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The energy consumption in the ceramic tile industry in Brazil
Accepted Manuscript The energy consumption in the ceramic tile industry in Brazil Eduardo F.S. Ciacco, Jose R. Rocha, Aparecido R. Coutinho PII: DOI: Reference:
S1359-4311(16)33156-8 http://dx.doi.org/10.1016/j.applthermaleng.2016.11.068 ATE 9479
To appear in:
Applied Thermal Engineering
Received Date: Revised Date: Accepted Date:
2 August 2016 18 October 2016 8 November 2016
Please cite this article as: E.F.S. Ciacco, J.R. Rocha, A.R. Coutinho, The energy consumption in the ceramic tile industry in Brazil, Applied Thermal Engineering (2016), doi: http://dx.doi.org/10.1016/j.applthermaleng. 2016.11.068
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The energy consumption in the ceramic tile industry in Brazil Eduardo F.S. Ciacco, Jose R. Rocha, Aparecido R. Coutinho* Methodist University of Piracicaba, Campus UNIMEP, SP 306, Km 24, 13451-900, Santa Bárbara d’Oeste, SP, Brasil.
Abstract The ceramic industry occupies a prominent place in the Brazilian industrial context, representing about 1.0% in the GDP composition. On the other hand, it represent about 1.9% of all energy consumed in the country, and 5.8% of the energy consumed in the Brazilian industrial sector in 2014. Regarding the power consumption by the ceramic industry, most is derived from renewable sources (firewood), followed by use of fossil fuels, mainly natural gas (NG). This study was conducted to quantify the energy consumption in the production of ceramic tiles (CT), by means of experimental data obtained directly in the industry and at every step of the manufacturing process. The step of firing and sintering has the highest energy consumption, with approximately 56% of the total energy consumed. In sequence, have the atomization steps with 30% and the drying with 14%, of total energy consumption in the production of ceramic tiles, arising from the use of NG. In addition, it showed that the production of ceramic tiles by wet process has energy consumption four times the dry production process, due to the atomization step.
Keywords: energy, energy balance, ceramics industry, ceramic tiles, sustainability. __________________ *Corresponding author. Tel.: 55 19 31241768; fax: 55 19 31241768 E-mail address: [email protected]
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1. Introduction Energy consists of a basic need for the different industrial sectors worldwide, highlighting the enormous amount of energy needed to leverage developing countries with high rates of economic growth in recent decades. Energy is therefore an important factor for the competitiveness of the economy and for maintenance and generation of employment around the world. The total energy consumption in the world was approximately 1.29 1019 toe in 2010, expected to reach 1.72 1019 toe in 2030. Specifically with regard to industry, the consumption reached around 0.46 1019 toe in 2010 with an expectation of reaching 0.61. 1019 toe in the year 2030, therefore, an increase of over 30% in the period [1, 3]. In Brazil, the power consumption in the industry reached a peak of 41% of the total energy consumed in the country in 2009. On the other hand, there was a sharp drop in the years 2013-2014, reaching ratio of 33%. This reduction was due to the economic downturn in the country and to the government programs aiming at the rational use of energy, by both the manufacturing sector as well as the general population, by encouraging energy efficiency policies, combined with conservation in the industrial environment. Among the measures there is the maintenance, renovation and replacement of equipment to avoid losses and improve production performance in terms of energy consumption, the management to minimize the consumption of thermal energy, the incentive for the rational use and search of other sources of renewable energy [4,5].
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Specifically, the ceramic industry occupies a prominent place in the Brazilian industrial scenario, with a share of 1.0% in the GDP composition, with approximately 5,000 active companies in this sector [5]. The ceramics industry accounts for approximately 5.8% of all energy consumed in the Brazilian industrial sector, which corresponds to 5.69 106 toe, where most of it is produced from renewable sources (biomass, firewood), followed by fossil fuels, particularly natural gas (NG) [4-6]. 1.1. Energy use in the ceramic industry Ceramic tiles (CT) are largely used in construction and are produced from a mixture of clays and other inorganic materials, which are calcined at high temperatures. The manufacturing process of the CT can be driven by two main routes: i) dry process (DP), in which the raw material is composed of clay mined in nature and ground dry, ii) wet process (WP), wherein the ceramic mass consists of different raw materials
milled with addition of water and subsequent removal of moisture by
atomization. In both cases the main steps of the processing of raw materials and preparation of ceramic mass are: grinding, spray drying, pressing, drying, glazing/enameling, firing/sintering, classification, packaging and shipping of the product ready. Fig. 1 shows a simplified diagram of CT production that relates the main steps and forms of energy used [7-14]. Fig. 1 The energy balance is carried out according to the amount of thermal or electric energy used at each step. Also, associated with each type of energy are included the
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resources required for their production, as well as environmental impacts from production and disposal of their waste. Ibanez-Flores et al. (2013) presented a case study on a ceramic tile industry to obtain of experimental data, in order to prepare the mass and energy balances in the various steps of the process. Their work showed high energy consumption mainly in the form of thermal energy from the burning of NG, which represents over 90% of the energy consumed in the manufacture of CT, followed by electricity consumption [9]. Studies by Monfort et al. (2012) aimed to measure the energy consumption and carbon dioxide emissions in ceramic industries of Brazil and Spain, showing that in the wet process energy consumption in both countries is similar, furthermore, they showed that the energy used in the atomizing step, obtained by co-generation, is an advantage related to energy efficiency to in favor of the Spain. On the other hand, in production by dry process, they observed that the thermal energy consumption in Brazil is lower when compared to the consumption of Spanish industry [15]. Other studies were performed by Bleicher et al. (2014) in order to optimize energy efficiency in production systems, through modeling and simulation of energy consumption in machinery and equipment. They employed mathematical modeling using a set of complex differential equations together with energy-relevant parameters, in addition to measurement data, such as energy consumption of machinery and equipment, internal energy conversion and its thermal behavior [16]. In this context, Popov (2013) utilized secondary energy in ceramic kilns, which allowed the development of a system for heat recovery from the principles of thermodynamics, obtaining increasing of 46-52% in energetic efficiency of the production system [17].
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Other studies were carried out for the use of secondary energy (heat) in direct production processes, through the evaluation of energy efficiency with an approach based on the concepts of sustainability. For this, the possibility of a system of co-generation of energy in the production plant was evaluated, in order to obtain economic benefits through better utilization of energy and at the same time, to obtain advantages from the environmental point of view as a result of reduction in the emission of pollutants into the atmosphere. The studies showed that a properly balanced system can produce energy efficiency between 70 and 85%, reaching an optimal index in the range of 95% [18]. This study was developed in order to quantify the energy consumption in the production of ceramic tiles (CT), through the survey of experimental data obtained directly in every step of the manufacturing process of two types of ceramic industries (dry and wet).
2. Methodology The methodology used in this study was surveying the energy balance in the production of CT, through the acquisition of experimental data in two ceramic industries of São Paulo State, Brazil. The data survey was carried out in a factory which employs the dry process – DP (Ceramics A) and in a factory that uses the wet process – WP (Ceramics B). At each step of the manufacturing process the power consumption was determined by measurement of the electric current and the applied voltage, considering the daily
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operating time of each one of equipment. The measurements were made by mean of electrical instruments (ammeter and voltmeter) which were connected to each device. For equipment with characteristics of electromagnetic induction, was considered its power factor, supplied by the manufacturer. The measurements of NG consumption were made directly by means of a rotameter connected to the supply line of each one equipment (furnace), also considering the respective daily operating time. Thus, the values were entered into spreadsheets and energy consumption calculations were made with respect to the daily production of CT.
3. Results Table 1 shows the energy consumption in key industrial sectors in Brazil, highlighting the growth in consumption by the metallurgical industries, which exceeded the consumption of the food and beverage industries. Regarding the ceramic industry, there was a gradual increase, remaining at the 5.8% level of the entire country's industrial consumption (Fig. 2), which is the result of growth in production in many sectors of the ceramics industry, as well as, the overall growth of the Brazilian economy in the last years [5]. Table 1 Fig. 2
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Fig. 3 shows the flowchart of the manufacturing of Ceramic Tiles (CT) by wet process (WP), which is responsible by the increased consumption of electric and thermal energy. The dry process (DP) is similar, without the presence of the atomization step. Obtaining raw materials consists of the extraction of minerals from nature, which is conditioned to the topographical situation of the deposit, the spatial distribution of the layers of clay, physical, scale of production and environmental care. The transport of raw materials from storage silos and dosing scale is done through machines and conveyor belt and subjected to magnetic separation to remove iron oxide. The energy consumed in these steps is in form of the electricity. The raw materials free of iron oxide are sent for grinding, with the addition of water (WP) or without the addition of water (DP), for the formation of the ceramic mass. In the WP case, the ceramic mass goes to the atomization step and then transported to storage silos by conveyor belt and then finally to pressing. In these steps, the supplied energy is also in the form of electricity. Fig. 3 Subsequently, the ceramic mass is compacted in hydraulic presses and, the energy consumed in this step is, again, in the electricity form. The formed parts are submitted for drying in special furnaces, with heating promoted by burning NG. The pressed and dried ceramic mass is brought to the enameling step, which uses NG. The glazes consist of solid materials and its processing is made by means of mills. After grinding, the material passes through vibrating sieves and is transported to tanks
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with the aid of pumps, thus, the glazes are stored and remain under agitation, by electric motors. As in most ceramic industries, decorating step is done by using rotary printing rollers, and dies are fed by electric pumps. The enameled pieces are transported by conveyor belts to the ovens for burning or sintering, which are powered by NG. Then the CT passes through quality control and is conducted by conveyor belts to step of packaging, in which is used electric energy. Finally, the finished and packed product is stored and dispatched to the marketing centers. The shipping and storage process are powered by forklifts which use NG, and trucks for external transport. 3.1. Energy consumption in Ceramics A The factory Ceramics A uses dry process (DP) and has total production capacity of 104,000 m2/day of CT, divided into two units. The unit 1 comprises four production lines and unit 2 comprises two production lines, which operate in parallel. Each unit occupies its own building. Table 2 shows data of daily production of CT in each unit. Table 2 The electricity consumption measured at each step of production of Ceramics A is shown in Table 3, and proportionately in Fig. 4. The step of grinding of raw materials, especially clay, is responsible for the higher consumption of electricity, close to 22%, which is justified by the use of electric motors with increased power and continuous operation. The following steps have electric consumption in decreasing order: grinding enamel, firing and sintering, drying, pressing, filtering, transport, compressor and the classification, packaging and shipping.
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Table 3 Fig. 4 Table 4 shows the thermal energy consumption in steps of drying and firing/sintering of CT, which is supplied by NG.
Fig. 5 shows the proportional
distribution of thermal energy consumption in Ceramics A. The firing/sintering CT represents the largest consumption of thermal energy of the order of 67%, in view of this step the temperature reaches 950 °C in continuous operation, while the drying step occurs in temperature range of 190-265 oC with mean duration of 13.5 minutes per step. Table 4 Fig. 5 The composition of the energy used in Ceramics A is shown in Fig. 6, highlighting the thermal energy used for heating the drying ovens and firing, which is supplied by NG and the electricity consumption, is due to the use of electrical equipment in general. Fig. 6 3.2. Energy consumption in Ceramics B The factory Ceramics B uses wet process (WP) and has total production capacity of 15,000 m2/day of CT, divided into two units, which is showed in Table 5. Table 5
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Table 6 shows the electricity consumption in equipment and in the unit operations involved in the various steps of the production of CT, by Ceramics B. Table 6 On the other hand, Fig. 7 shows the distribution of electric power consumption in the various steps of the wet process, which is employed by Ceramics B. The step of grinding of clay is responsible for the higher consumption of electricity, close to 28%, which is justified by the use of electric motors with increased power and continuous operation. Following appear in descending order: grinding enamel, pressing, firing/sintering, atomization, drying, filtration, transport, classification, packaging and shipping, rectification and the compressor. Fig. 7 Table 7 shows the consumption of thermal energy and Fig. 8 shows the energy distribution in steps of the Ceramics B. The firing and sintering process is the higher consumption of NG, while the atomization is the second largest consumer of thermal energy, followed by drying. Table 7 Fig. 8 Table 8 and Fig. 9 shows the share of each type of energy in the production of both industries of tiles, Ceramics A and B, indicating greater proportion in the NG consumption as a source of thermal energy compared to electricity. Table 8
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Fig. 9 Table 9 presents data comparing electricity consumption in the various steps of CT production process in Ceramics A and B, which shows that the total energy consumption in the ceramics B is overall approximately four times higher than the total consumption the energy Ceramics A. This allows understanding the impacts related to energy consumption in the two studied processes. The energy consumption in the compressors of Ceramics B is about 7 times larger than the Ceramics A, which is justified by the necessity of using higher amount of compressed air in the atomization step. Table 9 On the grinding step of the wet process, the amount of electric energy used in the Ceramics B is 5 times larger than the one in Ceramics A, because it requires a large number of mills, besides the need to implement the atomization step, which eliminates content of oxide and reduces significantly the moisture contents of the ceramic mass. Similarly, step of grinding of enamel in Ceramics B consumes 4.76 times more electricity than the grinding of the enamel in Ceramics A. Also, the step of pressing in Ceramics B consumes 3.83 times more electricity than Ceramics A. The steps of classification, packaging and shipment of Ceramics B consume around 3 times more electricity than Ceramics A. The step of firing/sintering the Ceramics B consumes 2.7 times more electricity than the Ceramics A, while the filtering step of Ceramics B consumes approximately 2 times more electric energy than the Ceramics A. Transportation is one of the steps that shows low disparity between
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electricity consumption of the two ceramic industries, in which the consumption of Ceramics B is approximately 1.75 times the consumption of Ceramics A. Also, there is the rectification step in the Ceramics B, which is absent in the Ceramics A, and gives quality and standardization to the CT. Therefore, there is the addition of energy consumption related to this process. On the other hand, the drying step shows less difference of energy consumption between the two types of industries, wherein the consumption in the Ceramics B is 1.5 times that of the Ceramics A. Table 10 shows comparatively the thermal energy consumption in the various production steps CT ceramic, employed by Ceramics A and B. Furthermore, it shows that the wet process (Ceramics B) have an overall consumption of approximately 2.43 times greater than the dry process (Ceramics A), due the step of atomizing in WP process. Also, the thermal energy consumption in the drying step is similar in both industries. On the other hand, the firing step in Ceramics B consumes almost twice the energy of the Ceramics A, while the total thermal energy consumption of Ceramics B is 3.26 times greater than the one in Ceramics A. Table 10 Finally, this study did not attempt to analyze mass balance, quality of the CT, equipment efficiency, and the layout of the CT production process, of either factory A or B. Thus, the present analysis of the consumption of electric and thermal energy in both industries corresponds to only one of the stages of Life Cycle Assessment (LCA) of ceramic tiles. Also, in the scientific literature there are few articles related to LCA and ceramics industry, and are rare the articles related to the ceramic tiles. In the articles consulted, the authors show mainly the mass balance of the production process, as well
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as emissions of the solid, liquid and gaseous wastes in the environment. In this context, this work can contribute a small part of the life cycle of ceramic tiles, specifically with the energy use in the production process. 4. Conclusions The energy balance made with respect to the two ceramic industries showed the largest energy consumption occurring during the firing, atomization and drying steps of the ceramic tiles production. Thus, that the step of firing and sintering has the highest energy consumption, with approximately 56% of the total energy consumed. In sequence, have the atomization steps with 30% and the drying with 14%, of total energy consumption in the production of ceramic tiles. Furthermore, it was observed that the wet process consumes larger amount of total energy compared to the dry process, due to the inclusion of the atomization step. On the other hand, the thermal energy consumption is around 80%, while electricity consumption is 20% of total energy consumption. Therefore, the experimental data indicate the need to seek ways to use energy more efficiently, since the main source of energy is fossil (NG), therefore, not renewable. For example, by reusing the thermal energy in some steps of the process, the energy consumption may be reduced, which in turns contributes to the sustainability of the industrial process. Finally, the strengthening of the ceramic industry, especially from the ceramic tile industry, must take into account the concern about energy consumption in the face of questions related to sustainability, keeping in mind the depletion of non-renewable energy resources.
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References [1] E.A. Abdelaziz, R. Saidur, S. Mekhilef. A review on energy saving strategies in industrial sector. Renewable Sustainable Energy Rev. 15 (2011) 150-168. [2] M. Hasanuzzaman, N.A. Rahim, M. Hosenuzzaman, R. Saidur, I.M. Mahbubul, Rashid MM. Energy savings in the combustion based process heating in industrial sector. Renewable Sustainable Energy Rev. 16 (2012) 4527-4536. [3] EIA International Energy Outlook 2015, US Energy information administration.
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[9] V. Ibanez-Flores, M.D. Bovea, A. Azapagic. Assessing the sustainability of best available techniques (BAT): methodology and application in the ceramic tiles industry. J. Cleaner Prod. 51 (2013) 162-176. [10] J. Peng, Y. Jiao, W. Zeng. CO2 emission calculation and reduction options in ceramic tile manufacture – the Foshan case. Energy Procedia 16 (2012) 467-476. [11] C. Agrafiotis, T. Tsoutsos. Energy saving technologies in the European sector: a systematica review. Appl. Therm. Eng. 21 (2001) 1231-1249. [12] Z. Utlu, A. Hepbasli, M. Turan. Performance analysis and assessment of an industrial dryer in ceramic production. Drying Technol. 29 (2011) 1792-1813. [13] Z. Utlu, A. Hepbasli. Exergoeconomic analysis of energy utilization of drying process in a ceramic production. Appl. Therm. Eng. 70 (2014) 748-762. [14] S. Kuhtz, C. Zhou, V. Albini, D.M. Yazan. Energy use in two Italian and Chinese tile manufacturers: A comparison using an enterprise input-output model. Energy 35 (2010) 364-374. [15] E. Monfort, A. Mezquita, E. Vaquer, G. Mallol, H.J. Alves, A.O. Boschi. Consumo de energia térmica y emisiones de dióxido de carbono na la fabricacion de baldosas cerâmicas – analisis de lãs industrias Española e Brasileña. Boletin de La Sociedad Española de Ceramica e Vidrio 51 (2011) 275-284. [16] F. Bleicher, F. Duer, I. Leobner, I. Kovacic, B. Heinzl, W. Kastner. Co-simulation environment for optimizing energy efficiency in production systems. CIRP Annals Manufacturing Technology 63 (2014) 441-444.
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[17] S. Popov. Secondary energy recovery in ceramic kilns: energotechnological characteristics. Glass Ceram. 70 (2013) 107-110. [18] J.J. Siirola, T.F. Edgar. Process energy systems: Control, economic, and sustainability objectives. Comput. Chem. Eng. 47 (2012) 134-144.
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Table 1 Sector
/
Year
2005
2010
2014
72,806
85,567
87,502
Metallurgy*
26,690 (36,6%)
27,814 (32.5%)
27,837 (31.7%)
Food and Beverages
17,926 (24.6%)
23,244 (27.3%)
22,209 (25.4%)
Paper and pulp
7,713 (10.6%)
10,131 (11.8%)
11,423 (13.1%)
Chemical
7,132 (9.8%)
7,214 (8.4%)
6,708 (7.7%)
Cement
2,902 (4.0%)
4,255 (5.0%)
5,338 (6.1%)
Ceramics
3,412 (4.7%)
4,485 (5.2%)
5,079 (5.8%)
Textiles
1,202 (1.7%)
1,212 (1.4%)
1,017 (1.2%)
Others 5,825 (8.0%) 7,211 (8.4%) * iron steel, nonferrous metals, minering, pelotization, etc.
7,893 (8.9%)
Industrial total Industrial Sector
Table 2 Production unit Unit 1
Unit 2 Total
Production line 1 2 3 4 1 2
Production of CT (m2/day) 15,000 13,000 14,000 14,000 24,000 24,000 104,000
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Table 3 Step
Grinding clay
Energy consumption (KJ/m2)
Energy consumption (KJ/day)
1,143.35
118,908,800
Grinding the glaze
878.85
91,400,400
firing and sintering
840.74
87,436,800
drying
677.91
70,502,400
Pressing
619.75
64,454,400
Filtering
404.58
42,076,800
Transport
328.57
34,171,200
Compressor
154.94
16,113,600
Classification, Packaging and Shipping
154.52
16,070,400
5,203.21
541,134,800
Total
Table 4 Step
Energy consumption (KJ/m2)
(KJ/day)
Firing / sintering
23,340.41
2,427,402,796
Drying
11,535.89
1,199,732,716
Total
34,876.30
3,627,135,512
Table 5 Production unit Unit 1 Total
Production line 1 2
Production of CT (m2/day) 7,500 7,500 15,000
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Table 6 Step
Energy consumption (KJ/m2)
Energy consumption (KJ/day)
Grinding clay
5,760.00
86,400,000
Grinding the glaze
4,184.64
62,769,600
Pressing
2,373.12
35,596,800
Firing / sintering
2,268.00
34,830,000
Atomization
1,679.04
25,185,600
Drying
1,036.80
15,552,000
Filtering
864.00
12,960,000
Transport
576.00
8,640,000
Classification, Packaging
460.80
6,912,000
Rectification
437.00
6,560,640
Compressor
1,071.36
1,607,040
Total
20,711.14
297,013,680
and Shipping
Table 7 Step
Energy consumption (KJ/m2)
Energy consumption (KJ/day)
Firing/sintering
47,218.08
708,271,200
Atomization
25,812.55
387,188,256
Drying
11,804.52
177,067,800
Total
84,835.15
1,272,527,256
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Table 8 Industry
Ceramics A
Ceramics B
Energy
(KJ/m2)
(KJ/m2)
Electricity
5,203.21
20,711.14
Thermal (NG)
34,876.30
84,835.15
Total
40,079.51
105,546.29
Table 9
Step Grinding clay
Ceramics A ______________________ Consumption Participation (KJ.m-2) (%)
Ceramics B _______________________ Consumption Participation (KJ.m-2) (%)
1,143.35
21.97
5,760.00
27.81
Grinding the glaze
878.85
16.89
4,184.64
20.21
firing / sintering
840.74
16.16
2,268.00
10.95
Pressing
619.75
11.91
2,373.12
11.46
1,679.04
8.11
Atomization
-
-
Drying
677.91
13.03
1,036.80
5.01
Filtering
404.58
7.78
864.00
4.17
Transport
328.57
6.31
576.00
2.78
Compressor
154.94
2.98
1,071.36
5.17
Classification, Packaging
154.52
2.97
460.80
2.22
437.00
2.11
20,710.77
100.00
and Shipping Rectification Total
5,203.21
100.00
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Table 10
Step
Ceramics-A ______________________ Consumption Participation (KJ.m-2) (%)
Ceramics-A _______________________ Consumption Participation (KJ.m-2) (%)
Firing / Sintering
23,340.41
66.92
47,218.08
55.66
Drying
11,535.89
33.08
25,812.55
30.43
Atomization
-
-
11,804.52
13,91
Total
34,876.30
84,835.15
100.00
100.00
Table captions
Table captions Table 1. Energy consumption in the industrial sector (103 toe) and proportion (%) of the total industrial energy consumption in Brazil (%) Table 2. Data of daily production of CT in each unit of the Ceramics A Table 3. Electricity consumption in Ceramics A Table 4. Consumption of thermal energy in Ceramics A Table 5. Data of daily production of CT in each unit of the Ceramics B Table 6. Electricity consumption in Ceramics B Table 7. Consumption of thermal energy in Ceramics B Table 8. Summary of energy consumption in the Ceramics A and B Table 9. Electricity consumption in the Ceramics A and B Table 10. Proportional consumption of thermal energy in ceramic A and B
Fig. 1
Raw material
Grinding (electricity) Dry method
Atomization, spray drying (electricity and thermal energy)
Pressing (electricity)
Drying (thermal energy)
Glazing, enameling (electricity)
Firing / sintering (thermal energy)
Floor tile, Wall tile Classification, packaging, shipping (electricity)
Fig. 1
Fig. 2
6.000
10³ TEP
5.000
4.000
3.000
2.000
1.000
0 2005
2006
2007
2008
2009
Fig. 2
2010
2011
2012
2013
2014
Fig. 3
Fig. 3
Fig. 4
drying 13,03%
7,78% filtering
firing 16,16%
compressor 2,98%
21,97% grinding clay
11,91% pressing 2,97% classification, packaging, shipping
16,89% grinding glaze
Fig. 4
6,31% transport
Fig. 5
33,08% drying 66,92% firing and sintering
Fig. 5
Fig. 6
13% electricity 87% thermal energy
Fig. 6
Fig. 7
filtering 5,01%
drying 5,17%
firing 10,95%
8,11% atomization
27,81% grinding clay
compressor 2,11% transport 4,17%
2,22% rectification
11,46% pressing 2,78% classification packaging shipping
20,20% grinding glaze
Fig 7
Fig. 8
30,43% atomization 55,66% firing and sintering
13,91% drying
Fig. 8
Fig. 9
20% electricity 80% thermal energy
Fig. 9
Figure captions
Figure Captions
Fig. 1. Simplified diagram in the productive process of the CT industry. Fig. 2. Energy consumption in the Brazilian ceramic industry between 2005-2014 [5] Fig. 3. Simplified flowchart of the CT manufacturing process Fig. 4. Composition of electricity consumption in Ceramics A Fig. 5. Consumption of thermal energy in Ceramics A Fig. 6. The composition of the energy used in Ceramics A Fig. 7. Electricity consumption in the Ceramics B Fig. 8. Composition of thermal energy consumption in the ceramics B Fig. 9. Composition of energy sources in Ceramics A and B
S1359-4311(16)33156-8 http://dx.doi.org/10.1016/j.applthermaleng.2016.11.068 ATE 9479
To appear in:
Applied Thermal Engineering
Received Date: Revised Date: Accepted Date:
2 August 2016 18 October 2016 8 November 2016
Please cite this article as: E.F.S. Ciacco, J.R. Rocha, A.R. Coutinho, The energy consumption in the ceramic tile industry in Brazil, Applied Thermal Engineering (2016), doi: http://dx.doi.org/10.1016/j.applthermaleng. 2016.11.068
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The energy consumption in the ceramic tile industry in Brazil Eduardo F.S. Ciacco, Jose R. Rocha, Aparecido R. Coutinho* Methodist University of Piracicaba, Campus UNIMEP, SP 306, Km 24, 13451-900, Santa Bárbara d’Oeste, SP, Brasil.
Abstract The ceramic industry occupies a prominent place in the Brazilian industrial context, representing about 1.0% in the GDP composition. On the other hand, it represent about 1.9% of all energy consumed in the country, and 5.8% of the energy consumed in the Brazilian industrial sector in 2014. Regarding the power consumption by the ceramic industry, most is derived from renewable sources (firewood), followed by use of fossil fuels, mainly natural gas (NG). This study was conducted to quantify the energy consumption in the production of ceramic tiles (CT), by means of experimental data obtained directly in the industry and at every step of the manufacturing process. The step of firing and sintering has the highest energy consumption, with approximately 56% of the total energy consumed. In sequence, have the atomization steps with 30% and the drying with 14%, of total energy consumption in the production of ceramic tiles, arising from the use of NG. In addition, it showed that the production of ceramic tiles by wet process has energy consumption four times the dry production process, due to the atomization step.
Keywords: energy, energy balance, ceramics industry, ceramic tiles, sustainability. __________________ *Corresponding author. Tel.: 55 19 31241768; fax: 55 19 31241768 E-mail address: [email protected]
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1. Introduction Energy consists of a basic need for the different industrial sectors worldwide, highlighting the enormous amount of energy needed to leverage developing countries with high rates of economic growth in recent decades. Energy is therefore an important factor for the competitiveness of the economy and for maintenance and generation of employment around the world. The total energy consumption in the world was approximately 1.29 1019 toe in 2010, expected to reach 1.72 1019 toe in 2030. Specifically with regard to industry, the consumption reached around 0.46 1019 toe in 2010 with an expectation of reaching 0.61. 1019 toe in the year 2030, therefore, an increase of over 30% in the period [1, 3]. In Brazil, the power consumption in the industry reached a peak of 41% of the total energy consumed in the country in 2009. On the other hand, there was a sharp drop in the years 2013-2014, reaching ratio of 33%. This reduction was due to the economic downturn in the country and to the government programs aiming at the rational use of energy, by both the manufacturing sector as well as the general population, by encouraging energy efficiency policies, combined with conservation in the industrial environment. Among the measures there is the maintenance, renovation and replacement of equipment to avoid losses and improve production performance in terms of energy consumption, the management to minimize the consumption of thermal energy, the incentive for the rational use and search of other sources of renewable energy [4,5].
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Specifically, the ceramic industry occupies a prominent place in the Brazilian industrial scenario, with a share of 1.0% in the GDP composition, with approximately 5,000 active companies in this sector [5]. The ceramics industry accounts for approximately 5.8% of all energy consumed in the Brazilian industrial sector, which corresponds to 5.69 106 toe, where most of it is produced from renewable sources (biomass, firewood), followed by fossil fuels, particularly natural gas (NG) [4-6]. 1.1. Energy use in the ceramic industry Ceramic tiles (CT) are largely used in construction and are produced from a mixture of clays and other inorganic materials, which are calcined at high temperatures. The manufacturing process of the CT can be driven by two main routes: i) dry process (DP), in which the raw material is composed of clay mined in nature and ground dry, ii) wet process (WP), wherein the ceramic mass consists of different raw materials
milled with addition of water and subsequent removal of moisture by
atomization. In both cases the main steps of the processing of raw materials and preparation of ceramic mass are: grinding, spray drying, pressing, drying, glazing/enameling, firing/sintering, classification, packaging and shipping of the product ready. Fig. 1 shows a simplified diagram of CT production that relates the main steps and forms of energy used [7-14]. Fig. 1 The energy balance is carried out according to the amount of thermal or electric energy used at each step. Also, associated with each type of energy are included the
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resources required for their production, as well as environmental impacts from production and disposal of their waste. Ibanez-Flores et al. (2013) presented a case study on a ceramic tile industry to obtain of experimental data, in order to prepare the mass and energy balances in the various steps of the process. Their work showed high energy consumption mainly in the form of thermal energy from the burning of NG, which represents over 90% of the energy consumed in the manufacture of CT, followed by electricity consumption [9]. Studies by Monfort et al. (2012) aimed to measure the energy consumption and carbon dioxide emissions in ceramic industries of Brazil and Spain, showing that in the wet process energy consumption in both countries is similar, furthermore, they showed that the energy used in the atomizing step, obtained by co-generation, is an advantage related to energy efficiency to in favor of the Spain. On the other hand, in production by dry process, they observed that the thermal energy consumption in Brazil is lower when compared to the consumption of Spanish industry [15]. Other studies were performed by Bleicher et al. (2014) in order to optimize energy efficiency in production systems, through modeling and simulation of energy consumption in machinery and equipment. They employed mathematical modeling using a set of complex differential equations together with energy-relevant parameters, in addition to measurement data, such as energy consumption of machinery and equipment, internal energy conversion and its thermal behavior [16]. In this context, Popov (2013) utilized secondary energy in ceramic kilns, which allowed the development of a system for heat recovery from the principles of thermodynamics, obtaining increasing of 46-52% in energetic efficiency of the production system [17].
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Other studies were carried out for the use of secondary energy (heat) in direct production processes, through the evaluation of energy efficiency with an approach based on the concepts of sustainability. For this, the possibility of a system of co-generation of energy in the production plant was evaluated, in order to obtain economic benefits through better utilization of energy and at the same time, to obtain advantages from the environmental point of view as a result of reduction in the emission of pollutants into the atmosphere. The studies showed that a properly balanced system can produce energy efficiency between 70 and 85%, reaching an optimal index in the range of 95% [18]. This study was developed in order to quantify the energy consumption in the production of ceramic tiles (CT), through the survey of experimental data obtained directly in every step of the manufacturing process of two types of ceramic industries (dry and wet).
2. Methodology The methodology used in this study was surveying the energy balance in the production of CT, through the acquisition of experimental data in two ceramic industries of São Paulo State, Brazil. The data survey was carried out in a factory which employs the dry process – DP (Ceramics A) and in a factory that uses the wet process – WP (Ceramics B). At each step of the manufacturing process the power consumption was determined by measurement of the electric current and the applied voltage, considering the daily
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operating time of each one of equipment. The measurements were made by mean of electrical instruments (ammeter and voltmeter) which were connected to each device. For equipment with characteristics of electromagnetic induction, was considered its power factor, supplied by the manufacturer. The measurements of NG consumption were made directly by means of a rotameter connected to the supply line of each one equipment (furnace), also considering the respective daily operating time. Thus, the values were entered into spreadsheets and energy consumption calculations were made with respect to the daily production of CT.
3. Results Table 1 shows the energy consumption in key industrial sectors in Brazil, highlighting the growth in consumption by the metallurgical industries, which exceeded the consumption of the food and beverage industries. Regarding the ceramic industry, there was a gradual increase, remaining at the 5.8% level of the entire country's industrial consumption (Fig. 2), which is the result of growth in production in many sectors of the ceramics industry, as well as, the overall growth of the Brazilian economy in the last years [5]. Table 1 Fig. 2
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Fig. 3 shows the flowchart of the manufacturing of Ceramic Tiles (CT) by wet process (WP), which is responsible by the increased consumption of electric and thermal energy. The dry process (DP) is similar, without the presence of the atomization step. Obtaining raw materials consists of the extraction of minerals from nature, which is conditioned to the topographical situation of the deposit, the spatial distribution of the layers of clay, physical, scale of production and environmental care. The transport of raw materials from storage silos and dosing scale is done through machines and conveyor belt and subjected to magnetic separation to remove iron oxide. The energy consumed in these steps is in form of the electricity. The raw materials free of iron oxide are sent for grinding, with the addition of water (WP) or without the addition of water (DP), for the formation of the ceramic mass. In the WP case, the ceramic mass goes to the atomization step and then transported to storage silos by conveyor belt and then finally to pressing. In these steps, the supplied energy is also in the form of electricity. Fig. 3 Subsequently, the ceramic mass is compacted in hydraulic presses and, the energy consumed in this step is, again, in the electricity form. The formed parts are submitted for drying in special furnaces, with heating promoted by burning NG. The pressed and dried ceramic mass is brought to the enameling step, which uses NG. The glazes consist of solid materials and its processing is made by means of mills. After grinding, the material passes through vibrating sieves and is transported to tanks
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with the aid of pumps, thus, the glazes are stored and remain under agitation, by electric motors. As in most ceramic industries, decorating step is done by using rotary printing rollers, and dies are fed by electric pumps. The enameled pieces are transported by conveyor belts to the ovens for burning or sintering, which are powered by NG. Then the CT passes through quality control and is conducted by conveyor belts to step of packaging, in which is used electric energy. Finally, the finished and packed product is stored and dispatched to the marketing centers. The shipping and storage process are powered by forklifts which use NG, and trucks for external transport. 3.1. Energy consumption in Ceramics A The factory Ceramics A uses dry process (DP) and has total production capacity of 104,000 m2/day of CT, divided into two units. The unit 1 comprises four production lines and unit 2 comprises two production lines, which operate in parallel. Each unit occupies its own building. Table 2 shows data of daily production of CT in each unit. Table 2 The electricity consumption measured at each step of production of Ceramics A is shown in Table 3, and proportionately in Fig. 4. The step of grinding of raw materials, especially clay, is responsible for the higher consumption of electricity, close to 22%, which is justified by the use of electric motors with increased power and continuous operation. The following steps have electric consumption in decreasing order: grinding enamel, firing and sintering, drying, pressing, filtering, transport, compressor and the classification, packaging and shipping.
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Table 3 Fig. 4 Table 4 shows the thermal energy consumption in steps of drying and firing/sintering of CT, which is supplied by NG.
Fig. 5 shows the proportional
distribution of thermal energy consumption in Ceramics A. The firing/sintering CT represents the largest consumption of thermal energy of the order of 67%, in view of this step the temperature reaches 950 °C in continuous operation, while the drying step occurs in temperature range of 190-265 oC with mean duration of 13.5 minutes per step. Table 4 Fig. 5 The composition of the energy used in Ceramics A is shown in Fig. 6, highlighting the thermal energy used for heating the drying ovens and firing, which is supplied by NG and the electricity consumption, is due to the use of electrical equipment in general. Fig. 6 3.2. Energy consumption in Ceramics B The factory Ceramics B uses wet process (WP) and has total production capacity of 15,000 m2/day of CT, divided into two units, which is showed in Table 5. Table 5
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Table 6 shows the electricity consumption in equipment and in the unit operations involved in the various steps of the production of CT, by Ceramics B. Table 6 On the other hand, Fig. 7 shows the distribution of electric power consumption in the various steps of the wet process, which is employed by Ceramics B. The step of grinding of clay is responsible for the higher consumption of electricity, close to 28%, which is justified by the use of electric motors with increased power and continuous operation. Following appear in descending order: grinding enamel, pressing, firing/sintering, atomization, drying, filtration, transport, classification, packaging and shipping, rectification and the compressor. Fig. 7 Table 7 shows the consumption of thermal energy and Fig. 8 shows the energy distribution in steps of the Ceramics B. The firing and sintering process is the higher consumption of NG, while the atomization is the second largest consumer of thermal energy, followed by drying. Table 7 Fig. 8 Table 8 and Fig. 9 shows the share of each type of energy in the production of both industries of tiles, Ceramics A and B, indicating greater proportion in the NG consumption as a source of thermal energy compared to electricity. Table 8
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Fig. 9 Table 9 presents data comparing electricity consumption in the various steps of CT production process in Ceramics A and B, which shows that the total energy consumption in the ceramics B is overall approximately four times higher than the total consumption the energy Ceramics A. This allows understanding the impacts related to energy consumption in the two studied processes. The energy consumption in the compressors of Ceramics B is about 7 times larger than the Ceramics A, which is justified by the necessity of using higher amount of compressed air in the atomization step. Table 9 On the grinding step of the wet process, the amount of electric energy used in the Ceramics B is 5 times larger than the one in Ceramics A, because it requires a large number of mills, besides the need to implement the atomization step, which eliminates content of oxide and reduces significantly the moisture contents of the ceramic mass. Similarly, step of grinding of enamel in Ceramics B consumes 4.76 times more electricity than the grinding of the enamel in Ceramics A. Also, the step of pressing in Ceramics B consumes 3.83 times more electricity than Ceramics A. The steps of classification, packaging and shipment of Ceramics B consume around 3 times more electricity than Ceramics A. The step of firing/sintering the Ceramics B consumes 2.7 times more electricity than the Ceramics A, while the filtering step of Ceramics B consumes approximately 2 times more electric energy than the Ceramics A. Transportation is one of the steps that shows low disparity between
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electricity consumption of the two ceramic industries, in which the consumption of Ceramics B is approximately 1.75 times the consumption of Ceramics A. Also, there is the rectification step in the Ceramics B, which is absent in the Ceramics A, and gives quality and standardization to the CT. Therefore, there is the addition of energy consumption related to this process. On the other hand, the drying step shows less difference of energy consumption between the two types of industries, wherein the consumption in the Ceramics B is 1.5 times that of the Ceramics A. Table 10 shows comparatively the thermal energy consumption in the various production steps CT ceramic, employed by Ceramics A and B. Furthermore, it shows that the wet process (Ceramics B) have an overall consumption of approximately 2.43 times greater than the dry process (Ceramics A), due the step of atomizing in WP process. Also, the thermal energy consumption in the drying step is similar in both industries. On the other hand, the firing step in Ceramics B consumes almost twice the energy of the Ceramics A, while the total thermal energy consumption of Ceramics B is 3.26 times greater than the one in Ceramics A. Table 10 Finally, this study did not attempt to analyze mass balance, quality of the CT, equipment efficiency, and the layout of the CT production process, of either factory A or B. Thus, the present analysis of the consumption of electric and thermal energy in both industries corresponds to only one of the stages of Life Cycle Assessment (LCA) of ceramic tiles. Also, in the scientific literature there are few articles related to LCA and ceramics industry, and are rare the articles related to the ceramic tiles. In the articles consulted, the authors show mainly the mass balance of the production process, as well
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as emissions of the solid, liquid and gaseous wastes in the environment. In this context, this work can contribute a small part of the life cycle of ceramic tiles, specifically with the energy use in the production process. 4. Conclusions The energy balance made with respect to the two ceramic industries showed the largest energy consumption occurring during the firing, atomization and drying steps of the ceramic tiles production. Thus, that the step of firing and sintering has the highest energy consumption, with approximately 56% of the total energy consumed. In sequence, have the atomization steps with 30% and the drying with 14%, of total energy consumption in the production of ceramic tiles. Furthermore, it was observed that the wet process consumes larger amount of total energy compared to the dry process, due to the inclusion of the atomization step. On the other hand, the thermal energy consumption is around 80%, while electricity consumption is 20% of total energy consumption. Therefore, the experimental data indicate the need to seek ways to use energy more efficiently, since the main source of energy is fossil (NG), therefore, not renewable. For example, by reusing the thermal energy in some steps of the process, the energy consumption may be reduced, which in turns contributes to the sustainability of the industrial process. Finally, the strengthening of the ceramic industry, especially from the ceramic tile industry, must take into account the concern about energy consumption in the face of questions related to sustainability, keeping in mind the depletion of non-renewable energy resources.
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References [1] E.A. Abdelaziz, R. Saidur, S. Mekhilef. A review on energy saving strategies in industrial sector. Renewable Sustainable Energy Rev. 15 (2011) 150-168. [2] M. Hasanuzzaman, N.A. Rahim, M. Hosenuzzaman, R. Saidur, I.M. Mahbubul, Rashid MM. Energy savings in the combustion based process heating in industrial sector. Renewable Sustainable Energy Rev. 16 (2012) 4527-4536. [3] EIA International Energy Outlook 2015, US Energy information administration.
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[9] V. Ibanez-Flores, M.D. Bovea, A. Azapagic. Assessing the sustainability of best available techniques (BAT): methodology and application in the ceramic tiles industry. J. Cleaner Prod. 51 (2013) 162-176. [10] J. Peng, Y. Jiao, W. Zeng. CO2 emission calculation and reduction options in ceramic tile manufacture – the Foshan case. Energy Procedia 16 (2012) 467-476. [11] C. Agrafiotis, T. Tsoutsos. Energy saving technologies in the European sector: a systematica review. Appl. Therm. Eng. 21 (2001) 1231-1249. [12] Z. Utlu, A. Hepbasli, M. Turan. Performance analysis and assessment of an industrial dryer in ceramic production. Drying Technol. 29 (2011) 1792-1813. [13] Z. Utlu, A. Hepbasli. Exergoeconomic analysis of energy utilization of drying process in a ceramic production. Appl. Therm. Eng. 70 (2014) 748-762. [14] S. Kuhtz, C. Zhou, V. Albini, D.M. Yazan. Energy use in two Italian and Chinese tile manufacturers: A comparison using an enterprise input-output model. Energy 35 (2010) 364-374. [15] E. Monfort, A. Mezquita, E. Vaquer, G. Mallol, H.J. Alves, A.O. Boschi. Consumo de energia térmica y emisiones de dióxido de carbono na la fabricacion de baldosas cerâmicas – analisis de lãs industrias Española e Brasileña. Boletin de La Sociedad Española de Ceramica e Vidrio 51 (2011) 275-284. [16] F. Bleicher, F. Duer, I. Leobner, I. Kovacic, B. Heinzl, W. Kastner. Co-simulation environment for optimizing energy efficiency in production systems. CIRP Annals Manufacturing Technology 63 (2014) 441-444.
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[17] S. Popov. Secondary energy recovery in ceramic kilns: energotechnological characteristics. Glass Ceram. 70 (2013) 107-110. [18] J.J. Siirola, T.F. Edgar. Process energy systems: Control, economic, and sustainability objectives. Comput. Chem. Eng. 47 (2012) 134-144.
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Table 1 Sector
/
Year
2005
2010
2014
72,806
85,567
87,502
Metallurgy*
26,690 (36,6%)
27,814 (32.5%)
27,837 (31.7%)
Food and Beverages
17,926 (24.6%)
23,244 (27.3%)
22,209 (25.4%)
Paper and pulp
7,713 (10.6%)
10,131 (11.8%)
11,423 (13.1%)
Chemical
7,132 (9.8%)
7,214 (8.4%)
6,708 (7.7%)
Cement
2,902 (4.0%)
4,255 (5.0%)
5,338 (6.1%)
Ceramics
3,412 (4.7%)
4,485 (5.2%)
5,079 (5.8%)
Textiles
1,202 (1.7%)
1,212 (1.4%)
1,017 (1.2%)
Others 5,825 (8.0%) 7,211 (8.4%) * iron steel, nonferrous metals, minering, pelotization, etc.
7,893 (8.9%)
Industrial total Industrial Sector
Table 2 Production unit Unit 1
Unit 2 Total
Production line 1 2 3 4 1 2
Production of CT (m2/day) 15,000 13,000 14,000 14,000 24,000 24,000 104,000
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Table 3 Step
Grinding clay
Energy consumption (KJ/m2)
Energy consumption (KJ/day)
1,143.35
118,908,800
Grinding the glaze
878.85
91,400,400
firing and sintering
840.74
87,436,800
drying
677.91
70,502,400
Pressing
619.75
64,454,400
Filtering
404.58
42,076,800
Transport
328.57
34,171,200
Compressor
154.94
16,113,600
Classification, Packaging and Shipping
154.52
16,070,400
5,203.21
541,134,800
Total
Table 4 Step
Energy consumption (KJ/m2)
(KJ/day)
Firing / sintering
23,340.41
2,427,402,796
Drying
11,535.89
1,199,732,716
Total
34,876.30
3,627,135,512
Table 5 Production unit Unit 1 Total
Production line 1 2
Production of CT (m2/day) 7,500 7,500 15,000
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Table 6 Step
Energy consumption (KJ/m2)
Energy consumption (KJ/day)
Grinding clay
5,760.00
86,400,000
Grinding the glaze
4,184.64
62,769,600
Pressing
2,373.12
35,596,800
Firing / sintering
2,268.00
34,830,000
Atomization
1,679.04
25,185,600
Drying
1,036.80
15,552,000
Filtering
864.00
12,960,000
Transport
576.00
8,640,000
Classification, Packaging
460.80
6,912,000
Rectification
437.00
6,560,640
Compressor
1,071.36
1,607,040
Total
20,711.14
297,013,680
and Shipping
Table 7 Step
Energy consumption (KJ/m2)
Energy consumption (KJ/day)
Firing/sintering
47,218.08
708,271,200
Atomization
25,812.55
387,188,256
Drying
11,804.52
177,067,800
Total
84,835.15
1,272,527,256
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Table 8 Industry
Ceramics A
Ceramics B
Energy
(KJ/m2)
(KJ/m2)
Electricity
5,203.21
20,711.14
Thermal (NG)
34,876.30
84,835.15
Total
40,079.51
105,546.29
Table 9
Step Grinding clay
Ceramics A ______________________ Consumption Participation (KJ.m-2) (%)
Ceramics B _______________________ Consumption Participation (KJ.m-2) (%)
1,143.35
21.97
5,760.00
27.81
Grinding the glaze
878.85
16.89
4,184.64
20.21
firing / sintering
840.74
16.16
2,268.00
10.95
Pressing
619.75
11.91
2,373.12
11.46
1,679.04
8.11
Atomization
-
-
Drying
677.91
13.03
1,036.80
5.01
Filtering
404.58
7.78
864.00
4.17
Transport
328.57
6.31
576.00
2.78
Compressor
154.94
2.98
1,071.36
5.17
Classification, Packaging
154.52
2.97
460.80
2.22
437.00
2.11
20,710.77
100.00
and Shipping Rectification Total
5,203.21
100.00
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Table 10
Step
Ceramics-A ______________________ Consumption Participation (KJ.m-2) (%)
Ceramics-A _______________________ Consumption Participation (KJ.m-2) (%)
Firing / Sintering
23,340.41
66.92
47,218.08
55.66
Drying
11,535.89
33.08
25,812.55
30.43
Atomization
-
-
11,804.52
13,91
Total
34,876.30
84,835.15
100.00
100.00
Table captions
Table captions Table 1. Energy consumption in the industrial sector (103 toe) and proportion (%) of the total industrial energy consumption in Brazil (%) Table 2. Data of daily production of CT in each unit of the Ceramics A Table 3. Electricity consumption in Ceramics A Table 4. Consumption of thermal energy in Ceramics A Table 5. Data of daily production of CT in each unit of the Ceramics B Table 6. Electricity consumption in Ceramics B Table 7. Consumption of thermal energy in Ceramics B Table 8. Summary of energy consumption in the Ceramics A and B Table 9. Electricity consumption in the Ceramics A and B Table 10. Proportional consumption of thermal energy in ceramic A and B
Fig. 1
Raw material
Grinding (electricity) Dry method
Atomization, spray drying (electricity and thermal energy)
Pressing (electricity)
Drying (thermal energy)
Glazing, enameling (electricity)
Firing / sintering (thermal energy)
Floor tile, Wall tile Classification, packaging, shipping (electricity)
Fig. 1
Fig. 2
6.000
10³ TEP
5.000
4.000
3.000
2.000
1.000
0 2005
2006
2007
2008
2009
Fig. 2
2010
2011
2012
2013
2014
Fig. 3
Fig. 3
Fig. 4
drying 13,03%
7,78% filtering
firing 16,16%
compressor 2,98%
21,97% grinding clay
11,91% pressing 2,97% classification, packaging, shipping
16,89% grinding glaze
Fig. 4
6,31% transport
Fig. 5
33,08% drying 66,92% firing and sintering
Fig. 5
Fig. 6
13% electricity 87% thermal energy
Fig. 6
Fig. 7
filtering 5,01%
drying 5,17%
firing 10,95%
8,11% atomization
27,81% grinding clay
compressor 2,11% transport 4,17%
2,22% rectification
11,46% pressing 2,78% classification packaging shipping
20,20% grinding glaze
Fig 7
Fig. 8
30,43% atomization 55,66% firing and sintering
13,91% drying
Fig. 8
Fig. 9
20% electricity 80% thermal energy
Fig. 9
Figure captions
Figure Captions
Fig. 1. Simplified diagram in the productive process of the CT industry. Fig. 2. Energy consumption in the Brazilian ceramic industry between 2005-2014 [5] Fig. 3. Simplified flowchart of the CT manufacturing process Fig. 4. Composition of electricity consumption in Ceramics A Fig. 5. Consumption of thermal energy in Ceramics A Fig. 6. The composition of the energy used in Ceramics A Fig. 7. Electricity consumption in the Ceramics B Fig. 8. Composition of thermal energy consumption in the ceramics B Fig. 9. Composition of energy sources in Ceramics A and B