risk Assessment for Sulphur Dioxide, Water and Air Quality Bureau Safe Environment Directorate Healthy Environments and Consumer Safety Branch Health Canada, 2016. [14] https://emsnews.wordpress.com/2015/11 /30/un-climate-scientist-penner-wants-to-fixclimate-change-via-sulfuric-acid-pollution/
