Outline of options for waste liquidation through gasification 1
Schematic diagram of co-gasification 2
Conditions for the waste and brown coal coprocessing - physical and mechanical properties (grain sizing, hardness, undersized particles content, abrasion, sintering capacity) - chemical composition: contained components must not contribute to reduce the ash melting point under 1,300 C content of halogens can be dangerous for consecutive technology halogen-infused plastics or mixtures containing increased contents of these materials must be eliminated from processing completely as potentially hazardous may also be indicated the waste containing hexavalent chromium, mercury, arsenic above 50 grams per ton 3
Alternative fuel - pellets 4
Elementary and basic fuel analysis Determination Unit Original sample r Waterless sample d Combustible daf Evaluation Water W % 8.0 - - complies Ash A % 29.50 32.20 - complies Combustible (100-W-A) % 62.50 67.80 100.00 complies HHV Q s MJ/kg 16.11 17.84 26.25 complies LHV Q i MJ/kg 14.90 16.40 24.51 complies Hydrogen H % 2.38 2.60 3.84 complies Carbon C % 36.90 40.20 59.30 complies Sulphur organic S o % 0.43 0.47 0.69 complies Nitrogen N % 0.50 0.55 0.81 complies Oxygen O % 21.45 23.07 34.03 complies Chlorine Cl % 0.84 0.91 1.33 Original values /r/ = state of sample delivered 5
Heavy metals content in bown coal and in the alternative fuel Element Content in SUAS coal mg/kg dry matter Content in fuel sample mg/kg dry matter Difference sample coal mg/kg dry matter As 5 20 Less than 5 ~ 0 Sb 2.1 2.3 17.3 + 15.1 Be 1.5 2.5 Less than 0.1-2.0 Cd 0.2 0.3 4.19 + 3.9 Cr 45 85 60.4 ~ 0 Cu 90 150 668.0 + 548 Co 10 20 8.62-6.4 Pb 3.5 8 185.0 + 179 Hg 0.4 0.55 1.32 + 0.8 Ni 20 35 50.0 + 22.5 Mn 70 120 510.0 + 415 Se 2.5 3 Less than 0.1-2.7 V 150 230 11.3-178 Tl 4.8 5.2 Less than 0.5-4.5 Zn 20 70 937.0 + 892 Sn 5 6 22.8 + 17.3 Te n.a. Less than 0.2-6
Diferences in the metals content I. Metals present in lower concentrations than in coal: Be, Se, V, Tl, Te, Co II. Metals present in approximately identical concentrations as in coal: As, Cr III. Metals present in higher concentrations than in coal: Cu, Pb, Zn, Mn, Sb, Sn, Cd, Hg, Ni IV. Metals present in considerably higher concentrations than in coal: Zn, Cu, Mn, Pb 7
Procedure of adding the alternative fuel 8
Income hall 9
Batching facility and the belt conveyor 10
Belt conveyor the general view 11
Alternative fuel silo 12
Main coal-handling belt and the gasification plant 13
Specific attributes of the co-gasification process The production of gas from brown coal in pressure gasifiers is a highly reductive process Primary oxidation only takes place in the oxidizing zone of the reactor Above all, the reducing processes take place in the next zones (reducing, carbonizing, drying) Reduction at temperatures of 700 1,000 C eliminates any formation of oxygen derivates of the type of dibenzodioxines or dibenzofuranes 14
Comment on the chlorine content SUAS coal Alternative fuel sample Content Cl d 125 180 mg/kg 8,400 mg/kg The medium content of chlorine in the fuel mixture for co-gasification with representation by weight of alternative fuel to 5% and at least 95% of gasifier coal will rise to 500 700 mg/kg (d) HCl generated in the gasification process is washed into a large surplus of raw phenol water with a ph of 8 8.5 as inorganic chlorides Their increased presence is only a technological problem of the process of waste water treatment 15
Conclusion The gasification process in SUAS has the following basic prerequisites for the alternative fuel exploitation: - Potential of using the existing gasifiers; - Potential of using the existing technological transports channels to and batching into single gasifiers; - Availability of a high-reduction atmosphere and a sufficient temperature enabling destruction of the PCDF/PCDD-based materials; - Existence of equipment already in place and subsequent to the gas production process, i.e. gas-cleaning (Rectisol) and the phase of burning in the CCPP burners as the last section of the whole technology line; - Availability of the cracking gasifier for processing liquid substances produced in the process and extra gasifying hazardous constituents that got liquidized in the coal gasification process; - Potential facility for introducing external liquid products into the gasification process in the cracking gasifier. 16
Thank you for your attention. Sokolovská uhelná JSC: www.suas.cz Petr Mika: mika@suas.cz Phone: +420 352 46 4480 Zdeněk Bučko: bucko@suas.cz Phone: +420 352 46 2161 17