Impact of quality and quantity of fuel on achieving PAT targets

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1 Impact of quality and quantity of fuel on achieving PAT targets Implementation of PAT Scheme in Thermal Power Stations Issues and Challenges India Habitat Centre, Lodhi Road, New Delhi Dr. W.A.Benesch Director Energy Technolgies

2 PAT and power industry India s PAT (Perform, Achieve, Trade) scheme provides a model to increase economic benefits with climate co-benefits The PAT scheme targets energy consumption reductions of 6.6 Mio t of oil equivalent in 478 covered facilities Plant specific targets are set instead of a sectorial target The average reduction target is 4.8% Power sector plays a dominant role

3 WE are STEAG. Our facts and figures WE are specialists in the generation of electricity and heat on the basis of a wide variety of technologies, and for the marketing of electricity and heat; with 9 hard coal fired and 2 refinery power plants in Germany, and 3 hard coal fired power plants in Colombia, Turkey and the Philippines; with more than 200 distributed generating facilities on the basis of renewable sources, for energy supply to industry and heat supply; with an installed capacity of 8,500 MW in Germany and 1,700 MW abroad; with a workforce of 3,700 in Germany and 2,300 abroad; with total sales of EUR 2.9 billion and EBITDA of EUR 366 million in 2013; with an investment volume of around EUR 363 million in Dr.Benesch

4 We do not have a PAT scheme in Germany but... according to the rules of our electricity market we have to follow the merit order. This means Highest efficiency and Lowest fuel price And here we are connected to PAT Dr.Benesch

5 Steag optimization experience with own power stations for more than 75 years Bergkamen A 780 MW Bexbach MW Walsum 7/9/ MW Herne 2/3/4 960 MW Bergkamen Bexbach Duisburg-Walsum Herne Iskenderun 1/2 1,320 MW Voerde A/B 1,522 MW West 1/2 712 MW Weiher MW Iskenderun Voerde Weiher Lünen 6/7 507 MW Mindanao 1/2 232 MW Termopaipa IV 165 MW MKV, HKV, MHK *) 466 MW Lünen Mindanao Paipa Völklingen-Fenne Dr.Benesch

6 How is coal affected by PAT? PAT sets targets for improvements in energy efficiency in thermal power plants. At least efficiency of power plants is monitored and should be improved by this tool. How is coal now affected? Coal quantity is an indicator for efficiency Coal quality is essential for efficiency

7 Some issues With high grade coal of cause higher efficiencies could be reached easier, but what to do if these coals are not available? The PAT scheme sets plant specific targets. If the achieved efficiency of a power station should be benchmarked -the question could be raised- how far is the coal quality influencing this comparison? Main influencing parameters are ash, water and sulfur content, but to what extend? Coal quality is heavily influencing slagging and fouling which itself influences boiler efficiency. Combustion efficiency is governed by volatile matter content but also by the boiler design. Design coal and operating coal show very often great differences. Accordingly the design efficiency and the reached efficiency in day to day operation are different. Coal washing can influence quality, uniformity and quantity of fuel.

8 Mixed and unmixed coals? When examining coal analyses, it has to be taken into consideration that one hardly ever has to do with one individual coal. Even in case of coal from one mining area, the power station is frequently supplied with mixed sorts of coal from different coal pits or, if they come from one pit, from different seems. Mixed sorts of coal as to their grinding and combustion qualities are basically different from one unmixed coal. So it becomes very important to discuss the possibilities and restrictions of coal mixing. Dr.Benesch

9 What is poor coal High ash content Hardness High water content High sulfur content Non-uniform quality

10 Implications of poor coal quality Emissions environment Wear costs, availability Maintanance costs El. consumption PAT related Boiler efficiency PAT related Slagging and fouling PAT related Less power output overall capacity

11 How to achieve a benefit in the PAT scheme fuel related Control coal quality If possible buy an appropriate coal Consider washed coal Homogenize

12 Definitions dealing with mixing of coal Homogenization Mixing Blending Minimize fluctuations in coal properties Definite new coal qualities, but some elements of the original coals can still be detected Definite new coal qualities In day to day operation with the existing equipment at the power stations, a homogenization other than a mixing or blending is usually possible. Quality of the process Dr.Benesch

13 Indirect effects of efficiency increase Higher capacity Cost reduction Environmental friendliness

14 Performance monitoring of power stations as part of the PAT scheme Online FGD / DENOX Fuel gas condition:: - CO 2 - temperature Steam parameters Reheater : spray - pressure attemperator: - temperature - flow rate Parasitic power consumption - auxiliaries load - exciter - equipment Fuel - mass flow - Quality firing: - O 2 - CO - after burning - leakage - NO X Feedwaterpreheating: - terminal temperature difference - boiler inlet temperature condenser - terminal temperature difference - temperature

15 Performance monitoring of power stations as part of the PAT scheme Offline with Mobile Measuring Vehicle Pulverized-coal measuring module Fly ash measuring module PC / fly ash analysing module Extensive gas analyzing module Portable gas analyzing module Calibration module for gas analyzers Temperature measuring module Volume flow rates measuring module Measuring module for turbines Measuring module for pumps Measuring module for condensers Measuring-value data logging and processing module

16 Performance monitoring of power stations as part of the PAT scheme Efficiency team Formation of an energy efficiency team (3 to 4 people) Plant visits (2 weeks on site) document review and discussions with the station personnel Creation of a database collecting the key information for the regarded power station Check of the current coal quality and comparison with the design coal Comparison of as built and theoretical boiler performance based on acceptance tests Check of every load case of the boiler and the current efficiency of the boiler Evaluation of the heat absorption in the different boiler parts and the air preheater Monitoring of the auxiliary power consumption, the air ingress, the milling system and the soot blowing system Evaluation of the turbine condition, main components of the water steam cycle, the whole cold end and the related heat rate Dr.Benesch

17 Coal quality influencing the entire power plant Fuel Parameters Coal handling Coal mills Dust firing system Steam generator Components Ash handling Air preheater FDF IDF ESP FGD Coal Ash Grain size Bulk density Specific weight Grindability Wear characteristic Pyrite content Sulphur content Sand content Wood content Salt content Heating values Elementary analysis Volatile matters Water content Ash content Ignition temperature Composition Viscosity Melting quality Cementability Water content Angle of slope

18 Availability and maintenance costs are governed by the parts being in contact with the coal - efficiency is part of the game -

19 Improper coal and influence on combustion system and boiler Bad or too late ignition Too early ignition Too long flames (touching the walls) Too high CO or NOx formation Wall corrosion Fouling problems Problems with bottom ash Limitation of part load and full load

20 Chlorine content of coals and influence on corrosion Relative corrosion rate country GB USA Australia Belgium India New Zeeland Poland South Africa Chlorine content in % (ar) Chlorine content in % (ar)

21 Slagging and Fouling current coal coal mixture coal history appropriate boiler design

22 Slagging and fouling indices

23 Example for unburnt carbon in filter ash for high grade coals depending on volatile matter content 25 Unburnt carbon in ash in % Volatile matter content in % (waf)

24 Furnace Design Depending on Unit Capacity

25 "Treatment of new coal" Offered Coal - Origin - Quantity Yes Known Quality No Special Conditions - Spotmarket - Special fuel Yes Data from - Coal data bank - Standard analysis No Check whether inside of range of a STEAG power station (- Technical criteria) No Blended inside range No Additional Test and Information - Theoretical - Laboritory - Fullscale test incinerations Blended Unblended Yes Rejected No Yes Economical Yes Definition of a Blend Technical Decision No Rejected Yes Combustion Incineration

26 Coal washing can influence quality, uniformity and quantity of fuel Advantages Efficiency increase Reduced land consumption Saved transport capacity lower transportation costs less investment for boiler, fuel- and ash- handling lower maintenance costs due to lower erosion Disadvantages Investment in coal washing plant operation costs Dr.Benesch

27 Coal washing yes or no ash 5% ash 20% transportation operating costs investment 100 transportation operating costs investment coal washing mine mouth 100km 5000km 0 coal washing mine mouth 100km 5000km Dr.Benesch Typically coal washing is more economic than transportation and combustion of low grade coals

28 Benchmarking needs PAT is asking for high efficiency Coal quality is a major factor influencing efficiency Examples had been given how poor coal reduces efficiency Appropriate coal has to be chosen if possible Efficiency loss due to poor coal quality has always cost increase as a result If PAT should be successful the influencing parameters have to be made transparent At least apples should not be compared with pears Dr.Benesch

29 Benchmarking Example for necessary adjustments Power Plant 1 Power Plant 2 Adjustments Site Power plant type/ "Comparative use Gap Energy Energy Power generating cost Operation Pay level Working hours Regulatory requirements Unit number Output Operation mode Coal type Organization Workflows External service material Technology Operation Power generating cost Capital Capital Administration Administration Dr.Benesch

30 Summary Coal quality is influencing efficiency values Typically coal quality can only be influenced limited Coal washing and Homogenization are of help Proper benchmarking of heat consumption needs consideration of coal quality and quantity Differences between design and really operated coal have to be considered Choosing a certain coal quality many parts of the power plant are affected, technical and commercial aspects are heavily linked. Dr.Benesch Every coal is black But not every black is coal

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