*Article* **A Techno-Economic Analysis of Sustainable Material Recovery Facilities: The Case of Al-Karak Solid Waste Sorting Plant, Jordan**

**Esra'a Amin Al-Athamin 1, Safwat Hemidat 2, Husam Al-Hamaiedeh 1,\*, Salah H. Aljbour 3, Tayel El-Hasan <sup>4</sup> and Abdallah Nassour <sup>2</sup>**


**Abstract:** Solid waste sorting facilities are constructed and operated to properly manage solid waste for both material and energy recovery. This paper investigates the possible technical and economic performance of the Al-Karak solid waste sorting plant in order to achieve financial sustainability and increase the profits that return on the plant to cover its operating costs. A standard procedure was followed to quantify and characterize the input materials of commercial solid waste by determining the recyclable materials in the sorting products. Thus, possible different equipment and material flows through the plant were proposed. An economic model was used in order to know the feasibility of the proposed options of the plant according to three economic factors, which are net present worth (NPW), return on investment (ROI), and payback period values. The results inferred that the characterization of the input materials contains a high portion of recyclable materials of paper, cardboard, plastic, and metals, which accounted for 63%. In this case, the mass of rejected waste to be landfilled was 9%. Results for the proposed options showed that the economic analysis is feasible when working loads on three and two shifts with ROI values of 4.4 and 3.5 with a payback period of the initial cost in 2 and 3 years, respectively. Working load on one shift was not feasible, which resulted in an ROI value of less than 2 and a payback period larger than 5 years. This paper recommended operating the sorting plant at a higher input feed with a working load on three shifts daily to ensure a maximum profit and to reduce the amount of commercial solid waste prior to landfilling through the concept of sorting and recycling.

**Keywords:** Al-Karak sorting plant; commercial solid waste; economic analysis; technical model structure; Jordan

#### **1. Introduction**

Solid waste (SW) is an environmental problem in both developed and developing countries. Solid waste management (SWM) is a challenge for municipalities in developing countries, owing to the growing amount of waste produced, the financial strain placed on municipal budgets as a result of the high costs associated with its management, and a lack of understanding of the many factors that influence the various stages of waste management and the interconnections required to enable the entire handling system to function [1].

The substantial volume increases in SW produced, as well as the qualitative changes in its composition as a result of major changes in living standards and conditions, have complicated SWM [2]. In Jordan, millions of tons of municipal solid waste (MSW) per year are generated from various sources such as agriculture, municipal, commercial, and

**Citation:** Al-Athamin, E.A.; Hemidat, S.; Al-Hamaiedeh, H.; Aljbour, S.H.; El-Hasan, T.; Nassour, A. A Techno-Economic Analysis of Sustainable Material Recovery Facilities: The Case of Al-Karak Solid Waste Sorting Plant, Jordan. *Sustainability* **2021**, *13*, 13043. https:// doi.org/10.3390/su132313043

Academic Editor: Silvia Fiore

Received: 25 October 2021 Accepted: 23 November 2021 Published: 25 November 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

industrial sectors, primarily due to population growth and the recent refugee influx, which have put additional strain on the country's already strained SW infrastructure. Landfilling is the primary disposal method of MSW in Jordan. Several types of landfills are located in different areas of Jordan [3–7]. These landfills are operated by Joint Service Councils (JSCs), which usually serve multiple municipalities in the same governorate with dual supervision from the ministry of environment and the ministry of municipalities [8].

The integrated solid waste management (ISWM) concept was introduced recently in Jordan. It contains the collection, sorting, composting, and incineration of medical wastes and sanitary landfills, which started to be implemented. However, recycling, reuse, and resource recovery are still at their initial stages [3].

Waste sorting is a key step in municipal solid waste management (MSWM) for materials recycling [9]. Jordan's MSW sorting and recycling processes are still in the early stages. Non-governmental organizations and other international organizations, such as the German International Cooperation Agency (GIZ), are responsible for the vast majority of recycling pilot programs in Jordan [10]. The idea of the sorting system is to be able to recycle valuable materials that can be sold to the market at competitive prices [11].

The Al-Karak sorting plant is one of these pilot projects in Al-Karak Governorate/Jordan. It was established in April 2019 in the El-Lajjun area. The plant is currently equipped with different basic kinds of SW handling equipment such as a mechanical conveyor belt, bale presses for cardboard and plastic, and a shredder for specific types of plastic waste. Additionally, it has two waste compression trucks. The plant was designed on infrastructure suitable to receive only dry waste (recyclable materials) from the targeted sources (separated at the source) that generated from commercial areas. The most important targeted materials according to the plant design are paper and cardboard, mixed types of plastics (polyethylene (PE) and polypropylene (PP), including colored type, polyethylene terephthalate (PET), and polystyrene (PS)), ferrous and non-ferrous metals, and any other recyclable material of a marketing value. Currently, there are no advanced mechanical treatment equipment such as screeners, air sifters, ballistic separators, or NIR separators being employed within the sorting plant to handle mixed recyclable materials efficiently. Re-designing the existing sorting plant to handle mixed recyclable materials can assist in increasing the profitability of the plant by increasing the capacity of the plant and ensuring a sustainable operation in the supply chain.

Techno-economic studies can assist in identifying the strengths and weaknesses in a proposed design or operation. They can assist in the reduction of unnecessary costs and investment risk. Raul et al. [12] performed a study by proposing different equipment or advanced technologies to an existing construction and demolition waste (C&DW) plant. The study assessed the feasibility of three different production rates of recycled aggregates (100 kt, 400 kt, and 600 kt). The economic analysis used the net present value (NPV) as a performance indicator. The economic analysis involved determining the initial investment costs and the cost of equipment. In addition, the operational costs, namely energy costs, labor costs, maintenance costs, water consumption, waste disposal costs, and insurance costs, were also determined. Operational costs showed that labor costs and energy costs were responsible for 4 and 25% of the incurred costs, respectively. Cimpan et al. [13] conducted a techno-economic assessment of central sorting at material recovery facilities. The study considered the case of lightweight packaging waste in Germany. The researchers developed four models, each with a different capacity (size) and technical degree. They revealed the cost impact of economies of scale, as well as complimentary relationships between capacity, technology, and process efficiency. As a result, a fourfold increase in capacity resulted in a threefold increase in total capital investment and a 2.4-fold increase in annual operational expense. Volk et al. [14] assessed the mechanical recycling, chemical recycling, and sequential complementary combination of both with respect to global warming potential (GWP), cumulative energy demand (CED), carbon efficiency, and product costs. The techno-economic and environmental assessment approach considered a case study on the recycling of separately collected mixed lightweight packaging (LWP) waste in

Germany. In comparison to the baseline scenario with the state-of-the-art mechanical recycling in Germany, combined mechanical and chemical recycling of LWP waste possessed significant savings potential in terms of GWP, CED, cost, and a 16% better carbon efficiency. Larrain et al. [15] investigated the economic feasibility of mechanical recycling for plastic waste. The findings revealed that the economic incentives for recycling plastic packaging are mostly determined by the product price and yield. In a scenario with steadily rising oil prices, the most profitable plastic fraction to be recycled is polystyrene, which has an internal rate of return of 14 percent, whereas the least profitable feed is a mixed polyolefin fraction, which has a negative internal rate of return. Mechanical recycling is not viable if no policy changes are enforced by governments, assuming a discount rate of 15% over a 15-year period.

The main objective of this study as to investigate the possible technical improvements that can be installed at the existing sorting plant in Al-Karak city, Jordan, in order to achieve financial sustainability that returns on the plant to cover its operating costs and to achieve an environmental aim by reducing the amount of commercial solid waste (CSW) that has to be disposed of in the landfill. First, a standard procedure was followed to characterize CSW generated in Al-Karak. Second, an economic analysis was used to evaluate the feasibility of the proposed options model of the sorting plant, which relies on present worth (PW), return on investment (ROI), and payback period values.

#### **2. Materials and Methods**

#### *2.1. Study Area*

The study area was restricted to Greater Al-Karak Municipality (Qasabah). According to the Jordan National Census, the population of Greater Al-Karak Municipality in 2019 was 112,060 [16].

The municipality and the JSC in Al-Karak are daily responsible for the cleaning, collection, and disposal of SW generated from households and commercial areas and management of the El-Lajjun landfill. MSW in Greater Al-Karak Municipality is collected from 15 districts. These districts are: Al-Karak city, Zaid Bin Al-Harithah, Al-Hiwiyah and Al-Talajah, Wadi Al-Karak, Al-Marj, Al-Thaniyah, Zahhoom, Al-Jadidah, Manshiat Abu Hammour, Al-Waysiyyah and Rakin, Al-Ghwair, Batir, Al-Adnanyah, Adr, and Al-Shihabiyah. A recent study carried out by Al-Hajaya et al. indicated that the average daily production rate of MSW in Greater Al-Karak Municipality is 61.50 tons/day [7].

The Al-Karak sorting plant is located opposite the El-Lajjun landfill site. The current daily MSW input feed to the landfill is between 200 and 250 tons/day, and the rate of CSW from the MSW is about 20% [17].

#### *2.2. Input Materials Definition*

CSW is defined as all types of SW generated by for-profit or non-profit retail stores, offices, restaurants, warehouses, education sectors, entertainment sectors, and other nonmanufacturing activities, excluding residential, industrial, construction, and institutional waste or other MSW generated by home-based businesses. CSW contains a high portion of recyclable materials [18]. In this study, CSW fed to the plant was collected from different commercial areas in order to investigate the potential of utilizing CSW as recyclable materials.

#### *2.3. CSW Collection Process*

The parent population for a CW analysis campaign is the whole quantity of commercial waste, which may be sampled from and subsequently analyzed. This may encompass the whole area of a municipality or a defined part of a municipality.

Based on the "Methodology for the Analysis of Solid Waste" of the European Commission [19], a number of criteria must be applied in conducting the sampling. The total number of samplings required must consider the variation (heterogeneity) of the waste, expressed by the natural variation coefficient, as well as the number of samplings required

to obtain the desired accuracy of results. In the case that the variation coefficient is unknown due to the unavailability of results from past waste analyses, it is recommended to have a sample size of 100 m3 to carry out the waste analysis. However, in our case, the above-mentioned procedure could not be applied since the variation coefficient was unknown due to the unavailability of results from past waste analyses. In addition, it was impossible to collect 100 m3 of CW due to limited logistics.

To avoid a low level of accuracy in the results, all the districts in Greater Al-Karak Municipality responsible for CW generations were considered for collecting the waste. The study included every sector in the commercial areas that consist of malls, supermarkets, restaurants, and garden centers. These commercial areas are supposed to supply the sorting plant of SW. Furthermore, CSW collected from offices and the educational sectors at the Military Wing in Mutah University was carried out through a collaboration between Greater Al-Karak Municipality and Mutah University. Table 1 indicates the targeted commercial areas in this study.

**Table 1.** Targeted commercial areas in Al-Karak city (Input materials).


It is worth mentioning that the targeted areas considered in this study for CW collection are responsible for approximately 48% of MSW generated in Greater Al-Karak Municipality [7]. The selected targeted areas being characterized by a high MSW contribution within the municipality will render an adequate and representative CW analysis result.

The study involved awareness programs for the staff responsible for SW sorting at the source in the selected targeted areas. Special bins are also distributed to collect the sorted SW. Table 2 shows the scheduled time for the source-separated CSW collection process.



According to the time schedule, all of the targeted areas were numbered by special codes based on the farthest area from the sorting plant to the closest area, then the sourceseparated CSW collection process was divided into two shifts during seven consecutive days in July 2020, based on the locations of the targeted areas and the business hours

(especially in the Military Wing at Mutah University). The first shift of the collection process involved the targeted areas (A1, A2, and A3), respectively, at 10:00 a.m. for a period of four days starting from Sunday to Wednesday. Then, the second shift, which targeted the areas (A4, A5, A6, and A7), respectively, at 2:00 p.m. for a period of three days starting from Thursday to Saturday. The sorting truck started the collection process of the source-separated SW from the bins and cardboard cages, then transported them to the plant in the El-Lajjun area. The weight of the collection truck was carried out through a weighbridge balance, then the collection truck unloaded the CSW at the reception site. At the end of the source-separated collection process, a total amount of 2242 kg was collected from the targeted areas.

#### *2.4. CSW Sorting Process*

After the delivery of about 2242 kg of CSW, the waste bags were opened by knives and sorted on site manually to separate the waste into fractions. The manual sorting was carried out on the floor of the reception site of the plant without using the conveyor belt. The sorting process was conducted by eight workers (two days, four working hours per day). The weight of each sorted fraction of waste was measured by using an electronic platform balance. The cardboard fraction was first pressed into a bale, then the weight of the bale was measured.

#### *2.5. CSW Categorization*

Waste characterization is an essential component of a waste analysis or the determination of waste composition. Waste characterization was carried out on the basis of the "Methodology for the Analysis of Solid Waste" of the European Commission [18]. The CSW compositions were divided into ten categories. As shown in Table 3, CSW was subdivided into two primary categories (organic fractions and inorganic fractions). The organic fraction consists of materials generated from garden centers and restaurants such as food waste and green waste. The inorganic fraction consists of plastic, cardboard, paper, and metals. Plastics were further classified into four types such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), and polystyrene (PS). Metals were divided into ferrous and non-ferrous (aluminum), while the rest of the waste consisted of textiles, glass, wood, hygienic products, and compound materials.


**Table 3.** Sorting fractions of waste samples (manual sorting analysis).

The percentage of each waste category of the sorted output products were calculated according to the following formula:

$$\% \text{ of sorted output products} = \frac{\text{M}\_{\text{output}}}{\text{M}\_{\text{input feed}}} \times 100 \tag{1}$$

where:

Moutput: the mass of an output product; Minput feed: the total feed input including residues quantities.

#### *2.6. Economic Model*

The information obtained from the sorting and categorization process is utilized to assess different technical scenarios for the sorting plant to operate. The different technical scenarios involve the installation of different equipment at the existing sorting plant in Al-Karak. Each scenario is economically analyzed and assessed. The economic feasibility comprised determining the capital investment costs, operating costs, and revenues of the plant's output recyclable products. The capital costs included the installed costs of the new equipment to be added to the existing sorting plant.

The operating costs included labor salaries, diesel consumption costs, electricity consumption costs, insurance costs, and maintenance and depreciation costs. The annual maintenance and depreciation costs are assumed to be 3.5% of the total capital cost. The annual insurance cost is assumed to be 0.25% of the total capital cost.

Transportation cost was not included in the operating cost. The recyclable products from the sorting plant are sold through bidding, in which bidders are committed to transferring the products from the plant. The disposal cost was not included in the operating cost because the process of waste disposal waste is the responsibility of Greater Al-Karak Municipality.

The revenues are estimated according to the current Jordanian market prices in Jordanian dinar (JOD). The selling price for either paper or cardboard is 35 JOD per ton. Ferrous metals will be treated as steel with a selling price of 65 JOD per ton. Non-ferrous metals are treated as aluminum with a selling price of 600 JOD per ton. The selling prices of PET, PP, and PE are 80, 250, and 130 JOD per ton, respectively.

The economic feasibility was assessed by calculating three economic indicators, namely: net present worth (NPW) of the project, return on investment (ROI), and payback period. The economic indicators used in the assessment process were calculated according to the following formulae:

$$\text{NPW} = \text{Initial Investment} + \sum \text{PW} \tag{2}$$

$$\text{PW} = \text{F} \times \frac{1}{(1+\text{i})^{\text{N}}} \tag{3}$$

$$\text{ROI} = \frac{\text{Sum of all profits}}{\text{Initial Investment}} \tag{4}$$

where:

F is the annual revenues = (Annual sales) − (annual expenses), i is the interest rate (10%), and N is the operating year. A lifetime of 15 years is assumed for the plant.

The payback period is the amount of time it takes to recover an investment's initial cost. It is the period of years it would take to recover a project's original expenditure [20].

#### **3. Results and Discussions**

*3.1. CSW Characterization*

CSW was classified into ten categories. Figure 1 shows the percentage of each waste fraction in the CSW. Table 4 shows the weight of each waste fraction in the CSW.

**Figure 1.** Waste fractions in the main input CSW from Al-Karak city (terms used in Table 3).


**Table 4.** Weight of waste fractions in the main input CSW from Al-Karak city.

An inspection of the waste fraction results indicates that the overall CSW composition contained three main parts, namely cardboard (41%), organic matter (28%), and plastics (15%). The remainder accounted for 16% of the total and contained 4% metals, 3% paper, and 9% other waste. The CSW contained a high portion of recyclable materials such as paper, cardboard, plastic, and metals, which accounted for 63%. These findings are in agreement with the results reported in the literature. For example, results of the federal ministry for the environment in Germany indicated the presence of around 52% of recyclable materials in CSW in Germany [21]. Another study indicated 60% of potential recyclables in CSW in Germany [22].

The organic fraction can be utilized for compost production by aerobic digestion in the compost plant, which is constructed beside the sorting plant. Pilot studies indicated that high-quality compost can be produced when the source-separated organics (food and green) are utilized [4]. Figure 2 shows the material flow of CSW from Al-Karak city.

**Figure 2.** Material flow of CSW compositions from Al-Karak city.

It can be seen that the waste recycling and recovery are 63% and 28%, respectively, while the expected waste to be sent to landfills is 9% of the generated CSW. From environmental and economic perspectives, waste recycling and recovery will reduce the demand for new raw materials, such as cardboard, paper, and plastic. It will reduce the amount of waste generated and thus decrease the pressure on landfills and contribute to increasing the lifetime of the landfill. In addition, it will reduce the emissions of odors, landfill gas, and leachate.

The best utilization of CWS requires technical improvements in the design of the current sorting plant. Different equipment can be installed at the existing sorting plant to enhance the recycling process to achieve maximum economic return. The next sections provide an economic analysis of the recycling process.

#### *3.2. Potential Revenues from Waste Recyclables*

The current daily MSW input feed to landfills is between 200 and 250 tons/day, and the rate of CSW from the MSW is about 20% [17]. Accordingly, an average of 45 tons/day (11,925 tons/year) of CSW is expected to be generated in Al-Karak Governorate. Assuming that the CSW fractions in Al-Karak city are the same as the CSW fractions in Al- Karak Governorate, then the potential amounts of waste recyclables can be estimated along with the expected sales (Table 5).

**Table 5.** Potential amounts of waste recyclables and the expected sales at Al-Karak Governorate.


\* Year for collection waste = 265 days.

In order to achieve these annual revenues from Al-Karak Governorate, high levels of awareness and public participation are needed. Appropriate legislation from the municipalities and financial incentives are also needed to promote public awareness with respect to separation at the source. Effective collection and sorting of CSW are expected to achieve annual sales at 549,743 JOD/year. The technical possible improvement that can be installed to the current situation of the sorting plant is to install an NIR separator and ballistic separator. Figure 3 shows the flow diagram of the new technical structure of the sorting process.

**Figure 3.** Flow diagram of the new technical structure of the sorting process.

As can be seen in Figure 3, after bulky waste sorting, the input feed (CSW) will be directed into a ballistic separator where materials are separated based on their shapes into 2D and 3D materials. The 2D feed is transferred to the manual sorting. Here, the components will mainly contain PE, paper, and cardboard, while the 3D feed is transferred to the manual sorting firstly to separate metals, then to the NIR separator in order to separate different kinds of plastics efficiently such as PET, PP, and PE.

#### *3.3. Capital Investment Costs*

The current sorting plant has a bale presser, one conveyor belt, plastics shredder, forklift, and two waste collection trucks, all operating at high efficiency. The sorting plant has a hanger constructed on land owned by the municipality. Therefore, the new proposed design of the sorting plant requires only the purchase and installation of the new equipment

along with their auxiliaries as capital costs. The total capital cost for the new design is detailed in Table 6.

**Table 6.** Total capital cost for the new design.


#### *3.4. Annual Operating Cost*

3.4.1. Worker and Personnel Salaries

The total number of employees at the sorting plant is 33, working three shifts a day. The employees are 6 drivers, 24 workers, and 3 officers. The annual costs due to salaries are illustrated in Table 7 [23].

**Table 7.** Labor and personnel salaries.


#### 3.4.2. Utility Costs

The utility costs comprised basically the cost of fuel consumed by the waste collection trucks and the cost of electricity consumed by the equipment. Each waste collection truck has a capacity for diesel fuel of 100 L. The 100 L will be consumed in 2 days; accordingly, the number of filling times in the year will be:

$$\text{Filling times per year} = \frac{\text{working days}}{\text{Diesel consumption days}} = \frac{264}{2} = 132 \text{ times} / \text{track/year}$$

The cost of 100 L diesel is 50 JOD; thus, the total diesel consumption per year will be:

$$132 \text{ times}/\text{true}/\text{year} \times 2 \text{ trucks} \times 50 \frac{\text{JOD}}{\text{Filling}} = 13,200 \text{ JOD}/\text{year}$$

Electricity is supplied to the Al-Karak sorting plant through the Electricity Distribution Company (EDCO). The electrical consumption category is considered as small industries according to the EDCO [24]. Electricity costs for this category are shown in Table 8.

**Table 8.** Electricity costs for the category "small industries".


The proposed model requires operating the plant for 24 h through three working shifts. The total electricity consumption and costs are shown in Table 9 [23].


**Table 9.** Electricity consumption Costs.

3.4.3. Maintenance and Depreciation Costs

Maintenance and depreciation costs are assumed to be 3.5% of the total capital cost.

Maintenance costs = 0.035 × 394,000 = 13,790 JOD/year

Depreciation costs = 0.035 × 394,000 = 13,790 JOD/year

3.4.4. Insurance Costs

Insurance costs are assumed to be 0.25% of the total capital cost.

Insurance costs = 0.0025 × 394,000 = 985 JOD

The above calculations indicate that the total annual operating cost is 266,772 JOD/year. Figure 4 shows the percentage of the contributing factors in the operating cost.

The results of the total yearly operating expenses revealed that labor and personnel costs are responsible for 50% of the yearly expenses. Electricity consumption costs accounted for 34% of the yearly expenses. Depreciation, maintenance, and fuel consumption costs were comparable to each other and contributed to 15% of the yearly expenses.

**Figure 4.** Percentage of operating cost components.

#### *3.5. Economic Feasibility Analysis*

To evaluate the economic feasibility of the new sorting plant design, three important economic indicators must achieve acceptable performance. Feasible investments must have a positive NPW value, an ROI of >2.0, and an acceptable payback period <5 years. Table 10 shows the cash flow calculations for the proposed sorting plant.


**Table 10.** Cash flow calculations for the proposed sorting plant.

The cash flow calculations indicate a potential NPW of 1,758,300 JOD. This indicates a rate of investment of 4.4. The payback period is less than 2 years.

The economic feasibility was re-assessed for cases when the plant is operated under one and two working shifts.

To operate the plant with two shifts, it is assumed that a total number of 22 personnel is needed and 2/3 the amount of diesel is needed. In this case, the total operating expenses in the two shifts = 187,370 JOD/year.

To operate the plant with one shift, it is assumed that a total number of 11 personnel is needed and 1/3 the amount of diesel is needed. In this case, the total operating expenses in the two shifts = 107,967 JOD/year.

The NPW, ROI, and the payback period for the new scenarios are shown in Table 11.



The results shown in Table 10 indicate that operating the sorting plant using two working shifts is economically feasible with an ROI value of 3.5 and a payback period of the initial cost in three years. However, operating the sorting plant using one working shift is economically not feasible, as the resulting ROI was less than 2 with a payback period of 8 years.

#### **4. Conclusions**

• The sorting analysis of the input materials inferred that the CSW was collected from seven targeted commercial areas and contains a high portion of recyclable materials of paper, cardboard, plastic, and metals, which accounted for 63%. In this case of the recovery of CSW materials from MSW, the mass of rejected waste to be landfilled was 9%.


**Author Contributions:** Conceptualization, A.N. and H.A.-H.; methodology, E.A.A.-A.; H.A.-H., software E.A.A.-A., S.H.A.; validation, T.E.-H. and S.H.; formal analysis, E.A.A.-A.; H.A.-H.; investigation, S.H.A.; resources, E.A.A.-A.; data curation, H.A.-H. and S.H.; writing—original draft preparation, E.A.A.-A.; writing—review and editing, H.A.-H., S.H.A. and T.E.-H.; supervision, H.A.- H.; project administration, H.A.-H.; funding acquisition, T.E.-H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) Grant number 84190076 in the framework of the Waste to Positive Energy (Wt(P)E) project, Jordan.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data reported in this study does not represent a publicly archived datasets.

**Acknowledgments:** This research is accomplished as a contribution to the Waste to Positive Energy (Wt(P)E) project in Jordan. The project is supported and funded by GIZ and with the participation of three German universities (University of Rostock (Rostock, Germany), TU Hamburg (Hamburg, Germany) and TU Dresden (Dresden, Germany)) and four Jordanian universities (Jordan University of Science and Technology (Irbid, Jordan), Mutah University (Karak, Jordan), University of Jordan (Amman, Jordan), and German-Jordanian University (Madaba, Jordan)).

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

