Present Day Practice and Future Challenges in GLASS INDUSTRY

Transcription

1 Present Day Practice and Future Challenges in GLASS INDUSTRY 1

2 by SUJAY BHATTACHARYYA M. Tech. (IIT-Kanpur), MBA Consultant Glass, Ceramics, Specialty Chemicals 2

3 Present Practice and Some Basics 3

4 Indian Glass Industry Market Share ( Per IBEF, October 2007 data) Container glass industry $ Other : Table wares, 0.87 Lighting, Jewellery, Fiber 12% Optics, growth, Float glass $ 0.76 billion % growth. Total Glass Industry is about $ 2.0 billion per annum. Data per fiscal year. Other : Table wares, Crystal glass, Opal glass, Lighting, Jewellery, Art wares, Decoratives, Fiber Optics, etc. have small market share not shown here. 4

5 Indian Glass Industry Export Data ( Per IBEF, October 2007 data) 5

6 Type of Glass Melting Furnaces 6

7 POT Furnaces S Single POT Electric POT (Single) Multiple POT 7

8 Day Tank 8

9 End Port Continuous Tank 9

10 Side Port Cross Fired Continuous Tank 10

11 Overview of Glass Manufacturing Process 11

12 A Typical Batch Calculation 12

13 Mechanisms inside Furnace (Longitudinal section) 13

14 Viscosity-Temperature Relationship of Glass 14

15 Some Common Glass Network Structures 15

16 Transmission Curves of Some Common Glasses Regular commercial glasses Mid-IR optical materials (e.g., fiber optics) IR materials (e.g. night vision camera lens) 16

17 Estimated Energy Use by Process Step Other includes cold end, glass handling, etc. Glass Manufacturing Expenditure cost center wise 17

18 Sankey Diagram for Glass Tank Furnace (Typical example, 1 kj = 239 Cal of energy) 18

19 Various Glass Currents inside Furnace Batch piles as seen by high temperature camera inside Furnace. 19

20 Various Batch Reactions inside Furnace Melt ( in a typical soda-lime-silicate batch ) Degassing Reactions : Na2CO3.H2O Na2CO3 + H2O (105 C) Ca,Mg(CO3)2 CaCO3 + MgO + 2CO2 (740 C) CaCO3 CaO + CO2 (880 C) Reactions in Solid State : Na2CO3 + CaCO3 Na2,Ca(CO3)2 [eutectic] ( C) 2 SiO2 + Na2,Ca(CO3)2 Na2O.2SiO2 + CaO + 2 CO2 (700 C) SiO2 + Na2,Ca(CO3)2 Na2O.3CaO.6SiO2 + 2 CO2 (850 C), for SiO2 < 50 µm Na2O.2CaO.3SiO2 + 2 CO2 (850 C), for SiO2 > 50 µm 2 CaO + SiO2 2CaO.SiO2 (850 C) x Na2CO3 + y SiO2 x Na2O.ySiO2 + x CO2 ( above 850 C) 20

21 Various Batch Reactions inside Furnace Melt ( in a typical soda-lime-silicate batch ) Reactions in Liquid State : Na2O.2SiO2 + 2CaO.SiO2 Na2O.3CaO.6SiO2 + Na2O.2CaO.3SiO2 ( C) Na2O.2SiO2 + Na2O.3CaO.6SiO2 + Na2O.2CaO.3SiO2 Ternary peritectic (750 C) Ternary peritectic Vitreous Phase + SiO2 (s) (850 C) Refining with salt Cake and Coke : Na2SO4 + 2 C Na2S + 2 CO2 (700 C) 3 Na2SO4 + n SiO2 + Na2S (Na2O)4.(SiO2)n + 4 SO2 (1100 C) Na2SO4 + n SiO2 Na2O.(SiO2)n + SO2 + ½ O2 (1200 C) 2 Na2SO4 (excess) 2 Na2O + 2 SO2 + O2 (1400 C) Unmelted salt cake forms a defect salt water gall 21

22 Theoretical heat requirement for soda lime glass 22

23 Future Challenges and Possible Road Map 23

24 Challenge Energy Efficiency ( An example) Considering highest temperature of glass (1575 C), efficiency is 32.7 % 24

25 Challenge Energy Efficiency Where is the problem? We have seen, theoretical thermodynamic value to convert Batch Glass is not more than 2662 kj (637 kcal) per kg of molten glass. But actually it s taking kcal/kg in continuous large tanks. Pots and Day Tanks are as high as kcal/kg. That means in reality it is consuming nearly 2 20 times of theoretical energy. Why? Because the heat energy from flame can penetrate the batch blanket 20 25% as it acts as a thick layer of insulation. Also some energy is consumed in endothermic reactions in the batch melt. Rest of the energy is lost as we have seen in Sankey diagram earlier. 25

26 What we can do? Challenge Energy Efficiency Avoid traditional firing : flame (from solid/liquid/gas fuels) over batch blanket. Utilize electric melting with heating elements (e.g. MoSi2) directly in contact with the batch using only oxides. Thus we can have almost 90% energy efficiency. However thermal power plants operate between 30 50% efficiency. Electric melting has been already started; but not yet possible above 150 T/d. Use renewable captive energy like wind mill, solar power, waste decomposition add these energies to the furnace, annealing lehr, etc. Install waste heat boiler in flue line. In a furnace with an output of 600 T/d, it is possible to generate 1 MW (239 kcal/sec) of electricity from waste heat boiler. Many Glass industries have already started this. Use Batch Preheating in fluidized bed utilizing waste heat. Use melting aids like electric boosters, bubblers, mechanical stirrers. They not only save energy (as they are dipped into the glass melt), but also improve quality of the glass substantially. Already many glass makers are using. Use pulse burner. It is already available upto 1250 / 1300 C in ceramics industry and very popular. But one need to design it for 1600 / 1700 C. Use catalytic combustion to reduce energy gap between theoretical and actual. 26

27 Challenge Energy Efficiency Increase in furnace capacity with electric boosting. (1kWh = kcal) Batch melting energy vs. cullet addition and batch moisture 27

28 Challenge Energy Efficiency US Glass Industry Strategy, GMIC report

29 Challenge Energy Efficiency US Glass Industry Strategy, GMIC report

30 Challenge EHS Concerns (Emissions from a furnace) + CO & CO2, VOC 30

31 Challenge EHS Concerns ( Process Emissions, Effluents, By-products and Wastes) 31

32 Challenge EHS Concerns (Emission Factors in lb/ton glass materials processed) CO2 emission is typically 441 lb/ton of glass in an end fired Container Glass furnace, uncontrolled. 32

33 Challenge EHS Concerns Dutch emission requirements since 1994 for Container Glass, NER (Nederlandse Emissie Richtlijnen). 1 MT of cullet ~ Reducing 230 Kg in CO2 emissions. 33

34 Challenge EHS Concerns (Summary of CO2 reduction potential cost & time analysis) Abbreviations : BAT (best available technology), CCS (carbon capture & storage) 34

35 Challenge EHS Concerns (Equipments for Pollution Control and Environment Protection) Electrostatic dust precipitator Wet scrubber Cyclone dust separator Bag filters 35

36 Challenge EHS Concerns (Equipments for Pollution Control and Environment Protection) Closed conveyor Fume hood Closed pipe pneumatic conveying Countercurrentflow packed bed scrubber 36

37 Challenge EHS Concerns (Personal Safety Gadgets) 37

38 Challenge EHS Concerns (Personal Safety Gadgets) 38

39 Challenge Product Mix in India In a $ 2.0 bn market ( ) Flat and Container Glasses cover ~ 90%. These are low value, low margin, low technology products. Share of high revenue Specialty glasses is not more than a meagre 2 %. Some of the Specialty glasses are Optical and Ophthalmic glasses Laboratory ware glass Medical and Analytical Equipment glasses Electrical and Lighting glass Display (CRT, LCD/LED/Plasma) glasses Solar panel glass Crystal (lead and non-lead) glasses Sealing (glass-to-glass and glass-to-metal) glasses Laser glasses (Nd-phosphate glass for high power Laser lasing at nm, Yb-silicate glass for high power Laser lasing at nm, Er-fluorophosphate glass lasing at nm). Nd (Neodymium), Yb (Ytterbium), Er (Erbium) all Lanthanoids. Quality and Cost effectiveness need to improve for International market. 39

40 Challenge Raw Materials (Cost, Quality & Consistency) QUALITY RAW MATERIALS MAKE QUALITY PRODUCTS. But what is the cost? Monthly price index (Base Jan 2006 = 100) Soda ash ~ 20% in batch Installed Capacity of Domestic Industry and India's Soda ash Demand 40

41 Challenge Raw Materials (Cost, Quality & Consistency) High purity natural Raw Materials becoming scarce and expensive. Too little (and partial) Beneficiation and Blending facility. Quality and Supply inconsistent and irregular in India. Mining restriction, law. Chemical analysis of a raw white silica After Requirement of Silica Sand per Sand from an Over- Beneficiation Beneficiation IS 488: 1980 for Glass making process Burden Lignite mine Trial at site lab available are Special Grade Grade - I Froth floatation, SiO2 = 91.5 SiO2 = 98.1 SiO2 = (min) Attrition, Fe2O3 = 1.4 Fe2O3 = 0.09 Washing in Fe2O3 = (max) Cyclone, TiO2 = 0.74 TiO2 = 0.13 Gravity TiO2 = (max) separation, Al2O3 = 4.22 Al2O3 = 0.28 Centrifugal Al2O3 = Shows contamination with separation in a heavy minerals like rutile Na2O = 0.16 Na2O = Na2O = Spiral, (TiO2), ilmenite (FeTiO3), K2O = 0.01 K2O = Demagnetization, Acid K2O = leucoxene (FeTiO3-TiO2); also some felspar. They were not CaO = 0.6 CaO = leeching, etc. CaO = removed by simple process. LOI = 1.37 LOI = 0.17 LOI = (max) The product is still not upto the mark. More and more advanced exploration necessary. 41

42 Challenges Overall (Objective & Goal, US Department of Energy Office of Industrial Technologies, Summary) 42

43 THANK YOU FOR YOUR ATTENTION 43