ENVIRONMENTAL FATE OF HEAVY METALS AND HYDROCARBONS IN ASH FROM MUKAH POWER GENERATION

PLANT

Azzudin Shebli

Master of Science (Environmental Science)

2014

ENVIRONMENTAL FATE OF HEAVY METALS AND HYDROCARBONS IN ASH FROM MUKAH POWER GENERATION PLANT

Azzudin Shebli

A thesis submitted in fulfillment of the requirement for The degree of Master of Science

In Environmental Science

Department of Chemistry Faculty of Resource Science and Technology

UNIVERSITY MALAYSIA SARA W AK 2014

A.SHEBLI

DECLARATION

No portion of the work referred to in this thesis has been submitted in support of an

application for another degree or qualification to this or any other university or institution of

higher learning.

Azzudin Shebli

09021510

Department of Chemistry Faculty of Resource Science and Technology Universiti Malaysia Sarawak

ACKNOWLEDGEMENTS

First, I would like to thank ALLAH the most merciful and most beneficent for His blessing

and guidance throughout this journey of my life.

I am greatly indebted to my principal supervisor Prof Dr Zaini Bin Assim for kindly

providing untiring guidance throughout the development of this study. His comments,

stimulating suggestion, encouragement and support have been of greatest help at all times in

this study and thesis writing. Thank you also goes to Prof Dr Zin Zawawi Bin Zakaria for his

academic assistance and moral support. Nonetheless, I also gratefully acknowledge the

General Manager of MPG Sdn Bhd for giving the permission to conduct this study within his

premise and the Jabatan Perkhidmatan Awam Malaysia for granting the scholarship that has

made this study possible.

I offer my heartfelt thank you to my parents, my wife, siblings and friends for their

everlasting encouragement support and for always being with me during high and low times

in my life.

Finally, very special thank you is extended to the laboratory assistant, Mr. Benedict, Mr.

Rajuna Tahir, Mdm. Dayang Fatimahwati Awang Ali and all supporting staff at Faculty of

Resource Science and Technology for their assistance and kindness throughout the duration of

my studies.

II

ABSTRACT

Coal power generation plant emits several pollutants linked to the environmental problems.

Ash produced during coal combustion is partitioned into bottom ash and flyash. A study has

been undertaken to investigate the environmental fate of heavy metals and hydrocarbons in

ash from Mukah Power Generation Plant (MPG). Soil and sediment samples collected from

seven sampling locations at the vicinity of MPG were analysed for aliphatic hydrocarbons,

polycyclic aromatic hydrocarbons (PAHs) and heavy metals. The hydrocarbons were

extracted from core samples by Soxhlet extraction method and analysed using gas

chromatography equipped with flame ionisation detector (GC-FID). Heavy metals were

extracted by digestion with aqua regia solution and analysed on the inductively coupled

plasma optical emission spectrometer (ICP-OES). The total concentrations of total aliphatic

hydrocarbons (TAHs) and PAHs in core samples ranged between 2512.4 to 6566.0 mg/kg and

518.0 to 1210.4 mg/kg dry weight, respectively. Relatively elevated concentration of the

hydrocarbons and heavy metals concentrations were found at sampling sites located near to

the plant and at the top layers of sample cores suggesting of anthropogenic inputs. Molecular

indices and distribution patterns of hydrocarbons were used to predict the sources of

hydrocarbons. The diagnostic indices showed the hydrocarbons are petrogenic (fossil fuel)

and pyrogenic in characters. The hydrocarbons were resulted from incomplete combustion of

coal from the plant. Total organic carbon (TOC) is one of the most important factors that can

influence the concentration of hydrocarbons in soils. The concentration of T AHs and total

PAHs in the core samples of MPG found to be significantly correlated with the Toe of soil.

The distribution patterns of heavy metals in the study area were also used to predicting their

sources. The dominant heavy metals in core samples were Mn, Zn, V and Pb. The fate and

iii

dispersal pathways of hydrocarbons and heavy metals in the sample from study area were

predicted using simple correlation analysis. High correlation of both hydrocarbons and heavy

metals with fly ash suggests the fly ash is the pollution source. Spatial distribution trend of the

hydrocarbons and heavy metals showed the meteorological condition have influenced the

pollutants distribution in the study area. The pollution index values (PI) for most sampling

sites within vicinity of MPG area showed the study area was contaminated with aliphatic

hydrocarbons, PAHs and heavy metals from the plant discharge. The results of this study can

be used as baseline data in health risks assessment associated with coal-fired power plant

impacts toward environment.

Keywords: Hydrocarbons, heavy metals, soil, gas chromatography-flame ionisation detector

(GC-FID), inductively couple plasma optical emission spectrometry, source identification.

IV

TABURAN SEKITARAN LOGAM BERAT DAN HIDROKARBON DALAM ABU DARI

LOJI JANAKUASA MUKAH

ABSTRAK

Loji janakuasa arang batu melepaskan beberapa bahan cemar yang berkaitan dengan

masalah alam sekitar. Abu yang dihasilkan semasa pembakaran arang batu dibahagikan

kepada abu bawah dan abu terbang. Satu kajian telah dijalankan untuk menyiasat taburan

sekitaran logam berat dan hidrokarbon dalam abu dari Loji Janakuasa arang batu Mukah

(MPG). Sampel teras tanah dan enapan dari tujuh lokasi persampelan dalam lingkungan

MPG telah dianalisis untuk menentukan kandungan hidrokarbon alifatik. hidrokarbon

aromatik polisiklik (HAP) dan logam berat. Hidrokarbon diekstrak dari sampel teras

menggunakan kaedah pengekstrakan Soxhlet dan dianalisis menggunakan kromatograji gas­

pengesan pengionan nyalaan (KG-PPN). Logam berat diekstrak secara pencernaan dengan

larutan aqua regia dan seterusnya dianalisis dengan aruhan gandingan plasma-spektrometer

pancaran optik (A GP-SPO). Jumlah kepekatan hidrokarbon alifatik dan HAP dalam sampel

teras adalah dalam julat 2512.4 - 6566.0 mg/kg dan 518.0 - 1210.4 mg/kg berat kering.

masing-masingnya. Kepekatan agak tinggi bagi hidrokarbon dan logam berat yang dicerapi

pada tapak persampelan berhampiran loji dan pada lapisan atas sampe/ teras mencadangkan

input antropogenik. Indek molekul dan corak taburan hidrokarbon telah digunakan untuk

meramal sumber hidrokarbon. Indek diagnostik menunjukkan hidrokarbon tersebut adalah

bersifat pelrogenik (bahan api fossil) dan pirogenik. Hidrokarbon ini terhasil dari

pembakaran tidak fengkap arang batu dari foji janakuasa. Jumlah karbon organik

merupakan salah satu faktor penting yang mempengaruhi kepekatan hidrokarbon dalam

v

tanah. Kepekatan jumlah hidrokarbon alifatik dan HAP dalam sampel teras dari kawasan

kajian berkait dengan jumlah karbon organik tanah. Corak taburan logam berat dalam

kawasan kajian juga digunakan untuk meramal sumber logam berat. Logam bera! yang

dominan dalam sampel teras adalah Mn, Zn, V dan Pb. Taburan dan tapalgalan

penyelerakan hidrokarbon dan logam berat dalam tanah di kawasan kajian diramal

menggunakan analisis korelasi mudah. Korelasi yang tinggi untuk kedua-dua hidrokarbon

dan logam berat terhadap abu terbang arang batu mencadangkan bahawa abu terbang

adalah sumber pencemaran. Corak taburan spatial hidrokarbon dan logam berat

menunjukkan keadaan cuaca mempengaruhi taburan pence mar di kawasan kajian. Nilai

indek pencemaran untuk kebanyakan tapak persampelan di sekitar kawasan MPG

menunjukkan bahawa kawasan kajian adalah tercemar dengan hidrokarbon alifatik, HAP

dan logam berat dari pelepasan loji. Hasil kajian ini boleh digunakan sebagai data garis

dasar dalam penilaian risiko kesihatan berkait dengan kesan loji janakuasa arang batu

terhadap persekitaran.

Kata kunci: Hidrokarbon, logam berat, tanah, kromatograji gas-pengesan pengionan

nyalaan (KG-PPN), aruhan gandingan plasma-spektrometer pancaran optik (A GP-SPO),

pengenalpastian sumber.

vi

TABLE OF CONTENT

Pages

DECLARATION

ACKNOWLEDGEMENTS ii

ABSTRACT iii

ABSTRAK v

TABLE OF CONTENT VII

LIST OF FIGURES xiii

LIST OF TABLES xvi

LIST OF ABBREVIATIONS xviii

CHAPTER ONE: INTRODUCTION

1.1 General Introduction

1.2 Coal in Malaysia 3

1.3 Significance of Studies 5

1.4 Objectives 6

1.5 Scope of the Study 7

CHAPTER TWO: LITERATURE REVIEW

2.1 Coal Formation 8

2.2 Classification of Coal to

2.3 Heavy Metals in Coal 13

2.3.1 Occurrence and distribution 13

2.3.2 Enrichment of heavy metals in coal 15

VII

2.3.3 Mode of occurrence of heavy metals in coal 16

2.4 Hydrocarbons in Coal 17

2.4.1 Aliphatic hydrocarbons in coal 17

2.4.2 Aliphatic hydrocarbons molecular indices 19

2.4.3 Aromatic hydrocarbons in coal 21

2.4.4 P AHs molecular indices 25

2.5 Coal Ash 27

2.5.1 Bottom ash 28

2.5.2 Fly ash 29

2.5.3. Chemical composition of coal ash 30

2.5.3.1 Heavy Metals in Coal Ash 31

2.5.3.2 Hydrocarbons in Coal Ash 33

2.6 Ash Disposal Area 34

2.7 Environmental Impacts of Coal-Fired Power Plant 35

2.7.1 Soil pollution 36

2.7.2 Sediment pollution 37

2.8 Anthropogenic Organic Pollutants: PAHs 38

2.8.1 PAHs in soils 38

2.8.2 PAHs in sediments 42

2.8.3 PAHs causitive agent associated with cancer 44

viii

CHAPTER THREE: DISTRIBUTION OF ALIPHATIC AND POLYCYCLIC

AROMATIC HYDROCARBONS (PAHs) IN ASH FROM MUKAH POWER

GENERATION PLANT

3.1 Introduction 45

3.2 Materials and Methods 47

3.2.1 Sampling sites and samples collection 47

3.2.2 Soil extraction and lipid fractionation 50

3.2.3 Gas chromatographic analysis of aliphatic hydrocarbons and P AHs 50

3.2.4 Total organic carbon (TOC) analysis 51

3.2.5 Particle size analysis 51

3.2.6 Coal quality testing 53

3.2.6.1 Proximate Analysis 53

3.2.6.1.1 Determination of moisture (Mq) 54

3.2.6.1.2 Determination of ash 55

3.2.6.1.3 Determination of volatile matter (VM) 55

3.2.6.1.4 Determination of fixed carbon (FC) 56

3.2.6.2 Ultimate Analysis 57

3.2.6.2.1 Determination of the percentage carbon, hydrogen 57 and nitrogen (CHN)

3.2.6.2.2 Determination of sulphur (S) 58

3.2.6.2.3 Determination of oxygen (0) 58

3.2.6.3 Determination of Gross Calorific Value (GCV) 58

3.3 Results and Discussion 60

3.3.1 Quality of feeds coal for MPG 60

3.3.2 Characteristics of soils and sediment sample 61

ix

3.3.3 Aliphatic hydrocarbons 63

3.3.3.1 Spatial Distribution of n-Alkanes 63

3.3.3.2 Vertical Distribution of n-Alkanes 66

3.3.3.3 Sources of n-Alkanes 69

3.3.4 Polycyclic aromatic hydrocarbons 80

3.3.4.1 Spatial Distribution of PAHs 80

3.3.4.2 Vertical Distribution of PAHs 82

3.3.4.3 Sources of P AHs 85

3.3.5 Fossil fuel derived n-alkanes versus TPAHs relationship 107

3.3.6 The role of total organic carbon (TOC) 108

3.3.7 Assessment of hydrocarbons contamination III

3.4 Conclusions 114

CHAPTER FOUR: HEAVY METALS IN ASH FROM MUKAH POWER

GENERATION PLANT

4.1 Introduction

4.2 Materials and Methods

4.2.1 Sampling sites and sample collection

4.2.2 Extraction of heavy metals

4.2.3 Inductively couple plasma-optical emission spectrometer (ICP-OES)

4.2.4 Determination of pH

4.2.5 Particle size distribution and total organic carbon (TOC)

4.3 Results and Discussion

4.3.1 Spatial distribution of heavy metals in MPG area

x

115

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120

121

122

122

123

123

4.3.2 Vertical distribution of heavy metals in MPG area 129

4.3.3 Correlation coefficient analysis 135

4.3.4 Source identification 138

4.3.5 Environmental assessment of heavy metals 139

4.4 Conclusions 145

CHAPTER FIVE: GENERAL CONCLUSIONS AND RECOMMENDATIONS

5.1 General Conclusions 146

5.2 Recommendations 149

REFERENCES 151

APPENDICES

Appendix 1: ASTM test methods for coal proximate analysis (ASTM, 2007c, d, e and f).

Appendix 2: ASTM test methods for coal ultimate analysis (ASTM, 2007i and j).

Appendix 3: Gas chromatogram from GC-FID analysis of n-alkanes in standard mixture.

Appendix 4: Typical GC-FID chromatograms for aliphatic fractions of core samples from MPG area.

Appendix 5: Concentrations (mg/kg dw) of individual n-alkanes in the soils and sediments from study area.

Appendix 6: Gas chromatogram from GC-FID analysis ofPAHs in a standard mixture.

Appendix 7: Typical GC-FID chromatograms ofPAHs fractions of core samples from MPG area.

Appendix 8: Concentrations (mg/kg dw) of 16 US EPA priority PAHs in the soils and sediments from study area.

Appendix 9: The results of the selected heavy metals contents (mg/kg dw) in nine core samples and flyash analysed in this study (n=3).

xi

LIST OF FIGURES

Figures Titles Pages

Figure 1.1 Electricity generation mix in Malaysia in 2010 (APEC, 2012) 5

Figure 2.1 Simplified coal genesis (Haenel, 1992). 10

Figure 2.2 Some structures of PAHs according to rings number 22

Figure 2.3 The molecular structures of benzopyridine, benzoquinone and 23 benzotropolone

Figure 2.4 Molecular structures of some carcinogenic PAHs (IARC, 1983) 40

Figure 3.1 The study area and the location of sampling sites. 48

Figure 3.2 Soil textural triangle ofthe USDA classification scheme (Starr et aI., 53 2000).

Figure 3.3 Distribution ofTNA in soil and sediment collected from study area. 65

Figure 3.4 Vertical profiles ofTNA in the cores soil from study area (SS1 - 68 SS5 and CSS).

Figure 3.5 Vertical profiles ofTNA in the core sediments from study area 69 (SD 1, SD2 and CSD).

Figure 3.6 Distribution of individual n-alkanes in soils near the plant chimney 71 from study area (SS 1, SS4 and SS5).

Figure 3.7 Distribution of individual n-alkanes in soils far from the plant 72 chimney in study area (SS2 and SS3).

Figure 3.8 Distribution of individual n-alkanes in sediments from study area 73 (SO 1 and SD2).

Figure 3.9 The vertical distribution of the ratio ofLMW/HMW n-alkanes in the 75 core soil samples from MPG area (SS 1 - SS5).

xii

Figure 3.10 The vertical distribution of the ratio ofLMW/HMW n-alkanes in the 76 core sediment samples from MPG area (SD 1 and SD2).

Figure 3.11 The vertical distribution of the CPI in the core soil from MPG area 77 (SSI- SS5).

Figure 3.12 The vertical distribution of the CPT in the core sediment from MPG 78 area (SD 1 and SD2).

Figure 3.13 The spatial distribution ofTPAHs in surface soils and sediments 81 from study area.

Figure 3.14 Vertical profiles of TPAHs in the cores soil from study area (SS 1 - 84 SS5 and CSS).

Figure 3.15 Vertical profiles of TPAHs in the cores sediment from study area 85 (SDl, SD2 and CSD).

Figure 3.16 Distribution of individual PAHs In soils near the chimney from 87 MPG area (SS 1, SS4 and SS5).

Figure 3.17 Distribution of individual PAHs in soils far from the chimney in 88 MPG area (SS2 and SS3).

Figure 3.18 Distribution of individual PAHs in sediments from MPG area (SDI 89 and SD2).

Figure 3.19 Percentage of PAHs in soils collected from MPG area according to 90 their benzene ring number.

Figure 3.20 Percentage of PAHs in sediments collected from MPG area 90 according to their benzene ring number.

Figure 3.21 Relative amount of PAHs from different sources in the soil and 92 sediment of MPG area.

Figure 3.22 Un burnt coal particles scattered in the ash ponds due to incomplete 93 combustion from MPG.

Figure 3.23 Plots ofLMW/HMW PAHs ratios versus TPAHs for the surface soil 99 and sediment of MPG area.

xiii

Figure 3.24 Plots of Ant/(Ant + Phe) ratios versus TPAHs for the surface soil 100 and sediment ofMPG.

Figure 3.25 Plots of Flua/(Flua + Pyr) ratios versus TPAHs for the surface soil 101 and sediment of MPG area.

Figure 3.26 Plots of B[a]Ant/(B[a]A + Chry) ratios versus TPAHs for the 103 surface soil and sediment ofMPG area.

Figure 3.27 Concentration ofPAHs in flyash samples from MPG area. 105

Figure 3.28 Concentration ofPAHs in soil samples from MPG area. 106

Figure 3.29 Concentration ofPAHs in sediment samples from MPG area. 106

Figure 3.30 Relationship of TPAHs versus fossil fuel n-alkanes in the soil and 108 sediment of MPG area.

Figure 3.31 The correlation between the concentrations of TNA with percentage 109 ofTOC.

Figure 3.32 The correlation between the concentrations of TPAHs with 110 percentage ofTOC.

Figure 3.33 Distribution of PIs for TNA and TPAHs in the surface soils and 113 sediments collected from MPG area.

Figure 4.1 Concentrations of individual heavy metals (Cr, Mn, Co, Ni and V) 125 in class I at surface soil and sediment of the study area.

Figure 4.2 Concentrations of individual heavy metals (Cu, Zn, Cd, As and Pb) 126 in class II at surface soil and sediment of the study area.

Figure 4.3 Distribution of heavy metals in the surface soils of study area (SS 1 - 127 SS5 and CSD).

Figure 4.4 Distribution of heavy metals in the surface sediments of study area 128 (SD 1, SD2 and CSD).

XIV

Figure 4.5

Figure 4.6

Figure 4.7

Figure 4.8

Vertical profile of heavy metals (Cr, Mn, Co, Ni and V) concentration within class I in core soils collected from MPG area.

Vertical profile of heavy metals (Cu, Zn, Cd, As and Pb) concentration within class II in core soils collected from MPG area.

Vertical profile of heavy metals (Mn, Co and V) concentration within class I in core sediments collected from MPG area.

Vertical profile of heavy metals (Cu, Zn, Cd, As and Pb) concentration within class II in core sediments collected from MPG area.

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134

Figure 4.9 Plots of heavy metals concentration in soils and sediments relative 140 to the heavy metals concentration in flyash released from MPG.

Figure 4.10 Plots of heavy metals pollution index (PI) in the soil and sediment 142 within vicinity of MPG.

xv

LIST OF TABLES

Tables Titles Pages

Table 1.1 List of the coal-fired power plants in the Malaysia (Jaffar, 2009). 4

Table 2.1 The classification of coal by rank according to ASTM (2007a). 12

Table 2.2 Enrichment factor of heavy metals in coal with respect to the average 16 composition of the earth's crust (USNCG, 1980).

Table 3.1 Location of nine sampling sites within study area. 49

Table 3.2 ASTM test methods for coal proximate analysis. 54

Table 3.3 ASTM test methods for coal ultimate analysis. 57

Table 3.4 MPG feeds coal quality. 61

Table 3.5 Distribution of particle size, total organic carbon, total nitrogen and 62 mole ratio of carbon over nitrogen in samples.

Table 3.6 TNA concentration (mg/kg dw) in soil and sediment cores collected 64 from study area.

Table 3.7 The grouping of the sampling sites for soil samples into two zones at 70 MPG area.

Table 3.8 The average value of CPI in core soils and sediments from MPG area. 78

Table 3.9 Comparison of CPI values with the reported values in other cities of 79 China.

Table 3.10 Diagnostic ratios of PAHs in the soil of MPG area. 94

Table 3.11 Diagnostic ratios ofPAHs in the sediment ofMPG area. 95

Table 3.12 The plant wax n-alkanes in the soil and sediment ofMPG area. 107

xvi

Table 3.13 The concentration of TNA and TPAHs in the surface soil and 112 sediment of the study area.

Table 4.1 The concentration of the selected heavy metals (mg/kg dw) in surface 124 soil from study area (n=3).

Table 4.2 The concentration of the selected heavy metals (mgikg dw) in surface 124 sediment from study area (n=3).

Table 4.3 Values for the heavy metals concentration, total organic carbon 136 (TOC), PAHs and pH for soil cores collected from MPG area.

Table 4.4

Table 4.5

Table 4.6

Pearson correlation coefficients, r, between heavy metals concentrations, TOC, PAHs and pH.

Heavy metals pollution index (PI) for soil and sediment within vicinity of MPG.

Distribution of heavy metals concentrations compared to the Netherlands Soil Contamination Guidelines (DSPN, 1994).

xvii

136

141

144

Acp

Acpy

Ant

ASTM

B[a]A

B[a]P

B[b]F

BCS

B[ghi]P

B[k]F

CCRs

CHN

Chry

CPI

CRM

DB [a,h]A

DCM

dw

EF

LIST OF ABBREVIATIONS

Acenapthene

Acenapthy lene

Anthracene

American Society for Testing and Materials

Benzo[ a ] anthracene

Benzo[ a ]pyrene

Benzo[b ]tluoranthene

British certified standard

Benzo[ghi]perylene

Benzo[k ]fluoranthene

Coal combustion residues

Carbon, Hydrogen and Nitrogen

Chrysene

Carbon preference index

Certified reference material

Dibenzo[a,h ]anthracene

Dichloromethane

Dry weight

Enrichment factor

xviii

FC

Flua

Flu

GC

GC-FID

GCV

GPS

HMW

IARC

i.d.

I[ 1 ,2,3-cd]P

IPP

L

LMW

MPG

mL

mtpa

MW

Nap

Fixed carbon

Flouranthene

Fluorine

Gas chromatography

Gas chromatograph-flame ionisation detector

Gross calorific value

Global positioning system

High molecular weight

International Agency for Research on Cancer

Internal diameter

Indeno[l,2,3-cd]perylene

Independent Power Producer

Liter

Low molecular weight

Moisture

Total moisture

Mukah power generation plant

milliliter

Million tonne per annum

Megawatt

Naphthalene

xix

NIST

TNA

PAHs

PFA

Phe

PI

PIC

ppm

Pyr

RSD

SOC

TPAHs

RSD

TN

TOC

UCM

USEPA

USDA

J.lglml

J.l1

National Institute of Standard and Technology

Total n-alkanes

Polycyclic aromatic hydrocarbons

Pulverised fuel ash

Phenanthrene

Pollution index

Products of incomplete combustion

Part per million

Pyrene

Relative standard deviation

Soil organic carbon

Total PAHs

Relative standard deviation

Total nitrogen

Total organic carbon

Unresolved complex mixture

United States Environmental Protection Agency

United States Department of Agriculture

Microgram per millimeter

Microliter

Micrometer

xx

VM

WCA

WNA

Volatile matter

World coal association

Wax n-alkanes

xxi

CHAPTER ONE

INTRODUCTION

1.1 General Introduction

Fossil fuels such as coal, petroleum and natural gas have supplied most of the world's

energy requirements. Energy is essential in transportation, agricultural and industrial and

constructional development, which are indispensable to the scientific, technical, cultural and

socio-economic progress of every nation. Coal represents the accumulation of organic

materials in sedimentary strata. In other words, coal is an organoc1astic sedimentary rock

composed essentially of lithified plant debris. The initial sediment formed by this process is a

moist, spongy material called peat. It becomes compressed, dried, and modified in both

texture and composition due to diagenesis associated with burial and tectonic activity. It is

more plentiful than oil and gas, at the current production rate with around 119 years of coal

remaining worldwide (WCA, 2011).

The energy crisis caused by the reduction of fuel oil availability and the consequent

continuous increase of the oil fuel prices contributes to the increase on the worldwide use of

coal. Global coal consumption has grown faster than any other fuel since 2000. The most

significant use of coals nowadays is in electricity generation. World net electricity generation

increases from 18.0 trillion kilowatt hours in 2006 to 23.2 trillion kilowatt-hours in 2015 and

31.8 trillion kilowatt hours in 2030 (Meawad et ai., 2010). Coal fired generation in 2006

accounted for 41 % of world electric supply and projected to be 43% by 2030. This reflects

coal continues to fuel the largest share of worldwide electric power production. In 2008, about

1