# Potential of Waste to Energy Conversion in Egypt

Authors: Mohamed Ezzat Salem; Hamdy Abd El-Halim; Amr Refky; Ibrahim Ahmed Nassar
Journal: Journal of Electrical and Computer Engineering
 (2022)

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## Abstract

This paper proposes a study on the potential of waste-to-energy (WTE) possibility in the Arab Republic of Egypt. WTE is a viable option for municipal solid waste (MSW) management and a renewable energy source. The issue of waste spread is a chronic environmental challenge in the Arab Republic of Egypt. The MSW practices in Egypt are simply done by collecting the waste and dumping it in open landfill sites. This research aims to assess the potential contribution of the WTE facility to meet electricity demand in Cairo City, which is Egypt’s capital and the biggest city in population as a sample, and then apply the results to all of Egypt. The paper introduced a step-by-step calculation for the electrical power that can be generated from Cairo MSW. Four scenarios for WTE utilization were developed: Mass Burn without any waste processing, Mass Burn with 25% recycling, Mass Burn excluding 50% of organic material, and Mass Burn excluding 50% of organic material with 25% recycling. The Mass Burn scenario implies full MSW stream incineration; the Mass Burn with recycling scenario considers a partial separation of reusable materials and the waste leftover for incineration; the Mass Burn with excluding 50% of organic material scenario considers a partial separation of organic materials and the waste leftover for incineration; the Mass Burn with excluding 50% of organic material with 25% recycling scenario considers a partial separation of organic materials and partial separation of reusable materials and the waste leftover for incineration. The analyses were done for the period 2011–2031 for Cairo with a total population of about 10 million in Nov 2021. The results show the huge potential of WTE conversion as a source of renewable energy, which is a key factor in Egypt’s sustainable development strategy 2030. Available data have been theoretically processed to show the decision-makers in Egypt the amount of electrical power that can be generated by using the WTE options to manage the MSW in Egypt.


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## Body

## 1. Introduction

For millennia, humans have faced great challenges in energy supply and waste management. Despite the last decade’s huge progress, these issues are still important today. To meet these challenges, every atom should be utilized in the best possible manner, which is called “atom economy.” Understanding the underlying mechanisms and processes of energy and waste generation is necessary to achieve these goals. In the last century, energy demand has increased rapidly and will continue as the rate of consumption increases as people strive to improve their living standards. The consequence of that is the rate of consumption should match the rate of conversion and generation leading to continuous power source upgrades from wood to coal to oil to natural gas to renewable energy. The energy sources cycle differs from one to another, biomass needs to be grown, harvested, dried, and processed before use, coal needs to be mined, transported, and processed before use, and oil needs to be transported and refined before use, whereas gaseous fuels, which are ready to use immediately, only need to be transported.Today, the world’s target is energy sources that are distributed and ready for immediate use with preferably no preprocessing, and a very short cycle. Energy is the main factor in any discussion about sustainable development. Solar radiation, wind, waves, and tides are all considered renewable energy sources; most scientists show their reliance on renewable energy technologies (RET) for sustainable development and long-lasting life on this planet earth for their daily energy needs, which have no negative social consequences. Accordingly, the transition to a sustainable renewable resource should be encouraged and developing countries should increase investments in it [1]. Due to inherent uncertainty and intermittency for renewable energy sources, the integration of it has brought huge challenges to the planning and operation of today’s power systems. At present, how to handle the uncertainty of renewable generations is currently the difficulty of studying the economic optimization of power systems [2, 3]. This issue has a minor effect on WTE technologies because MSW production depends on human living. Humans for thousands of years have had to take care of the waste effectively and they will have to continue to do so if the human species is to survive.Over the last decades, and all over the world, many health disasters had occurred; it was a consequence of insufficient or/and underestimates of the importance of treatment or management of waste. Today, particularly in developing nations, essentially all of society’s health concerns may be linked back to inefficient waste treatment or management. Initially, waste management focused only on human waste and sewage. It has now evolved into what we refer to as municipal solid waste (MSW), which encompasses all other non-hazardous solid trash and is increasingly concerned with gaseous pollutants [4].


## 2. Utilization of Waste-to-Energy as a Sustainable Source

WTE meets the two basic renewable energy resource criteria—its fuel source (trash) being sustainable and indigenous. According to Figure1, after efforts to “reduce, reuse, and recycle,” WTE facilities recover valuable energy from the trash. WTE facilities generate clean renewable energy and deserve the same treatment as any other renewable energy resource. Economic Forum’s Davos Report identifies eight emerging clean energy sectors including wind, solar, and waste-to-energy. The National Research Council of the National Academy of Science has identified “atom economy-zero waste” as the ideal goal for sustainability in the year 2100. Until we achieve that fully integrated system, today’s garbage should be treated to extract energy.Figure 1
Waste management hierarchy [5].WTE provides two important benefits over other forms of renewable energy. It works 24 hours a day to minimize base-load fossil fuel output and is positioned in densely populated regions where electricity is most required. In Sweden and the rest of the EU, the organic portion of waste-to-energy is recognized as a renewable resource. The United States Environmental Protection Agency USEPA states that waste-to-energy facilities “are clean reliable renewable sources of energy with less environmental impact than almost any other source of energy” [4].


## 3. Waste-to-Energy Technologies

WTE conversion is divided into main pathway conversions: thermochemical and biological conversion. Conversion technologies consist of various methods for extracting energy from waste materials. Figure2 provides an illustration of the various energy pathways for WTE [6, 7].Figure 2
Waste-to-energy technologies [6].Worldwide previous estimations related to WTE showed a twofold increase just only within 10 years from 0.68 billion tons/year in 2000 to 1.3 billion tons/year in 2010. Moreover, it is projected to reach 2.2 billion tons per year by 2025 and 4.2 billion tons per year by 2050, which will have huge potential effects on power generation. Thus, WTE is a potentially viable alternative source of energy for the future, since it can cover 10% of the world’s annual electricity demand [8].Another report argues implementing WTE technology to treat potentially 261 million tons of MSW per year by 2022, which would create around 283 tera-watt hours (TWh) of heat and electricity [9]. While solid waste incineration and landfill gas recovery (LFG) systems are the two most often used WTE approaches [10], the most financially viable alternative for the future energy system is combined MSW incineration [11]. For more than a century, several nations, such as Denmark and Sweden, have had well-established energy generating systems based on incineration. According to the statistics, trash incineration systems generate 4.8% of total electricity consumption and 13.7% of total home heat use in Denmark [12]. WTE technologies have received much attention due to significant waste volume reduction along with renewable energy production to meet the present as well as the future energy demands. The global market for these innovations is expanding at a rapid pace, as is the global need for energy and environmental sustainability. In 2013, the WTE market was valued at $25.32 billion USD, with a 5.5% raise over 2012. Thermal energy technologies dominated the market; the market is predicted to be worth approximately 40$US billion by 2023 [13].There have been a number of studies carried out to state the greater possibility of using WTE. Most of previous works did not introduce a simple and clear step-by-step calculation method for the amount of generated electric power that can be produced for WTE using incineration for quick guide for decision-makers. For example, the work in [14] introduced WTE potential in the Western Province of Saudi Arabia with three scenarios by two different technologies: incineration and refused derived fuel (RDF); it also introduced the environmental impact of using WTE. In [15], a general short study was conducted to determine the viability of electrical energy generation from the household waste using life cycle assessment (LCA) tool by two scenarios; the models generated for this study did not include the type of technology used in the conversion process but was based on simple basis of using generated gas from the waste to produce electricity. In [16], in a full study for pre-feasibility of a WTE plant, it focused on plant specification and payback; this type of research is the expected future extend work for proposed study. In [17, 18], a general overview of MSW is presented with the feasible waste-to-energy technologies only.For a research study country, a few studies were carried out to state the greater possibility of using WTE in Egypt. To the authors’ knowledge, only three academic research discussed the possibility of WTE technologies. All of them were focused on biochemical conversion for organic/agricultural waste treatment to produce a bioenergy/biogas [19–21].


## 4. Contribution of This Paper

The main contributions of this paper are summarized as the follows:(1)
This paper proposes an easy, simple, and clear step-by-step calculation method for the amount of generated electric power that can be produced for WTE using incineration for quick guide for decision-makers.(2)
To the authors’ knowledge, this is the first work to demonstrate the potential of waste-to-energy conversion in Egypt; it introduces the estimation of amount of electrical power that can be generated by using the WTE technologies by four scenarios including all available possibilities according to Egypt environmental and natural geographical conditions.(3)
Result analysis introduces a plan in three steps to implementation of WTE in Egypt.


## 5. Solid Waste Management Situation in Egypt

The issue of waste spread is a chronic environmental challenge in the Arab Republic of Egypt. Attention is paid by the State and the Ministry of Environment to this problem. The government has developed a program for developing waste management systems aiming at raising the efficiency of waste collection and transport to 80 percent and recycling efficiency to 25 percent based upon statistics and studies on population numbers and daily waste percentages, which are clearly shown in Figure3 [22].Figure 3
Percentage of solid waste collected and planned to be collected and managed appropriately [22].The Sustainability Development Strategy and “Egypt’s Vision 2030” identified pollution reduction and integrated waste management as a strategic objective to reduce air pollution loads and reduce pollution from untreated wastes with their serious environmental and health impacts while maximizing the utilization of natural resources by exploiting solid waste with a focus on municipal solid waste [23]. Table 1 summarizes Egypt’s technical performance.Table 1
Egypt technical performance [24].
Population102.598 million (2021) [25]MSW generation21.0 million tons (2010)Per capita MSW generation0.7–1.0 kg/day (urban areas)0.4–0.5 kg/day (rural areas)MSW generation growth3.4%Medical waste generation28,500 tons/year (2010)Industrial waste6.2 MT/yearHazardous waste0.2 MT/yearAgricultural waste23 MT/yearMSW collection coverage0–35% in rural areas40–85% in urban areasMSW final destination9%: composting2.5%: recycling5%: landfilling83.5%: open dumpedFigure4 shows the classification and percentage of waste materials in Egypt, illustrating that 13% plastic, 2% metal, and 4% glass may be recycled. Also, 56% of waste is organic materials plus 10% paper/cardboard which can be used in waste-to-energy conversion.Figure 4
Material composition of Egypt MSW (%) in 2010 [24].Table2 shows the municipal solid waste generated for different governments in Egypt, which shows that Greater Cairo generates 25000 tons of waste daily, which is almost 50% of daily waste generated in Egypt.Table 2
Municipal solid waste generated in different governorates [26].
AreaGovernorateUrban (%)Rural (%)Generated waste (tons/day)Greater CairoCairo100011000Giza60404000Qalubya47533500Helwan40006th October2500DeltaSharkeya23771800Monofeya20802000Damietta3961900Gharbeya31693000Kafr Sheikh2500Dakhleya30704500Behyra24763000Upper EgyptFayoum2278600Beni Suef750Menya18821000Assuit3070700Sohag2278900Qena20801000Luxor3070250Aswan650Wadi Gedid5050100Coastal zoneAlexandria10003700Matrouh6040250Port Said8020650Suez1000400Ismailia4456600Red Sea964450SinaiNorth Sinai6040200South Sinai5149350Total55250


## 6. Methodology

In this section, a step-by-step full detailed calculation of electric power generated from MSW in Cairo is presented. The calculation process has five main steps as shown in Figure5.Figure 5
Calculation process of electric power generated from MSW.


### 6.1. Calculation of the Projected MSW Generation in the Period 2010–2031

There are two methods to calculate projected MSW generation in Cairo for the studying period from 2011 to 2031.


#### 6.1.1. First Method

Depending on historical and future population trends in Egypt, 2011–2031 by the Central Agency for Public Mobilization and Statistics (CAPMAS), which are shown in the Population section, assume that per capita municipal solid waste (MSW) generation in 2010 stays the same until 2031 [27].For projected MSW calculation for Egypt. As mentioned in Section4, per capita (MSW) generation has two values: 0.4–0.5 (kg/p/d) for rural zones and 0.7–1 for urban zones, assuming average per capita (MSW) generation 0.45 (kg/p/d) for rural zones and 0.85 for urban zones. CAPMAS states in the 2013 population report that in midyear 2012 the total urban population was 35373 (42.9%) and the total rural population was 47177 (57.1%) (OCT. 2021 total population was 102.598 million) [25, 26]. Projected MSW generation in Egypt in two different zones is calculated using(1)P_MSW_G=PC_MSW∗ZP,whereP_MSW_G: projected MSW generationPC_MSW: per capita MSW (Kg/p)/dayZP: zone populationFor projected MSW calculation for Cairo, according to CAPMAS, Cairo city is a purely urban zone and has 11% of Egypt’s total population. So, by applying equation (1) and using high per capita (MSW) generation 1 (kg/p/d), as it is urban zones with the highest life expectancy in Egypt, Figure (1) shows projected MSW generation for Egypt (urban and rural zones) and Cairo in the study period 2011–2031 by using the per capita MSW generation value and by using estimated population by CAPMAS. This method gives results lower than that stated in Table 1, which states that all of Egypt (urban and rural zones) in 2010 generated 55250 1000 tons/day and Cairo itself generated 11000 tons/day. On the other hand, this method shows that Egypt in 2011 generated 49590 tons/day and Cairo generated 8775.8 tons/day.Figure 6
Projected MSW generation for Egypt (urban and rural zones) and Cairo in the studying period 2011–2031 by the 1st method.


#### 6.1.2. Second Method

Quantity of municipal solid waste (MSW) generated in 2010 (21 million tons) as stated in Egypt Technical Performance assumed to be the base of the study and by using an MSW growth rate of 3.4% the projected MSW generation in the studying period will be calculated. Figure7 shows the projected MSW generation for the whole of Egypt and Cairo in the studying period 2011–2031 by using an MSW growth rate of 3.4% with the year 2010 as a base. It shows also that the generated MSW will double in 20 years (the studying period) so if the solution does not start today, the problem will become a crisis in the near future.Figure 7
Projected MSW generation for Egypt (urban and rural zones) and Cairo in the studying period 2011–2031 by the 2nd method.Figures6 and 7 show that the projected MSW generation calculated by the 2nd method is higher than those calculated by the 1st method. The 2nd method is more accurate than the 1st method, so in this study generated MSW calculated by the 2nd method will be used and results from the 1st method will not be taken into consideration.Figures6 and 7 state that Egypt’s Governor should handle and manage at least 57000-ton residential MSW every day. In this study, other waste types, industrial waste (6.2 million tons/year) and agricultural waste (23 million tons/year), are not taken into consideration.In both methods, the material composition percentage of MSW (organic 56%, plastics 13%, paper/cardboard 10%, metal 2%, glass 4%, and others 15%) will also be assumed to be constant over the studying period 2011–2031. This assumption is not fully right because the material composition percentage of MSW for any community depends on its life level and it is not true that Egypt’s life level over about 20 years will be constant, but for simplifying study conditions this assumption will be considered. Another assumption will be used in this study; municipal solid waste percentage generated in different Egypt governorates from the total generated MSW will be assumed to be constant from the year 2010 until 2031. As shown in Table2, in 2010 Cairo generated about 20% of the total MSW generated in Egypt, so if this percentage is still constant for the studying period, the MSW generated in Cairo will be as shown in Figures 6 and 7. Cairo governorate is chosen to be a case study for the following reasons:(i)
As mentioned previously, it produced about 20% of the total MSW generated in Egypt(ii)
It has a very high MSW collection coverage percentage of about 90%(iii)
All areas are urban; any new system can be implemented more easily than in rural areas


### 6.2. First Scenario: Mass Burn

#### 6.2.1. Calculate the Physical Composition of Solid Waste

Information and data on the physical composition of solid wastes include(i)
Identification of the individual components that make up municipal solid wastes(ii)
Analysis of particle size(iii)
Moisture content(iv)
Density of solid wastesThe waste composition percentage for Cairo is assumed to be like Egypt which is tabulated in Table1 and Figure 4. First, calculate the total weight or wet weight for each waste component by using waste calculation data for the year 2016, which is tabulated in Table 3. Second, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to(2)DW=TW−MC∗TW,where DW: dry weightTW: total weightMC: moisture contentTable 3
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component.
MaterialWaste composition (%)Total weight (Kg)Moisture content (MC) %Dry weight (Kg)Organic material567528.421819702258.526546Plastic131747.66935111730.192657Paper101344.3610395.51270.421182Glass4537.74441563521.6120832Metals2268.87220783260.8060416Other materials including textiles152016.541559101814.887403Total13443.610397856.445913Specific weight is defined as the weight of a material per unit volume (e.g., kg/m3, lb/ft3); usually, it refers to uncompacted waste. It varies with geographic location, the season of the year, and the length of time in storage. Table 4 shows typical specific weight values according to the processing method. MSW specific for Egypt is assumed to be taken as 330 kg/m3.Table 4
Typical specific weight values.
ConditionDensity (kg/m3)Loose MSW, no processing or compaction90–150In compaction truck355–530Baled MSW710–825MSW in a compacted landfill (without cover)440–740The composition of waste components is critical for recycling and recovery, even more so when mechanical techniques such as trammel screens and magnetic separators are utilized.


#### 6.2.2. Identifying the Chemical Makeup of Solid Waste

Chemical information on solid wastes is critical for assessing potential processing and energy recovery alternatives. If solid wastes are to be utilized as fuel, the following four qualities must be recognized:(i)
Proximate analysis:(1)
Moisture (loss at 105)(2)
C for 1 h(3)
Volatile matter (additional loss on ignition at 950°C)(4)
Ash (residue after burning)(5)
Fixed carbon (remainder)(ii)
Fusing point of ash(iii)
Ultimate analysis:(i)
Percent of C (carbon), H (hydrogen), O (oxygen), N (nitrogen), S (sulfur), and ash(iv)
Heating value (energy value)In the previous Section 6.2.1 dry mass is calculated; then the amount of carbon, hydrogen, oxygen, nitrogen, sulfur, and ash content is calculated for each type of waste using a standard table of ultimate analysis of combustible waste (Table5 and equation (3)).where EC: element contentDM: dry massSUAMP: standard ultimate analysis mass percentTable 5
Typical percent by weight.
Percent by weight (dry basis)ComponentCarbonHydrogenOxygenNitrogenSulfurAshOrganicFood wastes48.06.437.62.60.45.0Paper43.56.044.00.30.26.0Cardboard44.05.944.60.30.26.0Plastics60.07.222.8——10.0Textiles55.06.631.24.60.152.5Rubber78.010.0—2.0—10.0Leather60.08.011.610.00.410.0Yard wastes47.86.038.03.40.34.5Wood49.56.042.70.20.11.5InorganicGlass0.50.10.4<0.1—98.9Metals4.50.64.3<0.1—90.5Dirt, ash, etc.26.33.02.00.50.268.0(3)EC=DS100∗SUAMP.From Table3, dry waste weights are 7856445.913 kg, and the total waste weights are 13443610.39 kg. Then, subtract the weight of the dry waste from the total weight of waste to give the weight of the water in the waste.(4)13443610.39−7856445.913=5587164.47KgH2O.Now to determine how much hydrogen and oxygen in kg there are in the waste, we do this by using(5)TWMWt−W∗MMWt−H,whereTW: total moisture in kgMWt-W: molecular Wt of waterMWt-H: molecular Wt of hydrogen(6)5587164.478.165∗0.907=620643.99KgH,TWMWt−W∗MMWt−O,where MWt-O is the molecular Wt of oxygen.(7)5587164.478.165∗7.257=4965836.19Kg O.Now, revised mass is calculated for solid waste, as moisture in solid waste converts into hydrogen and oxygen due to heat in incinerators. The final revised mass of element content of whole Cairo solid waste can be seen in Table6.Table 6
Revised element content.
ElementMass w/o water (kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3650622.4843650622.48427.85H (hydrogen)465170.29491085814.2858.28O (oxygen)1865341.2736831177.46352.12N (nitrogen)125850.7454125850.74540.96S (sulfur)15749.1895715749.189570.12Ash1396652.651396652.6510.66Total7519386.63713105866.82


#### 6.2.3. Calculation of Waste Heat Energy (Waste Calorific Value)

To calculate heat energy or calorific values (higher heating values HHV) generated by the whole of Cairo city’s solid waste, Dulong’s formula needs to be applied. Dulong’s formula is described in equation (7).(8)HEHHV=337C+1428H−O8+9S,whereHE = heat energy (kJ/kg)C = carbon (%)H = hydrogen (%)O = oxygen (%)S = sulfur (%)N = nitrogen (%)Putting percent by mass value from Table6 into Dulong’s formula, HHV generated by Cairo city’s total waste is obtained:(9)CairowasteHHV=337X27.85+14288.28−52.128+9X0.12=11906.95kJkg.The calorific values were again calculated by using the Dulong equation, considering nitrogen in(10)HEHHV=337C+1419H−0.125O+93S+23N.(11)CairowasteHHV=337X27.85+14198.28−0.125X52.12+93X0.12+23X0.96=11923.225kJkg.The difference between calculations using equations (8) and (10) is very small. So, less HHV value will be considered.Lower heat value (kJ/kg) (LHV) is the net energy released on combustion.(12)LHV=HHV−2.766XW,whereLHV (KJ/KG): lower heat value.W = moisture content2.766 kJ/kg = coefficient of heat requirement for evaporation.(13)CairoLHV=11906.95−2.766X41.56=11809.645KJKg.In the next sections, the lower heat value (LHV) for Cairo city’s waste will be used, which is the net heat energy generated = 11809.645 kJ/kg.


#### 6.2.4. Calculation of Electricity Generated

To figure out how much power a building needs, many processes must be taken. The heat created is first utilized to compute steam energy, which accounts for 70% of heat energy. A net electric power produced by solid waste is estimated after subtracting station service allowance and heat losses from the steam energy calculation. All of this may be seen in the gallery:(14)SEA=70%ofHE,where SEA is the steam energy available.Now, put the net heat energy value (LHV) from the previous section.(15)SEA=0.70X11809.645=8266.752.The turbines are driven by the steam energy calculated above; these turbines are linked to generators that generate electricity. The heat rate is the amount of energy needed to generate one unit of electricity (kWh).(16)1KW=3600KJh.According to the preceding calculation, assuming energy conversion is 100% efficient, 3600 kJ of energy is needed to generate one unit of electricity. However, no energy conversion is completely efficient; in fact, a conversion efficiency of 31.6% is necessary for a heat input of 3600. 31.6% = 11395 kJ/kWh in a power plant. Thus, 11395 kJ of steam energy is needed to generate 1 kWh of electrical energy.(17)1KW=11395KJKWh.Therefore,(18)EPG=SE÷11395KJKWh,whereSE: steam energyEPG: electrical power generation(19)EPG=8266.752÷11395=0.7255KWhKg.Total weight of solid waste collected from Cairo city = 10704.24 tons/day.(20)TotalEPG=0.7255X13443610.39=9753339.3379KWhday.Now,(21)SSA=6%of totalEPG,where SSA is the station service allowance.(22)SSA=0.06X9753339.3379=585200.36KWhday,UAHL=5%of totalEPG,where UAHL is the unaccounted heat loss.(23)UAHL=0.05X9753339.34=487666.97KWhday,Net EPG=EPG−SSA+UAHL,Net EPG=9753339.3379−585200.36+487666.97=8680472.0KWhday=8680.47MWhday.The amount of daily energy created is 24 hours long; thus utilizing this net electric power is computed on an hour-by-hour basis.(24)NetEPG=8680.47MWh24h,NetEPG=361.686MW≈362MW.Thus, it is possible to generate 8680.47 MWh/day by using WTE to incinerate Cairo’s 13443.61 tons of solid trash each day, or 362 MW. Figure8 shows the results of applying all of the processes for calculating the amount of power generated in 2016 throughout the whole period of research from 2011 to 2031.Figure 8
Net power generation potential (MW) for Cairo city for years 2011–2031 without recycling.Assume that all Egypt MSW can be fully utilized for WTE production. The result leads to that Egypt has the potential to generate 1842 MW from residential waste only in the year 2016. This is not applicable because the MSW management system which is essential for WTE implementation does not cover all of Egypt. For a more realistic assumption, assume that 50% of Egypt’s MSW can be fully utilized for WTE production. The result leads to only 50% of Egypt’s MSW having the potential of generating 921 MW from residential waste only in the year 2016. As shown in Figure9, this power increases with waste increasing which is naturally according to population growth and increase life living standard as mentioned in the previous sections.Figure 9
Net power generation potential (MW) for 50% of Egypt’s MSW for the years 2011–2031.


### 6.3. Second Scenario: Mass Burn with Recycling

Sustainable waste management necessitates that all recyclable and compostable products be separated from the MSW stream as much as feasible. So that the expense of sorting recyclable materials may be paid equally by generators (in terms of labour hours) and municipalities, these materials should be separated at the source, i.e., in homes, companies, and institutions (in terms of separate collection vehicles and processing systems).A landfill will be created if there is no need for source-separated waste. More than 80% of the US plastic garbage created is landfilled, despite significant efforts by the petrochemical industry and many towns to promote plastic recycling. This is an example of the lack of markets for some commodities. According to critics, waste-to-energy (WTE) discourages people from recycling. Those willing to invest time and resources in recycling often find that there are material and economic limits to how much of the MSW component may be recycled. Once they have exhausted all other options, they turn to WTE’s energy recovery to further reduce their reliance on garbage. The Earth Engineering Center’s Sustainable Waste Management Ladder demonstrates this impact (Figure10). Recycling and waste-to-energy programs have been the key to reducing or eliminating landfilling in many countries.Figure 10
The sustainable waste management ladder produced by the Earth Engineering Center, Columbia University (based on Eurostat 2008 data) [4].As shown in Figure9, the highest recycling percentage was in Germany with about 50% of its generated MSW. In this study, one recycling percentage will use 25% of the EGYPT target in 2030. Some researchers [12] assumed a 100% recycling percentage, it is not applicable for the high-income country as mentioned above, and it is impossible for a mid-income country like Egypt which has not started any steps toward an actual waste management system.Before starting the calculation, recyclable materials that are already used in Egypt are stated as follows:(i)
Paper: (newspaper-white paper-mixed cardboard)(ii)
Plastic: (mixed plastic-polyethylene plastic (high and low density) polyethylene plastic injection-PET bottles(iii)
Metal: (copper-aluminium-tin cans-iron)(iv)
Glass(v)
Other: textiles-bonesThe only waste component that is not recyclable is food. The first calculation of the new projected MSW is generated, by applying recycling percentages on the projected MSW generated for Cairo for the studying period that is calculated in Section6.1. Figure 11 shows the new projected MSW generated for Cairo with a recycling percentage value of 25%.Figure 11
Projected MSW generation for Cairo (wet and dry) for 25% recycling percentage in the studying period 2011–2031.Calculation of the total weight or wet weight for each waste component is by using waste calculation data for the year 2016. Then, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to equation (1) for a 25% recycling value; see Table 7.Table 7
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component for 25% recycling.
MaterialWaste composition (%)Wet weight (kg)Moisture content (MC) %Dry weight (kg)Organic material62.927528421.819702258526.546Plastic10.961310752.01311297644.493Paper6.411008270.7795.5952815.8865Glass3.37403308.31173391209.0624Metals1.69201654.15593195604.5312Other materials12.641512406.169101361165.552Total11964813.256456966.071To determine the chemical composition of solid wastes, repeat the same procedure as described in previous Section6.2.2.For recycling purposes, the mass of solid waste has been recalculated. Table8 shows the final corrected mass of element content for all of Cairo’s solid waste after excluding 25% of recyclable material.Table 8
Revised element content for 25% recycling.
ElementMass w/o water (kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3008.9900493008.99004925.69H (hydrogen)385.0141459996.84726168.51O (oxygen)1611.307456506.64694355.56N (nitrogen)109.0684816109.06848160.93S (sulfur)14.0704187314.070418730.12Ash1075.721071075.721079.19Total6204.17161411711.34422For Cairo, the net energy released during combustion may be estimated by repeating Section6.2.3 and using higher heating values (HHV) and lower heating values (LHV) as in the preceding section.For 25% recycling,(25)HHV=10904.58KJ/Kg,LHV=10774.49KJ/Kg.To determine the amount of energy recovered from Cairo’s municipal solid waste (MSW) with a 25% recycling rate, we may use the same methodology described in Section6.2.4. (26)SEA=0.70X10774.49=7542.143KJKg,EPG=7542.143÷11395=0.66KWhKg,Net EPG=7896.77MWh24h,NetEPG=329.032MW≈329MW.Figure12 shows the potential of electrical power generated from Cairo MSW by using WTE facility with 25% recycling of recyclable material.Figure 12
Net power generation potential (MW) for Cairo city for years 2011–2031 with 25% recycling.


### 6.4. Third Scenario: Mass Burn excluding Organic Material

In this scenario, a wider vision of the environmental and natural geographical conditions of Egypt is introduced. Egypt’s economy relies heavily on agriculture; Egypt has 9.4 million feddans [25] (approximately 40,000 square kilometers) of agricultural lands which need a regular suppling of compost/fertilizers. Organic waste is a rich source of compost/fertilizers; organic waste material forms about 56% of total Egypt MSW. Elfeki 2016 [20] demonstrated that applying biological treatment technologies to Egyptian municipal organic solid waste leads to the production of an amount of around 11.2 × 106–12.8 × 106 tons/year of compost and this amount of compost increases the compost production in Egypt with around 54% and contributes in compensating the shortage of compost demand in Egypt with an annual increase by the increase of waste generation.For the same reasons presented in the previous section for the recycling percentage, using 50% of organic material in biological treatment technologies is a future optimistic target.Calculation of the total weight or wet weight for each waste component is by using waste calculation data for the year 2016. Then, by using typical moisture content (MC) data, and dry mass of each type of waste is calculated according to equation (1) excluding 50% of organic material; see Table 9.Table 9
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component excluding 50% of organic material.
MaterialWaste composition (%)Total weight (kg)Moisture content (MC) %Dry weight (kg)Organic material38.893764210.91701129263.273Plastic18.061747669.35111730192.657Paper13.891344361.0395.51270421.182Glass5.56537744.41563521612.0832Metals2.78268872.20783260806.0416Other materials including textiles20.832016541.559101814887.403Total9679399.4826727182.64To determine the chemical composition of solid wastes, repeat the previous section6.2.2. Table 10 shows the final corrected mass of element content for all of Cairo’s solid waste after excluding 50% of organic material.Table 10
Revised element content excluding 50% of organic material.
ElementMass w/o water (Kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3008.9903108.57633.56H (hydrogen)385.014720.8417.78O (oxygen)1611.3074235.21945.72N (nitrogen)109.068109.0681.18S (sulfur)14.07014.0700.15Ash1075.7211075.72111.61Total6204.1729263.496For Cairo, the net energy released during combustion may be estimated by repeating Section 5.2.3 and using higher heating values (HHV) and lower heating values (LHV) as in the preceding section.For excluding 50% of organic material,(27)HHV=14270.49KJ/Kg,LHV=14182.34KJ/Kg.For Cairo MSW with excluding 50% of organic material, repeat Section 5.2.4 to compute the power produced.For excluding 50% of organic material,(28)SEA=0.70X14182.34=9927.64KJKg,EPG=9927.64÷11395=0.87KWhKg,Net EPG=7494.76MWh24h,NetEPG=312.3MW≈312MW.Figure13 shows the potential of electrical power generated from Cairo MSW by using WTE facility after excluding 50% of organic material for the production of compost by biological treatment.Figure 13
Net power generation potential (MW) for Cairo city for years 2011–2031 excluding 50% of organic material and without recycling.


### 6.5. Fourth Scenario (Optimal Scenario): Mass Burn excluding Organic Material and with Recycling

The optimal future target scenario is a fully integrated scenario that includes material recycling and biological treatment technologies for organic solid waste; it is a combination of the second and third scenarios.Calculation of the total weight or wet weight for each waste component is by using waste calculation data for the year 2016. Then, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to equation (1) excluding 50% of organic material and 25% recycling; see Table 11.Table 11
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component excluding 50% of organic material and 25% recycling.
MaterialWaste composition (%)Total weight (kg)Moisture content (MC) %Dry weight (kg)Organic material45.903764210.91701129263.273Plastic15.981310752.01311297644.493Paper12.301008270.7795.5952815.8865Glass4.92403308.31173391209.0624Metals2.46201654.15593195604.5312Other materials including textiles18.441512406.169101361165.552Total8200602.3395327702.798To determine the chemical composition of solid wastes, repeat Section 5.2.2.Table12 shows the final corrected mass of element content for all of Cairo’s solid waste after excluding 50% of organic material and 25% of recyclable material.Table 12
Revised element content excluding 50% of organic material and 25% recycling.
ElementMass w/o water (kg)Revised Massw water (kg)Percent by mass (%)C (carbon)3008.9902466.94429.15H (hydrogen)385.014631.8747.47O (oxygen)1611.3074164.72249.21N (nitrogen)109.068109.0681.29S (sulfur)14.07014.0700.17Ash1075.7211075.72112.71Total6204.1728462.400For Cairo, the net energy released during combustion may be estimated by repeating Section 5.2.3 and using higher heating values (HHV) and lower heating values (LHV) as in the preceding section.For excluding 50% of organic material and 25% recycling,(29)HHV=11713.64KJ/Kg,LHV=11619.74KJ/Kg.For Cairo MSW excluding 50% of organic material and 25% recycling, repeat section 5.2.4 to compute the power produced.For excluding 50% of organic material and 25% recycling,(30)SEA=0.70X11619.74=8133.818KJKg,EPG=8133.818÷11395=0.714KWhKg,Net EPG=5211.155MWh24h,Net EPG=217.13MW≈217MW.Figure14 shows the potential of electrical power generated from Cairo MSW by using WTE facility after excluding 50% of organic material for the production of compost by biological treatment and excluding 25% for recycling of recyclable material.Figure 14
Net power generation potential (MW) for Cairo city for years 2011–2031 excluding 50% of organic material and with 25% recycling.


## 6.1. Calculation of the Projected MSW Generation in the Period 2010–2031

There are two methods to calculate projected MSW generation in Cairo for the studying period from 2011 to 2031.


### 6.1.1. First Method

Depending on historical and future population trends in Egypt, 2011–2031 by the Central Agency for Public Mobilization and Statistics (CAPMAS), which are shown in the Population section, assume that per capita municipal solid waste (MSW) generation in 2010 stays the same until 2031 [27].For projected MSW calculation for Egypt. As mentioned in Section4, per capita (MSW) generation has two values: 0.4–0.5 (kg/p/d) for rural zones and 0.7–1 for urban zones, assuming average per capita (MSW) generation 0.45 (kg/p/d) for rural zones and 0.85 for urban zones. CAPMAS states in the 2013 population report that in midyear 2012 the total urban population was 35373 (42.9%) and the total rural population was 47177 (57.1%) (OCT. 2021 total population was 102.598 million) [25, 26]. Projected MSW generation in Egypt in two different zones is calculated using(1)P_MSW_G=PC_MSW∗ZP,whereP_MSW_G: projected MSW generationPC_MSW: per capita MSW (Kg/p)/dayZP: zone populationFor projected MSW calculation for Cairo, according to CAPMAS, Cairo city is a purely urban zone and has 11% of Egypt’s total population. So, by applying equation (1) and using high per capita (MSW) generation 1 (kg/p/d), as it is urban zones with the highest life expectancy in Egypt, Figure (1) shows projected MSW generation for Egypt (urban and rural zones) and Cairo in the study period 2011–2031 by using the per capita MSW generation value and by using estimated population by CAPMAS. This method gives results lower than that stated in Table 1, which states that all of Egypt (urban and rural zones) in 2010 generated 55250 1000 tons/day and Cairo itself generated 11000 tons/day. On the other hand, this method shows that Egypt in 2011 generated 49590 tons/day and Cairo generated 8775.8 tons/day.Figure 6
Projected MSW generation for Egypt (urban and rural zones) and Cairo in the studying period 2011–2031 by the 1st method.


### 6.1.2. Second Method

Quantity of municipal solid waste (MSW) generated in 2010 (21 million tons) as stated in Egypt Technical Performance assumed to be the base of the study and by using an MSW growth rate of 3.4% the projected MSW generation in the studying period will be calculated. Figure7 shows the projected MSW generation for the whole of Egypt and Cairo in the studying period 2011–2031 by using an MSW growth rate of 3.4% with the year 2010 as a base. It shows also that the generated MSW will double in 20 years (the studying period) so if the solution does not start today, the problem will become a crisis in the near future.Figure 7
Projected MSW generation for Egypt (urban and rural zones) and Cairo in the studying period 2011–2031 by the 2nd method.Figures6 and 7 show that the projected MSW generation calculated by the 2nd method is higher than those calculated by the 1st method. The 2nd method is more accurate than the 1st method, so in this study generated MSW calculated by the 2nd method will be used and results from the 1st method will not be taken into consideration.Figures6 and 7 state that Egypt’s Governor should handle and manage at least 57000-ton residential MSW every day. In this study, other waste types, industrial waste (6.2 million tons/year) and agricultural waste (23 million tons/year), are not taken into consideration.In both methods, the material composition percentage of MSW (organic 56%, plastics 13%, paper/cardboard 10%, metal 2%, glass 4%, and others 15%) will also be assumed to be constant over the studying period 2011–2031. This assumption is not fully right because the material composition percentage of MSW for any community depends on its life level and it is not true that Egypt’s life level over about 20 years will be constant, but for simplifying study conditions this assumption will be considered. Another assumption will be used in this study; municipal solid waste percentage generated in different Egypt governorates from the total generated MSW will be assumed to be constant from the year 2010 until 2031. As shown in Table2, in 2010 Cairo generated about 20% of the total MSW generated in Egypt, so if this percentage is still constant for the studying period, the MSW generated in Cairo will be as shown in Figures 6 and 7. Cairo governorate is chosen to be a case study for the following reasons:(i)
As mentioned previously, it produced about 20% of the total MSW generated in Egypt(ii)
It has a very high MSW collection coverage percentage of about 90%(iii)
All areas are urban; any new system can be implemented more easily than in rural areas


## 6.1.1. First Method

Depending on historical and future population trends in Egypt, 2011–2031 by the Central Agency for Public Mobilization and Statistics (CAPMAS), which are shown in the Population section, assume that per capita municipal solid waste (MSW) generation in 2010 stays the same until 2031 [27].For projected MSW calculation for Egypt. As mentioned in Section4, per capita (MSW) generation has two values: 0.4–0.5 (kg/p/d) for rural zones and 0.7–1 for urban zones, assuming average per capita (MSW) generation 0.45 (kg/p/d) for rural zones and 0.85 for urban zones. CAPMAS states in the 2013 population report that in midyear 2012 the total urban population was 35373 (42.9%) and the total rural population was 47177 (57.1%) (OCT. 2021 total population was 102.598 million) [25, 26]. Projected MSW generation in Egypt in two different zones is calculated using(1)P_MSW_G=PC_MSW∗ZP,whereP_MSW_G: projected MSW generationPC_MSW: per capita MSW (Kg/p)/dayZP: zone populationFor projected MSW calculation for Cairo, according to CAPMAS, Cairo city is a purely urban zone and has 11% of Egypt’s total population. So, by applying equation (1) and using high per capita (MSW) generation 1 (kg/p/d), as it is urban zones with the highest life expectancy in Egypt, Figure (1) shows projected MSW generation for Egypt (urban and rural zones) and Cairo in the study period 2011–2031 by using the per capita MSW generation value and by using estimated population by CAPMAS. This method gives results lower than that stated in Table 1, which states that all of Egypt (urban and rural zones) in 2010 generated 55250 1000 tons/day and Cairo itself generated 11000 tons/day. On the other hand, this method shows that Egypt in 2011 generated 49590 tons/day and Cairo generated 8775.8 tons/day.Figure 6
Projected MSW generation for Egypt (urban and rural zones) and Cairo in the studying period 2011–2031 by the 1st method.


## 6.1.2. Second Method

Quantity of municipal solid waste (MSW) generated in 2010 (21 million tons) as stated in Egypt Technical Performance assumed to be the base of the study and by using an MSW growth rate of 3.4% the projected MSW generation in the studying period will be calculated. Figure7 shows the projected MSW generation for the whole of Egypt and Cairo in the studying period 2011–2031 by using an MSW growth rate of 3.4% with the year 2010 as a base. It shows also that the generated MSW will double in 20 years (the studying period) so if the solution does not start today, the problem will become a crisis in the near future.Figure 7
Projected MSW generation for Egypt (urban and rural zones) and Cairo in the studying period 2011–2031 by the 2nd method.Figures6 and 7 show that the projected MSW generation calculated by the 2nd method is higher than those calculated by the 1st method. The 2nd method is more accurate than the 1st method, so in this study generated MSW calculated by the 2nd method will be used and results from the 1st method will not be taken into consideration.Figures6 and 7 state that Egypt’s Governor should handle and manage at least 57000-ton residential MSW every day. In this study, other waste types, industrial waste (6.2 million tons/year) and agricultural waste (23 million tons/year), are not taken into consideration.In both methods, the material composition percentage of MSW (organic 56%, plastics 13%, paper/cardboard 10%, metal 2%, glass 4%, and others 15%) will also be assumed to be constant over the studying period 2011–2031. This assumption is not fully right because the material composition percentage of MSW for any community depends on its life level and it is not true that Egypt’s life level over about 20 years will be constant, but for simplifying study conditions this assumption will be considered. Another assumption will be used in this study; municipal solid waste percentage generated in different Egypt governorates from the total generated MSW will be assumed to be constant from the year 2010 until 2031. As shown in Table2, in 2010 Cairo generated about 20% of the total MSW generated in Egypt, so if this percentage is still constant for the studying period, the MSW generated in Cairo will be as shown in Figures 6 and 7. Cairo governorate is chosen to be a case study for the following reasons:(i)
As mentioned previously, it produced about 20% of the total MSW generated in Egypt(ii)
It has a very high MSW collection coverage percentage of about 90%(iii)
All areas are urban; any new system can be implemented more easily than in rural areas


## 6.2. First Scenario: Mass Burn

### 6.2.1. Calculate the Physical Composition of Solid Waste

Information and data on the physical composition of solid wastes include(i)
Identification of the individual components that make up municipal solid wastes(ii)
Analysis of particle size(iii)
Moisture content(iv)
Density of solid wastesThe waste composition percentage for Cairo is assumed to be like Egypt which is tabulated in Table1 and Figure 4. First, calculate the total weight or wet weight for each waste component by using waste calculation data for the year 2016, which is tabulated in Table 3. Second, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to(2)DW=TW−MC∗TW,where DW: dry weightTW: total weightMC: moisture contentTable 3
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component.
MaterialWaste composition (%)Total weight (Kg)Moisture content (MC) %Dry weight (Kg)Organic material567528.421819702258.526546Plastic131747.66935111730.192657Paper101344.3610395.51270.421182Glass4537.74441563521.6120832Metals2268.87220783260.8060416Other materials including textiles152016.541559101814.887403Total13443.610397856.445913Specific weight is defined as the weight of a material per unit volume (e.g., kg/m3, lb/ft3); usually, it refers to uncompacted waste. It varies with geographic location, the season of the year, and the length of time in storage. Table 4 shows typical specific weight values according to the processing method. MSW specific for Egypt is assumed to be taken as 330 kg/m3.Table 4
Typical specific weight values.
ConditionDensity (kg/m3)Loose MSW, no processing or compaction90–150In compaction truck355–530Baled MSW710–825MSW in a compacted landfill (without cover)440–740The composition of waste components is critical for recycling and recovery, even more so when mechanical techniques such as trammel screens and magnetic separators are utilized.


### 6.2.2. Identifying the Chemical Makeup of Solid Waste

Chemical information on solid wastes is critical for assessing potential processing and energy recovery alternatives. If solid wastes are to be utilized as fuel, the following four qualities must be recognized:(i)
Proximate analysis:(1)
Moisture (loss at 105)(2)
C for 1 h(3)
Volatile matter (additional loss on ignition at 950°C)(4)
Ash (residue after burning)(5)
Fixed carbon (remainder)(ii)
Fusing point of ash(iii)
Ultimate analysis:(i)
Percent of C (carbon), H (hydrogen), O (oxygen), N (nitrogen), S (sulfur), and ash(iv)
Heating value (energy value)In the previous Section 6.2.1 dry mass is calculated; then the amount of carbon, hydrogen, oxygen, nitrogen, sulfur, and ash content is calculated for each type of waste using a standard table of ultimate analysis of combustible waste (Table5 and equation (3)).where EC: element contentDM: dry massSUAMP: standard ultimate analysis mass percentTable 5
Typical percent by weight.
Percent by weight (dry basis)ComponentCarbonHydrogenOxygenNitrogenSulfurAshOrganicFood wastes48.06.437.62.60.45.0Paper43.56.044.00.30.26.0Cardboard44.05.944.60.30.26.0Plastics60.07.222.8——10.0Textiles55.06.631.24.60.152.5Rubber78.010.0—2.0—10.0Leather60.08.011.610.00.410.0Yard wastes47.86.038.03.40.34.5Wood49.56.042.70.20.11.5InorganicGlass0.50.10.4<0.1—98.9Metals4.50.64.3<0.1—90.5Dirt, ash, etc.26.33.02.00.50.268.0(3)EC=DS100∗SUAMP.From Table3, dry waste weights are 7856445.913 kg, and the total waste weights are 13443610.39 kg. Then, subtract the weight of the dry waste from the total weight of waste to give the weight of the water in the waste.(4)13443610.39−7856445.913=5587164.47KgH2O.Now to determine how much hydrogen and oxygen in kg there are in the waste, we do this by using(5)TWMWt−W∗MMWt−H,whereTW: total moisture in kgMWt-W: molecular Wt of waterMWt-H: molecular Wt of hydrogen(6)5587164.478.165∗0.907=620643.99KgH,TWMWt−W∗MMWt−O,where MWt-O is the molecular Wt of oxygen.(7)5587164.478.165∗7.257=4965836.19Kg O.Now, revised mass is calculated for solid waste, as moisture in solid waste converts into hydrogen and oxygen due to heat in incinerators. The final revised mass of element content of whole Cairo solid waste can be seen in Table6.Table 6
Revised element content.
ElementMass w/o water (kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3650622.4843650622.48427.85H (hydrogen)465170.29491085814.2858.28O (oxygen)1865341.2736831177.46352.12N (nitrogen)125850.7454125850.74540.96S (sulfur)15749.1895715749.189570.12Ash1396652.651396652.6510.66Total7519386.63713105866.82


### 6.2.3. Calculation of Waste Heat Energy (Waste Calorific Value)

To calculate heat energy or calorific values (higher heating values HHV) generated by the whole of Cairo city’s solid waste, Dulong’s formula needs to be applied. Dulong’s formula is described in equation (7).(8)HEHHV=337C+1428H−O8+9S,whereHE = heat energy (kJ/kg)C = carbon (%)H = hydrogen (%)O = oxygen (%)S = sulfur (%)N = nitrogen (%)Putting percent by mass value from Table6 into Dulong’s formula, HHV generated by Cairo city’s total waste is obtained:(9)CairowasteHHV=337X27.85+14288.28−52.128+9X0.12=11906.95kJkg.The calorific values were again calculated by using the Dulong equation, considering nitrogen in(10)HEHHV=337C+1419H−0.125O+93S+23N.(11)CairowasteHHV=337X27.85+14198.28−0.125X52.12+93X0.12+23X0.96=11923.225kJkg.The difference between calculations using equations (8) and (10) is very small. So, less HHV value will be considered.Lower heat value (kJ/kg) (LHV) is the net energy released on combustion.(12)LHV=HHV−2.766XW,whereLHV (KJ/KG): lower heat value.W = moisture content2.766 kJ/kg = coefficient of heat requirement for evaporation.(13)CairoLHV=11906.95−2.766X41.56=11809.645KJKg.In the next sections, the lower heat value (LHV) for Cairo city’s waste will be used, which is the net heat energy generated = 11809.645 kJ/kg.


### 6.2.4. Calculation of Electricity Generated

To figure out how much power a building needs, many processes must be taken. The heat created is first utilized to compute steam energy, which accounts for 70% of heat energy. A net electric power produced by solid waste is estimated after subtracting station service allowance and heat losses from the steam energy calculation. All of this may be seen in the gallery:(14)SEA=70%ofHE,where SEA is the steam energy available.Now, put the net heat energy value (LHV) from the previous section.(15)SEA=0.70X11809.645=8266.752.The turbines are driven by the steam energy calculated above; these turbines are linked to generators that generate electricity. The heat rate is the amount of energy needed to generate one unit of electricity (kWh).(16)1KW=3600KJh.According to the preceding calculation, assuming energy conversion is 100% efficient, 3600 kJ of energy is needed to generate one unit of electricity. However, no energy conversion is completely efficient; in fact, a conversion efficiency of 31.6% is necessary for a heat input of 3600. 31.6% = 11395 kJ/kWh in a power plant. Thus, 11395 kJ of steam energy is needed to generate 1 kWh of electrical energy.(17)1KW=11395KJKWh.Therefore,(18)EPG=SE÷11395KJKWh,whereSE: steam energyEPG: electrical power generation(19)EPG=8266.752÷11395=0.7255KWhKg.Total weight of solid waste collected from Cairo city = 10704.24 tons/day.(20)TotalEPG=0.7255X13443610.39=9753339.3379KWhday.Now,(21)SSA=6%of totalEPG,where SSA is the station service allowance.(22)SSA=0.06X9753339.3379=585200.36KWhday,UAHL=5%of totalEPG,where UAHL is the unaccounted heat loss.(23)UAHL=0.05X9753339.34=487666.97KWhday,Net EPG=EPG−SSA+UAHL,Net EPG=9753339.3379−585200.36+487666.97=8680472.0KWhday=8680.47MWhday.The amount of daily energy created is 24 hours long; thus utilizing this net electric power is computed on an hour-by-hour basis.(24)NetEPG=8680.47MWh24h,NetEPG=361.686MW≈362MW.Thus, it is possible to generate 8680.47 MWh/day by using WTE to incinerate Cairo’s 13443.61 tons of solid trash each day, or 362 MW. Figure8 shows the results of applying all of the processes for calculating the amount of power generated in 2016 throughout the whole period of research from 2011 to 2031.Figure 8
Net power generation potential (MW) for Cairo city for years 2011–2031 without recycling.Assume that all Egypt MSW can be fully utilized for WTE production. The result leads to that Egypt has the potential to generate 1842 MW from residential waste only in the year 2016. This is not applicable because the MSW management system which is essential for WTE implementation does not cover all of Egypt. For a more realistic assumption, assume that 50% of Egypt’s MSW can be fully utilized for WTE production. The result leads to only 50% of Egypt’s MSW having the potential of generating 921 MW from residential waste only in the year 2016. As shown in Figure9, this power increases with waste increasing which is naturally according to population growth and increase life living standard as mentioned in the previous sections.Figure 9
Net power generation potential (MW) for 50% of Egypt’s MSW for the years 2011–2031.


## 6.2.1. Calculate the Physical Composition of Solid Waste

Information and data on the physical composition of solid wastes include(i)
Identification of the individual components that make up municipal solid wastes(ii)
Analysis of particle size(iii)
Moisture content(iv)
Density of solid wastesThe waste composition percentage for Cairo is assumed to be like Egypt which is tabulated in Table1 and Figure 4. First, calculate the total weight or wet weight for each waste component by using waste calculation data for the year 2016, which is tabulated in Table 3. Second, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to(2)DW=TW−MC∗TW,where DW: dry weightTW: total weightMC: moisture contentTable 3
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component.
MaterialWaste composition (%)Total weight (Kg)Moisture content (MC) %Dry weight (Kg)Organic material567528.421819702258.526546Plastic131747.66935111730.192657Paper101344.3610395.51270.421182Glass4537.74441563521.6120832Metals2268.87220783260.8060416Other materials including textiles152016.541559101814.887403Total13443.610397856.445913Specific weight is defined as the weight of a material per unit volume (e.g., kg/m3, lb/ft3); usually, it refers to uncompacted waste. It varies with geographic location, the season of the year, and the length of time in storage. Table 4 shows typical specific weight values according to the processing method. MSW specific for Egypt is assumed to be taken as 330 kg/m3.Table 4
Typical specific weight values.
ConditionDensity (kg/m3)Loose MSW, no processing or compaction90–150In compaction truck355–530Baled MSW710–825MSW in a compacted landfill (without cover)440–740The composition of waste components is critical for recycling and recovery, even more so when mechanical techniques such as trammel screens and magnetic separators are utilized.


## 6.2.2. Identifying the Chemical Makeup of Solid Waste

Chemical information on solid wastes is critical for assessing potential processing and energy recovery alternatives. If solid wastes are to be utilized as fuel, the following four qualities must be recognized:(i)
Proximate analysis:(1)
Moisture (loss at 105)(2)
C for 1 h(3)
Volatile matter (additional loss on ignition at 950°C)(4)
Ash (residue after burning)(5)
Fixed carbon (remainder)(ii)
Fusing point of ash(iii)
Ultimate analysis:(i)
Percent of C (carbon), H (hydrogen), O (oxygen), N (nitrogen), S (sulfur), and ash(iv)
Heating value (energy value)In the previous Section 6.2.1 dry mass is calculated; then the amount of carbon, hydrogen, oxygen, nitrogen, sulfur, and ash content is calculated for each type of waste using a standard table of ultimate analysis of combustible waste (Table5 and equation (3)).where EC: element contentDM: dry massSUAMP: standard ultimate analysis mass percentTable 5
Typical percent by weight.
Percent by weight (dry basis)ComponentCarbonHydrogenOxygenNitrogenSulfurAshOrganicFood wastes48.06.437.62.60.45.0Paper43.56.044.00.30.26.0Cardboard44.05.944.60.30.26.0Plastics60.07.222.8——10.0Textiles55.06.631.24.60.152.5Rubber78.010.0—2.0—10.0Leather60.08.011.610.00.410.0Yard wastes47.86.038.03.40.34.5Wood49.56.042.70.20.11.5InorganicGlass0.50.10.4<0.1—98.9Metals4.50.64.3<0.1—90.5Dirt, ash, etc.26.33.02.00.50.268.0(3)EC=DS100∗SUAMP.From Table3, dry waste weights are 7856445.913 kg, and the total waste weights are 13443610.39 kg. Then, subtract the weight of the dry waste from the total weight of waste to give the weight of the water in the waste.(4)13443610.39−7856445.913=5587164.47KgH2O.Now to determine how much hydrogen and oxygen in kg there are in the waste, we do this by using(5)TWMWt−W∗MMWt−H,whereTW: total moisture in kgMWt-W: molecular Wt of waterMWt-H: molecular Wt of hydrogen(6)5587164.478.165∗0.907=620643.99KgH,TWMWt−W∗MMWt−O,where MWt-O is the molecular Wt of oxygen.(7)5587164.478.165∗7.257=4965836.19Kg O.Now, revised mass is calculated for solid waste, as moisture in solid waste converts into hydrogen and oxygen due to heat in incinerators. The final revised mass of element content of whole Cairo solid waste can be seen in Table6.Table 6
Revised element content.
ElementMass w/o water (kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3650622.4843650622.48427.85H (hydrogen)465170.29491085814.2858.28O (oxygen)1865341.2736831177.46352.12N (nitrogen)125850.7454125850.74540.96S (sulfur)15749.1895715749.189570.12Ash1396652.651396652.6510.66Total7519386.63713105866.82


## 6.2.3. Calculation of Waste Heat Energy (Waste Calorific Value)

To calculate heat energy or calorific values (higher heating values HHV) generated by the whole of Cairo city’s solid waste, Dulong’s formula needs to be applied. Dulong’s formula is described in equation (7).(8)HEHHV=337C+1428H−O8+9S,whereHE = heat energy (kJ/kg)C = carbon (%)H = hydrogen (%)O = oxygen (%)S = sulfur (%)N = nitrogen (%)Putting percent by mass value from Table6 into Dulong’s formula, HHV generated by Cairo city’s total waste is obtained:(9)CairowasteHHV=337X27.85+14288.28−52.128+9X0.12=11906.95kJkg.The calorific values were again calculated by using the Dulong equation, considering nitrogen in(10)HEHHV=337C+1419H−0.125O+93S+23N.(11)CairowasteHHV=337X27.85+14198.28−0.125X52.12+93X0.12+23X0.96=11923.225kJkg.The difference between calculations using equations (8) and (10) is very small. So, less HHV value will be considered.Lower heat value (kJ/kg) (LHV) is the net energy released on combustion.(12)LHV=HHV−2.766XW,whereLHV (KJ/KG): lower heat value.W = moisture content2.766 kJ/kg = coefficient of heat requirement for evaporation.(13)CairoLHV=11906.95−2.766X41.56=11809.645KJKg.In the next sections, the lower heat value (LHV) for Cairo city’s waste will be used, which is the net heat energy generated = 11809.645 kJ/kg.


## 6.2.4. Calculation of Electricity Generated

To figure out how much power a building needs, many processes must be taken. The heat created is first utilized to compute steam energy, which accounts for 70% of heat energy. A net electric power produced by solid waste is estimated after subtracting station service allowance and heat losses from the steam energy calculation. All of this may be seen in the gallery:(14)SEA=70%ofHE,where SEA is the steam energy available.Now, put the net heat energy value (LHV) from the previous section.(15)SEA=0.70X11809.645=8266.752.The turbines are driven by the steam energy calculated above; these turbines are linked to generators that generate electricity. The heat rate is the amount of energy needed to generate one unit of electricity (kWh).(16)1KW=3600KJh.According to the preceding calculation, assuming energy conversion is 100% efficient, 3600 kJ of energy is needed to generate one unit of electricity. However, no energy conversion is completely efficient; in fact, a conversion efficiency of 31.6% is necessary for a heat input of 3600. 31.6% = 11395 kJ/kWh in a power plant. Thus, 11395 kJ of steam energy is needed to generate 1 kWh of electrical energy.(17)1KW=11395KJKWh.Therefore,(18)EPG=SE÷11395KJKWh,whereSE: steam energyEPG: electrical power generation(19)EPG=8266.752÷11395=0.7255KWhKg.Total weight of solid waste collected from Cairo city = 10704.24 tons/day.(20)TotalEPG=0.7255X13443610.39=9753339.3379KWhday.Now,(21)SSA=6%of totalEPG,where SSA is the station service allowance.(22)SSA=0.06X9753339.3379=585200.36KWhday,UAHL=5%of totalEPG,where UAHL is the unaccounted heat loss.(23)UAHL=0.05X9753339.34=487666.97KWhday,Net EPG=EPG−SSA+UAHL,Net EPG=9753339.3379−585200.36+487666.97=8680472.0KWhday=8680.47MWhday.The amount of daily energy created is 24 hours long; thus utilizing this net electric power is computed on an hour-by-hour basis.(24)NetEPG=8680.47MWh24h,NetEPG=361.686MW≈362MW.Thus, it is possible to generate 8680.47 MWh/day by using WTE to incinerate Cairo’s 13443.61 tons of solid trash each day, or 362 MW. Figure8 shows the results of applying all of the processes for calculating the amount of power generated in 2016 throughout the whole period of research from 2011 to 2031.Figure 8
Net power generation potential (MW) for Cairo city for years 2011–2031 without recycling.Assume that all Egypt MSW can be fully utilized for WTE production. The result leads to that Egypt has the potential to generate 1842 MW from residential waste only in the year 2016. This is not applicable because the MSW management system which is essential for WTE implementation does not cover all of Egypt. For a more realistic assumption, assume that 50% of Egypt’s MSW can be fully utilized for WTE production. The result leads to only 50% of Egypt’s MSW having the potential of generating 921 MW from residential waste only in the year 2016. As shown in Figure9, this power increases with waste increasing which is naturally according to population growth and increase life living standard as mentioned in the previous sections.Figure 9
Net power generation potential (MW) for 50% of Egypt’s MSW for the years 2011–2031.


## 6.3. Second Scenario: Mass Burn with Recycling

Sustainable waste management necessitates that all recyclable and compostable products be separated from the MSW stream as much as feasible. So that the expense of sorting recyclable materials may be paid equally by generators (in terms of labour hours) and municipalities, these materials should be separated at the source, i.e., in homes, companies, and institutions (in terms of separate collection vehicles and processing systems).A landfill will be created if there is no need for source-separated waste. More than 80% of the US plastic garbage created is landfilled, despite significant efforts by the petrochemical industry and many towns to promote plastic recycling. This is an example of the lack of markets for some commodities. According to critics, waste-to-energy (WTE) discourages people from recycling. Those willing to invest time and resources in recycling often find that there are material and economic limits to how much of the MSW component may be recycled. Once they have exhausted all other options, they turn to WTE’s energy recovery to further reduce their reliance on garbage. The Earth Engineering Center’s Sustainable Waste Management Ladder demonstrates this impact (Figure10). Recycling and waste-to-energy programs have been the key to reducing or eliminating landfilling in many countries.Figure 10
The sustainable waste management ladder produced by the Earth Engineering Center, Columbia University (based on Eurostat 2008 data) [4].As shown in Figure9, the highest recycling percentage was in Germany with about 50% of its generated MSW. In this study, one recycling percentage will use 25% of the EGYPT target in 2030. Some researchers [12] assumed a 100% recycling percentage, it is not applicable for the high-income country as mentioned above, and it is impossible for a mid-income country like Egypt which has not started any steps toward an actual waste management system.Before starting the calculation, recyclable materials that are already used in Egypt are stated as follows:(i)
Paper: (newspaper-white paper-mixed cardboard)(ii)
Plastic: (mixed plastic-polyethylene plastic (high and low density) polyethylene plastic injection-PET bottles(iii)
Metal: (copper-aluminium-tin cans-iron)(iv)
Glass(v)
Other: textiles-bonesThe only waste component that is not recyclable is food. The first calculation of the new projected MSW is generated, by applying recycling percentages on the projected MSW generated for Cairo for the studying period that is calculated in Section6.1. Figure 11 shows the new projected MSW generated for Cairo with a recycling percentage value of 25%.Figure 11
Projected MSW generation for Cairo (wet and dry) for 25% recycling percentage in the studying period 2011–2031.Calculation of the total weight or wet weight for each waste component is by using waste calculation data for the year 2016. Then, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to equation (1) for a 25% recycling value; see Table 7.Table 7
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component for 25% recycling.
MaterialWaste composition (%)Wet weight (kg)Moisture content (MC) %Dry weight (kg)Organic material62.927528421.819702258526.546Plastic10.961310752.01311297644.493Paper6.411008270.7795.5952815.8865Glass3.37403308.31173391209.0624Metals1.69201654.15593195604.5312Other materials12.641512406.169101361165.552Total11964813.256456966.071To determine the chemical composition of solid wastes, repeat the same procedure as described in previous Section6.2.2.For recycling purposes, the mass of solid waste has been recalculated. Table8 shows the final corrected mass of element content for all of Cairo’s solid waste after excluding 25% of recyclable material.Table 8
Revised element content for 25% recycling.
ElementMass w/o water (kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3008.9900493008.99004925.69H (hydrogen)385.0141459996.84726168.51O (oxygen)1611.307456506.64694355.56N (nitrogen)109.0684816109.06848160.93S (sulfur)14.0704187314.070418730.12Ash1075.721071075.721079.19Total6204.17161411711.34422For Cairo, the net energy released during combustion may be estimated by repeating Section6.2.3 and using higher heating values (HHV) and lower heating values (LHV) as in the preceding section.For 25% recycling,(25)HHV=10904.58KJ/Kg,LHV=10774.49KJ/Kg.To determine the amount of energy recovered from Cairo’s municipal solid waste (MSW) with a 25% recycling rate, we may use the same methodology described in Section6.2.4. (26)SEA=0.70X10774.49=7542.143KJKg,EPG=7542.143÷11395=0.66KWhKg,Net EPG=7896.77MWh24h,NetEPG=329.032MW≈329MW.Figure12 shows the potential of electrical power generated from Cairo MSW by using WTE facility with 25% recycling of recyclable material.Figure 12
Net power generation potential (MW) for Cairo city for years 2011–2031 with 25% recycling.


## 6.4. Third Scenario: Mass Burn excluding Organic Material

In this scenario, a wider vision of the environmental and natural geographical conditions of Egypt is introduced. Egypt’s economy relies heavily on agriculture; Egypt has 9.4 million feddans [25] (approximately 40,000 square kilometers) of agricultural lands which need a regular suppling of compost/fertilizers. Organic waste is a rich source of compost/fertilizers; organic waste material forms about 56% of total Egypt MSW. Elfeki 2016 [20] demonstrated that applying biological treatment technologies to Egyptian municipal organic solid waste leads to the production of an amount of around 11.2 × 106–12.8 × 106 tons/year of compost and this amount of compost increases the compost production in Egypt with around 54% and contributes in compensating the shortage of compost demand in Egypt with an annual increase by the increase of waste generation.For the same reasons presented in the previous section for the recycling percentage, using 50% of organic material in biological treatment technologies is a future optimistic target.Calculation of the total weight or wet weight for each waste component is by using waste calculation data for the year 2016. Then, by using typical moisture content (MC) data, and dry mass of each type of waste is calculated according to equation (1) excluding 50% of organic material; see Table 9.Table 9
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component excluding 50% of organic material.
MaterialWaste composition (%)Total weight (kg)Moisture content (MC) %Dry weight (kg)Organic material38.893764210.91701129263.273Plastic18.061747669.35111730192.657Paper13.891344361.0395.51270421.182Glass5.56537744.41563521612.0832Metals2.78268872.20783260806.0416Other materials including textiles20.832016541.559101814887.403Total9679399.4826727182.64To determine the chemical composition of solid wastes, repeat the previous section6.2.2. Table 10 shows the final corrected mass of element content for all of Cairo’s solid waste after excluding 50% of organic material.Table 10
Revised element content excluding 50% of organic material.
ElementMass w/o water (Kg)Revised Mass w water (kg)Percent by mass (%)C (carbon)3008.9903108.57633.56H (hydrogen)385.014720.8417.78O (oxygen)1611.3074235.21945.72N (nitrogen)109.068109.0681.18S (sulfur)14.07014.0700.15Ash1075.7211075.72111.61Total6204.1729263.496For Cairo, the net energy released during combustion may be estimated by repeating Section 5.2.3 and using higher heating values (HHV) and lower heating values (LHV) as in the preceding section.For excluding 50% of organic material,(27)HHV=14270.49KJ/Kg,LHV=14182.34KJ/Kg.For Cairo MSW with excluding 50% of organic material, repeat Section 5.2.4 to compute the power produced.For excluding 50% of organic material,(28)SEA=0.70X14182.34=9927.64KJKg,EPG=9927.64÷11395=0.87KWhKg,Net EPG=7494.76MWh24h,NetEPG=312.3MW≈312MW.Figure13 shows the potential of electrical power generated from Cairo MSW by using WTE facility after excluding 50% of organic material for the production of compost by biological treatment.Figure 13
Net power generation potential (MW) for Cairo city for years 2011–2031 excluding 50% of organic material and without recycling.


## 6.5. Fourth Scenario (Optimal Scenario): Mass Burn excluding Organic Material and with Recycling

The optimal future target scenario is a fully integrated scenario that includes material recycling and biological treatment technologies for organic solid waste; it is a combination of the second and third scenarios.Calculation of the total weight or wet weight for each waste component is by using waste calculation data for the year 2016. Then, by using typical moisture content (MC) data, the dry mass of each type of waste is calculated according to equation (1) excluding 50% of organic material and 25% recycling; see Table 11.Table 11
2016 Cairo MSW composition: percentage weight, wet weight, and moisture content (MC) % of each waste component excluding 50% of organic material and 25% recycling.
MaterialWaste composition (%)Total weight (kg)Moisture content (MC) %Dry weight (kg)Organic material45.903764210.91701129263.273Plastic15.981310752.01311297644.493Paper12.301008270.7795.5952815.8865Glass4.92403308.31173391209.0624Metals2.46201654.15593195604.5312Other materials including textiles18.441512406.169101361165.552Total8200602.3395327702.798To determine the chemical composition of solid wastes, repeat Section 5.2.2.Table12 shows the final corrected mass of element content for all of Cairo’s solid waste after excluding 50% of organic material and 25% of recyclable material.Table 12
Revised element content excluding 50% of organic material and 25% recycling.
ElementMass w/o water (kg)Revised Massw water (kg)Percent by mass (%)C (carbon)3008.9902466.94429.15H (hydrogen)385.014631.8747.47O (oxygen)1611.3074164.72249.21N (nitrogen)109.068109.0681.29S (sulfur)14.07014.0700.17Ash1075.7211075.72112.71Total6204.1728462.400For Cairo, the net energy released during combustion may be estimated by repeating Section 5.2.3 and using higher heating values (HHV) and lower heating values (LHV) as in the preceding section.For excluding 50% of organic material and 25% recycling,(29)HHV=11713.64KJ/Kg,LHV=11619.74KJ/Kg.For Cairo MSW excluding 50% of organic material and 25% recycling, repeat section 5.2.4 to compute the power produced.For excluding 50% of organic material and 25% recycling,(30)SEA=0.70X11619.74=8133.818KJKg,EPG=8133.818÷11395=0.714KWhKg,Net EPG=5211.155MWh24h,Net EPG=217.13MW≈217MW.Figure14 shows the potential of electrical power generated from Cairo MSW by using WTE facility after excluding 50% of organic material for the production of compost by biological treatment and excluding 25% for recycling of recyclable material.Figure 14
Net power generation potential (MW) for Cairo city for years 2011–2031 excluding 50% of organic material and with 25% recycling.


## 7. Results Analysis

Thus far, the paper formulated the problem of MSW in Egypt based on the previous information and data. The problem is that the annual growth of the population leads to the growth of solid waste generation and consequently the MSW. Available data have been processed to show the decision-makers in Egypt the amount of electrical power that can be generated by using the WTE options to manage the MSW in Egypt.This paper introduced a step-by-step calculation for the electrical power that can be generated from Cairo MSW. Four scenarios are presented, and they may be used as an implementation plan of WTE technologies in Egypt in three steps (Table13):1st step (first scenario) is to apply the mass burn without any waste processing, this step will help to control the amount of MSW and demonstrate the benefits of using WTE systems.2nd step (second and third scenarios) is to start applying waste processing (excluding organic material for biological treatment to produce compost and recycling) with mass burn; this step will be divided internally into many stages according to MSW processing implementations.3rd step (optimal future target) is the required target, the future target is excluding 50% of organic material and 25% recycling, but it should be continually updated.Table 13
The year 2031 estimated power generation in Cairo with different scenarios.
Net electric power generation MW without recyclingNet electric power generation MW excluding 50% of organic materialsNet electric power generation MW with 25% recyclingNet electric power generation MW excluding 50% of organic material and with 25% recycling597516484359Figure15 shows the potential of electrical power generated from Cairo MSW by using WTE facility for the four scenarios presented in the paper during the studying period from 2011 to 2031.Figure 15
Net power generation potential (MW) for Cairo city by using WTE facility with four scenarios for the years 2011–2031.


## 8. Conclusion

The issue of waste spread is a chronic environmental challenge in the Arab Republic of Egypt. It is estimated that 40% of the total waste generated is left uncollected and that only a fraction of this collected waste is treated and disposed of in facilities with a generally acceptable level of environmental control. The remainder is dumped on open land and along with watercourses, roads, railways etc. without any environmental controls.Unplanned waste dumping contributes to the contamination of the surface and ground waters, the spread of disease, and the degradation of the landscape. This situation is very harmful in a general way to the economic development of the country. A study by the World Bank (2019) has assessed that the estimated cost of health effects due to air and water pollution was equivalent to 2.5% of Egypt’s GDP in 2016/17 [28].This research aims to assess the potential contribution of the WTE facility to meet electricity demand in Cairo City, which is the EGYPT capital, and the biggest city in population as a sample, and then apply the results to all of Egypt and to provide an alternative solution to landfills. The analyses were completed for CAIRO with a current total population of about 10 million. The results show that, by the year 2031 and according to the lowest scenario, it has the potential to produce about 359 MW of electricity based on the mass burn with excluding 50% of organic material and with 25% recycling.



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*Source: 7265553-2022-06-23.xml*