Co-firing of high-ash anthracite coal into the wooden biomass in flame:

1. SIXTH INTERNATIONAL CONFERENCE ON CLEAN COAL TECHNOLOGIESCCT2013 Co-firing of high-ash anthracite coal into the wooden biomass in flame: Pulverized coal and biomass co-firing with the aim of reduction of natural gas consumption at Ukrainian power plants Dr.Nataliya Dunayevska, Taras Shchudlo, Dr.Yarosvav Zasiadko, Dr. Dmytro Bondzyk Coal Energy Technology Institute of National Academy of Sciences of Ukraine 12-16 MAY,THESSALONIKI, GREECE

2. Primary energy resources and energy intensity in Ukraine Proved reserves of primary energy (2011)* Energy intensity, tones o. e. / thousand $ 2005** The balance of primary energy, million tones o. e. (2011)* Some economical statistics***: Grossdomesticproduct (2012) – 135 billioneuro Averagewage per month (2012) – 295 euro * BP Statistical Review of World Energy, June 2012 ** IEA 2012, Energy Balances of Non-OECD Countries, OECD/IEA, Paris *** State Statistics Service of Ukraine, 2013 2

3. Structure of primary energy consumption (2010) 3

4. The energy potential of biomass in Ukraine (2011) 4

5. Straw and sawdust powerresources in Ukraine 5

6. Thermalpower plants that burn anthracite in Ukraine Total capacity of coal power units – 21778 MWe Total installed capacity of Ukraine – 53500 MWe 6

7. Research tasks • Research on possibilities to improvethe high-ash anthracite flame stabilization by its co-firingwith pine sawdust biomass • Partially or completely replace supporting natural gas consumed in the coal power with biomass, to support combustion of high-ash anthracite 7

8. Unit's characteristics: reactor: vertical downflow internal diameter: 280 mm diagnostic section length: 2400 mm Brick lining:fire layer - zirconium dioxide, thermal insulation - chamotte, thermal compensation - asbestos cloth Maximal load: 30 kg/hour, coal Experimental unit VGP-100 for pulverized coal/biomass co-firing study The unit VGP-100 models processes that take place in lower radiation part of the furnace and the near-burner area Schematics of VGP-100: 1 - diagnostic section of the reactor 2 - burner 3 - slag collector 4 -cyclone 5 - afterburner and cooling chambers 8

9. The objects of study 9

10. Summary on the experiments with biomass and coal co-firing conducted on the VGP-100 unit * – heat share of natural gas/sawdust, including losses for heating air to 320 C, which is done at real thermal power plants 10

11. Comparison of axis temperature distribution and coal conversion degree for natural gas and biomassco-firing 11 11 11

12. Comparison of axis temperature distributionand conversion degree of coal depending on the heat share of sawdust in the mix 12

13. The study of sawdust coke combustion kinetics • The experiments resulted in that anthracite and wood sawdust co-firing has shown its efficiency in comparison with the coal and supporting natural gas combustion • However, the particles residence time in the VGP-100 unit was approximately 0.8 seconds, which is not sufficient for complete burnout of the fuels • Furthermore, the coke particles burnout is the longest phase of fuel combustion, especially for biomass • All these results had led us to necessity to evaluate the residence time of wood particles in the boiler, so further investigation of combustion rate of the wood coke particles was carried out in experimental unit RSK-1D 13

14. The experimental unit RSK-1D for the study of sawdust coke combustion kinetics Key feature: • vertical differential pulse fluidized bed reactor • working in close to ideal displacement on the gas • and ideal mixing on solid phases • allows to maintain low temperature gradients (<10 K) • in the reaction zone range adjustment sample Schematics of RSK-1D: 1 - ADC 2 - thermocouple 3 - linkage of wood 4 - O2 absorber and drainer 5 - needle valves 6 –CO2 absorber and dryer unit 7 - dispenser 8 - voltage regulator 9 - filling of magnesium oxide; 10 - tube furnace, 11 - perforated grid, 12 - reactor, 13 - rheometer, 14 - the needle valve, 15 - gas analyzer, 16 - valve. 14

15. The experimental results of sawdust coke combustion kinetics • In the investigated temperature range, particle size of the wood coke does not affect the rate of reaction with oxygen, which indicates intrakinetic mode of sample combustion • After summarizing the results by Arrhenius approximation, reaction rate constant • K0І = 1,3  104 [1/c] / [kg/m3] and the activation energy E = 111,2 kJ/mol were obtained 15

16. Conclusions Analysis of present situation in Ukraine shows reasonability of biomass utilization at pulverized coal thermal power plants Experimental results showed that high-ash anthracite can be co-fired with sawdust biomass, which helps to reduce consumption of supporting natural gas, up to its full substitution. The obtained kinetic rate constants of coke of pyrolized wood can be used for further design of power equipment to burn wood, with or without coal 16 16

17. The statistics and research data described above were received within the framework of: • EC grant # DCI/ENV2010/243-936 “Demonstration, Dissemination and deployment of CCT and CCS in Ukraine” • NATO grant,program for Security Through Science, project“Co-firing of solid biomass and pulverized coal in coal fed boilers of power plants” • Comprehensive research program of National Academy of Science of Ukraine «Biofuel» • Fundamental research program of National Academy of Science of Ukraine “Scientific foundations of low-reaction coal combustion in flow” 17