A tool-supported approach towards water efficiency in manufacturing

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Selection and peer-review under responsibility of the International Scientific Committee of the “3rd CIRP Global Web Conference” in the person of the Conference Chair Dr. Alessandra Caggiano.

doi: 10.1016/j.procir.2015.04.007

Procedia CIRP 28 ( 2015 ) 34 – 39

ScienceDirect

3rd CIRP Global Web Conference

A tool-supported approach towards water efficiency in manufacturing

D. Kurle

a,

*, S. Thiede

a

, C. Herrmann

a

a_{Sustainable Manufacturing and Life Cycle Engineering Research Group, Institute of Machine Tools and Production Technology (IWF), Technische} Universität Braunschweig,Langer Kamp 19b,Braunschweig 38106,Germany

* Corresponding author. Tel.: +49-531-391-7622 ; fax: +49-531-391-5842 .E-mail address: d.kurle@iwf.tu-bs.de .

Abstract

Many manufacturing companies fail to exploit hidden potentials in optimizing their water operations. This aspect is often shown by unorganized water efficiency effort with sub-optimal results. Against this background, the paper presents a structured approach for systematically improving the water efficiency in manufacturing companies. It comprises the identification and visualization of water related hot-spots subdivided into different respective water flows as well as six different water consuming sectors of a factory. Based on the outcome, the approach further proposes basic principles each represented by promising measures to increase water efficiency which can be assessed individually.

Selection and peer-review under responsibility of the International Scientific Committee of the 3rd CIRP Global Web Conference in the person of the Conference Chair Dr. Alessandra Caggiano

Keywords:Resource efficiency; Water efficiency; Manufacturing; Water system; Work steps

1. Introduction

A growing world population and rising living standards require a higher demand of new products and an increased use of resources. Considering the world’s contemporary situation in regards of resource consumption per capita, today’s population already exceeds the planets natural bio-capacity [1,2]. This trend is expected to continue moving upwards causing an increased demand for energy and water by 40% over the next twenty years, provided that no major policy changes are realized. It is estimated that there will be a 4 to 10 fold increase in resource efficiency necessary by 2050. Taking this prediction into account each product will have to be produced using respectively 25% and 10% of today’s resource inputs [3,4].

Therefore, implementing sustainable concepts focusing on reducing the overall resource consumption seems to be a prerequisite for a sustainable business development. To achieve such a sustainable development, resource intensive enterprises need to tackle and structure their consumption patterns, not only from an environmental but also from an economical

perspective. In that context, enterprises need to understand that resources comprise different mediums such as electricity, gas, oil, raw and auxiliary materials as well as water [5]. Due to rising gas, coal and oil prices entailing strong cost pressure and competitiveness issue, enterprises have lately put a strong emphasis on increasing their energy efficiency.This endeavor favors not only their reputation and image towards the environment but also entails economic potentials for cost reduction [6,7].

Thus, many efforts have focused on reducing energy consumption and greenhouse gas emissions by increasing energy efficiency through different approaches [8-12]. However, resource efficiency comprises more than solely energy. Raw and auxiliary materials and resources are just as important for a production system as energy.

One vital resource that has often been neglected when it comes to considering resource consumption in industry is water. This awareness has recently gained momentum. Although natural water is covering 71% of the Earth’s surface, usable freshwater is limited to only 3% [13,14]. Regarding the rising demand of freshwater and its seasonal variation of availability, a survey © 2014 The Authors. Published by Elsevier B.V This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Selection and peer-review under responsibility of the International Scientifi c Committee of the “3rd CIRP Global Web Conference” in the person of the Conference Chair Dr. Alessandra Caggiano.

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approved by OECD countries has predicted that by 2030 half of the world population will be facing severe water shortage [15].

Global industry uses around 22% of the available freshwater. However, the amount of freshwater used in industry can vary depending on the water quality as well as the local perspective. Generally, industrial countries tend to have a higher water consumption compared to the global average due to more water-intense industrial production processes [16]. Thus, industrial countries, and in particular European Countries, waste 20-40% of its available freshwater by failing to deploy technological improvements which alone can account for up to 40% improvement in water efficiency [17].

This development includes manufacturing enterprises, as being a strong part of the global industry. Above that it has been acknowledged by the United Nations that there exists a gap of knowledge, particularly in manufacturing, concerning the amount of water withdrawal and consumption used for purposed manufacturing transformation and production needs [18]. This issue is of high of relevance for small, medium and large sized manufacturing enterprises alike since this gap of knowledge results in missing starting points for water minimisation efforts [19]. Information regarding water withdrawal and consumption are usually only monitored on a factory level and assigned to the respective process chains via allocation rules.

Against this background of insufficient information about possible starting points for exploiting hidden potentials there is a need for an easy-to-handle and systematic concept allowing a structured identification of water consuming hot spots and related measures for improvement. As known from other disciplines (e.g. lean management), the objective is to establish a structured improvement process for resource efficiency in manufacturing. This objective is also addressed by recent standardisation principles and guidelines like DIN EN ISO 14001 (environmental management system [20]). The proposed concept fosters resource efficiency by following three major steps that are all supported by user-friendly tools:

x Production data acquisition to provide transparency about the current situation

x Analysis of the current situation and derivation of measure for improvement

x Holistic assessment of the derived measures for improvement.

The initial section of this paper emphasizes different use of water in industry and underlines that water can vary in terms of quality. The subsequent section presents the proposed concept including a detailed description of the separate concept steps as well as selected remarks on a few supportive tools.

2. Use of water in industrial processes

Water for industrial purposes is usually withdrawn from aquifers, from surface water or the public drinking water net. Industry often considers water as a utility and uses it for different purposes, as shown in Table 1 [21]

Table 1. Functions of water use in industrial processes [21].

Function of process water Examples

Product, reactant Solvent, absorption Washing, adsorption (Energy) Transport Production of beverages, hydrolysis Gasscrubber, pickling Textile finishing

Cooling, steam circuits, solid wastes, sugar canes

Washing and rinsing Cleaning of equipment,

installation and piping

Table 1 indicates that water can either be used as a raw material or an irreplaceable utility due to its chemical properties. Industry uses an intensive amount of water particularly for cooling cleaning and rinsing purposes respectively. During the transformation process in manufacturing, water becomes polluted by conditioning and cleaning activities as well as through direct contact with water-soluble components. After that the water’s quality is deteriorated in such a way that it requires treatment prior to re-using it in the production or disposing it as wastewater [21]. Typical water treatment comprises water softening (e.g. by removing Ca, Mg), removal of suspended solids, iron (Fe), manganese (Mn) and glycol as well as other constituents which cause negative effects on the product and the production [22]. The amount of contaminants and water used for an industrial process can certainly vary significantly depending on the required product and production specifications.

Despite having suitable technologies for industrial water efficiency improvements available, enterprises often fail to seize opportunities for implementing such improvement technologies. Due to very different use of water within enterprises for various purposes and its demanding treatment processes afterwards, there exist several obstacles which impede the implementation of water efficiency improvements:

x The typical water system within an enterprise is fairly unknown

x Water is, as e.g. electricity or compressed air, an invisible resource in the production

x Water is needed in different qualities and amounts for different purposes

x High water demand for continuous supply and conditioning of water

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3. Tool-supported approach

Based on the stated demand for improving resource efficiency in manufacturing, it is this papers objective to provide a concept for systematically increasing the resource efficiency in manufacturing companies. The focus of the provided concept is specifically designed to improve the water consumption. The concept is shown in Fig. 1.

Fig. 1. Concept for improving the water efficiency in manufacturing Since water is an operating and auxiliary medium which has often been lacking attention in previous research activities, the designed concept is subdivided into three major objectives, namely 1) data acquisition,

2) analysis and 3) evaluation. These major objectives are

further clustered into work steps which are each supported by a respective tool. This approach aims not only at fostering transparency for water use and consumption in manufacturing operations but also enables the personnel to change the current situation by utilizing the supportive tools for each respective work step. The concept with all its work steps is described in the following.

3.1. Work steps of the methodology

The concept comprises six different work steps which are embedded in three major objectives, as shown in Fig. 2. It further needs to be understood as a logical flow starting at the top and ending at the bottom. According to this understanding the methodology starts with the objective of data acquisition and finishes with an evaluation of identified and promising improvement

measures. The inherent work steps of each objective are further explained in the following:

3.2. Requirements for data acquisition

In order to understand how much each section or department of an enterprise actually consumes it is inevitable to initially create transparency of the water flows within an enterprise. This work step further helps to understand to which extent each part of a company can contribute to achieve self-imposed water targets. Usually there exists a gap of input and output water flows which either cannot be explained or is caused by inaccurate predetermined allocation rules. To overcome these obstacles this work step focuses on deriving suitable system boundaries and appropriate allocation rules to determine the appropriate amount and depth of required data. This work step is facilitated by applying a measuring concept tool.

3.3. Taking stock of water flows

As aforementioned, typical obstacles for improving water efficiency in manufacturing is among others a lack of knowledge of the actual water system of an enterprise as well as differing qualities and amounts of required water. To facilitate the understanding of the actual water system of an enterprise, a generic water system has been identified.

Fig. 2. Generic water system containing six generic subsystems As shown in Fig. 2, this generic water system comprises six different subsystems which contain all required functions of a manufacturing enterprise and use water of different qualities and amounts. This approach supports the structuring as well as the understanding of the current water system and also helps to identify inconsistencies in input/output balances of water flows. To ease the implementation of this approach, a newly developed tool consisting of individual input screens ensures a systematic way to incorporate all required water flows of the respective subsystems. The tool also detects inconsistencies between the input and output flows and checks for completeness.

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Selection and peer-review under responsibility of the International Scientific Committee of the 3rd CIRP Global Web Conference in the person of the Conference Chair Dr. Alessandra Caggiano.

Fig. 3. Sankey diagram of the generic water system with five manufacturing area 3.4. Visualization of water flows and identification of

hot spots

Subsequent to identifying the company’s water system and all its subsystems, there is a need to communicate these results. One way of emphasizing the results is through visualization which eases not only the communication but also the distribution of the derived results. Particularly the latter aspect fosters the understanding of the water flows and the water system in general within an enterprise and reveals potential starting points and hot spots. These results can be visualized using E!Sankey [23]which allows an ad-hoc Sankey visualization of the factory’s water system subdivided into the six generic subsystems, as shown for five manufacturing areas (paint shop, casting, forge, mechanical manufacturing and pressing plant) in Fig. 3.

3.5. Check and prioritization of improvement

measures

The next work step involves an empowerment of the personnel to tackle the previously identified hot spots.

This can be achieved by supporting the personnel with suitable starting points to derive new ideas as well as to provide an individual list of efficiency measures that can be applied or reviewed. To structure this process, several principles to cluster different water efficiency measures have been identified. This aspect also forms the cornerstone of the supportive tool. The tool consists of the identified principles to cluster existing as well as potentially new water efficiency measures which are stated in the following (own representation based on [24]):

x Make use of good housekeeping measures and promote spare use of water

x Reduce environmentally hazardous materials and foster process optimization

x Close water cycles and increase re-utilization and recycling

x Use alternatives to water and find appropriate substitutes

x Save freshwater from contamination x Optimized end of pipe treatment

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Selection and peer-review under responsibility of the International Scientific Committee of the 3rd CIRP Global Web Conference in the person of the Conference Chair Dr. Alessandra Caggiano.

Fig. 4. Application process of the tool to check and prioritize improvement measures These principles show different fields of action and

can further be matched to prevailing manufacturing processes to indicate their transferability. Above that, the principles stimulate the personnel to think of new ideas for water efficiency measures that are not obvious but bear a high potential. To quickly assess the degree of potential the implementation period as well as the impact of the efficiency measure needs to be considered. By assigning numbers to these two criteria the product of both numbers states a fairly good estimate on how to prioritize the efficiency measures, starting with the highest number first.

The application process of the supportive tool comprises four different steps, as depicted in Fig. 4. After inserting individual data of the user, an individualized checklist is automatically generated. The checklist receives suitable efficiency measures from a detailed data base, structures the efficiency measures according to the derived principles and allows for prioritizing them. In case new ideas for efficiency measure come up, an automatic way of including them in the overall data base is provided. This structure allows for a continuous improvement process (CIP) making new ideas from one respective manufacturing area/department easily available to others.

3.6. Method of analysis for multiple water use and re-utilization

The previous steps give clear priorities on which area of a factory to focus on first and how to initiate a creative thinking process to derive new efficiency measures. However, from a technical perspective

another big leverage towards higher water efficiency is an increase in water utilization. This approach is known as Water Pinch Analysis and was developed to minimize the freshwater requirements in the process industry [25]. Multiple enhancements of the initial approach have made it a powerful method for identifying unforeseen optimization measures [26,27]. Yet, this work step strongly depends on the availability and acquisition of data for contaminant concentration levels and water flows.

3.7. Holistic evaluation of influences, potential and invest

The final work step assesses the previously derived efficiency measures with respect to economical, ecological as well as social criteria. From an economical perspective payback period, investment as well as total cost of ownership (TCO) is considered. Whereas, the ecological and social focus is e.g. on ܥܱଶemissions,

substitution of environmentally hazardous materials and employee involvement respectively.

Along with the presented methodology several supporting tools have been developed to ease the implementation of the proposed work steps. Some of these supportive tools have been briefly mentioned above, but have not been explained in detail.

4. Conclusion

This paper presents a tool-supported concept for improving water efficiency in manufacturing companies. The design of the concept takes particular needs and

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obstacles relevant to large, medium and small companies alike into account. The concept follows a methodology which comprises six different work steps. From a logical perspective, each work step is built upon the previous one. Provided the outcome resulting from certain work steps is already known, single work steps can also be executed separately. This aspect increases on the one hand the applicability of the concept and on the other hand the ease of a seamless integration. By providing supportive tools at each work step of the concept, this paper goes beyond mere conceptual description. The paper shows one example of a supportive tool which particularly focuses on easily checking efficiency measures and empowering the own personnel towards new ideas for potential efficiency measures. The latter aspect is embedded into a CIP to make new, innovative knowledge easily available for all users.

Future work will focus on further interactions of the individual tools, including more automatism when using one tool after another. In addition to that, the sophistication of some tools needs to be improved and validated in detailed case studies that represent real industry scenarios.

References

[1] Evans, S., Gregory, M., Ryan, C., Bergendahl, M. N., Tan, A., 2009. Towards a sustainable industrial system: With recommendations for education, research, industry and policy, University of Cambridge, Cambridge, United Kingdom, p. 7. [2] Rockström, J., W. Steffen, K. Noone, Å. Persson, F.S. Chapin, III,

E.F. Lambin, T.M. Lenton, M. Scheffer, C. Folke, H.J. Schellnhuber, B. Nykvist, C.A. de Wit, T. Hughes, S. van der Leeuw, H. Rodhe, S. Sörlin, P.K. Snyder, R. Costanza, U. Svedin, M. Falkenmark, L. Karlberg, R.W. Corell, V.J. Fabry, J. Hansen, B. Walker, D. Liverman, K. Richardson, P. Crutzen, and J.A. Foley, 2009. A safe operating space for humanity. Nature, 461, 472-475.

[3] European Commission, Committee of the Regions; Council; European Eco. & Soc. Committee; European Parliament, 2011. Roadmap to a Resource Efficient Europe.

[4] World Business Council for Sustainable Development, 2010. The Vision 2050: The new agenda for business. Available: http://www.wbcsd.org/pages/edocument/edocumentdetails.aspx?id =219&nosearchcontextkey=true.

[5] Hesselbach, J., Herrmann, C., Detzer, R., Martin, L., Thiede, S., Lüdemann, B., 2008. Energy Efficiency Through Optimized Coordination of Production and Technical Building Services, in: Proceedings of the 15th CIRP International Conference on Life Cycle Engineering (Sydney, Australia), 624–629.

[6] BMWi - German Federal Ministry of Economics and Technology, 2007. Energy Statistics.

[7] Erhardt, R., Pastewski, N., 2010. Ressourceneffizienz im produzierenden Gewerbe. Stuttgart: Fraunhofer-Verlag.

[8] Thiede, S., Posselt, G., Herrmann, C., 2013. SME appropriate concept for continuously improving the energy and resource efficiency in manufacturing companies, CIRP Journal of Manufacturing Science and Technology, 6/3: 204–211.

[9] Cannata, A., Karnouskos, S., Taisch, M., 2010. Energy Efficiency Driven Process Analysis and Optimization in Discrete Manufacturing. Industrial Electronics, IECON’09 – 35th Annual Conference of IEEE.

[10] Dietmair, A., Verl, A., 2009. A Generic Energy Consumption Model for Decision Making and Energy Efficiency Optimisation in Manufacturing, International Journal of Sustainable Engineering, 2/2: 123–133.

[11] Kuhrke, B., Schrems, S., Eisele, C., Abele, E., 2010. Methodology to Assess the Energy Consumption of Cutting Machine Tools, in: Proceedings of the 17th CIRP International Conference on Life Cycle Engineering (LCE 2010), Hefei, China, 76–82.

[12] Herrmann, C., Thiede, S., 2009. Process Chain Simulation to Foster Energy Efficiency in Manufacturing, CIRP Journal of Manufacturing Science and Technology, 1/4: 221–229; CIRP Annals - Manufacturing Technology 61 (2012), 587–609. [13] Gleick, P.H. (ed.), 1993. Water in Crisis: A Guide to the World’s

Freshwater Resources, Oxford University Press.

[14] Kara, S., Manmek, S., Herrmann, C., 2010. Global Manufacturing and the Embodies Energy of Products, CIRP Annals-Manufacturing Technology, 59/1: 29-32.

[15] Kara, S., Li, W., 2011. Unit Process Energy Consumption Models for Manufacturing Processes, CIRP Annals Manufacturing Technology, 60/1: 37–40.

[16] UN-Water, 2013. Statistics: Graphs & Maps, Water Resources. Available: http://www.unwater.org/statistics_res.html.

[17] Ecologic, Institute for International and European Environmental Policy, 2007. EU Water saving potential (Part 1 –Report), Berlin, Germany.

[18] UN-Water, 2012. Managing Water under Uncertainty and Risk, the United Nations World Report 4, UNESCO WWAP.

[19] Redmond, J., Walker, E., Wang, C., 2008. Issues for Small Businesses with Waste Management: Journal of Environmental Management, 88/2: 275-285.

[20] Deutsches Institut für Normung, 2009. DIN EN ISO 14001. Umweltmanagementsysteme. Anforderungen mit Anleitung zur Anwendung. Berlin: Beuth-Verlag.

[21] Assink, J.W. and Weenk, A., 1996. STEPS: a Systematic Approach for Integral Industrial Water Management. Report TNO, Apeldorn, The Netherlands.

[22] Department of Water Affairs and Forestry, 1996. South African Water Quality Guidelines – Volume 3 Industrial Use. Second Edition.

[23] IFU Hamburg GmbH, 2012, Company Website, www.ifu.com.which

[24] Lens, P., Pol, L.H., Wilderer, P., Asano, T., 2002. Water Recycling and Resource Recovery in Industry, in: Integrated Environmental Technology Series, IWA Publishing, London.

[25] Wang, Y.P., Smith, R., 1994.Wastewater Minimization, Chemical Engineering Science, 49/7: 981-1006.

[26] Hallele, N., 2002. A New Graphical targeting Method for Water Minimisation. Advances in Environmental Research, 6, 377-390. [27] Manan, Z.A., Tan, Y.L., Foo, D.C.Y., 2004. Targeting the

Minimum Water Flow Rate Using Water Cascade Analysis Technique. ALChE Journal, 50/12: 3169-3183