Toasting and Drying Oilseed Meals. Which is the Best Approach?

Transcription

1 Toasting and Drying Oilseed Meals. Which is the Best Approach? Anibal Demarco Crushing, Solvent Extraction Rosario, Argentina 31st October 2015

2 What we ll see?: Minimum OPEX 1) Desolventization Basic Technology 2) Different types of Meal Dryer and main design parameters 3) Psicometric Chart : bases / application to the process 2) Different types of Meal Dryer and main design parameters 4) Different types of Meal Dryer : Features 5) Different types of Meal Dryer : Steam and Electrical Consumptions 6) Different types of Meal Dryer : Conclusion

3 Meal Dryers : Moisture Levels vs Process Steps Material Moisture 18% 16% Trading rule : 12,5% 14% 12% 10% 8% 6% 4% 2% 0%

4 Meal Desolventizing

5 DT Unit Processes Predesolventizing Desolventizing Toasting & Stripping Steam Drying

6 DT Unit Processes Predesolventizing Purpose is to remove a minority of the solvent using indirect steam heat to reduce live steam condensed into the meal and thereby save DC steam 10-20% of solvent removed C meal temperature 12% typical meal moisture

7 DT Unit Processes Predesolventizing Need to maximize meal/tray contact for heat transfer Residence time not important (150 mm meal levels) 5-10 minutes total time Simplistic level control

8 DT Unit Processes Desolventizing Purpose is to remove the majority of the solvent using live steam 80-90% of solvent removed Mostly direct steam latent heat Some added indirect steam heat C meal temperature 12 20% meal moisture

9 DT Unit Processes Desolventizing Need minimum 1000 mm deep level and consistent level control Approx. 5 minutes time Uniform condensation plane is critical Rotary valve level control

10 DT Unit Processes Desolventizing Uneven steam distribution in the top countercurrent tray causes condensation of the steam in a wide band. Water mixes with 66 C meal, water balls form and encapsulate solvent.

11 DT Unit Processes Desolventizing Hollow Staybolt tray Poor Steam Distribution (2% open area)

12 DT Unit Processes Desolventizing Even steam distribution in the top countercurrent tray results in condensation of the steam in a narrow band. Fewer water balls form. Even steam distribution is critical for good performance.

13 DT Unit Processes Desolventizing Aerodynamic Sweeps Good Steam Distribution

14 DT Unit Processes Desolventizing 10% open area trays Good Steam Distribution

15 DT Unit Processes Toasting & Stripping Remove final traces of hexane Deactivate anti-nutritional factors Direct Steam Specific Heat Indirect Steam Heat C Meal Temperature 20 19% Meal Moisture minutes

16 DT Unit Processes Toasting & Stripping Optimizing Meal Quality for Poultry & Swine ph rise in urease activity PDI protein solubility minutes

17 DT Unit Processes Toasting & Stripping Optimizing Meal Quality for Dairy & Beef Cattle ph rise in urease activity PDI protein solubility minutes

18 Meal PDI of U.S. Soybean Processing Plants (2004) Standard Deviation =

19 DT Unit Processes Toasting & Stripping Optimizing solvent loss Increasing residence time allows more time for solvent to be stripped out. Increasing live steam flow increases the steam density, and therefore the intimate contact between the steam and the meal.

20 DT Unit Processes Toasting & Stripping Optimizing both solvent loss & meal quality So how do we keep toasting time down to minutes and also reduce solvent loss in the meal? The answer is to increase steam density passing through the meal.

21 Residual free Hexane in Meal 8 samples tested per Stack at each capacity residence time improves initial desolventization higher steam density improves stripping on sparge Stack DESIGN 3000 tpd soybeans 26 minutes under sparge 579 kg/hr/m2 steam density TRIAL tpd soybeans 32 minutes under sparge 450 kg/hr/m2 steam density TRIAL tpd soybeans 36 minutes under sparge 394 kg/hr/m2 steam density

22 DT Unit Processes Toasting & Stripping Optimizing both solvent loss & meal quality Existing DTs with higher steam density have experienced practical operational problems resulting from the pressure drop across each counter-current tray and meal increasing to 37 mbar.

23 DT Unit Processes Toasting & Stripping Optimizing both solvent loss & meal quality Level control problems arise. Steam short circuits behind the sweeps, the path of lowest resistance. Existing hollow stay-bolt trays with 2% open area will not allow higher steam density.

24 DT Unit Processes Toasting & Stripping Optimizing both solvent loss & meal quality So how do we reduce pressure drop across the DT counter-current trays to allow higher steam densities? The answer is increased open area for vapors in the counter-current trays design.

25 DT Unit Processes Toasting & Stripping Optimizing both solvent loss & meal quality 10% open area trays

26 DT Unit Processes Toasting & Stripping Optimizing both solvent loss & meal quality - CONCLUSIONS Taller, smaller diameter DT s with higher steam density 10% open area Stack s Aerodynamic sweep arms Rotary valves on every Stack

27 DT Unit Processes Steam Drying Purpose is to both dry the meal to save DC steam, and to enable low pressure water vapor heat to be recovered in extraction Half of drying heat is from meal Half of drying heat is from trays Water vapor captured via steam ejector for heat recovery

28 DT Unit Processes Steam Drying Shallow 300 mm meal level C meal temperature % meal moisture Rotary valve level control

29 Meal Drying and Cooling

30 Meal Dryers and Coolers Type Adiabatics Vertical or Stack Conveyor type fixed floor moving floor Counterflow Non Adiabatics Rotative Plates

31 Meal Dryer Type: Vertical or Stack

32 Meal Dryer Type: Vertical or Stack

33 Meal Dryer Type: Vertical or Stack CYCLONS AIR CHAMBER FAN AIR HEATER

34 Meal Dryer Type: Vertical or Stack Inlet and Outlet ducts with circular section Air Chamber Rotary Valve

35 Meal Dryer Type: Vertical or Stack Double Bottom

36 Meal Dryer Type: Vertical or Stack (DT+DC) To Solvent Recovery Item 20B/C AT M TV 5 TT 70 Steam From Steam And Condensate Steam From Steam And Condensate Steam From Waste Water Steam Generation XV 70 PT 70 PI 70 XV 70 TT 5 IE 5 52/70 DES OLV ENTI SE R ZS SLIDE GATE 52/70 PI 70 PT 70 TI 70 SN 29 SN 29 To Distillation It em 60A To Solvent Recovery Item 20B/C Steam From Steam And Condensate Steam From Steam And Condensate FT 70 TCV 70 AT M PS V 70 (OPTIONAL) PI 49/70 49/70 SPARGE ST EAM SUPERHEATER ZS 52/70 1 ST TRA Y 2 ND TRA Y 70 DES OLV ENTI SE R -TOA S TER LS 70 LT 29 SN 29 SN 29 PI 29 HYDRAULIC FI SEAL 29 FG 29 XV 29 Condensate F rom Steam And Condensate Item P46ATM Condensate F rom Steam And Condensate Item P46ATM/94 Steam From Steam And Condensate To Steam And Condensate It em 46/70 3 RD TRA Y 29 VAPOUR SCRUBBER FT 94 PRV 94 AT M AT M Purge From Waste Water Steam Generation Extracted Meal From Extraction It em 4 Gums From Water Degummi ng (OPTIONAL) 52/5 E XTRA CTED MEAL CONVEYOR SLIDE GATE LS 5 SS 5 ZS 52/5 ZS 52/5 5 E XTRA CTED MEAL CONVEYOR AT M PS V 70 PI 70 PT 70 TI TT 4 TH TRA Y LS 70 TI TT TH TRA Y TI TT TH TRA Y TI TT PT TH 70 TRA Y PT TI TT 8 TH TRA Y SS 70 SS 9 IE FS LT 70 LT 70 LT 70 LT 70 LT 70 SC 70 SC 70 SC 70 SC 70 SC 70 PCV 70 41/70 FLASH TRAY STEAM EJECTOR PI 41/70 9 DESOLVENTISED M EAL CONVEYOR A TM AT (OPTIONAL) 29 LV TI 29 P29 Caustic Additon S ys tem PI P29 P29 TI 94 From Sol vent Recovery Item 23A (OPTIONAL) 78/94 HEAT RECOVERY A CC U M ULA TOR TI 94 To Solvent Recovery Item 23A P78/94 XCV (OPTIONAL) 36A IE 36A 16 PI DRYING AIR 36A 36A INLET FILTER DRYING AIR F AN TI 94 A TM PI 36A XV 94 XV DRYING AIR HEAT ER XCV 36B PI 94 TI 94 XV 94 TT 94 PI 36B 36B COOLING AIR F AN PI 13 PI 13 PI 13 IE 36B IE SS 8/13 8/13 TI 13 PT 13 TI 13 PT 13 TI PT IE 9 LS 13 LS 13 LS 13 8/13 DRYER-COOLER FEEDING DEVICE SS 13 IE 13 FS 13 1 ST TRA Y 2 ND TRA Y 3 RD TRA Y SS 10A TT 13 B ATT ERY LIM IT SS 10C 13 DRYER-COOLER LT 13 SC 13 14A DRYING A IR CYCLONE 10A DC DISCHARGE MEAL CONVEYOR IE 10A 10C CROSS YARD MEAL CONVEYOR AT 14A B ATT ERY LIM IT 14B COOLING A IR CYCLONE 10B DC CYCLO NE DISCHARGE MEAL CONVEYOR IE 10C To Meal Sizing B ATT ERY LIM IT To Steam And Condensate It em 46/70 To Steam And Condensate Item 46ATM To Steam And Condensate It em 46/70

37 Meal Dryer Type: Vertical or Stack (DTDC) AT M TV To Solvent Recovery Item 20B/C TT XV PT XV PI Steam From Steam And Condensate Steam From Waste Water Steam Generation Steam From Steam And Condensate AT M (OPTIONAL) PI TT ZS ZS IE 52/70 DES OLV ENTI SE R SLIDE GATE PT TI 70/13 DIM AX TM DESOLVENTISER TOASTER DRYER COOLER Steam From Steam And Condensate PS V PI Steam From Steam And Condensate To Steam And Condensate It em 46/70 FT TCV 49/70 SPARGE ST EAM SUPERHEATER PRV 5 E XTRA CTED MEAL CONVEYOR 1 ST TRA Y 2 ND TRA Y LS AT A TM 14A DRYING AIR CYCLONE A TM 14B COOLING AIR CYCLONE SN SN SN SN PI To Distillation It em 60A To Solvent Recovery Item 20B/C Condensate F rom Steam And Condensate Item P46ATM Steam From Steam And Condensate FT 3 RD TRA Y XV PI Condensate F rom Steam And Condensate Item P46ATM/94 LS FI Gums From Water Degummi ng Purge From Waste Water Steam Generation From Sol vent Recovery It em 23A To Solvent Recovery It em 23A Extracted Meal From Extraction It em 4 (OPTIONAL) AT M PS V XV XV XV PI PT TI TI TI TI TT TT TT TT 4 TH TRA Y 5 TH TRA Y 6 TH TRA Y PT 7 TH TRA Y LT LT LT LT SC SC SC SC PCV 41/70 FLASH TRAY STEAM EJECTOR PI B ATT ERY LIM IT B ATT ERY LIM IT LT 29 VAPOUR SCRUBBER FG HYDRAULIC SEAL (OPTIONAL) E XTRA CTED MEAL CONVEYOR SLIDE GATE LS SS ZS ZS PS PI P78/94 78/94 HEAT RECOVERY A CC U M ULA TOR TI PI 94 DRYING AIR HEAT ER TI TT PI PI PT PT TI TI TI TT LS LS PT 8 TH TRA Y 9 TH TRA Y 10 TH TRA Y LT SC 10B DC CYCLO NE DISCHARGE MEAL CONVEYOR LV TI PI AT (OPTIONAL) Caustic Additi on S ys tem (OPTIONAL) XCV PI PI PT TI LS TT 11 TH TRA Y LT SC P29 A TM To Steam And Condensate Item 46ATM 16 DRYING AIR INLET FILTER PI 36A DRYING AIR F AN IE TI A TM XCV PI IE (OPTIONAL) BARRING MOTOR SS SS B ATT ERY LIM IT 10A DC DISCHARGE MEAL CONVEYOR IE 10C CROSS YARD MEAL CONVEYOR IE To Steam And Condensate It em 46/70 To Steam And Condensate It em 46/70 36B COOLING AIR F AN IE FS SS To Meal Sizing

38 Meal Dryer Type: Tunnel (Chain or Belt) Courtesy : Alloco

39 Meal Dryer Type: Tunnel (Chain or Belt) Air Outlet Meal Transport Chain Air Inlet Courtesy : Alloco

40 Meal Dryer Type: Counterflow Courtesy : Geelen

41 Meal Dryer Type: Counterflow Courtesy : Stolz

42 Meal Dryer Type: Rotative Bundle

43 Meal Dryer Type: Rotative Bundle

44 Meal Dryer Type: Rotative Bundle

45 Meal Dryer Type: Rotative Bundle Concentric Feed Excentric Feed

46 Meal Dryer Type: Plate (Solex)

47 Meal Dryer : Psichometric Chart Air Moisture (kg/kg) vs Temp AIR WATER CONTENT 1,400 1,200 1,000 0,800 0,600 0,400 0, % 90% 40% 10% TEMPERATURE - 50,0 60,0 70,0 80,0 90,0 100,0 110,0

48 Meal Dryer : Psichometric Chart (Adibatic Dryers) A: Amb Condition B: Dryer Outlet Humedad Absoluta Moisture increase in the DC B A Air Temp increase in air heater

49 Meal Dryer : Psichometric Chart (Adibatic & Non Ad. Dryers) A: Amb Condition B: Dryer Outlet (Adibatic) C:Dryer Outlet (Non Adibatic) C Humedad Absoluta Moisture increase in the DC B A Air Temp increase in air heater

50 Meal Dryer : Psichometric Chart (Delta Adiabatic/Non Adibatic) Courtesy : Solex

51 Meal Dryer (Adibatic): Operational Parameters AT M Material Inlet : Temp :100*C Moisture : 18% 54*C HR : 90% 140*C HR : <1% 1 ST TRA Y 2 ND TRA Y 3 RD TRA Y Material Outlet : Temp :60*C Moisture : 13% 31*C Temp Amb.25*C HR: 60%

52 Meal Cooler : Operational Parameter 46*C 1 ST TRA Y 2 ND TRA Y 60*C 3 RD TRA Y 31*C Temp Amb. 25*C 42*C

53 Meal Dryer (Non Adibatic): Operational Parameters Temp :90*C HR : 90% Material Inlet : Temp :100*C Moisture : 18% AIR Temp Amb. 25*C SOYA MEAL Material Outlet : Temp :60*C Moisture : 13%

54 Meal Dryer : Features

55 Meal Dryer Features Vertical or Stack Type High Material Layer : 900mm High Air Delta P : mmH2O Air Flowrate density : 1200 m3/h /m2» Or air spead of 21m/h High Delta Material Moisture Material quite isolate from ambiente (animal or other contaminations) Low potential to have wet spots (Salmonella formation) For small / medium capacities can be integrated with the DT Can be done Cooler in one single vessel Relative low air outlet temperature (low chances of heat recovery) Good air separation in between stages Plant Capacity : all (so far up to MTPD in a single vessel)

56 Meal Dryer Features Chain Type Low Material Layer : 300mm High Air Delta P : mmH2O Air Flowrate density : 1200 m3/h /m2 (about) High Delta Material Moisture High contamination potential (animal or other ) High potential to have wet spots (Salmonella formation) Can not be integrated with the DT Can be done Cooler in one single vessel Relative low air outlet temperature (low chances of heat recovery) Not as good air separation in between stages Plant Capacity : all (but normally medium)

57 Meal Dryer Features Counterflow High Material Layer : mm Medium Air Delta P : mmH2O Air Flowrate density : 1200 m3/h /m2 (about) High Delta Material Moisture High contamination potential (animal or other ) High potential to have wet spots (Salmonella formation) Can not be integrated with the DT Can t be done Cooler in one single vessel Relative low air outlet temperature (low chances of heat recovery) Air separation in between stages : full countercurrent Plant Capacity : low /medium

58 Meal Dryer Features Rotative «Very Low» Material Layer Minimun Air Delta P (not fan required) Air Flowrate density : Low Medium Delta Material Moisture (maximum 5%) Medium contamination potential (animal or other ) Low potential to have wet spots (Salmonella formation) Can not be integrated with the DT Can t be done Cooler in one single vessel High low air outlet temperature (High chances of heat recovery) Air separation in between stages : full countercurrent Plant Capacity : low / medium

59 Meal Dryers : «Clouds»

60 Meal Dryer «Clouds» : Vertical Equivalent to : 64kg Steam/ton Outcoming Air: 53 C kg water / kg dry air AT M 28kg/ton 1 ST TRA Y 2 ND TRA Y 3 RD TRA Y Fans : 1,12kwh/ton Drive : 0,9kwh/ton

61 Meal Dryer «Clouds» : Rotative Equivalent to : 48kg Steam/ton Outcoming Air: C 1.02 kg water / kg dry air Steam 23kg/ton Drive : 0,9kwh/ton

62 Meal Dryer «Clouds» : Vertical Air Flow : 533kg/ton Pollution : 47 g/ton AT M 1 ST TRA Y 2 ND TRA Y 3 RD TRA Y

63 Meal Dryer «Clouds» : Rotative Air Flow : 37kg/ton Pollution : 3 g/ton

64 Design values : Comparative Chart Vertical Rotative Units Steam Consumption : kg/ton Total Drying Air kg/ton FAN kw abosrbed. 1,1 0 kwh/ton Pollution : 47 3 g/ton Drive kw absorbed 0,9 0,9 kwh/ton Vents Temperature : *C

65 Meal Dryers : Savings

66 Steam Savings : With Vertical DCs Preheating air with stripper gases Benefits : Steam Saving : 7,0 kg/ton Parameters : -Air to meal dryer : kg/ h m2 -it94s : Air inlet/outlet : 36/55*C -it23a : Gas inlet/outlet : 95/68*C -it23a : Water inlet/outlet : 65/68*C

67 Steam Savings : With Vertical DCs Preheating air with condensate Benefits : Steam Saving : 4,0 kg/ton Parameters : -Air to meal dryer : kg/ h m2 -it94/b : Air inlet/outlet : 55/62*C -it46atm : Water inlet/outlet : 100/90*C

68 Steam Savings : With Vertical DCs Preheating air Benefits : Steam Saving : 7,0 kg/ton Steam Saving : 4,0 kg/ton Total steam Saving : 11,0 kg/ton

69 Steam Savings : With Rotative Dryer Incoming meal :100 C Moisture flakes : 18% SOYA MEAL Outcoming meal :65 C Moisture meal : 13% Outcoming Air: C 0.89 kg water / kg dry air AIR Incoming Air: 20 C (Ambient)

70 Steam Savings : With Rotative Dryer Equivalent to : 48kg Steam/ton Incoming meal :100 C Moisture meal : 18% Outcoming Air: C 1.02 kg water / kg dry air Steam:23kg/ton Outcoming mel :60 C Moisture meal : 13%

71 How to recover that energy? Temp : 20*C Moisture : 12-13% STEAM SEED STORAGE CLEANING & WEIGHING PRE-CONDITIONER CONDITIONING AIR+WATER Temp. Aprox : 60*C Temp : 75*C Moisture : 10,0% DEHULLING (WARM) ATMOSPHERE Concept FLAKING STEAM SOLVENT EXTRACTION PLANT Temp : 105*C Moisture : 18% MEAL DESOLVENTIZING OIL DISTILLATION OIL STORAGE STEAM MEAL DRYING AIR+WATER Temp. Aprox : 85*C Temp : 65*C Moisture : 13% MEAL COOLING MEAL PELLET STORAGE MEAL TREATMENT

72 How to recover that energy? Cold / Wet Seed Heat Hot / Wet Gases Seed Conditiner Water Loop E-Comyzer

73 How to recover that energy? Absolute Moist kg/kg Rotary Dryer Exhaust 1,02 0, Temp *C Stack DC 65 C 83 C 90 C

74 A TM How to recover that energy? Seed Conditioner Steam Cond SB Meal Rotary Dryer E-Comyzer P2720

75 A TM How much energy do we recover? Cold/Wet Seed T : 20*C T : 90*C RM: 90% T : 80*C T : 50*C T : 82*C Steam Cond Hot SB Meal T : 62*C T : 83*C RM: 100% T : 75*C Hot/Dry Seed P2720 Recirc. Flowrate : 80m3/h

76 How E-Comyzer looks like?!

77 How E-Comyzer looks?! Exhaust Fan E-comyzer

78 How E-Comyzer looks like?! E-comyzer Exhaust Fan

79 How E-Comyzer looks like?! Gases Inlet E-comyzer

80 How Seed Conditioner Solex looks like?! Solex : PHE for solids WATER PLATES SEED

81 How much energy do we recover? SUMMER TIME

82 How much energy do we recover? SUMMER Seed :20*C WINTER Seed :10*C Saving average: 25,6kg/ton Saving : 9,5 %

83 Conclusion For Minimum Opex the more convenient is a combination: *Meal Dryer : Rotary *Meal cooler : Vertical (or eventually a Rotary paddles ) For More compact & Simple installation : *DT & Meal Dryer & Meal Cooler in one piece : Vertical

84 Thank you! Anibal Demarco