Technologies for Energy and Operation Efficiency in Stainless Steel Production Dr. Joachim von Schéele Linde India Limited

Transcription

1 Technologies for Energy and Operation Efficiency in Stainless Steel Production Dr. Joachim von Schéele Linde India Limited

2 Industrial Gases Production and Supply Production Cryogenic (Oxygen, Nitrogen, Argon) Absorption (Oxygen, Nitrogen) Steam Reformer, Electrolysis (Hydrogen) Supply Gaseous via Pipeline Liquid via Tanker to Intermediate Onsite Storage and Vaporization Solutions Provider Cylinder The cost relates mainly to Way and Size of Production Efficiency and Age of Production Electricity Price Purity Requirement Pressure Requirement Way and Distance of Supply 28/01/2015 RSE - AD/MD-MI 2

3 Burners and Injectors in an EAF BGH Edelstahl Siegen, Germany Equipment OXYGENJET CARBONJET LIMEJET Results Heat size +2 t Electricity -45 kwh/t Power on time -13 min. Electrode -0.3 kg/t Oxygen Nm 3 /t Natural gas +6.6 Nm 3 /t Charge carbon kg/t Inject carbon +8 kg/t Lime/dolo +6 kg/t 28/01/2015 RSE - AD/MD-MI 3

4 Burners and Injectors in an EAF BGH Edelstahl Siegen, Germany Aluminium granulates injected for chromium recovery, size 1-2 mm Before After Electricity (kwh/t) Power-on-time (min.) C to tapping (min.) /01/2015 RSE - AD/MD-MI 4

5 Thermal efficiency, % Fuel saving, % Oxyfuel Solutions Energy Efficiency 1. No nitrogen in 2. No nitrogen out 3. Radiation 4. Lower flue-gas velocity Thermal efficiency & fuel saving, Oxy-fuel & Air Fuel lambda=1, % 90 90% 80 80% 70 70% 60 60% OF 20 oc Air fuel, cold air Saving 50% 40% 30% 20 20% 10 10% Flue gas temperature, oc 0% 28/01/2015 RSE - AD/MD-MI 5

6 Dominant Heat Transfer Mechanisms % convection radiation Reheat Temp. Op. Range T [C] 28/01/2015 Fußzeile 6

7 Emission Coefficient [-] Gas Radiation O 2 N 2 H 2 O CO 2 0,800 0,700 0,600 Sum of the emission coefficients H2O and CO2 eg Oxygen/Natural gas eg Air/Natural gas 0,500 0,400 0,300 0,200 0,100 CH 4 + 2O 2 + 8N 2 CO 2 + 2H 2 O + 8N2 CH 4 + 2O 2 CO 2 + 2H 2 O 0, Flue Gas Temperature [ C] Radiation % Convection T [C] Air-fuel burner Oxyfuel burner 28/01/2015 RSE - AD/MD-MI 7

8 Conventional and Flameless Oxyfuel Conventional oxyfuel Flameless oxyfuel 28/01/2015 RSE - AD/MD-MI 8

9 Beneficial Use of Low Calorific Fuels The limitations of using an LCV fuel, can be overcome by using Oxyfuel combustion thus in case of combustion with LCV fuels, oxyfuel combustion is an absolute requirement. -Partial replacement of air-fuel combustion of a high calorific value fuel gas by oxyfuel combustion of a low calorific value fuel gas can make great sense! -The nitrogen component is reduced hence efficiency is increased. -The flame by LCV fuel combusting with oxygen is stable and compact. -The flame temperature by this configuration is around 1900 Deg C. -The radiation heat transfer is restored by Oxyfuel in case of LCV fuels. 28/01/2015 RSE - AD/MD-MI 9

10 Beneficial Use of Low Calorific Fuels CO 2 & H 2 O from N 2, CO 2 & H 2 O combustion. inert content from air GJ energy basis N 2, CO 2 & H 2 O inert content from BFG. CO 2 & H 2 O from combustion. Natural Gas-Air Combustion BFG-Oxygen Combustion By removing the ballast (N 2 ) in the oxidant, by using oxyfuel instead of airfuel combustion, a high ballast in the fuel (N 2, CO 2, H 2 O) can be accepted. In-house gases such as Blast Furnace Gas, or Producer Gas, may then be used for high temperature applications, e.g. in ladle pre-heating and reheat furnaces. High Calorific Fuels can then be saved (or used elsewhere) without any negative impact on the operation. 28/01/2015 RSE - AD/MD-MI 10

11 General Benefits of Oxyfuel in Vessel Preheating Benefits from higher heating temperature of a steel-making vessel: No need to have too high temperature of the steel in the EAF/BOF/AOD Shorter heating cycles for less number of vessels needed Only 75-80% flue gases due to less fuel and no nitrogen in combustion smaller flue-gas system 50-55% lower fuel consumption compared to cold air fuel system Possibility to reach very high pre-heating temperatures when wanted (Example 1500 o C for atomizing customer) Simple, compact and low weight installation as compared to air-fuel system with recuperator or regenerative solution Added features in Flameless oxyfuel: Further improved heat distribution in vessel Ultra low NO x emissions Extended refractory lifetime due to higher and more even temperature distribution in vessel 28/01/2015 RSE - AD/MD-MI 11

12 Flameless Oxyfuel in Ladle Preheating Results from Acerinox, Spain Drying of refractory, 24 hours Final temperature of 1,175ºC Fuel consumption: 1,000 Nm 3 NG Average thermal efficiency is 84% Drying cycle of 12 hours Final temperature of 1,175ºC Fuel consumption : 759 Nm 3 NG From 900ºC to 1,175ºC Final temperature after 1 hour 325ºC outside temperature Fuel consumption: 111 Nm3 NG 28/01/2015 RSE - AD/MD-MI 12

13 Vessel Preheating with Flameless Oxyfuel Increased temperature uniformity in ladle/converter Decreased fuel consumption Lower NOx formation Increased heating capacity Examples of installations of flameless oxyfuel for preheating Sandvik (Sweden) 90 t converters 1.4 MW Outokumpu, Avesta (Sweden) 90 t ladles 1.5 MW Acerinox (Spain) 90 t ladles 2.0 MW Ovako, Hofors (Sweden) 90 t ladles 1.4 MW Ovako, Smedjebacken (Sweden) 100 t ladles 1.5 MW Ovako, Imatra (Finland) 80 t ladles 1 MW Kanthal (Sweden) 5 t ladles 0.2 MW Outokumpu, Tornio (Finland) 90 t converters 2 MW Mahindra Sanyo (India) 50 t ladles 0.6 MW Bradken (Malaysia) 12 t ladles 0.4 MW 28/01/2015 RSE - AD/MD-MI 13

14 Ferro Chrome Converter at Outokumpu, 2.5 MW Flameless Oxyfuel Used for Drying and Heating 28/01/2015 RSE - AD/MD-MI 14

15 REBOX Installations of REBOX Oxyfuel Solutions in Steel Reheating Have Resulted in: Capacity Increase by up to 50% Fuel Savings of up to 50% (some cases 65%) Reduction of CO 2 Emission by up to 50% Reduction of NO X Emission Improved temperature uniformity, max. +/- 10 C Decrease of Scaling Losses by up to 50% 28/01/2015 RSE - AD/MD-MI 15

16 136 REBOX Oxyfuel Installations Examples of Sites with Installations ArcelorMittal, Galati (RO) ArcelorMittal, Shelby (US) Ascométal, Les Dunes (FR) Ascométal, Fos-sur-Mer (FR) Brach, Bremen (DE) Buderus, Wetzlar (DE) Dongbei Special Steel, Dalian (CN) Ellwood City Forge, Ellwood City (US) Evraz Steel, Claymont (US) Jindal SAW, Nashik (IN) Kalyani Carpenter Special Steels, Pune (IN) Mahindra Sanyo Special Steel, Khopoli (IN) Michigan Seamless Tube, South Lyon (US) North American Forgemasters, New Castle (US) Outokumpu, Avesta (SE) Outokumpu, Degerfors (SE) Outokumpu, Nyby (SE) Outokumpu, Tornio (FI) Ovako, Hofors (SE) Ovako, Smedjebacken (SE) POSCO, Pohang (KR) Salzgitter Flachstahl, Salzgitter (DE) Sandvik Materials Technology, Sandviken (SE Scana Steel, Björneborg (SE) SSAB, Borlänge (SE) Tayo Rolls (Tata Group), Jamshedpur (IN) ThyssenKrupp Steel, Bruckhausen (DE) ThyssenKrupp Steel, Finnentrop (DE) Timken, Canton (US) Uddeholm Tooling, Hagfors (SE) Usiminas, Cubatao (BR) 28/01/2015 RSE - AD/MD-MI 16

17 Total Energy Requirement Comparison 28/01/2015 RSE - AD/MD-MI 17

18 Flameless Oxyfuel Increases Capacity Over Air-fuel and Conventional Oxyfuel Comparison of total heating time at Ovako s Hofors Works, Sweden, using different combustion technologies in Soaking Pit and Rotary Hearth Furnaces. 28/01/2015 RSE - AD/MD-MI 18

19 REBOX installations at Outokumpu Linde s first installation of flameless oxyfuel: Complete conversion of a Walking Beam Furnace at Outokumpu s Degerfors mill, Sweden in % Capacity Increas 30% Fuel Savings 28/01/2015 RSE - AD/MD-MI 19

20 REBOX Oxyfuel Solutions Outokumpu, Degerfors, Sweden Walking Beam Furnace Converted into All Flameless Oxyfuel Operation Linde Gas Turn-key delivery Combustion system with flameless burners, furnace upgrade, new flue gas system, flow train, control system Furnace data Dimensions: 27 m length, 5 m wide Fuel: LPG Stainless steel: all grades, 1,550 mm wide mm thickness Performance Guarantee 35% more through put 30% fuel savings (down to 0.97 GJ/ton cold charged) NO X emission <70mg/MJ (350 mg/m3) Revamped in 25 days 28/01/2015 RSE - AD/MD-MI 20

21 Temperature (C) REBOX at Outokumpu, Degerfors More Heating Capacity in Walking Beam Furnace Heating 166mm slabs (Walking beam) Time (s) Air-fuel Oxy-fuel Stainless steel slabs 166 mm thick Top fired with wall-mounted flameless oxyfuel burners 2.9 H 3.8 H 28/01/2015 RSE - AD/MD-MI 21

22 REBOX installations at Outokumpu Catenary furnace at Outokumpu, Avesta (Sweden). Conversion into all flameless oxyfuel operation. 40 MW Flameless Oxyfuel; Capacity 150 tph 28/01/2015 RSE - AD/MD-MI 22

23 ArcelorMittal Shelby Tubular Products, Ohio Rotary Hearth Furnace Before; Air-fuel After; REBOX 28/01/2015 RSE - AD/MD-MI 23

24 REBOX HLL No Full Conversion, but More Capacity and Less Fuel Consumption Continues using existing air-fuel burners Minimum installation down time Greater flexibility in operation techniques Optimized in response to fluctuating fuel cost and productivity requirement REBOX HLL at Outokumpu, Tornio (Finland) 28/01/2015 RSE - AD/MD-MI 24

25 REBOX installations at Kalyani Carpenter Special Steels Walking Beam Furnace for alloyed steel blooms; design capacity 30 tph REBOX installation commissioned in February 2012 Solution: 1 pair of Flameless Oxyfuel Burners added; HLL at existing air-fuel burners Fuel: Furnace Oil Results: Only HLL: +20% throughput Oxyfuel burners & HLL: +30% throughput Fuel consumption (and CO 2 ) down by >20% A second REBOX installation was made in a 40 tons Soaking Pit Furnace in mid /01/2015 RSE - AD/MD-MI 25

26 65% less oil consumption 65% less CO2 emissions NOx emissions down 28/01/2015 RSE - AD/MD-MI 26

27 REBOX installations at Mahindra Sanyo Special Steel Chamber Furnaces for alloyed steel blooms and billets; maximum batch size is 35 tons. REBOX installations in two furnaces commissioned in January Installations in two more furnaces commissioned in October Further installations in evaluation phase. Solution: Flameless Oxyfuel Fuel: Furnace Oil Results: Fuel consumption down by >50% CO 2 emission reduced by >50% Scale losses down by >50% Heating and soaking times decreased; throughput increased 28/01/2015 RSE - AD/MD-MI 27

28 REBOX installations at Mahindra Sanyo Special Steel Reduction of Scale Losses After Befor e 28/01/2015 RSE - AD/MD-MI 28

29 REBOX installations at Mahindra Sanyo Special Steel 28/01/2015 RSE - AD/MD-MI 29

30 REBOX installations at Mahindra Sanyo Special Steel 50% Hot Charged and 50% Cold Charged Average total oil per rolled ton 55% less oil!!! 28/01/2015 RSE - AD/MD-MI 30

31 Jindal SAW, Nashik REBOX HLL REBOX HLL installation in a Rotary Hearth Furnace, rated 75 t/h but operating at t/h due to the fuel used. The furnace is today running with producer gas (CV at 1,250 kcal/m 3 ) as fuel in the heating zones and oil in the soaking zones. The purpose of the installation is to make it possible to stop using oil, and run with producer gas' in all zones. 28/01/2015 RSE - AD/MD-MI 31

32 Jindal SAW, Nashik REBOX HLL 28/01/2015 RSE - AD/MD-MI 32

33 Jindal SAW, Nashik REBOX HLL Reference measurements of temperature uniformity using Thermovision camera Installation of measurement system for the producer gas 28/01/2015 RSE - AD/MD-MI 33

34 Some Additional REBOX Installations in 2014 Sandvik, Sweden Full conversion into REBOX flameless oxyfuel of 35 t/h LPG fired walking beam furnace. The purpose of the installation is to reduce the fuel consumption by 35% and increase the temperature uniformity. This is Linde s third REBOX installation at Sandvik. Commissioning successfully completed in August Tayo Rolls (Tata Steel), Jamshedpur Full conversion into REBOX flameless oxyfuel of an oil-fired 50 t bogie hearth furnace. The purpose of the installation is to reduced the fuel consumption. Commissioning successfully completed in December Fuel consumption decreased by 55%. 28/01/2015 RSE - AD/MD-MI 34

35 REBOX DST For Wire Annealing Reheating Furnace Hot Roll Mill 3 - Roll Block Finishing Block DST Line Wire Rod Less Fuel Consumption Faster Production, Less Time Better & More Uniform Quality Less Scale Losses HR Wire Rod Annealing Furnace 28/01/2015 RSE - AD/MD-MI 35

36 Some Technical Data from Linde s DST Installations Capacity 45 to 72.5 tph Length 30 to 35 m Inside width 1.45 t m Fuel LPG, gasified coal Cooling Water Spray Wire Dimensions 4.5 to 20 mm Coil Diameter 1,075 to 1,100 mm Steel Grade 300 Series Grain Size ASTM <6.5 Yield Strength up to 240 N/mm 2 Strength Variation <+/- 10 N/mm 2 within a coil Temperature Uniformity +/-3.5 C over width, +/5 C over length 28/01/2015 RSE - AD/MD-MI 36

37 REBOX DST For Wire Annealing 28/01/2015 RSE - AD/MD-MI 37

38 REBOX DST For Wire Annealing 28/01/2015 RSE - AD/MD-MI 38

39 Outokumpu, Nyby, Sweden REBOX DFI in Strip Annealing Line 4 MW installed power 120 oxyfuel flames, four burner rows 2 m long unit at entry of strip annealing furnace Furnace throughput capacity increased by 50%, from 23 to 35 tph 28/01/2015 RSE - AD/MD-MI 39

40 Oxyfuel Solutions Reduced CO 2 and NO X Emission Levels Fuel savings of up to 50% Reduction of CO 2 emissions by up to 50% 425 Nm 3 /t 70 Nm 3 /h A flue-gas volume that is % smaller and having a - CO 2 content of 95% (dry basis) 350 kwh/t 250 kwh/t Air fuel 70 mg NO X /MJ (as NO 2 ) 88 g NO 2 /t 80 kg CO 2 /t Oxyfuel 70 mg NO X /MJ (as NO 2 ) 66 g NO 2 /t 57 kg CO 2 /t AGA AGA This small flue-gas stream with a high CO 2 content AGA should be very suitable for cleaning, storage and sequestration. CO 2 emission directly proportional to fuel consumption 28/01/2015 RSE - AD/MD-MI 40

41 Creating Customer Value as a Solutions Provider Thank you very much for your kind attention joachim.von.scheele@linde-gas.com 28/01/2015 RSE - AD/MD-MI 41