Cement industry greenhouse gas emissions – management options and abatement cost

Journal of Cleaner Production xxx (2015) 1e12

Contents lists available at ScienceDirect

Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro

Cement industry greenhouse gas emissions e management options and abatement cost Raili Kajaste*, Markku Hurme Aalto University, Department of Biotechnology and Chemical Technology, PO Box 16100, FI-00076 AALTO, Finland

a r t i c l e i n f o

a b s t r a c t

Article history: Received 13 March 2015 Received in revised form 8 June 2015 Accepted 10 July 2015 Available online xxx

Growing anthropogenic greenhouse gas emissions and increasing global demand for cement are general drivers for managing greenhouse gas emissions (GHG) in the cement industry. Overall CO2 dominates cement sector GHG emissions. The aim was to study how the management of GHG emissions in the cement production chain is related to (1) clinker substitutes, (2) primary source of energy, (3) electricity emissions, (4) technology in use and (5) geographic location. Therefore regional CO2 emissions in the cement industry were analyzed by applying a climate impact management matrix on a cradle-to-gate basis. The use of clinker substitutes in cement varied from 3% to 36.4%. The results show that the variation of process technology and thermal energy use related CO2 emissions is more significant than that of electricity emissions. The highest near term potential to avoid emissions is replacing clinker with mineral components (MIC). Increasing the global use of MIC to a level of 34.2%in cement would save 312 Mt CO2 with the 2013 level of annual cement production. Similarly, a 2.7% reduction in thermal energy use would save 28 Mt CO2 annually, and a 10% decrease of emissions from electricity use would save 26 Mt CO2. The best long term options from 2030 onwards are different carbon capture technologies and MgO and geopolymer cements. In addition, the CO2 abatement costs of different investment projects were compared by using a uniform capital recovery factor. The abatement cost of avoided emissions varied from US$4 to US$ 448 per ton of CO2 depending on the technology, geographical location and initial level of CO2 emissions. © 2015 Elsevier Ltd. All rights reserved.

Keywords: Cement Climate impact Abatement cost CO2 emission management

1. Introduction Since 1950 the production of cement has gone up by a factor of 25, and China used more cement in 2011e2013 than the USA during the entire 20th century (Smil, 2013). Consequently, in 2010 the cement sector was responsible for 2823 million metric tons (Mt) of CO2 emissions (OECD, 2012). This corresponded to almost 9% of global CO2 emissions from burning of fossil fuels that year. In total, cement production accounts for roughly 5e8% of global CO2 emissions. Thus growing anthropogenic greenhouse gas emissions and increasing global demand for cement are general drivers that motivate finding solutions for managing greenhouse gas emissions (GHG) in the cement industry and comparing the abatement cost of different technological or technical solutions. The United Nations Intergovernmental Panel for Climate Change (IPCC) and the International Energy Agency (IEA) estimate that the annual mitigation

* Corresponding author. E-mail address: raili.kajaste@aalto.fi (R. Kajaste).

potential of GHG emissions in the cement industry will vary between 480 and 1700 million metric tons in 2030 (IPCC, 2007; IEA, 2006). Global reporting on cement industries is, however, not complete: available statistics on cement industry production volumes and GHG emissions do not fully cover global emissions and vary in different sources of information. The large amount of CO2 emissions, considerable use of energy, and depleting resources has pushed the cement industry to implement commitments like the Cement Sustainability Initiative (CSI, 2011; WBCSD, 2012). A roadmap for reducing the climate impact of cement industries gives the general framework (IEA, 2009) that is supported by other organizations (Gupta, 2011). Global cement production grew by over 73% between 2005 and 2013 from 2310 Mt to 4000 Mt (Cembureau, 2014), highlighting the importance of reducing CO2 emissions of cement production. Research on the management of cement industry GHG emissions and, in particular, those of CO2 has received considerable interest worldwide. The cement production process, energy use and related CO2 emissions are known from previous research

http://dx.doi.org/10.1016/j.jclepro.2015.07.055 0959-6526/© 2015 Elsevier Ltd. All rights reserved.

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

2

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12


n et al., 2013; Benhelal et al., 2012; Mikulcic et al., 2012). (Uso Traditional pathways to decrease cement production emissions are improved energy efficiency through improved technology, better process integration together with the use of clinker substitutes like waste fly ash and slags from power production and minerals processing (Ishak and Hashim, 2014; Worrell et al., 2008), and fuel switching and alternative fuels (McLellan et al., 2012; Rahman et al., 2015). Ash from agricultural wastes which constitute pozzolanic materials can be used as a replacement for cement (Aprianti et al., 2015). Hasanbeigi et al. (2012) reviewed eighteen emerging technologies and their benefits for the cement industry. One of the conclusions was that information is still scarce and scattered regarding energy-efficiency and low-carbon technologies. Also most of the technologies have an energy penalty associated with their operation. Considerable research effort is dedicated to reducing the cement production emissions in China, and accompanying investments in new kiln technologies have considerably reduced the CO2 emissions per ton of cement from 2006 onwards (Xu et al., 2014; Wang et al., 2014, 2013; Wen et al., 2015; Hasanbeigi et al., 2013). Cement is one of the key components in concrete. Several studies concentrate on the possibility to replace cement in concrete or mortar with recycled materials like porcelain polishing residues (Jacoby and Pelisser, 2015), glass (de Castro and de Brito, 2013),
n et al., 2013), basalt aggregates (Ingrao recycled tyre rubber (Uso et al., 2014), ceramic aggregates (Medina et al., 2013) or other aggregates (Mutuk and Mesci, 2014). Research on alternative binders to Portland cement that reduce the CO2 emission is progressing (Ponikiewski and Gołaszewski, 2014; Juenger et al., 2011), and e.g. the use of alkali-activated (AA) binder instead of ground granulated blast-furnace slag (GGBS) cement in concrete or in ordinary Portland cement (OPC)-based concrete reduces the CO2 emission of concrete by between 55 and 75% (Yang et al., 2013). GGBS can also be used as a soil stabilizer instead of cement in non-fired clay mixes (Kinuthia and Oti, 2012). Composite masonry bricks without Portland cement have been successfully tested (Turgut, 2012), and the

latest news report on compostable bricks grown on agricultural waste frames with the help of fungi for short life time constructions (NS, 2014). Carbon capture technologies are also one of the future options to reduce the CO2 emission of cement production leading to life cycle GHG emission reductions of 39e78% for cement production (Volkart et al., 2013; Hasanbeigi et al., 2012). Simulation models for oxy-combustion, calcium looping and amine scrubbing reduced the flue gas CO2 content by 63e85% but increased the specific energy consumption (Vatopoulos and Tzimas, 2012). A scenario analysis for Spain forecasts a 45% emission reduction from the 2010 level in 2030 (García-Gusano et al., 2015). The promising different options to reduce the GHG of cement production and partially incomplete and scattered data motivated us to study how the overall management of GHG emissions in the cement production chain is related to clinker substitutes, technology in use, primary source of energy, electricity emissions and geographic location. In addition, we compared the abatement costs of reducing the GHG of cement production by using a uniform capital recovery factor. Our focus in this paper is on managing GHG emissions in cement production chains. Other environmental burdens like particulate matter formation, terrestrial acidification and freshwater eutrophication are excluded. Methods are described in Section 2, and Section 3 presents the results of our study. The conclusions are highlighted in Section 4. 2. Methods The system boundary for a single plant GHG management was selected on a cradle-to-gate basis and is described in Figs. 1 and 2. For analyzing regional differences, data on cement production GHG emissions collected from several sources were grouped by geographic region. GHG emissions in the cement industry were analyzed and calculated in uniform unit (kg CO2/t cement) as shown in the resulting datasets (Table 2). The consistency and accuracy of contributors to the overall CO2 emissions in the cement industry in the datasets e clinker baseline, positive impact of

Fig. 1. System boundary for a cradle-to-gate LCA of a cement plant. Adapted from Finnsementti (2007).

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

clinker substitutes, fossil fuel emissions and electricity emissions e was assessed by using least square linear regression. The clinker baseline is defined as CO2 released from decomposition of mainly limestone and magnesium carbonate during the clinker production process (GNR, 2011). The resulting regional CO2 emissions together with previous research on managing energy and GHG emissions were used for a comparative analysis of different options to improve the GHG balance of cement industries based on found contributors. In addition, the abatement cost of emission reductions were calculated using a uniform capital recovery factor (CRF). 2.1. System boundary for single plant GHG management Cement sector GHG emissions are dominated by CO2, which constitutes 98.5% (Ingrao et al., 2014), and usually cradle-to-gate life cycle assessment (LCA) studies include only CO2 with few exceptions (Li et al., 2014). Most of the statistics cover only process emissions and related energy emissions excluding emissions from electricity use from the assessment. Usually LCA studies of cement production report life cycle inventories (LCI) on a plant or regional scale (Li et al., 2014; Moya et al., 2011) and evaluate possibilities to reduce the environmental impact either by alternative technologies (Chen et al., 2010; Huntzinger and Eatmon, 2009) or by upgrading an existing plant (Valderrama et al., 2012). The key functional unit (FU) used is either kg or m3 of produced clinker, cement or concrete in cases where the target is to reduce the amount of cement in concrete. The climate impact of raw material mining and quarrying including transport is generally considered to contribute about 5% of the overall CO2 emissions and, therefore, has often been left out of emission evaluations. A 50% increase in transport distance has a relative impact of 3e10% on the emission for OPC concrete (McLellan et al., 2011). This means that uncertainties in assessing GHG emissions of the cement raw material supply chain remain to be clarified.

3

A typical set of boundary limits for a cradle-to-gate basis life cycle assessment (LCA) for a modern dry cement plant with preheaters is shown in Fig. 1. A climate impact management matrix for the cement industry was developed based on a similar management matrix as for biorefinery production chains (Kajaste, 2014). The life cycle of a single cement production site, on a cradle-to-gate basis, consists of feedstock production, storage, transportation, intermediate storage, pretreatment, cement production operations, product storage, packaging and dispatching (Fig. 2). The importance of reducing GHG emissions of cement comes evident also in LCAs of its end users; it was found for all US roads studied that the majority of emissions occur in year one e from cradle-to-gate materials production e primarily due to cement production (Loijos et al., 2013). 2.2. Matrix for contributors The sum of CO2 specific emissions ETotal (kg CO2/t cement) is:

ETotal ¼ EClinker

Baseline

 EClinkerSubstitute þ EFossil

Fuel

þ EElectricity þ ETransport ;

(1)

and can be rewritten with regression parameters wi as

ETotal ¼ w1 EClinker baseline w2 EClinkerSubstitute þw3 EFossil Fuel þw4 EElectricity þw5 ETransport :

(2)

Since the information available does not allow the estimation of transport emissions (ETransport), these were excluded from the evaluation, and Eq. (1) was rewritten as:

ETotal ¼ EClinkerBaseline  EClinker þ EElectricity :

substitutes

þ EFossilFuel (1a)

Fig. 2. Climate impact management matrix for cement industries.

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

4

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

Table 1 Geographical distribution of 25% of the world cement production and CO2 emissions in 2011. Region

Production t/year

Emissions tCO2/year

Specific emission kg CO2/t clinker

Fuel carbon g CO2/MJ

MIC % wt

Coverage % of production

Europe North America Japan Aus NZ CIS Central America Brazil South America* China India Asia** Africa Middle East WORLD 25%

201,000,000 59,800,000 24,600,000 16,800,000 38,500,000 46,200,000 32,100,000 106,000,000 123,000,000 116,000,000 82,400,000 30,700,000 877,100,000

129,000,000 44,500,000 17,100,000 13,500,000 25,100,000 26,800,000 18,900,000 75,700,000 72,200,000 83,500,000 46,300,000 21,200,000 573,800,000

847 897 838 976 858 850 848 867 837 843 814 851 852

82.8 90.3 90.8 76.8 90.7 81.8 82.1 96.4 95.9 90.2 72.3 91.1 87.3

25.1 8.15 15.1 18.4 27.0 32.3 29.3 25.2 27.3 18.5 21.2 16.7 23.61

96 76 39 18 67 72 61 5 55 37 51 11 25

Notes: specific emission does not include emissions from the use of electricity. *ex. Brazil, **excl. China, India, CIS and Japan, MIC ¼ mineral components in Portland and blended cements. Adapted from GNR (2011). Table 2 Cement production carbon dioxide emissions in kg CO2/t cement. Dataset Dataset 1.1 1.2 1.3 1.4 1.5 1.6 Dataset 2.1 2.2 2.3 2.4 Dataset 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 Dataset 4.1 4.2 4.3 4.4 4.5 Dataset 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Dataset 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12

Etotal

Eclinker

baseline

ECSubstitute

Efossil

fuel

Eelectricity

Year

Location

1 806 823 860 824 872 848

521 532 529 525 527 525

68 73 69 68 70 67

333 344 380 346 394 370

20 20 20 21 21 20

2000 2001 2002 2003 2004 2005

Finland Finland Finland Finland Finland Finland

723 754 837 711

524 551 534 551

134 154 146 154

216 241 299 241

117 116 150 73

2004 2004 2004 2004

India India India India

729 748 755 863 790 680 727 664 664 673

520 547 557 712 607 532 546 547 547 547

156 164 167 214 182 202 162 187 202 205

291 291 291 291 291 275 269 229 243 255

74 74 74 74 74 75 74 75 76 76

2007 2007 2007 2007 2007 2007 2007 2009 2011 2011

China China China China China China China China China China

906 900 923 1000 940

510 510 510 510 510

0 0 0 0 0

293 287 318 389 331

103 103 95 101 99

2010 2010 2010 2010 2010

Iran Iran Iran Iran Iran

719 597 614 634 757 646 670

525 525 525 525 510 525 525

6*** 142 131 132 77 129 118

188 160 166 241 266 250 263

n.a. 54 54 n.a. 58 n.a. n.a.

2011 2011 2007 2011 2010 2010 2005

UK Germany Germany Europe Nordic Europe Europe

824 712 796 626 576 600 649 609 687 641 709 654

525 525 525 525 525 525 525 525 525 525 525 525

43 79 97 142 170 154 132 143 97 111 88 124

342 266 368 243 221 229 256 227 259 227 272 253

n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.

2011 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011

N. America Japan Aus NZ CIS C. America Brazil S. America* China India Asia** Africa M. East WORLD 25%

2

3

4

5

6

Adapted from Plant data Finnsementti, 2006

Plant data CDM, 2014 Project 0287

Countrywide Ke et al., 2013 Ke et al., 2013 Ke et al., 2013 Ke et al., 2013 Ke et al., 2013 Wang et al., 2013 Li et al., 2014 Li et al., 2014 Ke et al., 2013 Xu et al., 2014 Plant data Ostad-Ahmad-Ghorabi and Attari, 2013

Europe MPA Cement, 2012 VDZ, 2014 VDZ, 2014 GNR, 2011 Rootzen and Johnsson, 2015 GNR, 2011 GNR, 2011 Global

GNR, 2011

*excl. Brazil, **excl. China, India, CIS and Japan, ***does not reflect the actual situation. Calculations by the authors. Electricity emissions are missing from Dataset 6 and partly from dataset 5, therefore the lower summary emissions.

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

2.3. Uniform capital recovery factor for calculation of the GHG abatement cost Statistical data on investment costs in different regions were collected for the GHG abatement/mitigation cost calculations in the cement industry. For investment cost calculation we used a capital recovery factor (CRF),

 CRF ¼ ið1 þ iÞn ð1 þ iÞn  1;

(3)

where i is discount rate and n is the number of annuities received. The annual abatement cost for one ton of GHG reduction (CO2eq) was calculated by combining the emission reduction data with Eq. (3) using two discount rates (5% and 10%) and a 10-year payback period. The two discount rates also indicate the sensitivity of abatement cost for changes in the investment cost. 3. Results and discussion The object was to study how the overall management of GHG emissions in the cement production chain is related to (1) clinker substitutes, (2) primary source of energy, (3) electricity emissions, (4) technology in use and (5) geographic location. The results give the impact of the four first components for geographic regions. The impact of technology in use is directly linked to the amount of CO2 emissions from thermal energy used in kilns. There is a clear geographical variation in the CO2 emissions of the cement production that is also reflected in the comparative analysis of different options to improve the GHG balance of cement industries. 3.1. Regional distribution of cement production Global cement production is dominated by China, India and other Asian countries, which in 2013 produced almost 74% of the world's cement. The regional split of production is shown in Figs. 3 and 4. 3.2. Datasets developed Geographical differences in CO2 emissions from cement production were the reason to develop regional datasets. Formation of datasets was done for Eq. (1a). Initial data for dataset development is shown in Table 1 covering 25% of the world's cement production (but only 5% in China) in 2011. The emissions from electricity use are not included in the specific emission of Table 1. The emission unit in all the developed datasets is kg CO2/t cement.

Brazil 70 (2%)

2005 2010

Africa

Middle East

2005 America**

Turkey

China India Europe United States Japan, Aus, NZ Asia* CIS Brazil

Several estimates of the world's cement production and corresponding CO2 emissions exist, and one of them e based on satellite monitoring e reported for 2007, 2008 and 2009 gives estimates of 1382, 1417 and 1397 Mt CO2, respectively (ORNL, 2010). These emissions exclude emissions from fossil fuel and electricity use in the cement industry, and taking 3000 Mt as total cement production in 2009 we get a process emission of 466 kg CO2/t cement that compared to the theoretical 100% clinker in cement value of 510e525 indicates a MIC% of 8.63e11.24 in the cement. This is lower than the World 25% value of 22.55% for the same year (Table 1). The difference may be explained by the fact that the companies reporting to GNR have less clinker loss in dust emissions, are more efficient in their fossil fuel use and are overall more prone to replace clinker with mineral components that reduce the overall CO2 emission. Datasets (Table 2) are either based on single plant measured values or on country/region based data. In all, the datasets cover best the production in China (96%), Europe (96%), North America (76%), Brazil (72%), Central America (67%), India (55%) and Africa (51%). The percentages in brackets give the minimum coverage in the region. For the rest of the regions the coverage % is shown in Table 1. Conclusively, the datasets cover over 77% of the world's cement production in 2013 assuming that no significant technological improvements have occurred since 2011. The relative uncertainty of the estimates and confidence intervals including standard deviations of datasets differ (Table 4). Dataset 1 also presents measured clinker baseline values including the dust loss emissions, which are valuable when comparing the three internationally recommended baseline values of 510, 525 or 540 generally used in assessing cement production CO2 emissions (GNR, 2011). The relative uncertainty of the estimates in Dataset 1 is considered to be of the normal level of laboratory and plant instrument accuracy i.e. lower than 3%. The median value for Etotal is 836 and standard deviation 21. Dataset 2 represents plant benchmarks with unknown accuracy and therefore assumed uncertainty is over 5%. The relative uncertainty of the estimates of the CO2 emissions from China's cement production (Dataset 3, Table 2) is in the range of 10%e18% and reflects the discrepancies between different methodologies (Ke et al., 2013). This uncertainty range indicates that the total estimated CO2 emissions from China's cement industry in 2010 was lower than 1.1 Gt or higher than 1.4 Gt, a difference of more than 0.3 Gt. Dataset 4 gives the results of a recent emission assessment of five plants in Iran. The relative uncertainty of the estimates is considered to be higher than that of Datasets 1 and 2. Dataset 5

America** 126 Middle East 185 (4.6%) (3.2%) Turkey 70 (2%)

Mt/year 2500 2000 1500 1000 500 0

2011 2012 2013

Fig. 3. World cement production volumes by region 2005e2013 in million metric tons. Notes: *excl. China, India, CIS and Japan, **excl. Brazil and United States. Sources: GNR (2011), Cembureau (2014), Ke et al. (2013).

5

Africa 192 (4.8%) China 2344 (58.6%)

CIS 104 (2.6%) Asia* 310 (7.8%) Japan, Aus, NZ 72 (2%) United States 78 (2%) Europe 170 (4.3%)

Cement producƟon Mt in 2013

India 280 (7%) Fig. 4. World cement production in 2013 by regions in million metric tons. Notes: *excl. China, India, CIS and Japan, **excl. Brazil and United States. Source: Cembureau (2014).

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

6

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

Table 3 World cement production CO2 emissions by geographic region in 2011 in kg CO2/t cement. District

Production Mt cement/year

Emissions Mt CO2/year

Specific emission kg CO2/t cement

Clinker with MIC kg CO2/t cement

Fossil fuel kg CO2/t cement

Electricity emission kg CO2/t cement

China India Europe United States Japan, Aus, NZ Asia* CIS Brazil Turkey America** Middle East Africa WORLD

2085 210 209 79 63 270 93 63 64 111 168 162 3577

1440.74 174.93 143.79 70.63 49.52 205.47 81.38 41.08 45.31 77.15 149.04 134.30 2613.34

691 833 688 894 786 761 875 652 708 695 920 829 766

365 387 393 482 446 428 440 355 392 377 502 457 433

250 332 241 342 266 259 385 221 242 236 318 272 260

76 114 54 70 74 74 50 76 74 82 100 100 73

Notes: *excl. China, India, CIS and Japan, **excl. Brazil and United States, MIC ¼ mineral components in Portland and blended cements. National statistics usually excludes electricity emission to avoid double counting. Calculations by the authors. Table 4 Median values, standard deviations and relative uncertainties of CO2 emissions. Data

Median Etotal kg CO2/t cement

Standard deviation kg CO2/t cement

Relative uncertainty %

Reference

25% World Dataset 1 Dataset 2 Dataset 3 Dataset 4 Dataset 5 Dataset 6 World >77%

852* 836 739 728 923 646 649 766*

83 21 40 48 29 45 64 79

10e20 2.5 5.4 7e15 3e8 7e10 10 5e12

Table Table Table Table Table Table Table Table

1 2 2 2 2 2 2 3

*Weighted average.

reflects best the total CO2 emissions of cement production in Europe. The relative uncertainty comes from the values left outside the range of 10% and 90%. Dataset 6 is derived from the data given in Table 1, which covers 967 individual facilities that reported absolute net CO2 emission 556 MtCO2 and absolute gross emission 573 MtCO2 excluding emissions from electricity in 2011. Originally, the gross and net emissions per ton of clinker (Table 1) were estimated by GNR (2011) using linear regression e between 10% and 90% e resulting in weighted average values of 852 kg CO2/t clinker with a standard deviation of 83 for gross emissions and correspondingly 825 kg CO2/t clinker with a standard deviation of 100 for net emissions (net CO2 emissions ¼ gross CO2 emissions minus emissions from the use of alternative fossil fuels). Similarly the weighted average of electricity use was estimated at 107 kWh/t cement with a standard deviation of 53 (no estimate for CO2 emissions was included). The emission estimate of GNR (2011) covered 651 facilities and the electricity use of 254 companies. Datasets were further used to estimate regional emission data (Table 3) covering over 77% of the world's cement production. The emissions are expressed as total specific CO2 emission and include clinker baseline emission minus clinker substitute (MIC) impact, emission from fossil fuel use and emission from electricity use. Electricity emissions of cement production were estimated using values from Table 2 and regional data from IEA (2013). The emission values for the total world production in 2011 were calculated as summary emission of mass-fractional contributions of different regions. The estimate of 2613 Mt CO2 emissions from the cement industry in 2011 (Table 3) correlates with the preliminary estimate of 2823 Mt CO2 emissions from the cement industry in 2010 by OECD (2012) with a difference of 7.44%. A recent rough estimate for global emissions from cement production uses the following values: clinker baseline of 510 kg CO2/t clinker, clinker fuel emission of 353 kg CO2/t clinker, and for cement a process emission of 403 kg

CO2/t cement (assumes a 21% MIC content), cement fuel emission of 318 kg CO2/t cement and cement electricity emission of 100 kg CO2/ t cement. The corresponding summary specific emission is 821 kg CO2/t cement (Gupta, 2011). This is 7.05% higher than the corresponding value in Table 3 and gives a total global emission of 2933 Mt CO2 for the 2011 world production of cement. This is 3.9% higher than the OECD (2012) estimate for 2010. 3.3. Model for consistency testing and fitting total emissions The consistency and accuracy of Table 2 was checked by using Eq. (1a), in which the wi values were fitted by a least square regression. The regression parameters w1, w2, w3 and w4 all equaled to 1, confirming a perfect fit with less than a one percent error margin. The importance of correct EClinkerSubstitute values emerged from checking with data regression incomplete data from a CDM project number 0711 Mysore and Dalmia in India (CDM, 2014) that included only the impact of fly ash and slag on clinker baseline values. By assuming that Etotal equals 980 kg CO2/t cement we got the following weighted coefficients: w1 e 1.009, w2 e 5.69, w3 e 1.005 and w4 e 0.993, and by assuming that Etotal equals 833 kg CO2/t cement (global for India from Table 3) the weighted coefficients changed to: w1 e 1.004, w2 e 2,54, w3 e 1.002 and w4 e 0.997. The error margin for the generated emission values (Eq. (1a)) varied from 7.52% to þ6.38%. This means that selected EClinkerSubstitute values have a considerable impact on the total emissions of cement production. The relative uncertainty of the estimates and confidence intervals including standard deviations of datasets are shown in Table 4. 3.4. Comparative analysis of different options Various sustainability initiatives and recent research have already managed to reduce the CO2 emissions of the cement

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

industry. The specific emission level has dropped by 14.8% from the average 1000 kg CO2/t clinker in 2006 to 852 kg CO2/t clinker in 2011 (Hasanbeigi et al., 2012; GNR, 2011). The electric energy consumption has not dropped in similar tact; the global weighted average was 111 kWh/t cement in 2006 and 107 kWh/t cement in 2011 corresponding to a 3.6% reduction in 6 years (IEA, 2009; GNR, 2011). Despite improvements, the continuously increasing production volumes of cement mean that the magnitude of the problem is not diminishing, as shown in Fig. 5. The starting point for our comparative analysis of different mitigation options was the global cement industry emission data for 2011 estimated by the authors (Table 3). A minimum and maximum range for the possibilities to reduce CO2 emissions by increasing MIC in cement, by reducing the fossil fuel components, by improving the carbon balance of electricity use, and by changing the kiln technology were compared on the basis of the actual reduction potential. The addition of MIC reduces the clinker baseline (510e525e540 kg CO2/ t clinker) linearly. Emissions from fossil fuel use depend on the fuel mix and utilized kiln technology. Emissions from electricity depend on the fossil use of generation and on the efficiency of its use in the cement plant. The specific emission in kg CO2/t cement varies geographically from 652 in Brazil to 920 in the Middle East. Brazil has lower fossil fuel and electricity baselines than the Middle East and uses mineral components (34.2%) considerably more than is the practice in the Middle East (5%), where OPC dominates the market. The differences in fossil fuel and electricity baselines depend on several factors and are highly specific for each region. Kiln technology is one of the factors that impact the energy and electricity consumption of cement plants. The regional differences of cement production emissions are shown in Fig. 6. The total specific emission is shown as (clinker baseline e MIC impact) plus emission from fossil fuel use plus emission from electricity use as in Eq. (1a).

Million metric tons (Mt)

3.4.1. Management of CO2 emissions by increasing the MIC content in cement Substitution of clinker with MIC reduces the CO2 emission of calcination and is an efficient way to improve the GHG management in the cement industry. The current use of these clinker substitutes (Fig. 7) is less than the maximum allowable by current standards and national regulations (Bhushan, 2010). Regional differences in replacing clinker with other mineral substitutes are significant (Fig. 6) and can be assessed based on the “Clinker with MIC kg CO2/t cement” emission values that vary from 355 in Brazil to 502 kg CO2/t cement in the Middle East (Table 3) if clinker to cement ratios are not available. The widely used ASTM standard (2013) and the European cement standard EN 197-1 (2011) allow varying clinker to cement ratios. The latter includes 27 different variations for clinker content starting from 95% for CEM I 42.5 (ordinary Portland cement) and ending with 27% for CEM III/B 42.5 (a blended cement with ground granulated blast furnace slag). In the United States and in the

1000 800 600 400

Electricity

200

Fossil fuel Clinker+MIC

0

Fig. 6. Regional specific emissions in kg CO2/t cement in 2011.

Middle East, cement consumption is dominated by OPC, which explains the low clinker substitute use, and is also reflected in the high total specific emissions. The clinker substitute rate of Brazil is 34.2%. The clinker to cement ratio reached 62.6% in China in 2011 and is not expected to be lower than 60% before 2050 (Xu et al., 2014). The minimum reduction potential could be that the world average use of clinker substitutes in 2011 (17.52%) would be increased to the level of Brazil. This would mean a reduction of 78 kg CO2/t cement produced, meaning a total reduction of 312 Mt CO2/year (10.2%) with the production amount of 4000 Mt cement as in 2013 with the assumption that OPC can always be replaced with blended cement. The Cement Roadmap of IEA (2009) estimates a 27% average use of clinker substitutes in 2030 corresponding to a reduction of 50 kg CO2/t cement. The latter would mean a 200 Mt CO2/year reduction with the production level of 2013. The maximum reduction potential will depend on how quickly the positive mechanical and physical test results from high substitute content in cement (>35%) will be adapted to international standards and national regulations. The availability of additional fly ash, slag, pozzolan, limestone and recycled mineral components is not considered a hindrance (Gupta, 2011).

3.4.2. Management of CO2 emissions by reducing fossil fuel use or improving energy efficiency The energy balance and technical solutions of cement kilns have a considerable impact on CO2 emissions (Morrow et al., 2014). The use of high calorific municipal solid waste (MSW) and other refusederived fuel (RDF) as co-fired fuel in cement kilns significantly reduces GHG emissions (Garg et al., 2009; Genon and Brizio, 2008; Kara, 2012). Sewage sludge (SS) both reduces fossil fuel use and replaces up to 14% of the clinker in cement (Rodríguez et al., 2013). However, the use of sludge slightly increases the CH4 and N2O emission of cement production (Nakakubo et al., 2012). A review on the technical, economic and environmental effects of MSW, SS, biomass, meat and bone animal meal (MBM) and end-of-life tyres (ELT) as alternative fuels and raw materials in the cement industry concluded that by coupling the cement and waste management

Gypsum 4.46

4500 4000 3500 3000 2500 2000 1500 1000 500 0

World producƟon

Fig. 5. World cement production and corresponding CO2 emissions 2005e2013.

Limestone 6.52

Puzzolana 1.9 Slag 5 Fly ash 4.39 Others 0.98

CO2 emissions

2005 2010 2011 2012 2013

7

Grey clinker 76.77 Fig. 7. Use of clinker and clinker substitutes (%) at 25% of the world cement facilities in 2011. Adapted from GNR (2011).

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

8

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

industries, it is possible to significantly reduce the GHG emissions and natural resource consumption associated with cement pro
n et al., 2013). Similarly, the use of charcoal from duction (Uso sawmill residues reduces fossil fuel emissions by 83e91% compared to coal as fuel in a cement kiln (Sjølie, 2012). Up to 8% of the cement in mortar could be replaced by rice straw coke without a significant impact on the mechanical properties (Wang and Wu, 2013). The CO2 emission from fossil fuel use in the cement industry depends mainly on three factors: (1) the type of fossil fuel used; (2) the amount of biomass and waste materials replacing fossil fuels; and (3) the type of kiln used. The type or mix of fossil fuels available for cement production in a specific country or region has remained relatively unchanged for the last 10 years (GNR, 2011; IEA, 2009). Biomass and different waste materials can both be used to replace fossil fuel and as mineral substitutes for clinker (Rodríguez et al., 2013). However, there is little evidence that the use of alternative fuels has considerably increased in cement production. In China a massive replacement of old shaft kilns with new dry rotary kilns with suspension pre-heaters or pre-calciners (NSP kilns) has taken place so that in 2012 shaft kilns corresponded to 20% of production capacity (Xu et al., 2014). NSP kilns dominate the facilities of cement producers that report to the Cement Sustainability Initiative (CSI) (GNR, 2011), as shown in Fig. 8. The average fossil fuel emission of these producers is 253 kg CO2/t cement (Table 2), and the average carbon intensity of energy is 87.3 g CO2/ MJ (Table 1). From this data by calculation we get an average energy use of 2898 MJ/t cement, which corresponds to 3793 MJ/t clinker with the given average value of clinker substitutes (Table 1). The world average fossil fuel emission of 260 kg CO2/t cement (Table 3) gives with the same carbon intensity as in Table 1 an average energy use of 2978 MJ/t cement, which corresponds to 3611 MJ/t clinker with an average value of 17.52% of clinker substitutes. The difference between the world 25% and the world total estimates is 80 MJ/t cement or 2.76%. The difference is 5.04% if calculated for MJ/ t clinker. This variation reflects the uncertainty with which the amount of clinker substitutes (17.52%) is estimated in Table 3. The specific energy use varies between different kilns. The highest energy consumers are wet kilns with 5900e6700 MJ/t clinker, and vertical shaft kilns, long dry kilns, dry rotary kilns with preheater and NSP kilns consume 5000, 4600, 3100 and 2900 MJ/t clinker, respectively. The theoretical endothermic minimum is considered to be 1800 MJ/t clinker (IEA, 2007), and the best observed one is 2842 MJ/t clinker. The average CO2 emissions of different kiln types (Table 5) are based on the average fossil fuel emissions and average heat consumption of different kilns. The minimum reduction potential could be that the world average energy use of 2978 MJ/t cement in 2011 would be reduced by 2.7% to the current 2898 MJ/t cement of CSI member companies. This would mean a reduction of 80 MJ/t cement or 7 kg CO2/t cement, which on a global scale means 28 Mt avoided CO2

SemiMixed kiln wet/semi-dry type* 11.75 kiln 1.54 Wet kiln 3.19 Long dry kiln Dry with 3.43 preheater and precalciner 63.43 Dry with preheater 16.26 Fig. 8. Distribution of kiln technologies (%) at 25% of the world cement facilities in 2011. Note: *facility uses several types of kilns simultaneously. Adapted from GNR (2011).

emissions (1%) with the production level of 2013. Conclusively, taking into account that the cement industry could reduce its average energy use by 18.5% per ton of cement from current levels by 2030 (IEA, 2009), the minimum and maximum energy saving potential of the world cement industry would be from 7 to 48 kg CO2/t cement, which with the 4000 Mt/year production of 2013 would mean avoided emissions of between 28 and 112 Mt CO2/year on the global scale. The maximum avoided CO2 emissions from fossil fuel use would require an increase of up to 23e24% in the use of carbon neutral fuels like biomass or expensive carbon capture technologies and a global clinker to cement ratio of 73% (IEA, 2009). Even higher CO2 emission savings could be reached by increasing the use of carbon neutral fuels to over 24% of the fuel mix. 3.4.3. Management of CO2 emissions by improving the carbon balance of electricity use The electricity use in cement plants takes place dominantly in raw material preparation, grinding, homogenization and in cement finish grinding. In kilns, the biggest electricity consumers are the drives of rotary kilns. The carbon balance of electricity use is defined by the consumption of electricity (usually expressed as kWh/t cement) and by the CO2 emission of produced electricity (usually expressed as kg CO2/MWh). A cement plant can seldom impact the latter, and avoided emission measures are usually concentrated on the efficient use of electricity inside the facility. The weighted average of electricity use was 107 kWh/t cement with a standard deviation of 53 in 2011 (GNR, 2011). Depending on the source of electricity and on the efficiency of the electricity use, the CO2 emission level varied from 20 to 150 kg CO2/t cement (Tables 2 and 3). A reduction target could be to level the electricity use of all facilities to the average level of 107 kWh/t cement now used only among CSI member companies. The data available did not allow estimation of the corresponding CO2 emission reductions that this would bring with sufficient accuracy. A recent estimate on upgrading existing cement plants proposes electricity efficiency improvements with 90 Mt CO2/year savings e with assumed emission of 100 kg CO2/t cement from electricity use e on a global scale before 2020 (Gupta, 2011). One reference point could be the world average grid electricity emission of 516 g CO2eq/kWh for mineral producing countries (IEA, 2010), which gives with 111 kWh/t cement an emission of 57 kg CO2/t cement instead of the 73 kg CO2/t cement used in Table 3. The difference is mainly explained by the fact that coal and petcoke still dominate as the fossil fuel used in many cement kilns with their own electricity production (GNR, 2011; Gupta, 2011). A 10% decrease in the electricity emission would improve the carbon balance with 6e7 kg CO2/t cement savings which with the 2013 global production level means savings from 24 to 28 Mt CO2/year (0.9% on average). 3.4.4. Measures for the mitigation of CO2 emissions in the cement industry The implementation of energy efficiency and CO2 emission saving measures in the cement industry has been studied widely. A

Table 5 CO2 emissions by kiln type in kg CO2/t clinker in 2000 and 2011. Kiln type

2000

2011

Dry with preheater and precalciner (NSP) Dry with preheater without precalciner Long dry rotary kiln Semi-wet/semi dry kiln Wet kiln

847 866 965 892 1060

840 852 876 877 1020

Note: does not include CO2 emissions from the electricity use. Adapted from GNR (2011).

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

recent study on Germany found an annual 3.4% fuel and processrelated CO2 emissions reduction potential in relation to 2012 (Brunke and Blesl, 2014). A listing of possible measures to manage CO2 emissions in the cement industry is shown in Table 6. The measures are grouped into: (1) Raw material and fuel preparation, grinding, homogenization; (2) Clinker kiln; and (3) Product and fuel improvements. Conclusively, on global scale, the highest near term potential is in increasing the use of clinker substitutes, using more alternative fuels and in recycling of materials. A recent single cement plant analysis came to a similar conclusion (Feiz et al., 2015). 3.5. The abatement cost of reducing GHG emissions in cement production The mitigation of GHG emissions in the cement industry is progressing slower than the growth rate of production. Cement production grew by 73% between 2005 and 2013. The CO2 emissions calculated as kg CO2/t clinker dropped by 14.8%, and the electric energy consumption calculated as kWh/t cement was reduced by 3.6% from 2006 to 2011. Several reasons for the slow implementation of energy efficiency and CO2 emission reduction measures exist: (1) the average lifespan of a cement plant is 50 years, and the service life of key equipment is often more than 20 years; (2) new plants have high capital expenditure requirements; (3) emission trading systems have low CO2 prices; (4) the cement market is price dominated; and (5) the quality of cement is strictly standardized and regulated. All these factors together create barriers to changing the cement composition, investing in new kiln technology, improving the energy efficiency and reducing the electricity use at cement facilities. The price of decreasing CO2 emissions at a single facility level needs to be attractive enough to overcome these barriers. In order to demonstrate the sensitivity of

9

the abatement cost we collected cost data on different CO2 emissions reduction measures in the cement industry and estimated unit abatement costs using a uniform capital recovery factor (Eq. (3)) with a 10-year payback time with two different discount rates. Cement companies have initiated Clean Development Mechanism (CDM) projects on clinker substitution, fuel switch and waste heat recovery and on general energy efficiency projects. Clinker substitution projects are the most common. The expected financial benefits of CDM in Brazil and India varied from US$10 to US$18/ tCO2eq in 2005 (Hultman et al., 2012). Implemented projects give an indication of the price level for the abatement cost of CO2 reductions in the cement industry. Our results (Table 7) give a price variation from US$4 to US$75 for an avoided ton of CO2 with an average cost of US$26.3eUS$33.0/t of avoided CO2. The average cost for all 8 projects was calculated using Eq. (3) on the summary investment cost and summary avoided emissions for a year. A voluntary GHG saving program in the Taiwanese cement sector resulted in 1099 kt of avoided CO2 emissions in 2004e2008. The corresponding investment cost was US$202.6 million and the total 5-year operational cost savings US$71 million (Chen and Hu, 2012). By dividing the savings and avoided emissions by 5 and by applying Eq. (3) we get an abatement cost of US$55eUS$85/t of avoided CO2 originating mainly from energy and electricity savings. Table 8 shows additional costs of avoided CO2 emissions for the assumed construction of a new dry-process cement plant with a five-stage preheater and precalciner with either post-combustion carbon capture (CCS) or oxy-fuel combustion technologies in Europe and Asia. The oxy-combustion technology costs at a cement plant are about the same as the costs of similar technology installed at a typical coal-fired power plant. The estimated costs of postcombustion CCS are substantially higher at a cement plant (Barker et al., 2009). Both technologies are in the development phase, and several technical issues need to be solved before these

Table 6 Management measures for the mitigation of CO2 emissions in the cement industry. Management measure Raw material and fuel preparation, grinding, homogenization Efficient transport systems Raw meal homogenizing Use of roller mills High-efficiency classifiers/separators Clinker kiln Improved refractoriness and combustion system Energy management and process control systems Conversion of long dry kilns to pre-heater/precalciner kilns Conversion to reciprocating grate cooler Optimizing heat recovery/upgrading clinker cooler Replacing vertical shaft kilns with pre-heater/precalciner Cement finish grinding Process control and management Vertical roller mill High pressure (hydraulic) roller press High-efficiency motors and adjustable or variable speed drives Product and fuels improvements Blended cements Use of biomass derived charcoal Use of waste-derived fuels Limestone Portland cement Low-alkali cement Use of steel slag in kiln Use of calcium carbide residue Geopolymer cement CCS from precalcination of limestone Oxy-fuel technology Post-combustion carbon capture (CCS) MgO based cements

CO2 reduction in kg CO2/t clinker 0.4e3.2 0.3e2.7 0.2e10.5 0.5e5.2 2.6e24.1 2.5e16.6 20.5e112.6 6.3e20.5 0.8e40.7 62 0.9e4.1 8.8e26.7 1.3e25.1 1.0e47

Key references Madlool et al., 2013 Worrell et al., 2008

Worrell et al., 2008 Madlool et al., 2013

Worrell et al., 2008 Madlool et al., 2013

Worrell et al., 2008 0.3e212.5 308e394 12.0e76.3 8.4e29.9 4.6e12.1 4.9e50 Up to 374 Up to 300 Up to 410 404e658 Up to 725 Up to 750

Sjølie, 2012
n et al., 2013 Uso

Madlool et al., 2013 McLellan et al., 2011 Volkart et al., 2013 Vatopoulos and Tzimas, 2012 Hasanbeigi et al., 2012 McLellan et al., 2011

Note. The magnitude of potential CO2 reduction is shown in kg CO2/t clinker, which can be calculated to kg CO2/t cement if the MIC content of the cement or the clinker to cement ratio is known.

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

10

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

Table 7 Unit abatement cost of avoided CO2 emissions with 5% and 10% discount rates. Country

Investment cost US$

CO2 reduction t CO2/year

Abatement cost 5%, US$/tCO2

Abatement cost 10%, US$/tCO2

Reference in CDM, 2014

Indonesia Ukraine Ukraine Ukraine China China Mongolia Colombia TOTAL 8 projects

15,750,107 182,000,000 3,900,000 78,000,000 32,520,000 34,320,000 19,100,000 24,000,000 389,590,107

144,413 755,851 119,436 168,701 222,048 216,232 123,794 169,565 1,920,040

14 31 4 60 19 21 20 18 26.28

18 39 5 75 24 26 25 23 33.02

CDM493 JI UA01 JI UA JI UA100 CDM3522 CDM1676 CDM1730 CDM1790

Source: Calculations by the authors, data adapted from CDM (2014).

Table 8 Abatement cost of avoided CO2 emissions for CCS and oxy-fuel technologies. Location

Europe

Europe

Asia

Asia

Capacity Technology Abatement cost

1 Mt cement/year oxy-combustion US$/tCO2 56

1 Mt cement/year CCS US$/tCO2 149.8

3 Mt cement/year oxy-combustion US$/tCO2 32.2

3 Mt cement/year CCS US$/tCO2 82.6

Adapted from: Barker et al. (2009).

technologies are ready to be utilized on a large scale in cement production by 2030. Generally the cost of CCS is considered to be too high (Table 9) for the cement industry to implement without e.g. carbon trade benefits in the form of additional revenues. However, many countries including China and the Nordic countries have included both oxy-combustion and CCS in their long-term plans up to 2050 to reduce cement sector emissions (Rootzen and Johnsson, 2015; Wang et al., 2014). The CCS costs with a 10-year payback time (Table 9) compare well with a recent estimate for retrofitting a cement plant with CCS in 2012 costing US$70/t CO2 at a 14% discount rate with a 25-year payback time and using US$12/tCO2 as an estimated income from carbon trade. The estimate included no additional operational costs (Liang and Li, 2012). The average fuel cost with coal and petcoke as dominant sources
n et al., 2013). This makes of thermal energy is US$11/t cement (Uso replacing fossil fuels sensitive to the price of alternative fuels. For example, the marginal cost of CO2eq savings from a 10% replacement of fossil fuels with refuse derived fuel (RDF) varied from V4.38/tCO2eq when only the transport costs of RDF were covered to V0/tCO2eq when the RDF price is V2.7/t and up to V84.2/tCO2eq when the RDF price is V50/t (Schneider et al., 2012). Geopolymers are considered not competitive with OPC without carbon tax of US$20/t CO2 (McLellan et al., 2011). Conclusively, the cost of mitigation varies depending on the geographical location, on the plant capacity, on implemented mitigation measures and on the initial level of CO2 emissions. Even if the payback time of investments varies, the operational cost

savings make the investments viable in most of the cases, especially when carbon trade benefits exist. 4. Conclusions Different options to manage CO2 emissions in the cement production chain were analyzed by applying a climate impact management matrix on a cradle-to-gate basis. Key contributors to the overall CO2 balance are clinker substitutes, technology, primary source of energy and geographic location. Several regional datasets were analyzed by linear data regression. This approach was also used for estimating missing parameters. Regional variation of process and thermal energy use related CO2 emissions is more significant than that of electricity emissions. A comparative analysis of different options to improve the CO2 balance of cement industries revealed that the highest near term potential to avoid emissions is by replacing clinker with mineral components (MIC). Increasing the MIC use to the level of Brazil would save 312 Mt CO2 annually with the 2013 level of global cement production. Similarly, a 2.7% reduction in the thermal energy use of the cement industry would save 28 Mt CO2 and a 10% decrease of emissions from electricity use would save 26 Mt CO2. These three emission savings would reduce the global emissions from cement production by 12.1% from the level of 2013. The best future options under development are MgO and geopolymer cements, different oxycombustion and carbon capture technologies. In addition, the abatement cost of different investment projects were estimated using a uniform capital recovery factor. The cost of mitigation varied depending on the geographical location, technology used

Table 9 Abatement cost of avoided CO2 emissions for CCS in 2030 with a 10-year payback time. IEA scenario

Low

High

Low

High

Capacity Investment Operational cost CO2 savings Discount rate Abatement cost investment with oper. cost

2 Mt cement/year US$ 140,000,000 US$ 20,440,000/y 380,000 tCO2/year 5% US$/tCO2 47.71 101.50

2 Mt cement/year US$ 420,000,000 US$ 102,000,000/y 380,000 tCO2/year 5% US$/tCO2 143.13 411.55

2 Mt cement/year US$ 140,000,000 US$ 20,440,000/y 380,000 tCO2/year 10% US$/tCO2 59.96 113.75

2 Mt cement/year US$ 420,000,000 US$ 102,000,000/y 380,000 tCO2/year 10% US$/tCO2 179.88 448.30

Source: Calculations by the authors, data adapted from IEA (2009).

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

and on the initial level of CO2 emissions. Uncertainties in assessing GHG emissions of the cement production raw material supply chain need future analysis. Further research on the total GHG impact of the cement sector would benefit from including the transport emissions in the estimates. This paper focused on the cradle-to-gate management of cement industry CO2 emissions. Many other factors, in addition to those covered in this paper, impact the sustainability of cement. One of them is recycling concrete, which contributes to the full lifecycle impact of cement as well. Future research on managing the sustainability of cement needs to include long term testing programs aiming at changing the existing standard requirements for cements and recycled concrete to encourage the building sector to use more MIC e like geopolymers and alternative types of waste material e in cements, and to strive for a circular economy in the use of concrete.

Acknowledgements R. Kajaste acknowledges with gratitude a research grant from Fortum Foundation (201 300 147), Finland.

References Aprianti, E., Shafigh, P., Bahri, S., Farahani, J.N., 2015. Supplementary cementitious materials origin from agricultural wastes e a review. Constr. Build. Mater. 74, 176e187. ASTM, 2013. ASTM Volume 04.01, September 2013, ASTM C150/C150M e 12, Standard Specification for Portland Cement. Subcommittee C01.10 on Hydraulic Cements for General Concrete Construction. Barker, D.J., Turner, S.A., Napier-Moore, P.A., Clark, M., Davison, J.E., 2009. CO2 capture in the cement industry. Energy Procedia 1, 87e94. Benhelal, E., Zahedi, G., Hashim, H., 2012. A novel design for green and economical cement manufacturing. J. Clean. Prod. 22, 60e66. Bhushan, C., 2010. Challenge of the New Balance. Center for Science and Environment, New Delhi. Brunke, J.-C., Blesl, M., 2014. Energy conservation measures for the German cement industry and their ability to compensate for rising energy-related production costs. J. Clean. Prod. 82, 94e111. de Castro, S., de Brito, J., 2013. Evaluation of the durability of concrete made with crushed glass aggregates. J. Clean. Prod. 41, 7e14. CDM, (2014). htpps://cdm.unfccc.int/projects. (accessed 12.08.14.). Cembureau, 2014. The European Cement Association. http://www.cembureau.be/ about-cement/key-facts-figures (accessed 01.06.14.). Chen, C., Habert, G., Bouzidi, Y., Jullien, A., 2010. Environmental impact of cement production: detail of the different processes and cement plant variability evaluation. J. Clean. Prod. 18, 478e485. Chen, L.-T., Hu, A.H., 2012. Voluntary GHG reduction of industrial sectors in Taiwan. Chemosphere 88, 1074e1082. CSI, 2011. The Cement CO2 and Energy Protocol Version 3.0: CO2 Accounting and Reporting Standard for the 368 Cement Industry. Cement Sustainability Initiative (CSI), World Business Council for Sustainable Development (WBCSD). http://www.wbcsdcement.org/pdf/tf1_co2%20protocol%20v3.pdf (accessed 30.06.13.). European Standard EN 197-1, 2011. Cement- Part 1: Composition, Specification and Conformity Criteria for Common Cements. European Committee for Standardization. Feiz, R., Ammenberg, J., Baas, L., Eklund, M., Helgstrand, A., Marshall, R., 2015. Improving the CO2 performance of cement, part II: framework for assessing CO2 improvement measures in the cement industry. J. Clean. Prod. 98, 282e291. Finnsementti, 2007. Finnsementti Oy, Suomalainen Sementti. Parainen, Finland, p. 14 (in Finnish). €risto €keskus, Finnsementti, 2006. Environmental Permit. Kaakkois-Suomen Ympa € lupa. Nro A 2023, Dnro KAS2006Y101111, 21.12.2006 Finnsementti Oy Ymp€ aristo (in Finnish). García-Gusano, D., Cabal, H., Lechon, Y., 2015. Long-term behaviour of CO2 emissions from cement production in Spain: scenario analysis using an energy optimisation model. J. Clean. Prod. 99, 100e111. Garg, A., Smith, R., Hill, D., Longhurst, P.J., Pollard, S.J.T., Simms, N.J., 2009. An integrated appraisal of energy recovery options in the United Kingdom using solid recovered fuel derived from municipal solid waste. Waste Manag. 29, 2289e2297. Genon, G., Brizio, E., 2008. Perspectives and limits for cement kilns as a destination for RDF. Waste Manag. 28, 2375e2385. GNR, 2011. Cement Data Base. http://www.wbcsdcement.org/index.php/gnrdatabase (accessed 01.06.14.).

11

Gupta, A., 2011. In: Cullinen, M.S. (Ed.), Cement Primer Report. Carbon War Room, Washington D.C.. www.CarbonWarRoom.com (accessed 8.8.14.). Hasanbeigi, A., Morrow, W., Masanet, E., Sathaye, J., Xu, T., 2013. Energy efficiency improvement and CO2 emission reduction opportunities in the cement industry in China. Energy Policy 57, 287e297. Hasanbeigi, A., Price, L., Lin, E., 2012. Emerging energy-efficiency and CO2 emissionreduction technologies for cement and concrete production: a technical review. Renew. Sustain. Energy Rev. 16, 6220e6238. Hultman, N.E., SimonePulver, S., Guimar~ aes, L., Deshmukh, R., Kane, J., 2012. Carbon market risks and rewards: firm perceptions of CDM investment decisions in Brazil and India. Energy Polcy 40, 90e102. Huntzinger, D.N., Eatmon, T.D., 2009. A life-cycle assessment of Portland cement manufacturing: comparing the traditional process with alternative technologies. J. Clean. Prod. 17, 668e675. IEA, 2013. CO2 Emissions from Fuel Combustion Highlights (2013 Edition). OECD/ IEA, Paris, pp. 100e104. IEA, 2010. International Energy Agency, CO2 Emissions from Fuel Combustion. OECD/IEA, Paris, p. 512. IEA, 2009. International Energy Agency, ‘Cement Technology Roadmap 2009, Carbon Emissions Reductions up to 2050’. OECD/IEA, Paris. IEA, 2007. International Energy Agency, ‘Tracking Industrial Energy Efficiency and CO2 Emissions’. OECD/IEA, Paris. Available from: http://www.iea.org/ publications/freepublications/. IEA, 2006. International Energy Agency, 'Energy Technology Perspectives: Scenarios and Strategies to 2050'. OECD/IEA, Paris. IPCC, 2007. Climate change 2007, mitigation. In: Metz, Bert, et al. (Eds.), Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change 2007. Cambridge University Press. Ingrao, C., Giudice, A.L., Tricase, C., Mbohwa, C., Rana, R., 2014. The use of basalt aggregates in the production of concrete for the prefabrication industry: environmental impact assessment, interpretation and improvement. J. Clean. Prod. 75, 195e204. Ishak, S.A., Hashim, H., 2014. Low carbon measures for cement plant e a review, (2014). J. Clean. Prod. http://dx.doi.org/10.1016/j.jclepro.2014.11.003. Jacoby, P.C., Pelisser, F., 2015. Pozzolanic effect of porcelain polishing residue in Portland cement. J. Clean. Prod. 100, 84e88. Juenger, M.C.G., Winnefeld, F., Provis, J.L., Ideker, J.H., 2011. Advances in alternative cementitious binders. Cem.Concr. Res. 41, 1232e1243. Kara, M., 2012. Environmental and economic advantages associated with the use of RDF in cement kilns. Res. Conserv. Recycling 68, 21e28. Kajaste, R., 2014. Chemicals from biomass e managing greenhouse gas emissions in biorefinery production chains - a review. J. Clean. Prod. 75, 1e10. Ke, J., McNeil, M., Price, L., Zheng Khanna, N., Zhou, N., 2013. Estimation of CO2 emissions from China’s cement production: methodologies and uncertainties. Energy Policy 57, 172e181. Kinuthia, J.M., Oti, J.E., 2012. Designed non-fired clay mixes for sustainable and low carbon use. Appl. Clay Sci. 59e60, 131e139. Li, C., Nie, Z., Cui, S., Gong, Z., Wang, Z., Meng, X., 2014. The life cycle inventory study of cement manufacture in China, 2014. J. Clean. Prod. 72, 204e211. Liang, X., Li, J., 2012. Assessing the value of retrofitting cement plants for carbon capture: a case study of a cement plant in Guangdong, China. Energy Convers. Manag. 64, 454e465. Loijos, A., Santero, N., Ochsendorf, J., 2013. Life cycle climate impacts of the US concrete pavement network. Res. Conserv. Recycling 72, 76e83. Madlool, N.A., Saidur, R., Rahim, N.A., Kamalisarvestani, M., 2013. An overview of energy savings measures for cement industries. Renew. Sustain. Energy Rev. 19, 18e29. McLellan, B.C., Corder, G.D., Giurco, D.P., Ishihara, K.N., 2012. Renewable energy in the minerals industry: a review of global potential. J. Clean. Prod. 32, 32e44. McLellan, B.C., Williams, R.P., Lay, J., van Riessen, A., Corder, G.D., 2011. Costs and carbon emissions for geopolymer pastes in comparison to ordinary portland cement. J. Clean. Prod. 19, 1080e1090. Medina, C., de Rojas, M.I.S., Frías, M., 2013. Freeze-thaw durability of recycled concrete containing ceramic aggregate. J. Clean. Prod. 40, 151e160. Mikulcic, H., Vujanovic, M., Fidaros, D.K., Priesching, P., Minic, I., Tatschl, R., Duic, N., Stefanovic, G., 2012. The application of CFD modelling to support the reduction of CO2 emissions in cement industry. Energy 45, 464e473. Morrow, W.R., Hasanbeigi, A., Sathaye, J., Xu, T., 2014. Assessment of energy efficiency improvement and CO2 emission reduction potentials in India's cement and iron & steel industries. J. Clean. Prod. 65, 131e141. Moya, J.A., Pardo, N., Mercier, A., 2011. The potential for improvements in energy efficiency and CO2 emissions in the EU27 cement industry and the relationship with the capital budgeting decision criteria. J. Clean. Prod. 19, 1207e1215. MPA Cement, 2012. http://cement.mineralproducts.org/documents/MPA_Cement_ SD_Report.pdf (accessed 18.8.14.). Mutuk, T., Mesci, B., 2014. Analysis of mechanical properties of cement containing boron waste and rice husk ash using full factorial design. J. Clean. Prod. 69, 128e132. Nakakubo, T., Tokai, A., Ohno, K., 2012. Comparative assessment of technological systems for recycling sludge and food waste aimed at greenhouse gas emissions reduction and phosphorus recovery. J. Clean. Prod. 32, 157e172. NS, 2014. Urban Growth: Bio-bricks Offer a Whiff of the Future. www.newscientist. com/article/dn25952-urban-growth-biobricks-offer-a-whiff-of-the-future. html#.U9fAV7Evsxt (accessed 29.07.14.).

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055

12

R. Kajaste, M. Hurme / Journal of Cleaner Production xxx (2015) 1e12

OECD, 2012. OECD Environmental Outlook to 2050. OECD Publishing, pp. 72e135. Available from: http://dx.doi.org/10.1787/9789264122246-en. ORNL, 2010. Boden, T.A., Marland, G., Andres, R.J.. Global, Regional, and National Fossil-Fuel CO2 Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. ccsi.ornl.gov/Preliminary_CO2_emissions_2009 from 26 October 2011 (accessed 05.11.11.). Ostad-Ahmad-Ghorabi, M.J., Attari, M., 2013. Advancing environmental evaluation in cement industry in Iran. J. Clean. Prod. 41, 23e30. Ponikiewski, T., Gołaszewski, J., 2014. The influence of high-calcium fly ash (HCFA) on the properties of fresh and hardened self-compacting concrete and high performance self-compacting concrete. J. Clean. Prod. 72, 212e221. Rahman, A., Rasul, M.G., Khan, M.M.K., Sharma, S., 2015. Recent development on the uses of alternative fuels in cement manufacturing process. Fuel 145, 84e99. Rodríguez, N.H., Martínez-Ramírez, S., Blanco-Varela, M.T., Donatello, S., Guillem, M., et al., 2013. The effect of using thermally dried sewage sludge as an alternative fuel on Portland cement clinker production. J. Clean. Prod. 52, 94e102. Rootzen, J., Johnsson, F., 2015. CO2 emissions abatement in the Nordic carbonintensive industry e an end-game in sight? Ener 80, 715e730. Schneider, D.R., Kirac, M., Hublin, A., 2012. Cost-effectiveness of GHG emission reduction measures and energy recovery from municipal waste in Croatia. Ener 48, 203e211. Sjølie, H.K., 2012. Reducing greenhouse gas emissions from households and industry by the use of charcoal from sawmill residues in Tanzania. J. Clean. Prod. 27, 109e117. Smil, V., 2013. Making the Modern World: Materials and Dematerialization. Wiley. ISBN-13:9781119942535. Turgut, P., 2012. Manufacturing of building bricks without Portland cement. J. Clean. Prod. 37, 361e367.
n, A.A., Lopez-Sabiro, A.M., Ferreira, G., Sastresa, E.L., 2013. Uses of alternative Uso fuels and raw materials in the cement industry as sustainable waste management options. Renew. Sustain. Energy Rev. 23, 242e260.

Valderrama, C., Granados, R., Cortina, J.L., Gasol, C.M., Guillem, M., Josa, A., 2012. Implementation of best available techniques in cement manufacturing: a lifecycle assessment study. J. Clean. Prod. 25, 60e67. Vatopoulos, K., Tzimas, E., 2012. Assessment of CO2 capture technologies in cement manufacturing process. J. Clean. Prod. 32, 251e261. Volkart, K., Bauer, C., Boulet, C., 2013. Life cycle assessment of carbon capture and storage in power generation and industry in Europe. Int. J. Greenh. Gas Control 16, 91e106. VDZ., 2014. http://www.vdz-online.de/en/publications/factsandfigures/. (accessed 18.8.14.). €ller, S., Viebahn, P., Hao, Z., 2014. Integrated assessment of CO2 Wang, Y., Ho reduction technologies in China's cement industry. Int. J. Greenh. Gas Control 20, 27e36. Wang, Y., Zhu, Q., Geng, Y., 2013. Trajectory and driving factors for GHG emissions in the Chinese cement industry. J. Clean. Prod. 53, 252e260. Wang, W.-J., Wu, C.-H., 2013. Benefits of adding rice straw coke powder to cement mortar and the subsequent reduction of carbon emissions. Constr. Build. Mater. 47, 616e622. Wen, Z., Chen, M., Meng, F., 2015. Evaluation of energy saving potential in China's cement industry using the Asian-Pacific integrated model and the technology promotion policy analysis. Energy Polcy 77, 227e237. WBCSD, 2012. The Cement Sustainability Initiative e 10 Years of Progresse Moving on to the Next Decade. World Business Council for Sustainable Development, pp. 12e19. June 2012. Worrell, E., Galitsky, C., Price, L., 2008. Energy Efficiency Improvement Opportunities for the Cement Industry. Lawrence Berkeley National Laboratory, Berkeley CA. Paper LBNL-72E. http://ies.lbl.gov/publications/energy-efficiencyimprovement-oppor-3 (accessed 05.08.14.). Xu, J.-H., Fleiter, T., Fan, Y., Eichhammer, W., 2014. CO2 emissions reduction potential in China's cement industry compared to IEA's Cement technology roadmap up to 2050. Appl. Energy 130, 592e602. Yang, K.-H., Song, J.-K., Song, K., 2013. Assessment of CO2 reduction of alkaliactivated concrete. J. Clean. Prod. 39, 265e272.

Please cite this article in press as: Kajaste, R., Hurme, M., Cement industry greenhouse gas emissions e management options and abatement cost, Journal of Cleaner Production (2015), http://dx.doi.org/10.1016/j.jclepro.2015.07.055