opex in crushing optimizing heat recovery -...

OPEX in Crushing

Optimizing Heat Recovery

16th Latin American Congress on Fats & Oil ASAGA

Rosario – ARGENTINA / Oct 31 - Nov 4 (2015)

Desmet Ballestra Group, Zaventem, Belgium Represented by David de Schaetzen

Heat recovery in Crushing : in case of Soya

Heatreceovery between Extraction & Preparation …

Heat recovery in Crushing : in case of Soya

Soya Seed

Cleaning & Weighing Bean heater/dryer (Jet Dryer) Primary dehulling Secondary dehulling Flaking

Extraction Desolventiser Dryer / Cooler Distillation

PREPARATION EXTRACTION

Soya Flow sheet / Preparation Scale, cleaner, Destoner

Bean-heater

(Jet dryer)

Primary Dehulling

Secondary Dehulling

Bean-heater-drying

Bean Heater : tube module

Design for heating steam (0,5 barg)

Width: 3300 mm

Length: 3300 mm

Height: 1000 mm

Surface: 200 m2

New: Plate Modules

Width: 3300 mm

Length: 3300 mm

Height: 1000 mm

Surface: 400 - 500 m2

Optimal for lower temperature streams

… Hot water …

Heat Recovery from Dryer in Extraction : with new Rotary Tube Dryer RTD

Heat Recovery from Dryer in Extraction : with RTD

29

P29

10

9

8C

Steam

LIC

make-up water

Hexane vapour to 60A

MEAL FROM EXTRACTOR

FINISHED MEAL

14A

8D/ADryer 13A

Cooler 13B

14B

8D/B

Steam

36A

36B

Ambiant air

DIMAX DT

Rotary tube Dryer (RTD)

Rotary tube Cooler (RTC)

Why does it dry so well, versus Stack Dryer ?

94A

8C

Meal Inlet 105°C

Meal Outlet 65 - 75°C

Air Inlet 140°C

Air Outlet 65°C

Steam

Meal Inlet 105°C

Air Outlet 95°C

Air Inlet 20°C


Steam

Rotary dryer Stack dryer

Counter-Current ! Heated by tubes !

(What reduces air flow requirement)

Psychrometric Chart Psychrometric chart

0

10

20

30

40

50

60

70

80

90

100

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

kg water/ dry air

Tem

pera

ture

°C

100% 80% 60%

Rotary Dryer

1.3

95°C

Vertical Dryer

65°C

0.16 Kg Water / kg Air

Stack Dryer versus Rotary Tube

Rotary dryer Stack dryer

94A

8C

Meal Inlet 105°C


Air Inlet 140°C

Air Outlet 65°C

Steam

Meal Inlet 105°C

Air Outlet 95°C

Air Inlet 20°C


Steam

Rotary dryer :

8” x less air requirement ! less KW ! Higher outlet temperature (65C 95°C) !!! possible heatrecovery !!!

1,3 kg water / kg dry air

0,16 kg water / kg dry air

Heat Recovery via Hot water Loop : Soya

705 S

P13/20

85 °C

75 m3/h

95 °C 80 % HR

Expansion vessel

65 °C 100 % HR

P13/29

5 m3/h Effluent 3 m3/h

13/20

Steam

Condens

Condens

705

705

60 °C Steam

Condensate

E-comyzer

Soya Steam consumption

Where Conditions kg steam /T %

1A) Seed Pre Heating From 20 to 65°C 45 17%

1B) Seed Drying From 13 to 10,5% 35 13%

3) Toasting At 72°C 125 46%

4) Distillation 25% miscella 30 11%

5) Meal Drying with Rotary dryer from 18 to 13% 35 13%

Total 270 100%

6) Ecomiser (*) ..30.. ..11..%

Total net 240-235 89-87%

(*) Exact steam saving depends on Seed Temperature and Moisture

Heat recovery via : E-comizer

E-comyzer Patent pending

Installed

• Exhaust • Ecomyser

• Fan

Heat recovery in Crushing : in case of Rapeseed

Heatreceovery within preparation between Cooker & Pre-conditioner…


Rape Seed

Cleaning & Weighing Pre-Conditioning Flaking Cooking Press Cake crisper

Extraction Desolventiser (No dryer) / Cooler Distillation

PREPARATION EXTRACTION


1

2

From 10°C to 65°C

From 60°C to 105°C and from 8% to 4%

Conditioning

Flaking

Cooking

Pressing

Cake Cooling

Heat Recovery via Hot water Loop : Rapeseed

E-comyzer

705 S

P2720

Steam

Condens

Seeds from

Storage

45 m3/h

95 °C 80 % HR

80 °C

Expansion vessel

60 °C 100 % HR

P2720

5 m3/hEffluent 3 m3/h

Condensate 8 bar from

Cooker 180°C

Condensate 100°C

Hot Oil 23 TPH

95°C

Cold Oil 23 TPH

70°C

SOLEX

40 °C

40 °C

75 °C

1

2

3

Conditioning

Cooking

Heatrecovery in Extraction

Toaster DT

Steam

125 kg/T

Distillation

Steam 30 kg/T

How to optimize Energy ? : Toaster DT

Efficient DT design to optimize DT Vapor

Temperature.

Use of Pre-Desolventizing Tray

Use of FlashTray = heatrecovery

How to optimize Energy ? : Dimax® DT

Predesolventizing - 55..80°C (No direct steam, steam saving in DC)

Desolventizing - 80 ..100°C (Direct steam, 90% solvent evaporated)

Stripping > 100°C (Direct steam)

Flash Tray (Steam Drying) 7TH TRAY

6TH TRAY

5TH TRAY

4TH TRAY

8TH TRAY

1ST TRAY

3R D TRAY

2ND TRAY

Steam

How to optimize Energy ? : Dimax® DT

Desolventizing & Stripping

Accurate level control with rotary valve Stripping vapour through Screen

DT Vapor Temperature : From 80°C to 75°C = 12,5 kg/T steam saving

7TH TRAY

6TH TRAY

5TH TRAY

4TH TRAY

8TH TRAY

1ST TRAY

3R D TRAY

2ND TRAY

Steam

EFFICIENT Design

Heat recovery : Dimax® DT

FlashTray (Steam Drying)

Purpose is to both : • dry the meal to save DC steam • further reduce hexane residual

Water (& Hexane) vapor captured via steam ejector for heat recovery

7TH TRAY

6TH TRAY

5TH TRAY

4TH TRAY

8TH TRAY

1ST TRAY

3R D TRAY

2ND TRAY

Steam

Heat recovery : Dimax® DT

FlashTray (Steam Drying)

7TH TRAY

6TH TRAY

8TH TRAY

Steam

PT

Steam

How to optimize Energy ? : Distillation

Maximize Heat recovery & efficient design ! Big 1st Evaporator (Economiser).

Motive steam of final oil dryer = Oil stripping &

hexane pre-heating

Other steam saving : • Heat recovery Miscella / Hot Oil… • Oil stripper - Sieve tray design • Use of Flash Steam from condensate

Maximize heat recovery : Distillation

1 st Stage evaporator - economiser

DT vapor is used to evaporate hexane in miscella up to outlet concentration :

80-90% Oil / 10-20% Hexane

Important heating surface

DT Vapor

Condensed DT Vapor

Miscella 25% Oil

Miscella >80% Oil

Maximize heat recovery : Distillation

Motive steam of final Oil Dryer

Steam

Oil Stripper

Vacuum Pre-Condenser =

Hexane pre-heater

Hexane (Vapour) Vacuum Condenser

Steam Ejector (Oil Dryer)

Condensate Water

Hexane (Liq)

Hexane Final Heater

Hexane to EXTRACTOR

Steam

Steam + Hexane

Desmet Ballestra …

opex in crushing optimizing heat recovery -...

Documents