Sustainability - Energy and Water conservation in beverage manufacturing

Water and energy conservation in beverage processing

Ashok S. Dhruv, PepsiCo / QTG, ENGLEWOOD, COAmos Wu, PepsiCo / QTG, Barrington, ILMike Mastio, PepsiCo / QTG, Chicago, IL

Submitted for: 2007 Joint ACS – AIChERocky Mountain Regional Meeting

(August 29 – September 1, 2007), Denver, CO,

Session: Green chemistry and engineering

JULY 2007

2Water and energy conservation in food processing

July 2007

ABSTRACT:

Sustainability is a major imperative at PepsiCo, captured in “Performance with a purpose”, a sincere drive and desire to leave to-morrow better than to-day, in every aspect of the business – Economic,

Environmental and Social. Gatorade is a division of Quaker / Tropicana / Gatorade – QTG – a functional business unit of PepsiCo. PepsiCo manufactures and markets a full spectrum of Non-

Alcoholic beverages. Gatorade manufactures beverages, principally Sports drinks, Fitness waters and related performance enhancing beverages. Gatorade beverage is manufactured by a “hot fill” process. The beverage itself is filled hot, sealed and the beverage heat serves to thermally process

“product-container” unit for required shelf life, sensory properties and control of microbial organisms present in any industrial food processing operation. This “hot-fill” process is common in

the industry. The “product – container” unit has to be cooled down from filling temperatures, around 165 °F – 200 °F down to below 70 to 105 °F for downstream operations of labeling, storage and transport. Conventional practice is to cool these containers in a forced convection moving belt

cooler, wherein the containers travel countercurrent under a spray of cooling water. This cooling water picks up the heat from containers and rejects it at a cooling tower, as is common in industrial practice. Massive amounts of Energy and water (of evaporation) are rejected at the cooling tower. By application of basic tenets of Chemical Engineering – principally unsteady-state Heat Transfer thru solid body – beverage in bottle as a cylinder, an opportunity to conserve Energy and Water is created. Mathematical modeling to simulate multi-zone, forced convection, counter current cooler, to conserve Energy and Water is presented here. In a modern high speed line, 40 B BTU of Energy can be conserved per year. Simultaneously, 3.8 M Gallons of water, otherwise lost to atmosphere are also conserved. Extending the concept across installed manufacturing base, just for Gatorade, offers an opportunity to conserve 1.3 T BTU / Year and 120 M Gallons of water per year. Since fossil

fuels are the primary source of this energy and water purification and delivery systems, their burning is eliminated. This results in a corresponding economic benefit of reduced cost of

manufacturing. It environmentally leaves to-morrow better than today, and achieves PepsiCo’s business Performances with a Purpose.


July 2007

Bottle CoolerFOUR ZONES

DOUBLE DECK

Plate and Frame HX

E-3

E-4

P-2

570 gpm570 gpm

570 gpm570 gpm

90.6105

1,200 GPM

P-101HX PUMP

P-191,200 GPM1,200 GPM

1,200GPM

Bottle Flow600 bpm

Bottle Flow600 bpm

97.4104.2117.2140.8185

107.3121.2145 99.4185

91.89498105

94.498.7106.3

119.7

94.496.3102.1112.7

BOTTLE COOLER - CONVENTIONAL - DOUBLE DECKER DESIGN


July 2007

Cooling water spray

Heat transfer rate = q

“q” = U * A * (T - t) =

T

t

A

M G C PGT G

= m W C PW t W

Bottle of Gatorade

HOW A BOTTLE OF GATORADE COOLS


July 2007

Beverage bottle as a finite cylinder

0.1 < Biot Number < 100, Fourier Number < 0.2

Radial and Axial Symmetry

Multiple roots

To find roots of Transcedental equations:

Given

r

NBir

J0 r( )

J1 r( ) 0 Solve r( ) Find r( ) rp

Solve rp

rT 0 1 2 3 4 5 6 7 8 9

0 2.2 5.1 8 11 14 17.1 20.2 23.2 26.3 29.4

Given

cot j( )j

NBij 0 Solve j( ) Find j( ) jq

Solve jq

jT 0 1 2 3 4 5 6 7 8 9

0 1.5 4.6 7.6 10.7 13.7 16.8 19.9 23 26 29.1


July 2007

Solution to Unsteady state heat transfer – Dimensionless form

tc rv jv p q

Ar rv p Ajq Br tc p Bj tc q Cr rv p Cj jv q

0 0 0( ) 0.978

Br tc e r 2 NFor tc

Bj tc e j 2 NFoj tc

r rv rv in

rc j jv jv in

jc

Cr rv J0 r r rv Cj jv cos j j jv


July 2007

Time Vs Temperature variation inside the bottle: As function of location

hncr 40BTU

hr R ft2

Tli 642R p and q w ere 10

0 0.5 1 1.5 2 2.5 3140

145

150

155

160

165

170

175

180

185

Center bottle temperature , FMid point - TemperatureSurface - Top corner

Cooling in a bottle

Time of cooling, minutes

Tem

pera

ture

, de

g F

160

165

Tc tc 0 0 600 R1

Tc tcrc

2in

dc

2in 600

R1

Tc tcrc

1in

dc

1in 600

R1

1 2

tc


July 2007

Time Vs Temperature variation inside the bottle: As function of Spray water temperature

hncr 40BTU

hr R ft2

Tli 642R p and q w ere 10

0 0.5 1 1.5 2 2.5 3140

145

150

155

160

165

170

175

180

185

Spray water @ 120 FSpray water @ 130 FSpray water @ 140 FSpray water @ 150 F

Cooling in a bottle

Time of cooling, minutes

Tem

pera

ture

, de

g F

160

165

Tc tc 0 0 580 R1

Tc tc 0 0 600 R1

Tc tc 0 0 610 R1

Tc tc 0 0 620 R1

1 2

tc


July 2007

Comparison - Before and After Energy and Water Conservation – Conceptual Block Flow Diagram – Showing differences

Heat

INTERMEDIATECOOL

COOLBOTTLE - COOLER

INPUTS80-110 F

195-210 F

170-185 F

Heat

INTERMEDIATECOOL

COOLBOTTLE - COOLER

195 – 210 F

170 – 185 F

HEAT FROMEXTERNAL SOURCE

COOLANTEXTERNAL SOURCE

45 – 90 F

45 – 90 F

OUTPUTFILLED BOTTLES

80 – 110 F

P-13

120 – 160 F

120 – 160 F

Heat

HEAT FROMEXTERNAL SOURCE

INPUTS45 – 90 F

80 – 110 F

INPUTS80-110 F

P-19

HEAT AND WATERREJECTION

COOLING TOWER

80 – 110 F

80 – 110 F

EVAPORATIVE LOSSXXX B BTUYYY M GAL

TOO SMALLDELTA T

FOR RECOVERY

GOOD DELTA T

FOR CONSERVATION


July 2007

Comparison of Proposed Vs CurrentVA – 20 Oz, 9 Zones.

Bottle cooler heat recovery

60.00

80.00

100.00

120.00

140.00

160.00

180.00

200.00

- 3 6 9 12 15 18

Time in cooler - minutes

Tem

per

atu

res,

Sp

ray

and

Gat

ora

de

T of Gatorade - Heat recovery

T of spray water - Heat recovery

T of Gat - SH BR 9 Zones

T Of Spray water, SH BR 9 Zones


July 2007

Comparison of plates in Heat Exchangers

Pre-Heater Heater Trim

Cooler

Divert

Cooler

Original 85

90 -203

13

203 - 183

69

183 - <100

Updated 17

90 – 110

85

110-203

13

203 - 183

69

183 - <100

Proposed 91

90 - 175

31

195 - 203

31175 - 195

203 - 183

61

183 - <100


July 2007

Calculated Heat Transfer Coefficient: Theoretical Potential:

Calculation of heat transfer coefficient in forced convection as a fundtion of water velocity:

Set variable for water velocity. i 0 5

Water velocity setting: v 1ft

sec vi

i

25

ft

sec

Reynold's Number NReilc vi

f

f NRe

T0 1.9 10

3 3.8 103 5.7 10

3 7.5 103 9.4 10

3

Prandtl Number NPrcp f

f NPr 6.3

Heat TransferCoefficient - Calculated

hfci

f

lc0.683( ) NRei 0.466 NPr

1

3 hfcT

0 32.3 44.6 53.9 61.6 68.4( )BTU

hr ft2 R

Actual water velocity: ~ 0.11 ft /sec, ~ i = 3. Therfore theoretical possible somewhere around 44.6 to 61.6.


July 2007

Testing at Sander Hansen - week of 11 the SeptemberBottle size 20 Oz

Final data: Spray density

Spray temperature BR / TL° C ° F m^3/m^2/h m^3/m^2/h m^3/m^2/h

28 36 4520.00 68.00 38.47 35.98 43.4525.00 77.00 38.330.00 86.00 41.09 44.3435.00 95.00 41.240.00 104.00 36.04 44.7 41.4845.00 113.00 36.0550.00 122.00 45.4 46.0555.00 131.00 48.8160.00 140.00 55.19 56.8 56.0965.00 149.00 41.92 59.4370.00 158.00 43.175.00 167.00 40.31

Average, U 41.81 44.51 48.47

% Improvement 6.46% 15.94%

Static testing

Table values are calculated Overall Heat Transfer Coefficient - U- , BTUH/ft^2/F

Calculated Heat Transfer Coefficients

Water Heat

Temp Transfer F Coeff.

9560

10053

10555

11053

11546

120?


July 2007

Original Design

Zone 1 2 3 4 5 6 7 8 From Sub totals

Volume / bottle Oz/bottle 20 20 20 20 20 20 20 20 HXFeed rate of bottles BPM 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 Specific heat of Gatorade, adjusted for capper load BTU/lb/F 1.04 1.04 1.04 1.04 1.04 1.04 1.04 1.04 Temperature of gatorade in . ºF 182.00 157.00 139.00 126.00 116.70 110.00 105.30 101.90 Temp. of Gatorade out - . ºF 157.00 139.00 126.00 116.70 110.00 105.30 101.90 99.50

Vol. flow rate of Gatorade GPM 187.50 187.50 187.50 187.50 187.50 187.50 187.50 187.50 Heat removed per Zone BTUH 2,495,181 1,796,530 1,297,494 928,207 668,709 469,094 339,345 239,537 7,994,561 Water flow rate / tunnel GPM 550 550 550 550 550 550 550 550 550.62Residence time per zone min 2.45 2.45 2.45 2.45 2.45 2.45 2.45 2.45 19.58 Temp of coolant in - . ºF 103.15 100.38 98.38 96.94 95.91 95.16 94.64 94.27 temp of coolant out ºF 112.23 106.91 103.10 100.32 98.34 96.87 95.88 95.14

Overall heat transfer coeff - . BTU/hr/ft^2/F 37.91 38.04 38.37 38.37 38.71 37.87 38.22 37.50 Coolant flow rate lbs/hour 274,890 274,890 274,890 274,890 274,890 274,890 274,890 274,890 Specific heat of coolant BTU/lb/F 1 1 1 1 1 1 1 1 Coolant vol flow rate as sprayed GPM 550 550 550 550 550 550 550 550 4,400 Retainer flow rate 1,800 1,800 1,800 1,800 1,800 1,800 1,800 1,800 1,800 16,200 Heat carried by coolant BTUH 2,495,181 1,796,530 1,297,494 928,207 668,709 469,094 339,345 239,537 7,994,561 Temperature in reservoir ºF 103.15 100.38 98.38 96.94 95.91 95.16 94.64 94.27 94.00 7,994,561

ºC 39.53 37.99 36.88 36.08 35.50 35.09 34.80 34.59 34.44


July 2007

Cooler with 200 GPM and 75 F Water feed

Zone 1 2 3 4 5 6 7 8 FromVolume / bottle v Oz/bottle 20 20 20 20 20 20 20 20 HXFeed rate of bottles x BPM 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 Specific heat of Gatorade, adjusted for capper load Cp BTU/lb/F 1.04 1.04 1.04 1.04 1.04 1.04 1.04 1.04

Temperature of gatorade in . Ti ºF 177.00 168.00 159.00 150.00 140.50 131.20 122.00 113.00

Temp. of Gatorade out - . To ºF 168.00 159.00 150.00 140.50 131.20 122.00 113.00 104.00 Vol. flow rate of Gatorade v. GPM 187.50 187.50 187.50 187.50 187.50 187.50 187.50 187.50 Heat removed per Zone Q BTUH 898,265 898,265 898,265 948,169 928,207 918,227 898,265 898,265 Water flow rate / tunnel GPM 550 550 550 550 550 550 550 550 Residence time per zone Tau min 2.45 2.45 2.45 2.45 2.45 2.45 2.45 2.45 Temp of coolant in - . ti ºF 147.89 138.90 129.92 120.93 111.44 102.16 92.97 83.99 temp of coolant out to ºF 151.16 142.17 133.18 124.38 114.82 105.50 96.24 87.25

Overall heat transfer coeff - . U BTU/hr/ft^2/F 36.70 36.72 36.74 39.42 38.37 37.87 36.83 36.86 Coolant flow rate m.w lbs/hour 274,890 274,890 274,890 274,890 274,890 274,890 274,890 274,890 Specific heat of coolant cp.w BTU/lb/F 1 1 1 1 1 1 1 1 Coolant vol flow rate as sprayed Q.w GPM 550 550 550 550 550 550 550 550 Retainer flow rate 200 200 200 200 200 200 200 200 200 Heat carried by coolant Q BTUH 898,265 898,265 898,265 948,169 928,207 918,227 898,265 898,265 Temperature in reservoir ºF 147.89 138.90 129.92 120.93 111.44 102.16 92.97 83.99 75.00

Counter current bottle cooler


July 2007

Cooler with 240 GPM and 75 F Water feed


July 2007

Cooler with 300 GPM and 82 F Water feed --- U=40


July 2007

Cooler with 250 GPM and 82 F Water feed --- U=50


July 2007


July 2007

SustainabilityHeat and Water Conservation – CHWC – One High speed Line

Base

Case

105 F

Trim Cooler

Saving

Regen I

20 F

TC +

45 F BC

CHWR – TL L5

65 F

CHWC

Bottle cooler only

45 F

Energy

B BTU / YR

65 12 40 28

Water

MM

Gal / YR

6 1.2 3.8 2.6

% 100 18 62 44

M $ / Year 723 132 456 324


July 2007

Sustainability - Advantage:Heat and Water Conservation – Across all volume ~ 30 equivalent Lines

TC +

45 F BC

65 F

Total base

~ 30 X

Energy

B BTU / YR

40 1,200

Water

MM

Gal / YR

3.8 114

Green House Gas

Tons of CO2 / Year

4,200 126,000

K $ / Year 456 13,680


July 2007

E-67

Spray water Cooler

Condenser

E-70

R-008Existing

P-008

P-169

P-170

R-007 P-007

P-172

P-171

R-006 P-006

P-173P-176

R-005 P-005

P-175P-174

R-004 P-004

P-179P-178

R-003 P-003

P-180P-184

R-002 P-002

P-182P-177

R-001 P-001

P-183P-181

Bottles In175 to 182 FBottles out

90 to 105 F

Single deck Hybrid bottle cooler with Evaporative option and Condenser

Recirc Pump

Hot water to HX122 F

Cold recirculationWater86 F

P-189

P-190

Air Blower

P-191

P-192

Hot water toHot water Surge Tank

Cold water from Cold water surge tank

Condensate toHot water Surge Tank


Cold water from Cold water surge tank Hot water to

Hot Water Surge Tank


Hybrid Cooler with Energy and Water Recovery


July 2007

Hybrid cooler -

Zone 1 2 3 4 5 6 7 8 FromVolume / bottle Oz/bottle 20 20 20 20 20 20 20 20 HXFeed rate of bottles BPM 1,200 1,200 1,200 1,200 1,200 1,200 1,200 1,200 Specific heat of Gatorade, adjusted for capper load BTU/lb/F 1.04 1.04 1.04 1.04 1.04 1.04 1.04 1.04

Temperature of gatorade in . ºF 179.00 159.00 143.00 130.00 120.00 112.00 106.00 101.00

Temp. of Gatorade out - . ºF 159.00 143.00 130.00 120.00 112.00 106.00 101.00 97.00 Vol. flow rate of Gatorade GPM 187.50 187.50 187.50 187.50 187.50 187.50 187.50 187.50 Heat removed per Zone BTUH 1,996,145 1,596,916 1,297,494 998,072 798,458 598,843 499,036 399,229 Water flow rate / tunnel GPM 550 550 550 550 550 550 550 550 Residence time per zone min 2.45 2.45 2.45 2.45 2.45 2.45 2.45 2.45 Temp of coolant in - . ºF 118.05 109.98 103.36 99.48 95.35 93.88 90.92 88.90 temp of coolant out ºF 125.27 115.77 108.06 103.10 98.25 96.06 92.73 90.36

Temperature diff at inlet ºF 54 43 35 27 22 16 13 11 Temp difference at outlet - . ºF 41 33 27 21 17 12 10 8 Log mean temp diff - . ºF 47 38 31 24 19 14 12 9 Overall heat transfer coeff - . BTU/hr/ft^2/F 39.62 39.35 39.59 39.55 39.07 40.11 40.17 40.04 Coolant flow rate lbs/hour 276,140 275,890 275,790 275,515 275,490 275,190 275,140 274,965 Specific heat of coolant BTU/lb/F 1 1 1 1 1 1 1 1 Coolant vol flow rate as sprayed GPM 552.5 552.0 551.8 551.3 551.2 550.6 550.5 550.2 Retainer flow rate 200 203 205 206 208 209 209 210 210 Heat carried by coolant BTUH 1,996,145 1,596,916 1,297,494 998,072 798,458 598,843 499,036 399,229 Temperature in reservoir ºF 122.04 113.20 106.28 101.52 97.32 94.87 91.74 89.15 86.00 Coolant evaporated GPM 2.50 2.00 1.80 1.25 1.20 0.60 0.50 0.15 Temperature of spray water F 118.05 109.98 103.36 99.48 95.35 93.88 90.92 88.90

Technology

Sustainability - Energy and Water conservation in beverage manufacturing