The paper addresses the global and local shift towards the circular economy as a tool to achieve environmental sustainability and reduce climate impacts, given the global challenges of converting waste into energy. Through an analysis of global studies, the trend towards the circular economy and successful global standards, specifically the Danish model (Copenhill WTE plant) and Singapore (Tuas One WTE Plant), and how we utilize waste and achieve sustainability, this study discusses global strategies in the local context in Jordan, where it identifies current infrastructure challenges and proposes a sustainable local framework aimed at improving waste management and supporting the goals and strategy for sustainability in Jordan for 2030.
The world is moving toward sustainability, which involves bringing about a radical change to transform what is traditionally viewed as an environmental burden into a sustainable resource that delivers benefits in many areas.
Sustainable development, according to the United Nations, is development that meets the needs of the present without compromising the ability of future generations to meet their own needs [1]. Sustainable development has multiple facets and benefits in several areas, including human health, the environment, social justice and equality, livelihoods, security, and well-being for all, as recognized by AASHE[2]. The circular economy system prevents materials from becoming waste; instead, it revitalizes nature. This system focuses on waste elimination, material recycling, and the restoration of natural resources to protect the environment. This approach addresses climate change and other challenges. The system is based on three principles: first, waste and pollution reduction; second, the circulation of products and materials; and third, the restoration of natural systems. This system relies on the principle of “closing the loop.”
Among the organizations aiming to accelerate the global transition to a circular economy is the Ellen Foundation, which focuses on waste reduction through reuse to achieve a fundamental approach to a sustainable system [3]. The organization indicates that cities contribute 80% of global GDP, making them the largest consumers of resources and the primary driver of the transition to a circular economy. This is because they consume 75% of natural resources, generate 50% of global waste, and are responsible for 60% to 80% of greenhouse gas emissions. Artificial intelligence (AI) solutions are used to identify patterns, predict processes, improve operations, and provide recommendations using diverse data sources [4].
To scientifically implement the principles of the circular economy, the twelfth Sustainable Development Goal (SDG 12) of the United Nations stands out. It stipulates a substantial reduction in waste production by 2030 through prevention, reduction, recycling, and reuse, emphasizing the environmentally sound management of chemicals and waste throughout their lifecycle [5]. Denmark is a world leader in the circular economy model. While many countries have successfully harnessed waste for their benefit, Denmark has transformed waste management facilities into sustainable projects. Although Denmark boasts numerous sustainable factories, the Copenhill waste-to-energy plant stands out for embodying the concept of social and urban sustainability. It integrates an industrial facility with a 400-meter-long artificial ski slope on its roof, serving as a public space for the area and its residents. Its smokestacks are designed to emit emissions in the form of visual vapor rings, symbolizing visual awareness. This has made Copenhagen the first carbon-neutral city [6].
Despite the magnitude of the challenges in Denmark, where the average individual generates about 755 kg of waste per year, compared to the European Union where the average individual generates about 517 kg per year, Denmark has made a historic leap. While the percentage of landfill waste was about 44% before the 1990s, it has now decreased to levels close to zero, about 0.7%. In contrast, municipal waste is converted into energy for cities at a rate of 55% through the burning of non-recyclable waste, and recycling rates have reached between 45%-50%, with goals to raise these rates to 60% by 2030 [7].
Jordan produces approximately 2.7 – 3 million tons of waste annually. The problem in Jordan is that the landfill rate reaches over 85-90%, with most of it going to the (Ghabawi and Akeeder) landfills. The recycling rate is minimal, between 7-10%. Organic waste, particularly food scraps, constitutes over 50-60% of the total waste volume[9]. A very high percentage that generates methane gas. In line with the goals and vision of the Jordanian state to modernize the economy towards a circular economy, reduce the landfill rate, and strive to achieve its 2030 targets of diverting 60% of solid waste from landfills and reducing the landfill rate from approximately 85% to less than 40% by 2030, efforts are underway to increase recycling rates and material recovery to 30%, and to process 30% of organic waste into compost and biogas for energy production[8].
Case Study 1: Denmark (The CopenHill WTE Plant)
The Copenhill ski resort, designed by the architectural firm Bjarke Ingels Group (BIG), was completed in October 2019 in Copenhagen, Denmark. It is a truly unconventional facility.
The feasibility of building a ski slope at the top of an existing facility was uncertain, as Denmark lacks natural mountains and snowfall is scarce. Skiing on an artificial surface is a novel concept. However, some studies analyzed the number of visitors to ski slopes and the number of active skiers in the area. Based on this data, they estimated that between 42,000 and 57,000 visitors use the site annually. The biggest challenge of the project was helping all stakeholders understand that it was not merely an engineering, sporting, or architectural project, but rather a multi-faceted endeavor requiring a holistic approach to design and implementation.
The ingenious concept behind the resort is to transform a state-of-the-art waste-to-energy plant into a clean energy facility serving 150,000 homes. This station converts 440,000 tons of waste annually into electricity and heating. At the top of the station is a recreational park featuring a 450-meter ski slope, a walking trail, and an 85-meter-high artificial climbing wall. The design goes beyond simply providing enjoyment for local residents; it aims to propel the Danish capital towards sustainability. Costing $670 million USD, this is a crucial step towards making Copenhagen the first carbon-neutral capital, a goal it is expected to achieve by 2025.
Among the key technologies used at the station are waste-to-energy conversion, emission reduction systems, selective catalytic reduction (SCR), and carbon capture technology.
The station also features sustainable architecture and integrated recreational facilities, including a ski slope, climbing wall, and green spaces[9].
Detailed Timeline and Construction Phases of the Project between (2009 – 2019).
In 2009, the Ministry of Environment won the engineering contract. In 2011, Bjarke Inglesa Group (BIG) won the competition to replace the old station. In March 2014, contracts for the structural pouring and concrete work were awarded, marking the start of the foundation phase. In March 2017, the power station was officially completed, and the machinery and thermal processing units began operation. In the fall of 2019, the roof and recreational facilities, including the world’s tallest climbing wall and ski slope, were officially opened to the public.
The aesthetic engineering and roof preparation phase (2017-2019) included the construction of a 400m long ski slope at an altitude of 900m, the building of hiking trails, an 85m high external climbing wall, and the integration of an emissions station designed to produce the distinctive smoke rings[10].
The building’s concept and design are divided into interactive green energy elements. The idea breaks the traditional image of factories, and considering the natural topography of Copenhagen, the designers created a mountain that offers various sports, including skiing and mountaineering, in the heart of the city. The building also houses administrative offices and an environmental education center to raise awareness among visitors about the importance of recycling and clean energy production.
The building’s architectural masses form a sloping shape, precisely tailored to the requirements of the industrial machinery and waste incineration equipment inside. The masses slope down from the top of the building, creating a contemporary industrial style. The facades of the station are composed of massive, overlapping, and stacked aluminum pieces, like bricks, which reinforces the building’s industrial identity. Double-glazed windows in the facades incorporate long strips of glass that allow natural air to penetrate deep into the factory, and the office spaces are illuminated at night to reflect the rhythm of work within the station[11].
The plant is equipped with two furnace lines and a combined turbine and generator system. Each line burns 35 tons of waste per hour. It is designed to process approximately 400,000 tons of waste annually, generated by 600,000 people and at least 46,000 companies. Electricity is supplied to at least 50,000 households and central heating to 120,000 households. Steam at 440°C and 70 bar pressure is provided, doubling electrical efficiency. The innovative DynaGrate combustion grid technology is characterized by its flexibility in using waste fuels, optimal combustion, and low maintenance costs. The entire cooling system is fully integrated and protected within a steel column, with the grid components not touching, thus reducing friction. The mechanical agglomeration of the waste layer on the grid ensures thorough mixing and combustion conditions. The water cooling system provides the high calorific value necessary for the flexibility in using different fuel types. The organic carbon content is approximately 0.2% in the bottom ash[12].
| Process Parameters | Guaranteed values | Unit |
| Waste capacity | 35 | t/h |
| Lower heating value | 11,5 | MJ/kg |
| Steam output | 141,1 | t/h |
| Steam temperature | 440 | C |
| Steam pressure | 70 | bar |
| Boiler outlet flue gas temp | 160 | C |
| Feed water temperature | 130 | C |
Plant design data (Per line)
The Dyna-Grate water-cooled system does not cool the air but provides complete control over the primary combustion air. This improves the combustion process to reduce nitrogen oxides. B&W Volund options operate at oxygen levels between 4.5% and 5% and nitrogen oxide levels between 200 and 250 mg/m³ before the combustion gases reach the SCR filter. Furthermore, reducing excess air leads to lower nitrogen oxide emissions. The VoluMix excess air system is designed using computational dynamics (CFD), which reduces carbon monoxide and total organic carbon emissions. VoluMix also injects secondary air into the combustion zone, resulting in complete combustion in the gaseous phase[12].
The original concept behind BIG’s CopenHill chimney mechanism involved creating a steam ring generator. The mechanism works by capturing rising steam, while an internal unit condenses and traps the steam in a circular chamber. This steam is then released as a giant smoke ring made of pure steam each time 25 kg of CO2 is burned, serving as a tangible visual representation of emissions. Despite the success of the prototypes, the steam ring-blowing mechanism was not permanently implemented in the final building.
Currently, the plant operates as one of the cleanest waste-to-energy plants in a world where 440,000 tons of waste are converted annually into electricity and heating. Instead of a continuous upward movement, the chimney releases a massive steam ring into the sky. The purpose of these rings is to provide a tangible visual representation, with a smoke ring being released into the air for every ton of CO2 emitted, alerting local residents and the world to the scale of emissions[13].
The factory’s architectural envelope is made of 3.3-meter-wide extruded aluminum blocks. Aluminum was chosen for its ease of recycling, longer lifespan, and corrosion resistance. It is laid in an interlocking, brick-like pattern, improves water quality, does not require external coatings, and is easy to disassemble and recycle at the end of its lifecycle. Light enters the factory to its deepest point through integrated glass strips, providing natural lighting for the administrative spaces. The structure is built of steel and concrete and is designed to support an integrated public program that superimposes its basic service infrastructure[14].
Case Study 2: The Tuas One WTE Plant (Singapore)
The Tuas One waste-to-energy plant is located in the Tuas Industrial Estate in southwestern Singapore. Spanning approximately 4.8 hectares, this sixth waste-to-energy plant in Singapore can incinerate 3,600 tons of waste daily, generating 120 megawatts of electricity. The electricity produced powers approximately 240,000 residential units belonging to the Housing and Development Board. The Tuas One plant was developed as a public-private partnership to provide waste incineration services.
Initial operations commenced on July 27, 2022, at the National Environmental Company, while a second phase, developed under a design, build, own, and operate model, began in December 2021. Since then, operational capacity has increased. The plant will provide waste services for at least 25 years, helping Singapore meet its long-term waste management and energy needs. The incineration process generates energy to meet the demand for waste-to-energy conversion, with 90% of the waste being reduced to ash [15].
Integrated Waste Management Facilities
In 2019, the total solid waste amounted to 7.23 million tons, with 59% of this waste being recycled. Waste-to-energy plants in Singapore incinerated approximately 2.98 million tons in the same year. With the increasing population, waste is expected to rise. Unlike existing waste-to-energy plants, the organization adopts a different approach to comprehensive waste management, processing multiple types of waste to maximize resource and energy recovery and minimize environmental impact and land consumption. Waste consists of incinerable and recyclable waste collected by the National Recycling Programme[15].
| Waste Treatment Facility | Capacity (tonnes per day) |
| WTE Facility | 5,800 |
| Material Recovery Facility (MRF) | 250 |
| Food Waste Treatment Facility | 400 |
| Sludge Incineration Facility | 800 |
The table shows the processing facilities and their capacities.
Timeline of Tuas Water Rehabilitation Project
On July 3, 2019, the project was awarded to a joint venture between Brothers Engineering and Civil Contracting Company and China Harbour Engineering Singapore Limited. This followed the construction of internal pumping stations to the plant. These stations consist of five shafts extending 80 meters underground. units within the Tuas wastewater treatment plant.
The second phase of the technical decision support system extends under the Air Rajah Road and terminates at the Tuas Water Treatment Plant. This phase includes a 40-kilometer southern tunnel connecting to the existing deep tunnels and creating an interconnected network that transports wastewater from the existing sewage system to a depth of 60 kilometers. Upon completion of the second phase in 2025, the existing conventional water treatment plants in Jurong and Ulu Bandan will be decommissioned. 37 intermediate pumping stations will thus free up approximately 83 hectares of land for alternative uses[15].
Process flow diagram of Tuas One WTE plant
The building, completed in 2019, operates at a massive capacity, processing 3,600 tons of solid waste daily and generating approximately 120 MW of clean, renewable electricity. The core of the thermal treatment process relies on a sophisticated reversible system. This system ensures the rapid drying and combustion of waste. Furthermore, the dynamic mechanical movements of the reversible system guarantee exceptional combustion efficiency, producing minimal carbon content from the remaining ash and maximizing the overall combustion energy output.
The facility prioritizes environmental safety and emissions control. Each thermal treatment unit features a dedicated flue gas treatment system and an advanced consolidation system. This system fully complies with Singapore’s Environmental Protection and Management Regulations of 2001. Key emission reduction processes incorporate non-catalytic selective reduction (SNCR) technology to lower nitrogen oxide (NOx) concentrations in flue gases. Additionally, a highly efficient dry catalytic fabric filtration system is designed to capture and extract dust particles, acid compounds, and other hazardous pollutants[15].
One of the most prominent sustainability features at the Tuas WTE facility is its combustion management, specifically bottom ash. Instead of being disposed of in landfills, it undergoes a recycling and stabilization process to extract ferrous and non-ferrous metals. The remaining ash is then processed into an environmentally friendly building material known as “news-side.” This material is used in recycling infrastructure projects such as roads and landfill sites, thus promoting a circular economy and achieving the goal of a waste-free landfill[15].
The table aims to provide a comprehensive evaluation of the waste-to-energy models that have been researched. This comparison highlights how different urban contexts and functional outcomes of infrastructure projects affect the process.
| Design Criteria | CopenHill (Denmark) |
Tuas Nexus/Tuas One (Singapore) |
| Primary urban objective | Social integration, recreation, and urban landmark. | Industrial symbiosis, land optimization and resource recovery |
| Integration synergy | Waste-to-energy mixed with public sports ( ski slope). | Waste-to-energy co-located with water reclamation plant. |
| Byproduct innovation | Clean steam rings for environmental awareness. | NEWS and production for land reclamation and building . |
| Land allocation | Compact footprint within a high-density city center . | Highly optimized multi-level facility for land scarcity. |
Based on the comparative data shown in the table, it is clear that sustainable engineering philosophies focus heavily on industrial-technological synergy to solve the problem of material and land scarcity, while the Danish city of Copenhagen prioritizes social and architectural integration and heavy infrastructure in public life based on recreational urban planning. Both strategies redefine the traditional concept of waste management, shifting burdens to economic models
Local Context and Project Site Analysis: The New Amra City (Amman)
Jordan is making significant strides towards transitioning from an economy based on resource extraction, manufacturing, and waste disposal to a circular economy. This economy relies on resource reuse, waste recycling, and reprocessing. The circular economy presents Jordan with a promising opportunity to achieve sustainable development, encompassing environmental commitments, economic growth, increased GDP, and job creation.
Regarding waste management, the most prominent feature of the waste management system is the collection and disposal method. Municipalities and the Greater Amman Municipality are responsible for collecting solid waste from residential areas and transporting it to the Ghabawi landfill, which receives waste from the capital, and the Al-Akeeder landfill in the north.
Recycling is currently limited to only 7% of waste, compared to 60% of biodegradable organic waste. Jordan is currently working to increase support for programs and projects that encourage sorting at the source and converting waste into energy. However, one of the most significant shortcomings in Jordan’s waste management is the heavy reliance on open landfills, along with structural and environmental challenges.
Population growth is placing immense pressure on infrastructure, and the primary drawback is the lack of sorting and recycling. The Kingdom relies on mixed waste collection, with organic waste constituting the largest percentage (63%), and depends on traditional landfills. The practice of burying waste and not utilizing it creates a significant burden, leading to groundwater and soil pollution and greenhouse gas emissions. There is also limited private sector participation in attracting major investments to convert waste into energy[16].
General Waste Generation and Composition Rates in Amman
Amman’s current population is 3 million. The average waste generation per person ranges from 0.6 to 1 kg/person/day, equivalent to an average design capacity of 0.8 kg. The total volume of waste in Jordan is expected to increase to 6.57 million tons by 2050, based on an estimated population growth of 22.5 million. The table below shows the proportions of solid waste components in Amman, representing the overall mix of waste generated in the city. This is essential for determining the economic and environmental viability of recycling processes[17].
| Component | Percentage (%) | Nature and characteristics |
| Organic waste ( food scraps) | 63,4% | It represents the largest part and is characterized by a high humidity level. |
| Paper and cardboard | 14,76% | Recyclable and increasing in high-income areas |
| Plastic | 13,57% | Its proportion increases in industrial and poor areas. |
| Metals and cans | 3,20% | It is heavily concentrated in East Amman, reaching up to 12%, due to workshops and factories. |
| Glass | 2,56% | A biodegradable material with good recycling potential |
| Other miscellaneous waste | 2,87% | Includes textiles, wood, and various umbrellas |
Site Selection Criteria
Despite the previous environmental indicators and challenges facing the solid waste management sector in Jordan, it has become necessary to move away from traditional solutions based on total landfilling to well-studied and smart engineering and architectural solutions. The (New Amra) project in Amman was chosen to be the first area to embody sustainability and environmental friendliness. Since the smart project is under study and implementation, which I will present with hypothetical statistics in the area, and based on precise planning and environmental parameters that serve sustainability goals, the strategic open location of the New Amra area is located in an expansion area and provides high flexibility for designing an integrated environmental facility.
Its proximity to the planning road network is located within a geographical route that facilitates the process of collecting waste from different areas and redirecting it. The diversity of the nature of the waste, as the site is close to the eastern and southern sides of Amman, the site receives a mixture of collecting residential organic and solid waste. The site will establish a waste station suitable for the New Amra area itself and the eastern and southern extensions.
Estimated and hypothetical design calculations for the new city of Amra
Given that the new city of Amra is a future city under development and expansion, and has not yet been fully implemented, the projections were based on a hypothetical planning model with projected target population (phase one)
For phase one, we assume the area will accommodate 250,000 people, and the average waste generation per capita, according to national studies in Amman, is 0.8 kg/person/day.
Equation for calculating the city’s total daily waste
Converting kilograms to tons
Total=200,000/1000=200 tons/day
Estimate of component sizes based on official Amman city proportions
The percentage is based on a hypothetical total of 200 tons/day, resulting in the calculation of the waste entering the factory daily:
| Component | Default percentage % | Expected quantity (tons/day) |
| Organic waste (food scraps) | 63% | 126 tons/day |
| Paper and cardboard | 15% | 30 tons/day |
| Plastic | 13,5% | 27 tons/day |
| Metals, glass and other materials | 8,5% | 17 tons/day |
| Total | 100% | 200 tons/day |
Adapting the power supply of the plant/station designed with the default outputs
The mechanical sorting line, with its conveyor belts and magnetic separators, is designed to accommodate any future population growth or peak, with an operational capacity of up to 250 tons/day. This includes 57 tons of plastic waste.
The biological recycling and composting unit, given that organic waste constitutes 126 tons/day, occupies the largest section of the station. It features anaerobic digesters and a mechanical aerobic composting units capable of handling large quantities.
The design aims to reduce landfill volume by 80-90%, leaving only non-organic materials for recycling as the final disposal method. This makes the city more sustainable.
Architectural Design Vision
The design vision for the project is to move away from traditional industrial facilities, which are merely places for waste disposal, towards a redesign of a vibrant green infrastructure that integrates with the future urban fabric of the new city of Amra. The design vision focuses on three axes:
The massing and site simulation through the ground architecture are inspired by the open land of Amra, and the design masses are on horizontal lines that are in harmony with the topography, thus reducing the visual impact Intelligent building orientation involves orienting architectural openings to maximize prevailing winds, while designing facades to deflect sunlight on heat-exposed sides.
Complete separation is maintained between the movement of trucks responsible for transporting waste and the path of employees and visitors. Operations that produce odors or emissions are confined within isolated and airtight concrete blocks under negative air pressure, while offices and educational facilities open green internal courtyards to provide a healthy and suitable working environment.
Sustainability and transforming the facility into an environmental landmark
The waste-to-energy project is self-sufficient, embodying the principle of sustainability and transforming the project into a net-zero energy facility. The project, with its rooftop terrace surrounded by gardens, is not limited to engineering; it also includes an environmental awareness and innovation center containing educational halls and elevated glass walkways that allow visitors and students to observe smart sorting and recycling processes.
References
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[3] Ellen MacArthur Foundation, “Towards a Circular Economy: The Economic and Commercial Reasons for Accelerating the Transition,” KAWS, United Kingdom, White Paper, 2013.
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[6] Copenhagen Municipality, “Copenhagen Climate Plan: Towards a Carbon-Neutral Capital,” Copenhagen, Denmark, Official Policy Document, 2012.
[7] Greater Amman Municipality, “Solid Waste Management Strategy for the Greater Amman Area: Operational Assessment of the Ghabawi and Al-Akaider Landfills,” Amman, Jordan, Technical Report, 2021.
[8] Ministry of Environment, “National Solid Waste Management Strategy and Bioenergy Targets in the Hashemite Kingdom of Jordan,” Amman, Jordan, Strategic Report, 2020.
[9] Bjarke Ingels Group (BIG), “Copenhell/Amager Pack: Project Documentation, Rooftop Ski Slopes, and Architectural Study,” Copenhagen, Denmark, 2019.
[10] Babcock & Wilcox Volund, “DynaGrate® Technology: Advanced Mechanical Combustion Grids for Waste-to-Energy Plants,” Technical Specifications Manual, Denmark, 2018.
[11] Architectural Review, “Industrial Landmarks: Materiality, Spatial Fluidity, and Architectural Rhythm of Copenhall Station,” International Journal of Space and Structure, Vol. 44, No. 1.3, pp. 202–215, 2020.
[12] E. Hansen, “Chemical Composition and Recyclability of Bottom Ash and Flue Gas Residues from Modern Waste-to-Energy Plants,” Waste Management, Vol. 3, pp. 202-215, 2020. 92, pp. 45-56, 2019.
[13] Environmental Protection Agency, “Visualizing the Carbon Footprint: CO2 Emission Scale and Public Awareness Initiatives in Modern Industrial Design,” Environmental Technology Review, 2021.
[14] Aluminum Engineering Society, “Extruded Aluminum Casings, Interlocking Systems, and the Longevity of Waste-to-Energy Infrastructure,” Industrial Design Studies, 2022.
[15] National Environment Agency of Singapore, “Tuas Nexus: Singapore’s First Integrated Waste Treatment and Water Recycling Facility,” Singapore, Strategy Executive Report, 2020
[16] Public Utilities Council and National Environment Agency, “Co-Site Synergies, Thermal Efficiency, and Phase I Design Criteria for the Tuas Nexus Project,” Singapore, Technical Review. 2021.
[17] Kippel Segers, “Waste-to-Energy Plant in Tuas Wan and Co-Site Infrastructure with the Water Reclamation Plant in Ulu Bandan,” Industrial Engineering Case Studies, Singapore, 2022.,
