Global Status of Waste-to-Energy Technology

CHAPTER 3

Global Status of Waste-to-Energy Technology Mukesh Kumar Awasthi1, Surendra Sarsaiya2, 4, Hongyu Chen1, Quan Wang1, Meijing Wang1, Sanjeev Kumar Awasthi1, Jiao Li1, Tao Liu1, Ashok Pandey3, Zengqiang Zhang1 1

College of Natural Resources and Environment, Northwest A&F University, Yangling, China; Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, China; 3Centre for Innovation and Translational Research, CSIR e Indian Institute of Toxicology Research, Lucknow, India; 4Department of Microbiology, Sri Satya Sai University of Technology and Medical Sciences, Sehore, India 2

1. Overview The rising global population is accompanied by rising energy demand, and hostile environmental influences (air pollution and global warming) are the results of energy generation. Bioenergy is anticipated to be the leading prospect for fulfilling the forthcoming energy needs and as a viable means of establishing a natural fuel reservoir. Currently, fossil fuels are by far the most consistent energy sources, meeting virtually 84% of the entire energy requirement. We are at the stage of realizing the prospects of WTE (waste to energy) as an opportunity for sustainable waste processing and as one of the noteworthy future renewable energy bases, one that is frugally feasible and environmentally viable [1]. Many emerging nations are seriously facing the climbing challenges of treating and compacting waste, because its improper management causes hazards to the environment and society. Municipal solid waste (MSW) is a valued supply for WTE, with a capacity for the production of biogas for collective heat and power generation by way of the applicable WTE processes. These approaches must be designed based on the composition, valuation, and economics of waste. Selection of the suitable technology for WTE is not an easy task because waste generation is continuously influenced by the producer’s season, region, and socioeconomic level. Policy components for sustainable waste conversion correspondingly have a noteworthy impact on the assortment of WTE technologies [2]. Existing WTE procedures can be categorized into thermochemical and biochemical processes, whereas municipal waste can be considered as

Current Developments in Biotechnology and Bioengineering. https://doi.org/10.1016/B978-0-444-64083-3.00003-8 Copyright © 2019 Elsevier B.V. All rights reserved.

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32 Chapter 3 nonbiodegradable and biodegradable, which are appropriate for thermochemical and biochemical processes, respectively. Biochemical approaches are connected to the anaerobic process for breakdown to produce biogases (including methane), and thermochemical approaches are associated with gasification, pyrolysis, and incineration. In contrast, the landfill gas consumption processes are also considered, along with biorefineries, as WTE technologies. These technologies have the potential to mitigate greenhouse fumes in regionalized energy-from-waste processes. The global WTE business in industrialized nations is well recognized, in contradiction to the situation in India. While concerns still occur in advanced nations (public opposition, effluent gas treatment [flue gas] measurements, removal of air contamination control deposits, and entangling and corrosion of boiler temperature exchanger surfaces), the most suitable processes for treating waste are recognized [3]. Pollutant emission from WTE units is the chief problematic issue addressed by investigators and plant manufacturers in the past decades; lower contaminant discharges have been achieved as effluent outlet gas treatment has become more proficient. To counter the rise in cost, research is now focused on refining the WTE plant’s energy efficiency [4]. The world energy requirement is likely to reach in excess of six times higher compared with the current demand. The currently available energy supply is much lower than the concrete energy required for consumption in numerous developing countries. At present, the primary energy source in the world is fossil fuels, which provide around 84% of the entire electricity demand [1]. In the past few decades, the strategy of WTE has been further focused on dropping the liberation rate of contaminants, while making the most of the waste quantity and curtailing expenses. The first of these goals has been attained by using costly flue gas treatment units, which has led to an increase in the capital budget of WTE units. To balance this cost upsurge, examination is needed to focus more on refining the overall WTE plant efficiency [5,6].

2. Present Scenario and Outlook The technology of energy capture from waste has progressed to the point that the system produces energy efficiently; meets the requirements for public strength, a clean situation, and air eminence; and cuts the obligatory number of dumping locations [6]. The world energy intake was around 520 quadrillion BTUs in 2010 and is predicted to increase by 56% by 2040 [7]. In India, nearby 40 million tons of MSW is generated every year, and the main stream of this waste is directed to unsanitary landfill places or amenably dumped [3]. In 2011, 2 billion tons of MSW was produced globally and this is expected to increase to 9.5 billion tons/year by the year 2050. A World Bank 2012 report also has similar findings attributable to urban and economic development. MSW generation is foretold to overtake

Global Status of Waste-to-Energy Technology 33 the urbanization mark in 2025, reaching 2.2 billion tons/year. In the imminent future, the entire MSW generation proportion in emerging nations will also surge rapidly [8]. WTE was identified as one of eight technologies having a strong potential influence on forthcoming low-carbon energy arrangements, by the 2009 World Economic Forum, “Green Investing: In the Direction of a Clean Energy Infrastructure.” It is expected that WTE prospects will find preference, as a minimum of 261 million tons/year of waste will produce an estimated 283 TWh of electricity and heat by 2022 [9,10]. Direct ignition followed by energetic retrieval of the high temperature produced, which is the most widely used operative platform worldwide. In the European Union (EU) nearly 61 million tons of municipal waste, amounting to about 26% of the whole quantity generated, is treated for energetic retrieval in about 450 WTE plants [11,12]. Some studies have shown that the entire prospective energy recovery was predicted to surge from 252,130 GJ/year in 2012 to 525,540 GJ/year in 2021. In terms of proportion per ton of waste, the impending energy recovery was expected to surge from 0.87 GJ/ton in 2012 to 1.25 GJ/ton in 2021. In the meantime, greenhouse gas removal by WTE was estimated to surge from 16,061 tons CO2 eq/year in 2012 to 33,477 tons CO2 eq/year. The energy capacities of both incineration and mechanical biotreatment would surge up to 2.34 and 2.94 GJ/ton, respectively, as of the energy conceivable from landfilling at 0.122 GJ/ton, when Daejeon Metropolitan City, with its population of 1.5 million, mitigates the landfilled waste materials and, in its place, uses machine-driven biological treatment and incineration [11]. Information accessible from the Eurostat database ACME indicated that municipal waste was managed by diverse means in the EU in 2014: 28.2% was reprocessed, 16.1% was converted into compost (Eurostat defines it as biological treatment), 27.3% was incinerated (overall incineration including energy recovery), and 28.4% was landfilled. Moreover, treatment methods diverge substantially among the member states: on one hand, Germany, Belgium, Sweden, Denmark, the Netherlands, and Austria have a share of landfilled waste less than 4%. The volume of waste recovered by WTE has increased from 5815 to 6279 kilotons (þ8%) in the 2013e14 period. It depends on the size of unusual wastes (þ558 kilotons), although the quantities of city waste have reduced from 5396 to 5302 kilotons. The supply percentages in 2014 were unsorted waste (43%), a dehydrated fraction from machine-driven biological treatment (27%), secondary solid fuels (14%), and special waste (16%) [12]. The processing of waste for energy production is an imperative exemplary move in municipal waste management. During previous decades, several countrywide as well as local governments have improved cooperation between the public and the private sector through publiceprivate partnerships (PPPs), in which the private area invests in public schemes, whereby investors obtain a return on their venture within an exact legal

34 Chapter 3 framework. PPPs are long-term indentures among the community and the private area in which the private area has accountability for the significant characteristics of the building and processing of a setup for the transfer of public services that the public part should deliver, while both share risks, costs, and benefits [13].

3. Global Waste Generation and Composition With the fast growing economy and global population, solid waste has become a big issue and a social phenomenon worldwide. Previously, MSW was generated at about 300,000 tons/day in the 1900s and gradually increased to 3,000,000 tons in the 2000s, while it is estimated to double by 2025 [14]. This is a remarkable growth in per-capita waste production, amounting to a 0.22-kg increase, respectively, [15]. Waste generation varies widely in different regions and is influenced by economic development and even by time period. There is evidence that the nations of the Organization for Economic Cooperation and Development (OECD), because of some substantial city populations in addition to profitable activities, are the major waste producers, producing nearly 1,750,000 tons every day. However, Japan is noted for less rubbish production and a high gross local product worldwide as a result of its dense population and high handling charge for waste. Most commonly, waste significantly increases after some festivals and certain activities. The worldwide generated waste can be categorized by diverse regions consistent with a report by Hoornweg and Bhada-Tata [15]. In sub-Saharan Africa, the waste production was reported to be 62,000 kilotons/year. Although the generation of waste was relatively low compared with other regions, the per-capita generation of waste had big variations, ranging from 0.09 to 3.0 kg every day. China is the foremost generator in East Asia and the Pacific Region, where almost 270 million tons of waste was generated per year and about 0.44e4.3 kg of waste produced per person. Moreover, the entire waste production per year 160 million tons in the Caribbean and Latin America, 63 million tons in North Africa along with the Middle East, 572 million tons in OECD nations, and 70 million tons in South Asia. The total waste generated in the EU included commercial and household, waste to 250.3 million tons in 2014 [16]. In Serbia, the entire amount of waste produced was 2.62 million tons in 2012 [17]. Waste is generated by various kinds of social activities; its composition is affected by factors such as economic development, sources of materials, climate, geographical location, and cultural norms [17,18]. The composition of total waste in the EU in 2014 is shown in Fig. 3.1. The organic waste, such as that from households, reached about 8.3%, which was nearly 208 million tons generated in 2014 [16]. As for MSW, the composition can be classified as organic, paper, plastic, glass, metal, and so on, which contain a considerable amount energy. Bandara et al. [18] stated that the average waste generation per capita in Sri Lanka contained nearly 90% biodegradable organic compounds,

Global Status of Waste-to-Energy Technology 35 construction mining and quarrying manufacturing waste and water services households remaining

28.2% 10.2%

34.7%

9.1% 9.5%

8.3%

Figure 3.1 Waste composition in the European Union [16].

which provided valuable guidance for their local waste management department that the management practices should focus on biodegradable organic waste. There is a great production of global waste every year, and it is always in a sustained state of growth. So the technological practices of its reuse are worth understanding, promoting, and developing [19]. Furthermore, waste composition could be taken into account to promote the proper technologies.

4. National and International Waste-to-Energy Technologies The worldwide energy mandate is predicted to be nearly six times more than the existing demand. The existing energy stream is less than the definite energy needed for growth in numerous developing countries [1]. The goals of all types of waste management schemes are material profit, recovery of energy, and residue removal. However, the best highquality technologies for waste treatment not only address financial requirements, recovery of energy, and waste obliteration, but also are amenable to ecological concerns in the troubled zone. Therefore, it is essential to make the best waste treatment selections to meet the standards of all effective procedures [20]. Technological progression, improved pollution regulator systems, governmental inducements, and stringent guidelines have made WTE technology a possible alternative, particularly for the developed nations. It not only affords an energy source, but also decreases the potentially harmful influences of waste on the atmosphere. The landfill restriction sites for MSW disposal and the upsurge in public consciousness of the environmental influences of MSW have forced governments to find more operative conducts of MSW authorization and ecofriendly management [19,20]. The land obligation for WTE amenities is much less than that for landfill services handling the same amount of waste [21]. A WTE plant processing 1 million tons of waste per year has a regular working life of more than 30 years and involves less than 100,000 m2 of land area, whereas a landfill for 30 million tons of MSW requires a land area of 300,000 m2 [1]. There are variations in WTE structures, for example, organic

36 Chapter 3 waste anaerobic digestion, combustion, gasification, pyrolysis, and incineration options [19]. WTE selections can be sorted into biochemical and thermochemical processes. Biochemical methods are associated with anaerobic digestion possibilities to produce biogas and thermochemical developments are connected with gasification, pyrolysis, and ignition.

4.1 Thermal Conversion Technology Thermal conversion is mostly used for dry (less water content) refuse containing a high percentage of nonbiodegradable waste. Infrequently, the thermal conversion possibility is valuable for refuse-derived fuel (RDF), an advanced calorific combustible material. To produce RDF, recyclable and noncombustible materials are removed from the MSW, followed by comminution and/or granulation of the remaining waste [22]. Incineration is the measured ignition of waste at high temperature and is the most extensively used method of the thermal conversion option [1]. Further thermal conversion approaches (gasification and pyrolysis) are still in the investigation stage and they are not practicable for commercial use in large measure, possibly due to the nonexistence of appropriate MSW characterization information, poor feedstock value, and inappropriate strategies for facilities. Various classes of thermal alternatives are itemized in Table 3.1. Nonetheless, in a few newer studies [22e24], scientists have emphasized some other compensations of incineration apart from volume reduction and electricity generation, such Table 3.1: Types of Thermal Conversion Progression Parameter

Incineration

Partial oxidation

850e1200 Presence of sufficient oxygen

Absence of oxygen

Bottom ash, fly ash, slag, other noncombustible substances like metals and glass

Ash, char (combination of noncombustibles and carbon)

Controlled supply of oxygen Ash, slag

Full oxidative combustion

Operation temperature ( C) Atmosphere Solid

Liquid Gas

Pretreatment

Gasification

Thermal degradation of organic materials in the absence of oxygen 400e800

Principle

Reaction products

Pyrolysis

800e1600

Condensate of pyrolysis gas (pyrolysis oil, wax, tar) CO2, H2O, O2, N2

Not necessary

Required

Syngas (H2, CO, CO2, CH4, H2O, N2) Required

Global Status of Waste-to-Energy Technology 37

•Drying & degassing •Pyrolysis and gasificaƟon •OxidaƟon

Second Process •IncineraƟon •Energy recovery •Air polluƟon control

First Process

•Waste delivery & storage •Waste combusƟon •Energy recovery & conversion •Flue gas cleaning

Third Process

Figure 3.2 Different phases of the thermal conversion process [1].

as utilization of the bottom and fly ash of incineration plants in road construction and cement production and recovery of ferrous and nonferrous substances. Therefore, additional technological expansion in metal recovery from the dry lowest ash of incineration will enhance the energy acceptance of these waste facilities. Neverthless, in the developing countries, incineration is measured as the most dependable and inexpensive method when it is used for build burning without pretreatment of waste for production of energy. Incineration generally takes place in different phases (Fig. 3.2), dependent upon the operating circumstances and kinds of waste incinerated [1].

4.2 Biological Conversion Approach The biological conversion approach is built on the microbial breakdown of MSW organic matter. Many investigators have reported this approach as environmentally appropriate for energy recovery from waste materials [25,26]. It is normally ideal for wastes with a higher percentage of organic matter (putrescible) and with high moisture concentration. The chief technological possibility for energy recapture of this type is anaerobic digestion/ biomethanation. 4.2.1 Anaerobic Digestion Biomethanation or anaerobic digestion is a normal process of microbial breakdown of organic biodegradable matter in the absence of oxygen that forms biogas and stabilizes sludge [27]. The value of the generated biogas is contingent on the course parameters and substrate arrangement; the biogas is characteristically composed of CH4 (50%e75%), CO2

38 Chapter 3

HYDROLYSIS

• Carbohydrate, Fat, Proteins

ACEDOGENESIS

• FaƩy acid, Sugar, Amino Acid

ACETOGENESIS

• VolaƟle FaƩy Acid

METHANOGENESIS

• AceƟc Acid, Hydrogen, Carbon Dioxide • Methane, Carbon Dioxide

Figure 3.3 Different phases of anaerobic digestion.

(25%e50%), and other gases in the range of 1%e15% (such as NH3, water vapor, H2S, etc.) [28]. The formed sludge can be useful as a soil nourisher or as a carbon-based alternative in the agrarian arena [29]. Anaerobic digestion is widely used to recover both nutrients and biodegradable waste energy (Fig. 3.3).

4.3 Microbial Fuel Cell Approach Microbial fuel cells (MFCs) are a strategy that uses microbes as a biocatalyst and changes the chemical energy deposited in chemical compounds into an energy current. The MFC approach is an alternative to other bioenergy-concentrating approaches, for example, activated sludge and trickling filters, as well as offering benefits by reducing sludge formation, refining odor, and removing aeration supplies, all at the rate of waste reaction for electricity creation. In MFCs, there is no outside energy necessity for running the procedure; actually, it can form electricity by itself. However, the power creation from MFCs is still low, and therefore efforts should be engaged in improving the production power density by the scaling up of this approach (Table 3.2).

Global Status of Waste-to-Energy Technology 39 Table 3.2: Power Generation reproduced From Different Types of Substrate and Microbial Communities in Microbial Fuel Cells Pure Strain Type Clostridium butyricum Enterobacter cloacae Clostridium cellulolyticum and Geobacter sulfurreducens E. cloacae Pseudomonas sp.

Substrate

Highest Power Generation (mA/m2)

Starch Yeast and malt extract and glucose Carboxymethylcellulose

13,000 670 500

Cellulose units Orange waste

200 847  18.4

M.D. Khan, N. Khan, S. Sultana, R. Joshi, S. Ahmed, E. Yu, K. Scott, A. Ahmad, M.Z. Khan, Bioelectrochemical conversion of waste to energy using microbial fuel cell technology, Process Biochemistry 57 (2017) 141e158, https://doi.org/10.1016/j.procbio.2017.04.001.

4.4 Landfilling Sanitary landfilling is well defined as the meticulous disposal of waste materials on land to decrease the negative influence on the environment through biogas recovery with leachate processing [30]. However, unsanitary landfilling seems a meeker and reasonable solution for the disposal of cumulative waste amounts and is the most common form used in developing nations, which poses a considerable hazard to the environs [31]. When influences such as health impact, environmental impact, land degradation, and groundwater contamination are measured, landfilling converts to the worst option.

5. Global Benefits From Waste to Energy 5.1 Energy Production and Reduction of Greenhouse Gases In accordance with the prior information, combusting 1 metric ton of MSW in a contemporary WTE plant produces a gross of 600 kWh of electricity, therefore avoiding the mining of 1/4 ton of high-value US coal or trade of one oil barrel [23]. Landfills are the only alternative to dispose of nonrecoverable waste by decomposing trash to produce carbon dioxide and methane, an effective greenhouse gas that makes up a minimum 25% of greenhouse gases in the atmosphere, even though modern sanitary landfills provide gas collection networks and biogas utilization engines or turbines [24]. Considering the quantity of electricity generated and methane emissions avoided, a sum of independent studies have concluded that carbon dioxide release per ton of waste from the ignition of WTE is estimated to be reduced by 1 ton of carbon dioxide compared with landfilled waste. Thus, in addition to energy efficiency, the burning of waste in WTE facilities decreases the volume of greenhouse gases released by about 26 million tons of carbon dioxide.

40 Chapter 3

5.2 Recycling and Waste to Energy According to the previous report, the municipal recycling rate at this writing is 28% in the United States. In contrast, 57% of the WTE group of people achieved a 33% recovery rate. In 2008, the average WTE community recovery rate was 21%, compared with 17% across the country. The following takes the United States as an example. For the WTE units in the United States, 77% have on-site black metal recycling projects. These projects recuperate more than 702,727 tons of iron annually [25]. Most of the metals are recuperated from high-volume WTE plants from postcombustion bottom ash. Furthermore, 43% of the functioning facilities recover other materials collected on site (for example, plastics, nonferrous metals, white goods, glass, and ashes to be used in road construction outside the landfills). More than 776,364 tons of these recyclables can be processed per year. Combined with all on-site WTE recycling, nearly 1,479,091 tons were recovered by 82% of US facilities. Actually, all communities that operate WTE units are associated with off-site recycling programs. Recycling operations linked with these lineups may be private or public, residential or commercial. These programs can also be routed outside the community in a factory-specific location [32].

5.3 Saving of Land Through appropriate maintenance, WTE units can operate for more than 30 years [26]. Seeing that WTE units do not need more acreage than originally requested, the WTE units do not take ongoing land costs unless they are expanded to handle more municipal waste. In addition, the land required is substantially less than the land needed for the same amount of municipal waste, so the initial capital for the land is correspondingly small. For example, in landscaping and supplementary buildings, the land area required for processing 1 million tons of WTE units each year does not exceed 100,000 m2. In contrast, 30 million m2 of landfill (Greece’s total waste produced in about 8 years) is estimated to require 3 million m2 of land. Moreover, a new unit can be constructed on the base of an existing WTE plant, reducing the rate of land capital for the new plant to zero. Landfills, on the other hand, cannot be used for anything else, and new green spaces must be converted to landfills.

6. Economics of Waste-to-Energy Technologies Energy from waste is the key course of energy production in electricity or heat usage from key waste treatment. This process produces electricity and combustible fuels such as methanol, methane, ethanol, and synthetic fuels by incineration, anaerobic digestion, gasification, etc. WTE technology reduces greenhouse gas emissions while producing final products (fuel, chemical and electric power), and helps to effectively promote management

Global Status of Waste-to-Energy Technology 41 and recapture with the exploitation of organic materials. These are all well-known strengths of WTE technology, the economic viability of which needs to be recognized for widespread distribution of WTE pathways for better utilization of waste. The circular economy system (CES) is built on the “winewin” philosophy, in which a prosperous economy and healthy environs can be coexisting [33]. If WTE technology can fulfill the energy demand while realizing waste management and greenhouse gas emission reduction, a winewin circular economy can be achieved. The economic environment and environmental problems should establish a circular relationship in a direction that copes with the existing environmental problems and resource insufficiency. This means that the environment (freshwater production and waste production), energy, and carbon dioxide release should be related together, including a closed circulation system of material flow together with biological and technological nutrients, establishing the CES business model in an industrial system [34]. However, in the hierarchical edifice of waste management, WTE’s ranking is before final disposal, indicating that WTE has always been limited in terms of financial and environmental assistance [35]. As population development and landfills are the worst environmental alternatives, WTE will be the main excellent alternative for the future. Compared with landfills or other disposal methods, analysis of revenues through energy generation shows that the value of incineration is very high (32.64 euros/ton), trailed by gasification (25.68 euros/ton) [36]. Here is an example of the capital, operating charges, and revenues of a 500,000 ton/year WTE plant commissioned in Shanghai, China. The gate fee paid by the Shanghai municipality to the WTE plant is about $30/ton, the WTE electricity sold to the grid is credited at $40/MWh, the capital charge and operating charge per ton of waste processed are estimated at $48, while the electricity revenues amount to $60/ton. Under the above assumptions, the WTE plant would be profitable [37]. This way, the WTE unit, the environment, and energy production will win. Many developed countries in the world now use WTE technology, and in excess of 800 thermal WTE units convert about 11% of waste into about 429 TWh of power per day. To improve environmental quality while maintaining economic growth and achieving CES, we must solve the contradictory relationship between greening and growth, improve the efficiency of drive and resource (including waste resources) utilization, and make use of renewable energy, and WTE technology is a decent high-quality solution.

7. Potential Impacts of Waste to Energy WTE is documented as a promising original energy source for waste management and potential renewable energy source. Energy can be transformed from nonbiodegradable and biodegradable substances through thermal biochemistry [38]. WTE can reduce greenhouse

42 Chapter 3 gas emissions from waste treatment by converting CH4 into carbon dioxide. Research from Malaysia [39] showed that 2775 tons of CO2 were released under the baseline scenario of a landfill, while the WTE scheme produced 524.2 tons/day, achieving a lower net emission. Therefore, this factor is considered to be new hope for waste management, and in some developed countries, a number of large-scale WTE programs have been implemented, for instance, in Japan, Britain, Germany, and Sweden. WTE is the most economical alternative for profitability and environmental protection; it also could reduce greenhouse gas emissions and realize the potential for the financial feasibility of byproducts in the assembly process. Although incineration (WTE) and energy retrieval are a significant part of the comprehensive garbage management system and effectively reducing greenhouse gas emissions, they still need strict control. If there are no effective control measures, the discharge of harmful pollutants may affect the natural environment and human health. Consistent with the United Nations Environment Programme, kilns are the leading source of dioxin emission into the worldwide environs. Waste gases from the incinerator, wastewater, or bottom ash may contain heavy metals, dioxin, and furan. Plastics and metals are the chief sources of the heat value of waste, and their burning can produce these extremely toxic pollutants. Toxic substances are produced in different stages of heat treatment and have different forms; they can be individually fixed through a filtering device at high cost, but the final release is inevitable. Thus we need to contract with a special hazardous waste landfill, there is no safer way to avoid them or destroy them. In a effort to maximize the retrieval of energy, the technology is not compatible with reducing dioxin emissions. The incinerator ash will be dispersed into the environment and our food chain. And humans may be harmed by the toxic substances by breathing contaminated air or consuming locally contaminated food and water. The other problem is the economics. Maximum incinerators are utilized for waste mitigation equipment. In developed nations, part of the investment has been put into control systems to reduce cadmium, mercury, lead, dioxin, furan, volatile organic compounds, and other toxic substances. Another problem in developing nations is that other auxiliary fuels must be supplemented to make the combustion technology successful. Finally, municipal waste incineration requires a special and expensive landfill to deal with the flay ash or residue. In addition, the power acquired by the WTE industry often disrupts the price balance of local traditional energy generation. These are all potential impacts that WTE may bring, but the good thing is that with the progress of technology and the accumulation of practice, there is a lot of optimism. The environmental protection agency (EPA) in most countries will strictly demand and monitor the pollution level from the incineration plant. On the other hand, the government will introduce corresponding emission reduction incentives to encourage technological transformation, adding combustion supporting agents to promote clean

Global Status of Waste-to-Energy Technology 43 energy, and encouraging recycling of heavy metals and other substances in the ash can. So the situation has been moving in a better direction.

8. Waste-to-Energy Global Research and Development and Improvement With the development of the world’s population, the production of municipal waste is also increasing rapidly. It is projected that by 2050, the world population would reach 8.2 billion, mainly in developing nations and Africa [40], and the rate of waste generation would increase by 1.2e1.42 kg per person per day [41]. At this writing, many countries of the world are gradually paying consideration to and developing WTE factories to replace traditional waste disposal methods. Perhaps, in Germany, only 1% of the waste is sent to landfill, and the incineration segment is about 35% of the total waste treatment, which is more developed than the EU’s waste incineration rate of 24%. Sweden is another example of success, achieving 50% waste incineration and energy retrieval [42]. In addition, Sweden has also made use of methane, from the landfill to central heating, car fuel, and power plants [21]. There were around 434 WTE units running in China in early 2016. The country with the most garbage incineration units in the world is Japan (1900 waste incineration units), and 10% of the equipment producing and 80% of the city waste is treated by incineration [43]. Some of the latest units use stoker equipment and others use the progressive oxygen enhancement technology. There are also 100 heat treatment units using comparatively different procedures, for instance, straight smelting, the Ebara fluidization route, and JFE Thermo gasification, as well as melting system development. To decrease national greenhouse gas emissions and the reliance on fossil fuels, India has established its first Energy Bioscience Center. Since June 2014, Indonesia has had a total 93.5 MW installed volume of WTE units, with a pipeline of schemes in different research phases composed, amounting to an additional 373 MW of capacity. Research shows that burning is the main WTE technology used so far, and other advanced technologies, such as plasma arc gasification is under investigation. Considering the maturity level of municipal waste management, waste characteristics, land area, available capital, technology complexity and labor skills needed, geographic position, and technical efficiency, different regions should choose WTE models suitable for their development. The purpose of the combined waste management method is to optimize the production of waste, reduce waste sources, reuse and recycle materials, and manage final disposal. Most North American and European countries have formulated new directive policies. The underdevelopment of the waste control infrastructure and socioeconomic conditions have made the progress of urban garbage policies in other portions of the world relatively slow,

44 Chapter 3 but they are developing in a good direction. This will trigger a massive global development of the waste incineration market and technology [44].

9. PublicePrivate Waste-to-Energy Efforts At this writing, 420 WTE plants in Europe have burned about 53 million tons of MSW, which can provide electricity for 7 million households and heat 13 million homes. In the interim, they avoided about 23 million tons of carbon dioxide gas equivalent release by decreasing methane emissions from landfills and sidestepping the fiery breakdown of remnant fuels [45]. If the entire EU succeeded in converting landfills into a combination of recycling and WTE, as in countries like Denmark and the Netherlands, this would require the WTE capacity to be more than doubled, but that could decrease by nearly three times the equivalent emissions of carbon dioxide as a greenhouse gas. This will make a significant contribution to the EU’s ambitious goal of achieving 20% sustainable energy production by 2020, as it will account for 6% of the EU’s overall target for CO2 emissions reduction [45]. The best practice experience of European WTE plants is under review from an energy efficiency perspective. And this can provide guidance on maximizing energy recovery when planning new WTE projects, in terms of both key design elements and infrastructure and planning for power with heat supply. Essentially, to optimize capital and operating costs to facilitate large-scale operations, one needs to identify a location close to the customer to provide heat, preferably industrial properties or other district heating, and select designs based on the most advanced and mature technologies: grate furnaces combined with high steam conditions. All countries and governments, irrespective of whether they are developing or developed countries, are paying more and more attention to WTE tools. Governments encourage the research and innovation of WTE technologies and enhance the application of new technologies in industrial practice and then gradually promote them. Especially in most developing countries, due to the lack of policies and technologies, there are not enough infrastructure, planning, and funding in this area. However, most of the countries have not stopped trying to extract energy from waste. As for the developed nations, the laws and regulations regarding WTE becoming more perfect and technologies more and more advanced, energy conversion is becoming more and more effectual. WTE ignition is a significant part of contemporary waste management, which can deliver safe waste removal as well as electricity as well as heat production. Future projections show that, in particular, new EU member states who want to catch up with economic growth will produce more and more waste in the coming decades. Meanwhile, most of these countries choose to landfill wastes, which causes serious environmental impacts and

Global Status of Waste-to-Energy Technology 45 greenhouse gas emissions, while the EU is encouraging safe waste clearance. As a result, many of them are already rising up to meet the ever-increasing environmental standards because they must comply with EU legislation and the increased environmental awareness of their citizens and of international standards in general. Waste-to-energy capabilities appear to have saturated in some old member states. This has had a reflective consequence on the sustained growth of the WTE marketplace since 1995, but nonetheless now it appears to be losing its pace of expansion. Therefore, all eyes have shifted to countries with insufficient waste incineration capacity, such as the United Kingdom and Spain, as well as countries in eastern Europe and southeastern Europe. The second large-scale expansion still faces some challenges, however. Several countries in the east as well as the south need some time to forget the bad memories of past environmental abuse caused by harsh industrialization. It is also essential that they improve their comprehension of the original and innovative technologies. Many of them also suffer from limited financial means, economic instability, and lack of basic data to determine future plans in the area of waste. Despite this, the future of WTE in Europe is certain. WTE is a fully developed waste management system that allows waste producers to choose the best treatment options. Through the use of WTE, waste becomes an important source of renewable energy, and it also mitigates the impact of climate change and saves valuable resources and raw materials. Consequently, the extension of WTE will turn out to be part of a new approach of self-governing resource- and environmentally aware societies, and the fossil-based budget will be left in the previous era [45].

10. Waste-to-Energy Legislation The waste management sector is one of the greatest developed arenas in the EU. Its legislation in the EU is above national law and subordinate law [46]. The national law must be consistent with the secondary law of the EU. New European legislation was adopted on October 20, 2008, which sets out the basic procedures for waste disposal. It put the prevention of waste production in first place. Also it suggested that the current method of waste treatment (landfills) should be changed. Goals of 50% and 35% of this kind of waste handling by the years 2013 and 2020 compared with 1995 were set. And energy use should take priority over landfills, as WTE uses energy-efficient waste incineration as a recycling operation [47]. The application of the new legislation has affected the quantity and class of municipal waste and the process of WTE systems. Nevertheless, the legislations everywhere are not similar. In 1995, the USEPA endorsed state-of-the-art energy from the waste and capability discharge integrity in the Clean Air Act. Their maximum achievable control technology (MACT) regulations stipulate that WTE facilities with large units should abide by the new Clean Air Act values by

46 Chapter 3 December 19, 2000. Small unit services interpretation for only 5% of the WTE capacity in the United States and must comply with similar MACT rules by 2005. As of this writing, WTE services are less than 1% of the US issues of dioxin and mercury [46]. In addition, thermal waste handling equipment with a thermal capacity exceeding a certain limit must comply with the requirements of the Integrated Prevention and Pollution Control Directive. The EU Waste Framework Directive offers the governmental agenda for the collection, transportation, recovery, and disposal of waste, and comprises a common waste explanation. The directive necessitates all member provinces to take essential measures to ensure that waste is improved or disposed of without jeopardizing human health or triggering harm to the environment and comprises permitting, registering, and inspection necessities [44]. The edict also requires member provinces to take suitable measures to inspire, first, the deterrence or decrease of waste production and its destructiveness and, second, the retrieval of waste by way of recycling, reuse, or recovery or any other procedure with a view to removing secondary raw resources, or the usage of waste as a basis of energy. The directive’s requirements are complemented by other directions for detailed waste streams [47]. The Waste (England & Wales) (Amendment) Regulations 2012 were placed before Parliament and the Welsh Assembly on July 19, 2012, and took effect on October 1, 2012. The revised regulations address the separate assortment of waste [48]. They are a revision of the Waste (England & Wales) Regulations 2011. From January 1, 2015, the authorities of waste collection must amass waste paper, plastic, metal, and glass separately. It is also lays a responsibility on the waste collection system, from that date, to make preparations to ensure the separate collection of those waste items. These responsibilities apply wherever separate gathering is necessary to safeguard that waste is recovered in accordance with the directive and to ease or improve retrieval, where it is strictly, ecologically, and economically feasible [45]. The duties apply to waste categorized as that from houses and waste that is categorized as profitable or industrial wastes. The amended guidelines also substituted Regulation 14(2) to reproduce the changes to Regulation 13 to safeguard a consistent method. Consequential revisions were also completed to reflect variations in the new Regulation 13. Recovery and waste disposal necessitate a permit under EU legislation with the major objective of avoiding harm to anthropological health and the atmosphere. This legislation also permits member states to apply for exceptions from the necessity for a license, providing general instructions are laid down for each kind of exempt action, and the operation is recorded with the pertinent registration expert. Hazardous waste is fundamentally waste that comprises hazardous materials, which, if mishandled, have the potential to cause larger harm to the milieu and anthropological health than

Global Status of Waste-to-Energy Technology 47 nonhazardous materials [44]. Consequently, strict rules apply from the time of its production, to its use, management, and recovery or disposal.

11. Waste-to-Energy Environmental Impact and Climate Change 11.1 Conservation of Land The required land for WTE plants is significantly less than that needed for landfilling a similar amount of MSW, so the initial cost for the land is very small. In addition, WTE plants can last more than 30 years with appropriate maintenance, which does not necessitate more land than originally requested, so WTE plants do not have continuing land costs unless they are rebuilt to manage more municipal waste. Moreover, a new unit can be built on the base of an existing WTE plant, reducing the cost of land capital for the new plant to zero. Landfills, in contrast, cannot be recycled for anything else, and new green spaces must be converted to landfills [44,45].

11.2 The Decrease in Waste-to-Energy Dioxin Emissions The poisonous properties of dioxins and furans did not receive due attention in the United States or other countries until the late 1980s. With the application of the MACT regulations, the “toxic equivalent” (TEQ) dioxin releases from WTE units in the United States have dropped 1000-fold since 1987 to a total of 12 g TEQ/year. Table 3.3 presents the reductions in emissions from US WTE amenities between 1990 and 2000. In contrast, the USEPA reported that the main source of dioxins now is backyard waste burning, which reaches nearly 600 g each year.

11.3 Mercury Emissions In the 1970s, the use of mercury in US processes and products reached 2727 tons/year. As the greatest applications of the metal have been phased out, conforming to the USEPA’s regulations, by 2002 the quantity of mercury was condensed to less than 364 tons. Moreover, many communities have applied strong recycling plans to send old mercurycontaining products to WTE facilities [44]. This strategy, combined with the MACT Table 3.3: Emissions From US Waste-to-Energy Facilities Pollutant Dioxins/furans, g TEQ Mercury Sulfur dioxide Cadmium TEQ, toxic equivalents.

Annual Emissions 1990 4260 41.1 tons 27,909 tons 4.32 tons

Annual Emissions 2000 12 2.0 tons 3,705 tons 0.3 tons

Reduction (%) 99.7 95.1 86.7 93.0

48 Chapter 3 regulations, has concentrated the mercury emissions of WTE facilities from 81 tons in 1989 to less than 1.2 tons/year now [45]. The chief mercury source is through coal-fired energy units released into the troposphere.

12. Challenges and Way Forward With fossil fuel sources gradually decreasing and becoming more expensive, the conversion of waste to energy is becoming more and more attractive. However, the pathway to waste expansion to energy has numerous limitations. Most importantly, current techniques are not sufficient to recover available energy effectively enough to compete with fossil fuel technology [46]. Continuous attention and improvement are crucial to obtaining the best economical, technological, and environmental solutions by developing more effective processing systems, optimizing the ecological situation, refining utilization competence, and developing additional well-organized reactors. In the meantime, it is understandable that variations in the authorized framework are also of vital importance. A series of new taxes, subventions, and direct rules has provided strong incentives for the improvement of city waste management. Therefore, with the expansion of skill and engineering and more attention from countries and governments, the limitations of WTE technology can be solved and considered as a key and frugally viable component of the renewable energy economy [48].

13. Conclusions and Perspectives This chapter is explored the development of biomass waste and its co-conversion technologies, highlighting the complementarities of the energy and the drawbacks of individual utilizations. An overview of the actual energy production, utilization, and environmental shortcomings was given, contextualizing the need for alternative solutions like WTE approaches. Economic development and the related increase in worldwide energy demand have created pressure on the supply of energy resources. To promote viable development a harmless and renewable vitality is essential. In this connection, MSW can play a meaningful role in generating safer environs and renewable energy. WTE transformation is an environmentally and economically appealing practice that is speedily growing along with energy requirements, waste production, and environmental monitoring. The generally known WTE technologies are thermal alternatives (pyrolysis, incineration, and gasification), biochemical conversion (anaerobic digestion and fermentation), and landfilling. Pyrolysis, incineration, and gasification are the major practices that generate heat, vapor, and gases, in addition to char, syngas, methane, and lower molecular weight compounds from waste, respectively. For the private sectoral regions, policy updates, the widespread application of PPPs, and the composite characteristics of MSW are considered to be serious issues that should be deliberated.

Global Status of Waste-to-Energy Technology 49 With the growth of a new kind of development and the improvement in the status of environment protection, the policies regarding the energy through waste incineration industry have been uninterruptedly upgraded, which signifies an important challenge for the private sector. As it will require change and fuel a desire to renegotiate support, investment approaches, and technical standards. In the meantime, the continued development of the industry can also be considered a new opportunity for investors in the world market to meet the emerging demand. Currently, in the developing nations, shortages of energy and the normal means of MSW removal have produced a number of ecological and socioeconomic difficulties. This circumstance calls investigators to improve the diverse WTE transformation options under numerous scenarios. Investigators have established different technologies with improved strategies to convert more and more waste into energy. But the application is lacking when it is expanded to the large scale. Some issues relating to the application of sustainable technologies on a large scale are being discussed and need to be addressed in the future for proper utilization of the technology. It has limitless potential but nonetheless is still immature. More investigation is needed for expansion and proper execution of these technologies for large-scale uses.

Acknowledgments The authors are grateful for financial support from a Research Fund for International Young Scientists from the National Natural Science Foundation of China (Grant 31750110469) and the Guizhou Science and Technology Cooperation Platform Talents Fund (Grant [2017] 5733-001). We also thank all our laboratory colleagues and research staff members for their constructive advice and help.

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52 Chapter 3

Further Reading [1] K.C. Surendra, D. Takara, A.G. Hashimoto, S.K. Khanal, Biogas as a sustainable energy source for developing countries: opportunities and challenges, Renewable and Sustainable Energy Reviews 31 (2014) 846e859. [2] J.M. Ferna´ndezgonza´lez, A.L. Grindlay, F. Serranobernardo, M.I. Rodrı´guezrojas, M. Zamorano, Economic and environmental review of waste-to-energy systems for municipal solid waste management in medium and small municipalities, Waste Management 67 (2017) 360. [3] L. Qiu, Y. Dong, N.J. Themelis, Rapid growth of WTE in China: current performance and impediments to future growth, in: North American Waste-to-energy Conference, 2012, pp. 167e175. [4] R. Johri, K.V. Rajeshwari, A.N. Mullick, Technological Option for Municipal Solid Waste Management. Wealth from Waste, third ed., Trends and Technologies, The Energy and Research Institute, New Delhi, 2011, pp. 342e378. [5] United Nations, Department of Social and Economic Affairs, Population Division. World Population Prospects: The 2012 Revision. ST/ESA/SER.A/345, United Nations, New York, 2012.