Presentation is loading. Please wait.

Presentation is loading. Please wait.

ENERGY SELF-SUFFICIENCY AND COGENERATION IN LOUISIANA CANE SUGAR FACTORIES Harold Birkett and Jeanie Stein Audubon Sugar Institute.

Similar presentations


Presentation on theme: "ENERGY SELF-SUFFICIENCY AND COGENERATION IN LOUISIANA CANE SUGAR FACTORIES Harold Birkett and Jeanie Stein Audubon Sugar Institute."— Presentation transcript:

1 ENERGY SELF-SUFFICIENCY AND COGENERATION IN LOUISIANA CANE SUGAR FACTORIES Harold Birkett and Jeanie Stein Audubon Sugar Institute

2 BOILERS & COGENERATION OBJECTIVES To present actual data on bagasse availability and analysis To present data on boiler efficiencies and suggestions for improving them To discuss factory modifications to reduce steam usage and increase electricity cogeneration

3 GAS COST ($) / MCF

4 GAS / TON CANE Hurricane Lili Tropical Storm Isidore

5 ELECTRICITY COST

6 TRUE FIBER % CANE 1998-2006 AVG = 11.85; 2006 = 12.39

7 TRUE FIBER % PREPARED CANE 2005 & 2006 CROPS; AVG = 11.88

8 TRUE FIBER % BAGASSE 2005 & 2006 CROPS; AVG = 38.08

9 DRY FIBER (BAGACILLO) % MIXED JUICE 2005 CROP; AVG = 0.39

10 BAGASSE % CANE 2005 & 2006 MILL TEST DATA; AVG = 31.41 VS 28.77

11 BAGASSE % CANE FACTORY REPORTED DATA; AVG = 31.8

12 MOISTURE % BAGASSE 2005 & 2006 CROP (MILLING & BOILER SAMPLES); AVG = 53.86

13 ASH % BAGASSE 2005 & 2006 CROPS (MILLING & BOILER SAMPLES); AVG = 5.19

14 ASH % BAGASSE

15 PRIMARY FACTORS AFFECTING BOILER EFFICIENCY 1.The quality of the fuel (bagasse). 2.The quantity of excess air used for combustion. 3.The temperature of the flue gases. 4.The completeness of the combustion.

16 OXYGEN % FLUE GAS 2005 & 2006 CROPS; AVG = 7.99

17 BOILER EXCESS AIR 2005 & 2006 CROPS; AVG = 72.8

18 FLUE GAS TEMPERATURE 2005 & 2006 CROPS; AVG = 450

19 PREHEATED AIR TEMPERATURE 2005 & 2006 CROPS; AVG = 457 F

20 BOILER EFFICIENCY 2005 & 2006 CROPS; AVG = 55.45

21 POUNDS STEAM PRODUCED PER POUND BAGASSE BURNED 2005 & 2006 CROPS; AVG = 1.89

22 METHODS TO IMPROVE BOILER EFFICIENCY 1.Improve the bagasse quality (lower moisture & ash). 2.Reduce the level of excess air. 3.Reduce the temperature of the flue gases.

23 EFFECTIVE MOISTURE EFFECTIVE MOISTURE = 56.75 % MOISTURE = 53.99 % FIBER+S.S.= 41.15 ASH = 4.86 MOISTURE = 53.99 TOTAL = 100.00

24 EFFECTIVE BAGASSE MOISTURE VS BOILER EFFICIENCY 2005 & 2006; r=0.58; Effective Moisture = Moisture % Ash-Free Bagasse

25 EFFECT ON BOILER EFFICIENCY DECREASEINCREASE MOISTURE % BAGASSE BY 1% EFFICIENCY BY 0.8% ASH % BAGASSE BY 1% EFFICIENCY BY 0.5%

26 BOILER EFFICIENCY VS FLUE GAS TEMPERATURE USING AVG INPUTS, VARYING FLUE GAS TEMP ONLY 62 60 56

27 BASIC ASSUMPTIONS: Grinding rate, tcd 10,000 Cane, % pol 13.0 % fiber (true) 11.24 Bagasse, % moisture 54.0 % ash 3.00 Imbibition % cane 30.0 Syrup purity 85.0

28 BASIC ASSUMPTIONS: Boiler efficiency,% 55.0 Boiler feed water temp, F 250.0 Power required, hp/tch 25.0 Electricity required, kw/tch 9.6 Turbine efficiency, % 50.0 Turbo-generator efficiency, % 68.0 Misc. steam usage, lb/hr Live steam 20,000 Exhaust steam 10,000

29 CASE 1 TYPICAL LOUISIANA FACTORY 10,000 TCD BAGASSE FROM MILL = 238,043 LB/HREXCESS BAGASSE = 16,449 LB/HR = 6.9 % BOILERS CONDENSATEEVAPORATORLOW GRADE PANS BFW DEAERATOR 447,620 LB/HR 221,594 LB/HR BAGASSE STEAM 210 PSIG 392°F 20,000 LB/HR MISCELLANEOUSMAKE-UP TO EXHAUST 0 LB/HR BACK PRESS T-G (870 KW) FACTORY TURBINES (10,417 HP) 395,088 LB/HR32,512 LB/HR MISCELLANEOUS 10,000 LB/HR24,193 LB/HR26,752 LB/HR350,796 LB/HR QUAD, V1 FOR JUICE HEATERS & HIGH GRADE PANS 15,859 LB/HR BUY 3,130 KW

30 CASE 2 HIGH PRESSURE STEAM & QUINTUPLE EFFECT EVAPORATOR 10,000 TCD BAGASSE FROM MILL = 238,043 LB/HREXCESS BAGASSE = 36,812 LB/HR = 15.5 % BOILERS EVAPORATORLOW GRADE PANS BFW DEAERATOR 344,105 LB/HR 201,231 LB/HR BAGASSE STEAM 650 PSIG 750°F 20,000 LB/HR MISCELLANEOUSMAKE-UP TO EXHAUST 0 LB/HR BACK PRESS T-G (6,392 KW) FACTORY TURBINES (10,417 HP) 201,984 LB/HR122,121 LB/HR MISCELLANEOUS 10,000 LB/HR19,661 LB/HR0 LB/HR315,141 LB/HR QUINTUPLE V1 TO ALL PANS & 3 RD LJH V2 TO 2 ND LJH, V3 TO 1 ST LJH DESUPER- HEATING WATER 20,697 LB/HR SURPLUS 2,392 KW

31 CASE 3 HIGH PRESSURE STEAM, TOPPING TURBINE & QUINTUPLE EFFECT EVAPORATOR 10,000 TCD BAGASSE FROM MILL = 238,043 LB/HREXCESS BAGASSE = 35,658 LB/HR = 15.0 % BOILERS EVAPORATORLOW GRADE PANS BFW DEAERATOR 346,079 LB/HR 202,385 LB/HR BAGASSE STEAM 650 PSIG 750°F 20,000 LB/HR MISCELLANEOUSMAKE-UP TO EXHAUST 0 LB/HR BACK PRESS T-G (221 KW) FACTORY TURBINES (10,417 HP) 319,402 LB/HR6,676 LB/HR MISCELLANEOUS 10,000 LB/HR19,667 LB/HR0 LB/HR315,141 LB/HR QUINTUPLE V1 TO ALL PANS & 3 RD LJH V2 TO 2 ND LJH, V3 TO 1 ST LJH DESUPER- HEATING WATER 18,730 LB/HR TOPPING TURBINE7,277 KW 210 PSIG/570°F SURPLUS 3,498 KW

32 SUMMARY Improving quality of bagasse (lower moisture and lower ash) can improve boiler efficiency and increase steam production. Boiler efficiency can be improved (in La. primary area of improvement can be through installation of economizers to reduce high average flue gas temperature). Even without improvements in bagasse quality or boiler efficiency, use of high pressure steam and more efficient evaporator schemes can make La. factories energy independent or exporters of electricity.

33 ACKNOWLEDGMENTS AMERICAN SUGAR CANE LEAGUE ALL LOUISIANA SUGAR MILLS

34

35 BOILER WASTE HEAT RECOVERY ASSUMPTIONS (State Average for 2005 & 2006) –Moisture % Bagasse53.86 –Ash % Bagasse 5.19 –Oxygen % Flue Gases 7.99 –Flue Gas Temperature, F 450 –Preheated Air Temperature, F 457 –Boiler Outlet Gas Temperature, F 707 –Flue Gas Dew Point, F 150

36 PRACTICAL DEGREE OF COOLING OF FLUE GASES Boiler Outlet Gas Temperature, F= 707 Minimum Practical Flue Gas Temperature, F= 250 Degree of Cooling of Flue Gases, F 457 POTENTIAL COOLING OF FLUE GASES BY VARIOUS METHODS, F Theoretical Actual Using Air Preheaters 438 257 Economizers 150 150 Bagasse Dryers 427 ? RELATIVE WEIGHTS OF BOILER FLOWS Bagasse= 1.00 BF Water= 2.10 Air= 3.92 Flue Gas= 4.87

37 Air preheaters and economizers have no moving parts and are very dependable. Their use may require fans and pumps or higher head and horsepower. Bagasse dryers have the following disadvantages: 1.Complex – multiple conveyors, rotating equipment, and cyclones. 2.High horsepower requirements – especially for fan on cyclone. 3.Dry bagasse is a fire hazard. 4.Higher furnace temperature may improve combustion but may also cause the ash to melt. 5.Increased pollution (particulate carryover).

38 BOILER EFFICIENCY VS FLUE GAS TEMPERATURE No waste heat recovery, flue gas = 707 F Current operation with a/h = 450 F (using only air preheaters) Practical final flue gas temp = 250 F (requires air preheaters + economizers) 46.02 56.76 64.84

39

40 PREPARATION INDEX and MILLING

41 PREPARATION INDEX VS TANDEM POL EXTRACTION 2005 DATA, r = 0.49

42 PREPARATION INDEX VS TANDEM POL EXTRACTION 2006 DATA, r = 0.23

43 PREPARATION INDEX VS FIRST MILL POL EXTRACTION 2005 DATA, r = 0.73

44 PREPARATION INDEX VS FIRST MILL POL EXTRACTION 2006 DATA, r = 0.18

45 FIRST MILL POL EXTRACTION VS TANDEM POL EXTRACTION 2005 DATA, r = 0.66

46 FIRST MILL POL EXTRACTION VS TANDEM POL EXTRACTION 2006 DATA, r = 0.83

47 FIRST MILL EXTRACTION VS TANDEM (5 MILLS) EXTRACTION 2005 DATA, r = 0.92

48 FIRST MILL EXTRACTION VS TANDEM (5 MILLS) EXTRACTION 2006 DATA, r = 0.98

49 FIRST MILL EXTRACTION VS TANDEM (6 MILLS) EXTRACTION 2005 DATA, r = 0.53

50 FIRST MILL EXTRACTION VS TANDEM (6 MILLS) EXTRACTION 2006 DATA, r = 0.89

51 PREPARATION INDEX VS INDIVIDUAL FACTORY TANDEM EXTRACTION

52

53

54

55

56

57

58

59

60

61

62

63 ACKNOWLEDGMENTS AMERICAN SUGAR CANE LEAGUE ALL LOUISIANA SUGAR MILLS

64

65 TRUE FIBER % BAGASSE AVG = 37.04


Download ppt "ENERGY SELF-SUFFICIENCY AND COGENERATION IN LOUISIANA CANE SUGAR FACTORIES Harold Birkett and Jeanie Stein Audubon Sugar Institute."

Similar presentations


Ads by Google