Energy Fuels 2010, 24, 1396–1401 Published on Web 12/04/2009
: DOI:10.1021/ef900702b
Carbon Dioxide Emissions from Coal-Fired Power Plants in Greece in Relation to Mined Lignite Quality Despina Vamvuka* and Michael Galetakis Department of Mineral Resources Engineering, Technical University of Crete, University Campus, Hania 73100, Greece Received July 8, 2009. Revised Manuscript Received October 12, 2009
Carbon dioxide emissions were shown to vary with the calorific value and carbonate content of lignite burned at three large power plants. Carbon dioxide emission factors for these power plants ranged from 1.18 to 1.43 tons of CO2 MW-1 h-1. These emissions must be reduced to minimize the cost of CO2 certificates required by the Emission Trading Scheme of the European Community. The additional cost is higher for plants fed with lower quality lignite or those with lower power plant efficiency. To enhance the competitiveness of domestic lignite, improved CO2 mitigation strategies, such as selective mining and homogenization/blending, are required.
Future exploitation of lignitic seams and the contribution of lignite and coal to power production in Greece, as well as Europe, will greatly depend upon the ability of industry to meet CO2 emission limits, as specified by the Kyoto Protocol. In December 1998, the European Community agreed to this protocol, which requires an 8% reduction of greenhouse gas emissions from 1990 levels, by 2012. Greece has committed to a 25% emissions reduction by 2012. As of 2003, the European Community has achieved a 2% reduction of emissions, compared to 1990 levels.8,9 According to the National Allocation Plan (NAP) issued by the European Commission (2003/87/EC10), power plants should reduce CO2 emissions to a certain level for the period 2008-2012, otherwise they will be obliged to cover the difference by buying CO2 certificates through the Emission Trading Scheme (ETS). For Greece, emission certificates have been set to 325 megatons of CO2 (65 megatons of CO2/year). For the power generation sector, a cap has been set to 230 megatons of CO2 (46 megatons of CO2/year), which accounts for 71% of total certificates.6,11 Greece’s greenhouse gas emissions are closely related to an energy mix composed mainly of lignite and oil.12 Lignite produces about half of the CO2 emissions generated from energy and industrial sectors.13 The application of ETS will greatly affect the power generation sector, by increasing the operating cost of current lignite units, as well as the investment cost for new units. Given current allocation prices for CO2,
Introduction Energy accounts for over 80% of the global anthropogenic greenhouse gases. The energy sector is dominated by the direct combustion of fuels, which leads to large emissions of carbon dioxide. Because of the combustion of fossil fuels and deforestration, the percentage of carbon dioxide in the earth’s atmosphere has increased by about 35% since pre-industrial times (280-380 ppm).1 Scientists project that excessive carbon dioxide emissions will increase the earth’s surface temperature, by approximately 1.5-4 °C during the next 30-40 years.2-5 In Greece, lignite is the most important fossil fuel for power production, because it offers safety in energy supply, low electricity cost, and a high rate of employment. Over the last 5 years, lignite production has been almost constant at 70 megatons per annum (from about 63 to 70 megatons per annum between 2003 and 2007).6 With this production, Greece is the second largest lignite producer in the European Union (EU) and the fifth largest in the world. Mined lignite is used almost exclusively for power generation and accounts for about 60% of the total electricity generation in Greece. Moreover, electricity generated from lignite is significantly cheaper than that generated by oil or gas.6,7 *To whom correspondence should be addressed. Telephone: þ302821-37603. Fax: þ30-2821-69554. E-mail:
[email protected]. (1) di Norcia, V. Global warming is man-made. Key Points in the International Panel on Climate Change. Report, 2007. (2) United Nations Framework Convention on Climate Change, 2009. http://unfccc.int. (3) Demirbas-, A. Potential applications of renewable energy sources, biomass combustion problems in boiler power systems: Combustion related environmental issues. Prog. Energy Combust. Sci. 2005, 31 (2), 171. (4) Quadrelli, R; Peterson, S. The energy-climate challenge: Recent trends in CO2 emissions from fuel combustion. Energy Policy 2007, 35, 5938–5952. (5) Vamvuka, D. Biomass, Bioenergy and the Environment; Tziolas Publications: Salonica, Greece, 2009. (6) Kavouridis, K. Lignite industry in Greece within a world context: Mining, energy supply and environment. Energy Policy 2008, 36, 1257– 1272. (7) Galetakis, M.; Alevizos, G.; Pavloudakis, F.; Roumpos, C.; Kavouridis, C. Prediction of the performance of on-line ash analyzers used in the quality control process of a coal mining system. Energy Sources, Part A 2009, 3, 1127–1142. r 2009 American Chemical Society
(8) Pavloudakis, F.; Galetakis, M.; Roumpos, C. A spatial decision support system for the optimal environmental reclamation of open-pit coal mines in Greece. Int. J. Min., Reclam. Environ. 2009, in press. (9) Agoris, D.; Tigas, K.; Giannakidis, G.; Siakkis, F.; Vassos, S.; Vassilakos, N.; Kilias, V.; Damassiotis, M. An analysis of the Greek energy system in view of the Kyoto commitments. Energy Policy 2004, 32, 2019–2033. (10) http://eur.europa.eu/environment/climat/emission/2nd_phase_ep.htm. (11) National allocation plan for CO2 certificates. www.minenv.gr/4/ 41/000/eskde.2008-2012teliko.doc. (12) Liaskas, K.; Mavrotas, G.; Mandaraka, M.; Diakoulaki, D. Decomposition of industrial CO2 emissions: The case of European Union. Energy Econ. 2000, 22 (4), 383–394. (13) Koukouzas, N.; Ziogou, F.; Gemeni, V. Preliminary assessment of CO2 geological storage opportunities in Greece. Int. J. Greenhouse Gas Control 2009, 3, 502–513.
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pubs.acs.org/EF
Energy Fuels 2010, 24, 1396–1401
: DOI:10.1021/ef900702b
Vamvuka and Galetakis
Table 1. Proximate and Ultimate Analyses and Low Calorific Values, on an As-Received Basis, of Main Coal Basins in Western Macedonia (Range and Mean Concentration in Parentheses) proximate analysis (%) coal basin Ptolemais Megalopolis
ultimate analysis (%)
moisture
volatiles
fixed C
ash
C
H
N
ST
O
43.4-60.6 (56) 57.5-65.5 (60)
8.9-33.1 (17.2) 13.3-25.2 (16.1)
7.3-26.9 (14.0) 7.4-13.5 (9.0)
6.7-24.6 (12.8) 12.3-23.5 (14.9)
9.4-36.0 (18.7) 12.2-22.8 (15.2)
0.8-3.1 (1.6) 0.9-1.8 (1.2)
0.1-0.4 (0.2) 0.2-0.5 (0.3)
0.2-0.8 (0.4) 0.9-1.8 (1.2)
5.4-19.8 (10.3) 5.8-10.2 (7.1)
calorific value (MJ/kg) 4.6-6.5 (5.9) 3.6-4.6 (4.0)
Table 2. Concentration Range of Major Elements Encountered in Coal Ashes (%)14 coal basin
SiO2
Al2O3
TiO2
Fe2O3
CaO
MgO
Na2O
K2O
P2O5
SO3
Ptolemais Megalopolis
9.1-55.3 51.8-57.5
8.1-24.3 20.8-23.4
0.4-1.1
