ATMOSPHERIC IMPACT REPORT in Support of Eskom's Application for a Variation Request of the Atmospheric Emission Licence
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ATMOSPHERIC IMPACT REPORT In support of Eskom’s application for a variation request of the Atmospheric Emission Licence for Duvha Power Station uMoya -NILU Consulting (Pty) Ltd Eskom PReport O Box issued 20622 by PReport O Box issued 1091 to Durban North, 4016 Johannesburg, 2001 South Africa South Africa M Zunckel A Raghunandan January 2014 i This report has been produced for Eskom by uMoya-NILU Consulting (Pty) Ltd. The intellectual property contained in this report remains vested in uMoya-NILU Consulting (Pty) Ltd. No part of the report may be reproduced in any manner without written permission from uMoya-NILU Consulting (Pty) Ltd and Eskom. When used in a reference this document should be cited as follows: uMoya-NILU (2014): Atmospheric Impact Report in support of Eskom’s application for a variation request of the Minimum Emission Standards compliance timeframes for the Duvha Power Station, Report No. uMN002-14, January 2014. ii EXECUTIVE SUMMARY Eskom’s coal-fired Duvha Power Station in Mpumalanga Province has a base generation capacity of 3 600 MW. The purpose of this Atmospheric Impact Report (AIR) is to assess the impact of the grace period of 37 days per year requested by Eskom from the particulate emission limit stipulated in Duvha’s Atmospheric Emission Licence for human health and the environment. Two operational scenarios are assessed to determine the effect of the grace period for Duvha Power Station. The application for the grace period considers PM10 emissions only. The two scenarios are: Scenario 1: Current particulate emission limits stipulated in the Atmospheric Emission Licence to assess the relative contribution to ambient PM10 concentrations near the Duvha Power Station. Scenario 2: Eskom’s variation request for emission limits that will provide operational flexibility, in terms of PM10. The emission limits that have been modelled to give effect to Eskom's variation request are presented in Table A1. Table A1: Eskom's requested PM emission limits for the Atmospheric Emission Licence variation request Operational 328 days of the year 37 days of the year scenario Emission Unit 1-3: 100 mg/Nm3 Unit 1-3: 300 mg/Nm3 limits Unit 4-6: 200 mg/Nm3 Unit 4-6: 600 mg/Nm3 Emission concentrations and rates for PM for this scenario are listed in Table A2. Table A2: Eskom’s requested emission grace period limits (mg/Nm3) for Duvha Power Station Emission Scenario Source Emission rates (tons/annum) concentration (mg/Nm3) Current emission limits Stack 1 5,841 100 Stack 2 11,683 200 100 for 328 days Stack 1 5,429 + 1,176 = 7,026 AEL variation request 300 for 37 days 200 for 328 days Stack 2 10,499 + 3,553 = 14,052 600 for 37 days For the purposes of the assessment, the 37 day grace period is applied as 3 consecutive days every month from January to November and 4 consecutive days in December. During these periods Units 1, 2 and 3 (Stack 1) and Units 4, 5 and 6 (Stack 2) emit at the higher rate simultaneously. This approach provides for the worst case. For current emission limits at Duvha Power Station the predicted annual average PM10 concentration is significantly less than the current and 2015 PM10 national ambient air quality standard (NAAQS) of i 50 µg/m3 and 40 µg/m3. At the point of maximum ground-level impact, the predicted 99th percentile of 3 the 24-hour PM10 concentration is well below the current and 2015 NAAQS of 120 µg/m and 75 µg/m3, respectively. For requested particulate emission limits at Duvha Power Station from now to 1 April 2015 the predicted annual average PM10 concentration is somewhat higher than for the current emission limits and significantly less than the 2015 national ambient PM10 standard. At the point of maximum th ground-level impact, the predicted 99 percentile 24-hour concentration for PM10 is somewhat higher than for current emission limits and significantly less than the 2015 NAAQS. Modelling results therefore confirm that Eskom’s requested PM emission limits during the grace period will not result in additional health risk in the areas potentially impacted upon by the emissions, as both the annual average and 99th percentile 24-hour concentrations fall well below the NAAQS limit values. Ambient PM measured at Komati monitoring station indicates non-compliance with both the daily and annual NAAQS (with the annual average in 2010 being more than double the limit value). The same pattern of non-compliance with the NAAQS for both daily and annual averages is seen for Middleburg and Witbank. However, the power station is seen to contribute only marginally to the measured concentrations at all three monitoring sites, bearing in mind that the bulk of the contribution to PM10 concentrations arises from low level sources, especially domestic fuel use. The higher emissions during the grace period will thus not materially affect ambient air quality. ii LIST OF ACRONYMS µm 1 µm = 10-6 m AEL Atmospheric Emission License AIR Atmospheric Impact Report APPA Atmospheric Pollution Prevention Act, 1965 (Act No. 45 of 1965) AQMP Air Quality Management Plan BID Background Information Document DEA Department of Environmental Affairs DoE Department of Energy ESP Electrostatic precipitator FFP Fabric Filter Plant FGD Flue gas desulphurisation IRP Integrated Resource Plan LNB Low NOX Burner LPG Liquid Petroleum Gas NAAQS National Ambient Air Quality Standards NEMAQA National Environment Management: Air Quality Act, 2004 (Act No. 39 of 2004) NEMA National Environmental Management Act, 1998 (Act No. 107 of 1998) NO Nitrogen oxide NO2 Nitrogen dioxide NOX Oxides of nitrogen (NOX = NO + NO2) OFA Overfire Air PM Particulate Matter PM10 Particulate Matter with a diameter of less than 10 µm PM2.5 Particulate Matter with a diameter of less than 2.5 µm SO2 Sulphur Dioxide TSP Total Suspended Particulates WHO World Health Organisation iii TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................................... i LIST OF ACRONYMS .................................................................................................................................. iii TABLE OF CONTENTS .............................................................................................................................. iv TABLES ........................................................................................................................................................ vi FIGURES ..................................................................................................................................................... vii 1. Enterprise Details ................................................................................................................................ 8 1.1 Enterprise Details ............................................................................................................................... 8 1.2 Location and extent of the Plant ....................................................................................................... 9 1.3 Atmospheric Emission License and Other Authorisations ......................................................... 10 1.3.1 Minimum Emission Standards ............................................................................................... 11 1.3.2 National Ambient Air Quality Standards (NAAQS) ............................................................. 11 2. Nature of the Process ....................................................................................................................... 12 2.1 Listed Activity or Activities ............................................................................................................... 12 2.2 Process Description ......................................................................................................................... 13 2.2.1 Atmospheric emissions resulting from power generation .................................................. 14 2.3 Unit Processes .................................................................................................................................. 14 3. Technical Information ....................................................................................................................... 16 3.1 Raw Materials Used ......................................................................................................................... 16 3.2 Appliances and Abatement Equipment Control Technology ..................................................... 16 4. Atmospheric Emissions ................................................................................................................... 17 4.1 Point source parameters ................................................................................................................. 17 4.2 Point source maximum emission rates (normal operating conditions) ..................................... 17 4.3 Point source maximum emission rates (start-up, shut-down, upset and maintenance conditions) ...................................................................................................................................................... 18 4.4 Fugitive emissions ............................................................................................................................ 19 4.5 Emergency Incidents ....................................................................................................................... 20 5. Impact of Enterprise on the Receiving Environment .................................................................