Professor in Operations Management and …online.sfsu.edu/cholette/WFSC-2014/slides/Akkerman-slides.pdfTUM School of Management Technische Universität München ... Professor in Operations

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TUM School of Management Technische Universität München

Dept. of Chemical and Biochemical Engineering

Modelling water reuse in the food industry Opportunities and challenges

Renzo Akkerman

Professor in Operations Management and Technology, TUM School of Management,

Technische Universität München

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REWARD This presentation is

part of the 2014 SFSU Business Ethics Week



Outline

•  Background: •  Water as a resource •  Context: REWARD project à Interdisciplinary research

•  State of the art

•  Current research challenges

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Water as a resource

•  Lots of water wasted in food and bioprocessing industries •  Cleaning, cooling, heating, transportation, … •  Increasingly scarce resource à costs •  Also: environmental impact à Legislation

•  Significant reuse opportunities, but lacking technical and management methods to assure high-quality and safe reuse

•  “Companies that fail to take action face the threat of business interruption, reputational and regulatory risks” (PriceWaterhouseCoopers, 2011)

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Water as a resource

•  …

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What are we using water for?

Freshwater availability…

Sources: http://www.unep.org/dewa/vitalwater/article77.html; http://www.fao.org/nr/water/aquastat/water_use/index.stm

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Water as a resource

•  …

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and water scarcity (also in developed countries)

What are we using water for?

Freshwater availability…

Sources: http://www.unep.org/dewa/vitalwater/article77.html; http://www.fao.org/nr/water/aquastat/water_use/index.stm



REWARD – Interdisciplinary research

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Appendix B – Project description - REWARD

REWARD: REuse of WAteR in the food and bioprocessing inDustry

1. Summary

Water is not only a resource, it is a life source. We all share the responsibility to ensure a healthy, secure and sustainable way of applying water now and in the future for our communities, environment and economy – our lives depend on it. Unless sustainable water practices are implemented, half of the world’s population will be exposed to water scarcity by 20501. The massive volumes of process water wasted in the food and bioprocessing industries represent an environmental burden that can be turned into a resource. The hypothesis behind our proposal is that, using sensor-based “fingerprinting”2, process water can be utilized in a far more intelligent manner than present practice. Our project - titled “REuse of WAteR in the food and bioprocessing inDustry” (REWARD) - proposes the novel idea of applying the successful principles of HACCP, Process Analytical Technology and Quality by Design to production and cleaning water management in the food and bioprocessing industry3.

REWARD will establish a research community that provides the knowledge to bring Danish industry closer to self-sustainability - the closed factory principle - where water intake is diminished by re-using production streams. This will provide the Danish food and bioprocessing industry, challenged by productivity and outsourcing problems, with a leading edge and will put Danish processing and measurement equipment businesses at the forefront of modern process water management practice. REWARD focuses on process water cases from the food and bioprocessing industries with multi-product lines and includes technology providers working with generic principles adaptable to other industries with related challenges such as the brewing industry, vegetable/fruit processing, bio-refineries and the fermentation industries.

Side/Page 13 af/of 61

“Combining real-time monitoring and sensor development with clear quality and safety guidelines in pro-active management support”

See also: http://models.life.ku.dk/reward

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REWARD – Role of TUM

Water Supply Chain Management in food and bioprocessing

•  Develop decision support tools for water reduction and reuse •  Strong link to water quality parameters and measuring

technologies from the project partners •  Application/development of tools for cases •  Reduction and reuse of water resources

•  Within the process •  Within the factory •  Within the supply chain

•  Relate to production planning and control / supply chain integration

•  Contribute to environmentally friendly and competitive industry

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Work package leader: Other participants:

School of Management



State of the art

Extensive literature review: •  Keyword search in

•  Web of Science •  ScienceDirect

•  Title and abstract review •  Identification of related papers •  Full-text review + citation analysis

à Final sample: 46 relevant papers

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State of the art

Extensive literature review:

Results / categorization •  Mostly chemical engineering journals •  Both batch and continuous processes

(food industry à Mainly batch) •  Variety of industries covered •  Single contaminant vs. multiple •  Mostly modelling approach + case example

•  Graphical methods •  Optimization methods

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State of the art





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State of the art – Example paper

•  Oliver et al. (2008), Journal of Cleaner Production •  More infrastructure design than management (use of averages) •  Basis: Winery in San Juan, Argentina •  Focus on water use in cleaning operations •  Contaminants:

•  Chemical oxygen demand (COD) •  Total suspended solids (TSS)

•  Optimization model focuses on: •  Number of necessary tanks •  Destination tanks and feedings tank of every water stream •  Additional freshwater flowrate above the minimum

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6. Rules to minimize the water consumption

The alternative presented in this paper is more related to in-frastructure than to management, but in spite of that, major en-gineering changes are not required as it is a different designusing the same kind of pipes, pumps and accessories but dif-ferently interconnected to reduce the water consumption.

The water saving is achieved by synthesizing the new waternetwork. If the network is designed, once a water managementplan is implemented, then the water consumption reductionwill be the one achieved with the management plus the oneachieved with the optimized water network.

Some of the main practices to reduce the water consump-tion in the wine industry are listed below.

Segregate rain water from wastewater and use it for clean-ing floors.Install water meters to control leaks and measure the waterconsumption.Use high pressurized equipment for cleaning.Use hoses provided with automatic shut down nozzles.Use centrifuges to eliminate tartrate from wine, which min-imizes cleaning water consumption and avoid waste gener-ation since no earth filters are utilized.Use ecologic earth filter, which permit to obtain a dry cake,avoiding high contaminants mass load in the wastewaters.Once used, accumulate the filter earths in a vessel for laterfiltering in a press filter, in order to manage them as a solidwaste.Prefer dry cleaning as opposed to wet cleaning, wheneverpossible.Implement training to carry out the cleaning tasks.In washing tasks, recover waters from the final rinsing.Recover detergent solutions for further use.Include production indexes for the different sectors of thewinery, fixing achievable environmental targets and posi-tive incentives for the employees.Implement plans, for employees, oriented to water savingby installing instructive posters, training courses to improvecleaning tasks.Install screens to retain solid matters coming from grapeprocessing sector and bins washing.pH meters.Implement continuous neutralization systems.

Make improvements in the production efficiency, especiallyin the bottling lines.Replace old equipment.

7. Conclusions

An approach to synthesize the optimal water network forbatch processes has been developed. The new formulationcombines the water pinch technology, to determine theMWR, with the mathematical modelling, to design the waternetwork for batch processes that satisfies the MWR and re-quires the minimum amount of tanks.

The data used for the analysis are mainly the average valuesthat are measured, thus some discrepancies are bound to occur.The water consumption in most of the cleaning activities

Et’

i

Ft

fj,tt ft’,j’

ft,i fi,t’t’

Fig. 15. Simplified water using operation.

Contaminant concentration

t’ i t i’

k j k’ j’

Ft’Et’ Ft Et

EkFk Ek’Fk’

Fig. 16. Simplified superstructure.

t

Ft

fi,tfts,i’

Ets

Fig. 14. Water using operation i after considering constraints 10e12.

Table 3Tanks, flowrates and reuse streams for the batch system analyzed

Tank Inputstream

Flowrate(m3/d)

Outputstream

Flowrate(m3/d)

Freshwaterdemand(m3/d)

Watersurplus(m3/d)

1 22 1 4 10 10.0021 1

2 8 0.3 1 1 0.810 0.5 3 124 2 6 0.526 1 7 0.329 12.8 9 0.5

11 3.512 0.520 123 225 127 130 3.528 113 22 15 10

14 0.5

1284 P. Oliver et al. / Journal of Cleaner Production 16 (2008) 1275e1286

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State of the art – Example paper

•  Oliver et al. (2008), Journal of Cleaner Production •  More infrastructure design than management (use of averages) •  Basis: Winery in San Juan, Argentina •  Focus on water use in cleaning operations •  Contaminants:

•  Chemical oxygen demand (COD) •  Total suspended solids (TSS)

•  Optimization model focuses on: •  Number of necessary tanks, •  Destination tank and feeding tank of every water stream •  Additional freshwater flowrate above the minimum

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6. Rules to minimize the water consumption

The alternative presented in this paper is more related to in-frastructure than to management, but in spite of that, major en-gineering changes are not required as it is a different designusing the same kind of pipes, pumps and accessories but dif-ferently interconnected to reduce the water consumption.

The water saving is achieved by synthesizing the new waternetwork. If the network is designed, once a water managementplan is implemented, then the water consumption reductionwill be the one achieved with the management plus the oneachieved with the optimized water network.

Some of the main practices to reduce the water consump-tion in the wine industry are listed below.

Segregate rain water from wastewater and use it for clean-ing floors.Install water meters to control leaks and measure the waterconsumption.Use high pressurized equipment for cleaning.Use hoses provided with automatic shut down nozzles.Use centrifuges to eliminate tartrate from wine, which min-imizes cleaning water consumption and avoid waste gener-ation since no earth filters are utilized.Use ecologic earth filter, which permit to obtain a dry cake,avoiding high contaminants mass load in the wastewaters.Once used, accumulate the filter earths in a vessel for laterfiltering in a press filter, in order to manage them as a solidwaste.Prefer dry cleaning as opposed to wet cleaning, wheneverpossible.Implement training to carry out the cleaning tasks.In washing tasks, recover waters from the final rinsing.Recover detergent solutions for further use.Include production indexes for the different sectors of thewinery, fixing achievable environmental targets and posi-tive incentives for the employees.Implement plans, for employees, oriented to water savingby installing instructive posters, training courses to improvecleaning tasks.Install screens to retain solid matters coming from grapeprocessing sector and bins washing.pH meters.Implement continuous neutralization systems.

Make improvements in the production efficiency, especiallyin the bottling lines.Replace old equipment.

7. Conclusions

An approach to synthesize the optimal water network forbatch processes has been developed. The new formulationcombines the water pinch technology, to determine theMWR, with the mathematical modelling, to design the waternetwork for batch processes that satisfies the MWR and re-quires the minimum amount of tanks.

The data used for the analysis are mainly the average valuesthat are measured, thus some discrepancies are bound to occur.The water consumption in most of the cleaning activities

Et’

i

Ft

fj,tt ft’,j’

ft,i fi,t’t’

Fig. 15. Simplified water using operation.

Contaminant concentration

t’ i t i’

k j k’ j’

Ft’Et’ Ft Et

EkFk Ek’Fk’

Fig. 16. Simplified superstructure.

t

Ft

fi,tfts,i’

Ets

Fig. 14. Water using operation i after considering constraints 10e12.

Table 3Tanks, flowrates and reuse streams for the batch system analyzed

Tank Inputstream

Flowrate(m3/d)

Outputstream

Flowrate(m3/d)

Freshwaterdemand(m3/d)

Watersurplus(m3/d)

1 22 1 4 10 10.0021 1

2 8 0.3 1 1 0.810 0.5 3 124 2 6 0.526 1 7 0.329 12.8 9 0.5

11 3.512 0.520 123 225 127 130 3.528 113 22 15 10

14 0.5

1284 P. Oliver et al. / Journal of Cleaner Production 16 (2008) 1275e1286

depends on how the personnel carry out the task, the tools andthe equipment employ.

The total minimum freshwater requirement for this plant is41.10 m3/d. The current total freshwater used in the plant forthe water using operation accounted is 58.90 m3/d. Based onthe minimum freshwater requirement for batch processes, ascalculated above, the maximum theoretical freshwater reduc-tion achievable is 30.22%. Table 5 points out the percentagesin which the freshwater flowrates can be reduced comparedwith those of the actual situation of the plant.

Despite the freshwater saving including batch constraints inthe MILP are less than the obtained applying just water pinchtechnology, 30.22% is a substantial reduction in water and

hence, wastewater minimization. Depending on the specificnecessities of the real process plant and/or the region whereit is located, the focus of the study will vary. Reductions ofthe magnitudes achieved, requires structural changes of thewater network, which implies capital investment. In somecases, unless there were strict environmental regulations, littlewater availability, or an effluent treatment plant that becamesub-size because of no planned production increases, the in-vestment may not be justified and, the savings achieved bygood water using practices, are sufficient.

The above arguments demonstrate that to minimize thewater consumption, it is necessary to synthesize the waternetwork when the plant construction is planned. Besides, todetermine the optimal reduction, an economic evaluation hasto be made, because the lower the water flowrate required,the more the storage tanks needed.

With regard to the effluents, it has been proved thatoptimizing the treatment network the treatment flowrates areminimized. These reductions, besides to make smaller the

Tank washing 1º (4)

Tk1

Tank washing 2º (22) Tank washing 1º (21)

Floor cleaning (1)

Floor cleaning (3)

Floor cleaning (6)

Land filter washing 1º (7)

Land filter washing 2º (8) Vacuum filter washing 1º (9)

Vacuum filter washing 2º(10) Vacuum pump seal 1º (11)

Land filter washing 2º (24) Tk2 Floor cleaning (12)

Cartridge filter washing 2º (26) Floor cleaning (20)

Bottles rinsing (29) Plates filter washing 1º (23)

Cartridge filter washing 1º (25)

Floor cleaning (27)

Vacuum pump seal 1º (30)

Equipment washing (28)

Centrifugation (13)


Tank washing 2º (5)


Fig. 17. Winery water network.

Table 4Results comparison

Tanks Freshwaterflowrate(m3/d)

Reuseflowrate(m3/d)

Totalpumpedwater(m3/d)

Effluentflowrate(m3/d)

Minimum withreuse (continuous)

23 31.77 24.53 56.29 31.77

Minimum withreuse (batch)

2 41.10 17.60 58.70 41.10

Without rationalization 0 58.90 0.00 58.90 58.90

Table 5Flowrate reduction

Batch system Pinch technology

Freshwater flowrate 30.22% 46.06%

1285P. Oliver et al. / Journal of Cleaner Production 16 (2008) 1275e1286



State of the art





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Single vs. multiple contaminants

graphical optimization

mul

tiple

si

ngle

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Graphical vs. optimization methods

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State of the art – Conclusions

•  Clear distinction between: •  Graphical methods for a single contaminant in continuous

processes •  Optimization methods for multiple contaminants in batch processes

à relevant for food production settings

•  Mostly focused on design of production systems à Consideration of timing / planning decisions? à Especially for batch production, this would be essential

•  Link to engineering disciplines à Improved measuring à on-line decision making on reuse

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Possibilities - Immediate reuse or recycle (w/o lag)

•  direct reuse •  after treatment (usually continuous)

- Reuse at a later stage (with lag à may need buffer storage)

•  Treatmentà Storageà Reuse •  Treatment(Slower process) à Reuse •  Storage w/o treatment à Reuse à Link to planning (and/or design)?

Current work in REWARD P 1 P 2

waterflow

P 1 treatment P 2

P 1 treatment

P 1 treatment P 2

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Possibilities - Immediate reuse or recycle (w/o lag)

•  direct reuse •  after treatment (usually continuous)

- Reuse at a later stage (with lag à may need buffer storage)

•  Treatmentà Storageà Reuse •  Treatment(Slower process) à Reuse •  Storage w/o treatment à Reuse

Factors to consider: -  Legal Restrictions -  Time lag in treatment -  Storage & treatment expenses -  Piping & network costs -  ….

Optimization

Trade offs

Current work in REWARD

How much is increasing water reuse worth in relation to operational efficiency, customer service, …?



Final remarks

•  Water increasingly in focus

•  Idealist: “Lot of opportunity to improve on our use of limited natural resources”

•  Realist: “Often not enough financial incentive to do so…”

•  However, more and more restrictive legislation sometimes leads to limitations on growth (capacity extensions not possible) à Here, the financial incentive is there!

•  Relation to food waste?

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(UNwater.org)

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Acknowledgements

REWARD project •  Funding: Danish Council for Strategic Research •  Project partners at: Copenhagen University; Technical University of

Denmark; DHI; Arla; Novozymes; Alectia; DSS; LiqTech Technische Universität München •  Pulluru Sai Jishna, PhD student •  Ludwig Graf, BSc student •  Christian Weiner, MSc student

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REWARD



References

•  Oliver, P., Rodríguez, R., Udaquiola, S. (2008), Water use optimization in batch process industries. Part 1: design of the water network. Journal of Cleaner Production 16(12): 1275–86.

•  PriceWaterhouseCoopers (2011). “The true value of water: Best practices for managing water risks and opportunities.” PwC Global Best Practices Focus Paper.

•  Websites: •  http://www.unep.org/dewa/vitalwater/article77.html •  http://www.fao.org/nr/water/aquastat/water_use/index.stm •  http://unwater.org

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Contact

Prof. Dr. Renzo Akkerman E-Mail: [email protected] Webpage: www.oscm.wi.tum.de

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Documents

Professor in Operations Management and …online.sfsu.edu/cholette/WFSC-2014/slides/Akkerman-slides.pdfTUM School of Management Technische Universität München ... Professor in Operations