A System Dynamic Model for Polyethylene Terephthalate Supply Chain in the United Arab Emirates—Status, Projections, and Environmental Impacts
Abstract
:1. Introduction
2. Current Status
2.1. Generation, Step 1
- Daily: in homes and workplaces;
- Outing: in parks, malls, and recreational areas;
- Hospitality: in restaurants and hotels;
- Education: in schools and universities;
- Others: gyms, sports events, and outdoor recreational activities.
- Encourage everyone to stop using PET water bottles and replace them with refillable ones;
- Install water stations in Dubai;
- Raising environmental awareness about the harmful effects of plastics.
2.2. Source Sorting, Step 2A
- Using classical waste separation bins in malls and workplaces. These bins would directly separate plastic bins.
- Having separation bins in some neighborhoods. However, these bins would have mixed types of plastics that would require additional processing to isolate PET bottles.
- Using a mobile application (app) to collect recyclable waste. Recapp, a free door-to-door recycling service, started in Abu Dhabi in November 2020 and expanded its work to cover Dubai in February 2022 [33]. Using a mobile application, 15,000 registered users in Abu Dhabi can schedule pick-ups for plastic bottles and aluminum cans.
- Private companies organizing the collection of PET bottles from places like schools and workplaces to downcycle PET into other products [36].
2.3. MRF Sorting, Step 2B
2.4. Recycling, Step 2C
2.5. Downcycling, Step 2D
2.6. IwER, Step 3A
2.7. Landfilling, Step 3B
3. SD Models
3.1. PET Consumption SD Model
- Population growth. The UAE population estimates in 2023 range between 9.48 and 10.67 million inhabitants [7]. Thus, 10 million is taken as the starting population in 2023. The population growth rate before 2010 was above 5%; however, it slowed down from 2011 to 2023, and growth rates during this period were below 1%. Thus, the growth rate is a uniform random number between 0.65% and 1%. The green arrows in Figure 2 show the SD model of the population calculations.
- Bottled water consumption. Two stocks are used to study the effects of all efforts to replace PET water bottles with other alternatives: PET users with an initial value of 1 and non-PET users with an initial value of 0, where these values represent population percentages, i.e., one means 100%. An awareness success variable shows how these efforts will convince people to stop using PET bottles, i.e., moving from the PET users’ stock to non-PET users.As stated earlier, the average percentage of bottled water consumed per capita per year is 285 L in the UAE. This number is multiplied by the percentage of people who still use PET bottles to find the volume of water drunk from PET bottles per year.
- GHG emission calculations. Knowing the volume of water consumed using PET bottles per year, the weight of PET produced is calculated. The weight of PET is then multiplied by the sum of GHG emissions generated due to PET production and incineration.
3.2. PSC SD Model
- Producing PET water bottles from virgin PET, ;
- Recycling PET to rPET, ;
- Downcycling PET to yarn, ;
- Incinerating PET, ;
- Savings due to replacing cotton yarn with plastic, .
- Q1: What is the least separation percentage that needs to be maintained to satisfy the recycling and downcycling demands?A1: Measures taken and technologies used need to separate 33% of the consumed PET. If this separation value is maintained, then the expected GHG emissions are 228,568.9643 , which is a 31% saving compared to the default situation shows no increase or decrease in PET consumption. It is intuitive to assume that source-separation is cheaper than waste mainstream separation, which should be the focus of decision-makers.
- Q2: If a tax is imposed on virgin PET and consumers start to prefer rPET, what will happen to GHG emissions?A2: The current situation assumes that around 2000 PET tons are recycled into water bottles, around 64 million bottles. Figure 5 shows the decrease in GHG emissions for using rPET instead of virgin PET. For 10,000 tons of rPET water bottles, and assuming the same volume of downcycled used PET, GHG emissions would be ; however, the sum of separation percentages needs to be around 45% to satisfy the market demand for used PET.
- Q3: How much can the demand for virgin PET drop before the downcycling and recycling industries face a shortage in used PET, assuming 40% separation rate?A3: If measures are taken to reduce PET usage by 1.5% per year, then the UAE will face a shortage of used PET in 2050. In this case, it is necessary to increase separation percentages.
4. Discussion
5. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
- Zaki, Y. How Much Money Will Filtered Tap Water Save You? 2020. Available online: https://gulfnews.com/your-money/saving-investment/how-much-money-will-filtered-tap-water-save-you-1.1582815501994 (accessed on 15 June 2023).
- Ajaj, R.; Abu Jadayil, W.; Anver, H.; Aqil, E. A Revision for the Different Reuses of Polyethylene Terephthalate (PET) Water Bottles. Sustainability 2022, 14, 4583. [Google Scholar] [CrossRef]
- Rajput, H.; Maraqa, M.A.; Zraydi, F.; Al Khatib, L.A.; Ameen, N.; Ben ElKaid, R.; Al Jaberi, S.S.; Alharbi, N.A.; Howard, R.; Aly Hassan, A. A survey on the use of plastic versus biodegradable bottles for drinking water packaging in the United Arab Emirates. Sustainability 2022, 14, 2664. [Google Scholar] [CrossRef]
- El Essawy, N.A.; Ali, S.M.; Farag, H.A.; Konsowa, A.H.; Elnouby, M.; Hamad, H.A. Green synthesis of graphene from recycled PET bottle wastes for use in the adsorption of dyes in aqueous solution. Ecotoxicol. Environ. Saf. 2017, 145, 57–68. [Google Scholar] [CrossRef] [PubMed]
- Bałazińska, M.; Kruczek, M.; Bondaruk, J. The environmental impact of various forms of waste PET bottle management. Int. J. Sustain. Dev. World Ecol. 2021, 28, 473–480. [Google Scholar] [CrossRef]
- Benavides, P.T.; Dunn, J.B.; Han, J.; Biddy, M.; Markham, J. Exploring comparative energy and environmental benefits of virgin, recycled, and bio-derived PET bottles. ACS Sustain. Chem. Eng. 2018, 6, 9725–9733. [Google Scholar] [CrossRef]
- United Nations. United Arab Emirates Population Statistics 2023. 2023. Available online: https://www.globalmediainsight.com/blog/uae-population-statistics/ (accessed on 15 June 2023).
- Islam, M.S.; Uddin, M.J.; Alshehri, K. Plastic waste and carbon footprint generation due to the consumption of bottled waters in Saudi Arabia. Res. Dev. Mater. Sci 2018, 5, 1–3. [Google Scholar] [CrossRef]
- EPA. Documentation for Greenhouse Gas Emission and Energy Factors Used in the Waste Reduction Model (WARM)-Containers, Packaging, and Non-Durable Good Materials Chapters. 2020. Available online: https://www.epa.gov/sites/default/files/2020-12/documents/warm_containers_packaging_and_non-durable_goods_materials_v15_10-29-2020.pdf (accessed on 15 June 2023).
- World Health Organization. World Health Statistics 2023: Monitoring Health for the SDGs, Sustainable Development Goals. 2023. Available online: https://www.who.int/publications/i/item/9789240074323 (accessed on 15 June 2023).
- Staff Reporter. UAE Announces Blanket Ban on Single-Use Plastic Bags from 2024. 2023. Available online: https://www.khaleejtimes.com/uae/uae-announces-blanket-ban-on-single-use-plastic-bags-from-2024 (accessed on 15 June 2023).
- Coyle, R.G. System dynamics modelling: A practical approach. J. Oper. Res. Soc. 1997, 48, 544. [Google Scholar] [CrossRef]
- Kollikkathara, N.; Feng, H.; Yu, D. A system dynamic modeling approach for evaluating municipal solid waste generation, landfill capacity and related cost management issues. Waste Manag. 2010, 30, 2194–2203. [Google Scholar] [CrossRef]
- Xiao, S.; Dong, H.; Geng, Y.; Tian, X.; Liu, C.; Li, H. Policy impacts on Municipal Solid Waste management in Shanghai: A system dynamics model analysis. J. Clean. Prod. 2020, 262, 121366. [Google Scholar] [CrossRef]
- Al-Shihabi, S.; Aydin, R.; Al Nahlawi, M. Forecasting the effects of municipal solid plastic waste generation and streaming using system dynamics: A case study in Dubai. Sci. Total Environ. 2023, 897, 165204. [Google Scholar] [CrossRef]
- The United Arab Emirates’ Government Portal. 13. Climate Action. 2021. Available online: https://u.ae/en/about-the-uae/leaving-no-one-behind/13climateaction (accessed on 15 August 2023).
- Elmuti, D.; Kathawala, Y. An overview of benchmarking process: A tool for continuous improvement and competitive advantage. Benchmarking Qual. Manag. Technol. 1997, 4, 229–243. [Google Scholar] [CrossRef]
- Geyer, R.; Jambeck, J.R.; Law, K.L. Production, use, and fate of all plastics ever made. Sci. Adv. 2017, 3, e1700782. [Google Scholar] [CrossRef] [PubMed]
- Van Eygen, E.; Feketitsch, J.; Laner, D.; Rechberger, H.; Fellner, J. Comprehensive analysis and quantification of national plastic flows: The case of Austria. Resour. Conserv. Recycl. 2017, 117, 183–194. [Google Scholar] [CrossRef]
- Commission, E. A European Strategy for Plastics in a Circular Economy: Brussels, Belgium. 2018. Available online: https://eur-lex.europa.eu/resource.html?uri=cellar:2df5d1d2-fac7-11e7-b8f5-01aa75ed71a1.0001.02/DOC_1&format=PDF (accessed on 15 August 2023).
- Perugini, F.; Mastellone, M.L.; Arena, U. A life cycle assessment of mechanical and feedstock recycling options for management of plastic packaging wastes. Environ. Prog. 2005, 24, 137–154. [Google Scholar] [CrossRef]
- Brouwer, M.T.; van Velzen, E.U.T.; Augustinus, A.; Soethoudt, H.; De Meester, S.; Ragaert, K. Predictive model for the Dutch post-consumer plastic packaging recycling system and implications for the circular economy. Waste Manag. 2018, 71, 62–85. [Google Scholar] [CrossRef] [PubMed]
- ISWA. TADWEER. 2023. Available online: https://www.iswa.org/blog/platinum-members/platinum-tadweer/?v=ea8a1a99f6c9 (accessed on 15 June 2023).
- BEEAH. BEEAH. 2023. Available online: https://www.beeahgroup.com/about-beeah-group/ (accessed on 15 June 2023).
- The United Arab Emirates’ Government Portal. Waste Management. 2023. Available online: https://u.ae/en/information-and-services/environment-and-energy/waste-management#:~:text=Dubai%20Municipality%27s%20Waste%20Management%20Department,an%20integrated%20and%20innovative%20approach (accessed on 15 June 2023).
- Government of Dubai. One Small Change, One Big Impact. 2023. Available online: https://www.visitdubai.com/en/dubai-can#:~:text=Dubai%20Can%20is%20a%20sustainability,to%20use%20refillable%20water%20bottles (accessed on 15 June 2023).
- Keogh, L. Refill Your Water Bottles for Free Across Dubai with New Dubai Can Initiative. 2022. Available online: https://www.timeoutdubai.com/things-to-do/dubai-can-launches (accessed on 15 June 2023).
- BT NEWS DESK. Dubai Festival City Mall Installs Aquafina Water Stations to Promote Reuse and Refill. 2023. Available online: https://www.biznesstransform.com/dubai-festival-city-mall-installs-aquafina-water-stations-to-promote-reuse-and-refill/ (accessed on 15 June 2023).
- Report, G.N. Watch: ‘Dubai Can’ Cuts Plastic Bottle Use by over 7 Million. 2023. Available online: https://gulfnews.com/uae/environment/watch-dubai-can-cuts-plastic-bottle-use-by-over-7-million-1.93953135 (accessed on 15 June 2023).
- ACCOR. Accor Joins Forces with Dubai Sustainable Tourism to Launch ‘Dubai Can’. 2022. Available online: https://press.accor.com/middle-east-africa-turkey-asia-pacific/accor-joins-forces-with-dubai-sustainable-tourism-to-launch-dubai-can/?lang=en (accessed on 15 June 2023).
- Hoteliers. Opening Date Revealed for ‘Green Hotel’ Holiday Inn & Suites Dubai Science Park. 2022. Available online: https://www.hoteliermiddleeast.com/properties/opening-date-revealed-for-green-hotel-holiday-inn-suites-dubai-science-park (accessed on 15 June 2023).
- Gulf News. IHG Hotels at Dubai Festival City Will do Away with 2 m Single-Use Bottles in a Year. 2022. Available online: https://gulfnews.com/business/corporate-news/ihg-hotels-at-dubai-festival-city-will-do-away-with-2m-single-use-bottles-in-a-year-1.95535549 (accessed on 15 June 2023).
- Business, G. Free Door-to-Door Recycling Service Comes to Dubai. 2023. Available online: https://gulfbusiness.com/free-door-to-door-recycling-service-comes-to-dubai/ (accessed on 15 June 2023).
- Clarke, K. Trade in Your Plastic for Rewards or a Netflix Subscription at These UAE Shops and Malls. 2023. Available online: https://www.thenationalnews.com/uae/environment/2022/07/06/trade-in-your-plastic-for-rewards-or-a-netflix-subscription-at-these-uae-shops-and-malls/ (accessed on 15 June 2023).
- Zaman, S. Now, Return Used Plastic Bottles to Earn Free Bus Trips in Abu Dhabi. 2023. Available online: https://gulfnews.com/uae/now-return-used-plastic-bottles-to-earn-free-bus-trips-in-abu-dhabi-1.86791494 (accessed on 15 June 2023).
- DGADE. Simple Bottles Recycling Initiative. 2023. Available online: https://dgrade.com/ (accessed on 15 June 2023).
- Municipality, D. Dubai Chamber Sustainability Network Integrated Waste Management to Contribute to Achieve Waste Diversion Goals in UAE. 2023. Available online: https://www1.dubaichamber.com/wp-content/uploads/2020/02/Dubai-Municipality-Waste-Management.pdf (accessed on 15 June 2023).
- Farz. Farz is a State of the Art Material Recovery Facility (MRF) Launched by Imdaad in 20202 in Line with Dubai’s Vision 2021. 2023. Available online: https://www.farz.ae/ (accessed on 15 June 2023).
- BEEAH. Material Recovery Facility (MRF). 2023. Available online: https://www.beeahgroup.com/services/beeah-recycling/ (accessed on 15 June 2023).
- Pinter, E.; Welle, F.; Mayrhofer, E.; Pechhacker, A.; Motloch, L.; Lahme, V.; Grant, A.; Tacker, M. Circularity study on PET bottle-to-bottle recycling. Sustainability 2021, 13, 7370. [Google Scholar] [CrossRef]
- Homayouni, Y. Rebound Plastic Exchange Member Horizon Technologies Officially Recognized by MOIAT UAE for Its Food Grade rPET. 2023. Available online: https://www.zawya.com/en/press-release/companies-news/rebound-plastic-exchange-member-horizon-technologies-officially-recognized-by-moiat-uae-for-its-food-grade-rpet-ikui26h9 (accessed on 15 June 2023).
- Business, G. UAE to Set Up First Food-Grade Plastic Recycling Facility. 2023. Available online: https://gulfbusiness.com/uae-plastic-recycling-facility/ (accessed on 15 June 2023).
- News, G. UAE’s First Locally Produced 100% rPET Bottle Launched by Al Ain Water. 2023. Available online: https://gulfnews.com/lifestyle/uaes-first-locally-produced-100-rpet-bottle-launched-by-al-ain-water-1.1679459264465 (accessed on 15 June 2023).
- Release, P. DGrade Plastic Flake Recycling Factory Opens in KIZAD to Support a Closed Loop in the UAE. 2023. Available online: https://www.zawya.com/en/press-release/companies-news/dgrade-plastic-flake-recycling-factory-opens-in-kizad-to-support-a-closed-loop-in-the-uae-v7j0yeoz (accessed on 15 June 2023).
- Business, G. UAE Builds Waste-to-Energy Plant to Manage Growing Trash. 2023. Available online: https://gulfbusiness.com/uae-builds-waste-to-energy-plant-to-manage-growing-trash/ (accessed on 15 June 2023).
- News, A. UAE to Build Waste-to-Energy Plants to Burn Two Thirds of Trash. 2023. Available online: https://www.arabnews.com/node/1902616/business-economy (accessed on 15 June 2023).
- Forum, W.E. Dubai Has Just Increased the Cost of Landfill. Can It Hit Zero Waste by 2030? 2022. Available online: https://www.weforum.org/agenda/2022/02/dubai-waste-recycling/ (accessed on 15 June 2023).
- UAE, T.N. Abu Dhabi Plans to Stop Sending Waste to Landfill by 2071. 2022. Available online: https://www.thenationalnews.com/uae/2022/04/14/abu-dhabi-unveils-ambitious-zero-waste-plan/#:~:text=Abu%20Dhabi%20has%20plans%20to,the%20Environment%20Agency%20Abu%20Dhabi (accessed on 15 June 2023).
- Zawya. BEEAH Group Leads the Way to “Net-Zero” Goals with 76% of Waste Already Diverted from Landfills. 2022. Available online: https://www.zawya.com/en/press-release/events-and-conferences/beeah-group-leads-the-way-to-net-zero-goals-with-76-of-waste-already-diverted-from-landfills-iz29zmwx (accessed on 15 June 2023).
- Richardson, G.P.; Otto, P. Applications of system dynamics in marketing. J. Bus. Res. 2008, 61, 1099–1101. [Google Scholar] [CrossRef]
- Sterman, J. System Dynamics: Systems Thinking and Modeling for a Complex World; Massachusetts Institute of Technology, Engineering Systems Division: Cambridge, MA, USA, 2002. [Google Scholar]
- Mingers, J.; White, L. A review of the recent contribution of systems thinking to operational research and management science. Eur. J. Oper. Res. 2010, 207, 1147–1161. [Google Scholar] [CrossRef]
- Tseng, C.H.; Hsu, Y.C.; Chen, Y.C. System dynamics modeling of waste management, greenhouse gas emissions, and environmental costs from convenience stores. J. Clean. Prod. 2019, 239, 118006. [Google Scholar] [CrossRef]
- Hao, J.; Yuan, H.; Liu, J.; Chin, C.S.; Lu, W. A model for assessing the economic performance of construction waste reduction. J. Clean. Prod. 2019, 232, 427–440. [Google Scholar] [CrossRef]
- Franco, M.A. A system dynamics approach to product design and business model strategies for the circular economy. J. Clean. Prod. 2019, 241, 118327. [Google Scholar] [CrossRef]
- Guzzo, D.; Pigosso, D.; Videira, N.; Mascarenhas, J. A system dynamics-based framework for examining Circular Economy transitions. J. Clean. Prod. 2022, 333, 129933. [Google Scholar] [CrossRef]
- Sterman, J. Business Dynamics: Systems Thinking and Modeling for a Complex World; Irwin/McGraw-Hill: New York, NY, USA, 2010. [Google Scholar]
- Barlas, Y. Formal aspects of model validity and validation in system dynamics. Syst. Dyn. Rev. J. Syst. Dyn. Soc. 1996, 12, 183–210. [Google Scholar] [CrossRef]
- Bevilacqua, M.; Ciarapica, F.E.; Mazzuto, G.; Paciarotti, C. Environmental analysis of a cotton yarn supply chain. J. Clean. Prod. 2014, 82, 154–165. [Google Scholar] [CrossRef]
Variable/Flow | Equation/Value | Unit |
---|---|---|
Growth rate | Uniform (0.65–1%) | person/year |
Population | Growth rate × Population | person |
Behavior change | PET users × Awareness success | % |
Bottled water/year | PET users × Default: bottled water/person year | L |
PET | Bottled water/year × PET g/L | tonne |
Bottle Size (mL) | Average Weight (g) | PET g/L |
---|---|---|
250 | 6.41 | 25.64 g |
330 | 14.31 | 43.36 g |
600 | 19.71 | 32.85 g |
1500 | 32.6 | 21.73 g |
Generic (1000) | 30.89 | 30.89 g |
Awareness Success | Bottled Water Volume | PET | GHG | |
---|---|---|---|---|
% | (Million L) | (Tonnes) | % Dev. | |
0 | 2814.0 | 109,454 | 422,491 | 0 |
0.85 | 2543.3 | 86,922 | 335,522 | −20.6 |
5 | 887.1 | 27,401 | 105,768 | −75.9 |
10 | 206.0 | 6365 | 24,568 | −94.2 |
15 | 44.0 | 1360 | 5250 | −98.8 |
20 | 8.6 | 265 | 1022 | −99.8 |
Variable/Flow | Equation/Value | Unit |
---|---|---|
new PET | PET-rPET used | tons/year |
to mainstream waste | New PET × (1 − Source separation effectiveness) | tons |
Separated PET | New PET × Source separation effectiveness + Main-stream waste × MRF separation effectiveness | tons |
PET-based yarn demand | RANDOM UNIFORM (25,000, 30,000) | tons/year |
rPET demand | RANDOM UNIFORM (1000, 3000) | tons/year |
to incineration | Main-stream waste × (1 − MRF separation effectiveness) | tons |
to rPET | IF (Separated PET (tons) > rPET and downcycle demand (tons)) Then (rPET demand) Else (Separated PET (tons) × | tons/year |
to downcycle | IF (Separated PET (tons) > rPET and downcycle demand (tons)) Then (PET-based yarn demand (tons)) Else (Separated PET (tons) × | tons/year |
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Al-Shihabi, S.; Barghash, M. A System Dynamic Model for Polyethylene Terephthalate Supply Chain in the United Arab Emirates—Status, Projections, and Environmental Impacts. Sustainability 2023, 15, 13119. https://doi.org/10.3390/su151713119
Al-Shihabi S, Barghash M. A System Dynamic Model for Polyethylene Terephthalate Supply Chain in the United Arab Emirates—Status, Projections, and Environmental Impacts. Sustainability. 2023; 15(17):13119. https://doi.org/10.3390/su151713119
Chicago/Turabian StyleAl-Shihabi, Sameh, and Mahmoud Barghash. 2023. "A System Dynamic Model for Polyethylene Terephthalate Supply Chain in the United Arab Emirates—Status, Projections, and Environmental Impacts" Sustainability 15, no. 17: 13119. https://doi.org/10.3390/su151713119