A Primer on Waste-to-Energy

Waste-to-Energy is the use of modern combustion and biochemical technologies to recover energy, usually in the form of electricity and steam, from urban wastes. These new technologies can reduce the volume of the original waste by 90%, depending upon composition and use of outputs.

Energy is the driving force for development in all countries of the world. The increasing clamor for energy and satisfying it with a combination of conventional and renewable resources is a big challenge. Accompanying energy problems in different parts of the world, another problem that is assuming critical proportions is that of urban waste accumulation.

The quantity of waste produced all over the world amounted to more than 12 billion tonnes in 2006, with estimates of up to 13 billion tonnes in 2011. The rapid increase in population coupled with changing lifestyle and consumption patterns is expected to result in an exponential increase in waste generation of upto 18 billion tonnes by year 2020.

Waste generation rates are affected by socio-economic development, degree of industrialization, and climate. Generally, the greater the economic prosperity and the higher percentage of urban population, the greater the amount of solid waste produced. Reduction in the volume and mass of solid waste is a crucial issue especially in the light of limited availability of final disposal sites in many parts of the world. Millions of tonnes of household wastes are generated each year with the vast majority disposed of in open fields or burnt wantonly.

The main categories of waste-to-energy technologies are physical technologies, which process waste to make it more useful as fuel; thermal technologies, which can yield heat, fuel oil, or syngas from both organic and inorganic wastes; and biological technologies, in which bacterial fermentation is used to digest organic wastes to yield fuel.

The three principal methods of thermochemical conversion are combustion in excess air, gasification in reduced air, and pyrolysis in the absence of air. The most common technique for producing both heat and electrical energy from wastes is direct combustion. Combined heat and power (CHP) or cogeneration systems, ranging from small-scale technology to large grid-connected facilities, provide significantly higher efficiencies than systems that only generate electricity.

Biochemical processes, like anaerobic digestion, can also produce clean energy in the form of biogas which can be converted to power and heat using a gas engine. In addition, wastes can also yield liquid fuels, such as cellulosic ethanol, which can be used to replace petroleum-based fuels. Cellulosic ethanol can be produced from grasses, wood chips and agricultural residues by biochemical route using heat, pressure, chemicals and enzymes to unlock the sugars in biomass wastes.

Waste-to-energy plants offer two important benefits of environmentally safe waste management and disposal, as well as the generation of clean electric power.  The growing use of waste-to-energy as a method to dispose of solid and liquid wastes and generate power has greatly reduced environmental impacts of municipal solid waste management, including emissions of greenhouse gases.

Waste-to-Energy Prospects in the Middle East

wastetoenergy-plant-qatarA combination of high fuel prices and a search for alternative technologies, combined with massive waste generation has led to countries in the Middle East region to consider Waste to Energy (or WtE) as a sustainable waste management strategy and cost-effective fuel source for the future. We look at the current state of the WtE market in the region.

It is estimated that each person in the United Arab Emirates produces 2 kg of municipal solid waste per day – that puts the total waste production figure somewhere in the region of 150 million tonnes every year. Given that the population currently stands at over 9.4 million (2013) and is projected to see an annual average growth figure of 2.3% over the next six years, over three times the global average, it’s clear that this is a lot of waste to be disposed of. In addition, the GCC nations in general rank in the bottom 10% of the sustainable nations in the world and are also amongst the top per capita carbon-releasers.

When we also consider that UAE are actively pursuing alternative energy technologies to supplement rapidly-decreasing and increasingly-costly traditional fossil fuels, mitigate the harmful effects of landfill, and reduce an ever-increasing carbon footprint, it becomes apparent that high on their list of proposed solutions is Waste to Energy (WtE). It could be an ideal solution to the problem.

What is WtE

Waste-to-Energy works on the simple principle of taking waste and turning it into a form of energy. This can be electricity, heat or transport fuels, and can be achieved in a variety of ways – the most common of which is incineration. MSW is taken to a WtE plant, incinerated at high temperatures and the resultant heat is used to boil water which creates steam to turn turbines, in the same way that burning gas or coal produces power. Gasification and anaerobic digestion are two further WtE methods which are also used.

However, WtE has several advantages over burning fossil fuels. Primarily amongst them are the potential to minimise landfill sites which have caused serious concern for many years. They are not only unsightly, but can also be contaminated, biologically or chemically. Toxic waste can leach into the ground beneath them and enter the water table.

Landfill sites also continuously emit carbon dioxide and methane, both harmful greenhouse gases – in addition methane is potentially explosive. Sending MSW to landfill also discourages recycling and necessitates more demand for raw materials. Finally, landfill sites are unpleasant places which attract vermin and flies and give off offensive odours.

WtE has been used successfully in many countries around the world for a long time now. Europe is the most enthusiastic proponent of WtE, with around 450 facilities; the Asia-Pacific region has just over 300; the USA has almost 100. In the rest of the world there are less than 30 facilities but this number is growing. Globally, it is estimated that the WtE industry is growing at approximately US $2 billion per annum and will be valued at around US $80 billion by the year 2022.

The USA ranks third in the world for the percentage of waste which is incinerated for energy production. Around 16% of the rubbish that America produces every day is burned in its WtE plants. Advocates claims the advantages are clear: reducing the amount of greenhouse gas emitted into the environment (estimates say that burning one ton of waste in a WtE plant saves between one half and one ton of greenhouse gases compared to landfill emissions, or the burning of conventional fuels), freeing up land which would normally be used for landfill (and, therefore, extending the life of existing landfill sites), encouraging recycling (some facilities have managed to reduce the amount of waste they process by up to 90% and the recycling of ferrous and non-ferrous metals provides an additional income source), and, perhaps most importantly, producing a revenue stream from the sale of the electricity generated.

In one small county alone, Lancaster, Pennsylvania, with a population of just over half-a-million people, more than 4.4 billion kWh of electricity has been produced through WtE in the last 20 years. This has generated over USD $256 million through its sale to local residents.

WtE in the Middle East

Given WtE’s potential to not only reduce greenhouse gas emissions and pollution on a local scale, but also to produce much-needed electricity in the region, what is the current state of affairs in the Middle East. There are several WtE initiatives already underway in the region. Qatar was the first GCC country to implement a waste-to-energy programme and currently generates over 30MW of electricity from its Domestic Solid Waste Management Center (DSWMC) located at Messeid (Doha). Saudi Arabia and the UAE have both stated that they have WtE production capacity targets of 100MW. Bahrain, Kuwait and Oman are also seriously considering waste-to-energy as a means to tackle the worsening waste management problem.

Abu Dhabi’s government is currently spending around US $850 million to build a 100 MW plant which is expected to be operational by 2017 and which will supply around 20,000 households with electricity. In Sharjah, the world’s largest household waste gasification plant, costing in excess of US $480 million, is due to be open in 2015.

However, not all the GCC members are as enthusiastic about WtE. Dubai’s government has recently scrapped plans for a US $2 billion project which would have made use of the 7,800 tonnes of domestic waste which is produced in Dubai every single day.

We asked Salman Zafar, Founder of Doha-based EcoMENA, a popular sustainability advocacy, why given the sheer scale of the waste in the Gulf region, the production of this form of energy is still in its infancy. “The main deterrent in the implementation of WtE projects in the Middle East is the current availability of cheap sources of energy already available, especially in the GCC,” he commented.

Salman Zafar further says, “WtE projects demand a good deal of investment, heavy government subsidies, tipping fees, power purchase agreements etc, which are hard to obtain for such projects in the region.” “The absence of a sustainable waste management strategy in Middle East nations is also a vital factor behind the very slow pace of growth of the WtE sector in the region. Regional governments, municipalities and local SWM companies find it easier and cost-effective to dump untreated municipal waste in landfills,” he added.

So, how can WtE contribute towards the region’s growing power demand in the future?

“Modern WtE technologies, such as RDF-based incineration, gasification, pyrolysis, anaerobic digestion etc, all have the ability to transform power demand as well as the waste management scenario in the region,” he continued. “A typical 250 – 300 tons per day WtE plant can produce around 3 – 4 MW of electricity and a network of such plants in cities across the region can make a real difference in the energy sector as well as augmenting energy reserves in the Middle East. In fact, WtE plants also produce a tremendous about of heat energy which can be utilised in process industries, further maximising their usefulness,” Salman Zafar concluded.

New technologies naturally take time to become established as their efficiency versus cost ratios are analysed. However, it is becoming increasingly clearer that waste-to-energy is a viable and efficient method for solid waste management and generation of alternative energy in the Middle East.

Date Palm as Biomass Resource

date-wastesDate palm is one of the principal agricultural products in the arid and semi-arid region of the world, especially Middle East and North Africa (MENA) region. There are more than 120 million date palm trees worldwide yielding several million tons of dates per year, apart from secondary products including palm midribs, leaves, stems, fronds and coir. The Arab world has more than 84 million date palm trees with the majority in Egypt, Iraq, Saudi Arabia, Iran, Algeria, Morocco, Tunisia and United Arab Emirates.

Egypt is the world’s largest date producer with annual production of 1.47 million tons of dates in 2012 which accounted for almost one-fifth of global production. Saudi Arabia has more than 23 millions date palm trees, which produce about 1 million tons of dates per year. Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits. Some studies have reported that Saudi Arabia alone generates more than 200,000 tons of date palm biomass each year.

Date palm is considered a renewable natural resource because it can be replaced in a relatively short period of time. It takes 4 to 8 years for date palms to bear fruit after planting, and 7 to 10 years to produce viable yields for commercial harvest. Usually date palm wastes are burned in farms or disposed in landfills which cause environmental pollution in dates-producing nations. In countries like Iraq and Egypt, a small portion of palm biomass in used in making animal feed.

The major constituents of date palm biomass are cellulose, hemicelluloses and lignin. In addition, date palm has high volatile solids content and low moisture content. These factors make date biomass an excellent waste-to-energy resource in the MENA region. A wide range of thermal and biochemical technologies exists to convert the energy stored in date palm biomass to useful forms of energy. The low moisture content in palm wastes makes it well-suited to thermochemical conversion technologies like combustion, gasification and pyrolysis which may yield steam, syngas, bio oil etc. On the other hand, the high volatile solids content in date palm biomass indicates its potential towards biogas production in anaerobic digestion plants, possibly by codigestion with sewage sludge, animal wastes and/and food wastes. The cellulosic content in date palm wastes can be transformed into biofuel (bioethanol) by making use of the fermentation process. The highly organic nature of date palm biomass makes it highly suitable for compost production which can be used to replace chemical fertilizers in date palm plantations. Thus, abundance of date palm trees in the MENA and the Mediterranean region, can catalyze the development of biomass and biofuels sector in the region.

Biomass Wastes to Energy for MENA

The high volatility in oil prices in the recent past and the resulting turbulence in energy markets has compelled many MENA countries, especially the non-oil producers, to look for alternate sources of energy, for both economic and environmental reasons. The significance of renewable energy has been increasing rapidly worldwide due to its potential to mitigate climate change, to foster sustainable development in poor communities, and augment energy security and supply.

The Middle East is well-poised for waste-to-energy development, with its rich feedstock base in the form of municipal solid wastes, crop residues and agro-industrial wastes. The high rate of population growth, urbanization and economic expansion in the Middle East is not only accelerating consumption rates but also accelerating the generation of a wide variety of waste. Bahrain, Saudi Arabia, UAE, Qatar and Kuwait rank in the top-ten worldwide in terms of per capita waste generation. The gross urban waste generation quantity from Arab countries is estimated at more than 80 million tons annually. Open dumping is the most prevalent mode of municipal solid waste disposal in most countries.

Waste-to-energy technologies hold the potential to create renewable energy from waste matter, including municipal solid waste, industrial waste, agricultural waste, and industrial byproducts. Besides recovery of substantial energy, these technologies can lead to a substantial reduction in the overall waste quantities requiring final disposal, which can be better managed for safe disposal in a controlled manner. Waste-to-energy systems can contribute substantially to GHG mitigation through both reductions of fossil carbon emissions and long-term storage of carbon in biomass wastes.

Modern waste-to-energy systems options offer significant, cost-effective and perpetual opportunities for greenhouse gas emission reductions. Additional benefits offered are employment creation in rural areas, reduction of a country’s dependency on imported energy carriers (and the related improvement of the balance of trade), better waste control, and potentially benign effects with regard to biodiversity, desertification, recreational value, etc. In summary, waste-to-energy can significantly contribute to sustainable development both in developed and less developed countries. Waste-to-energy is not only a solution to reduce the volume of waste that is and provide a supplemental energy source, but also yields a number of social benefits that cannot easily be quantified.

Biomass wastes can be efficiently converted into energy and fuels by biochemical and thermal conversion technologies, such as anaerobic digestion, gasification and pyrolysis. Waste-to-energy technologies hold the potential to create renewable energy from waste matter.  The implementation of waste-to-energy technologies as a method for safe disposal of solid and liquid biomass wastes, and as an attractive option to generate heat, power and fuels, can significantly reduce environmental impacts of wastes. In fact, energy recovery from MSW is rapidly gaining worldwide recognition as the fourth ‘R’ in sustainable waste management system – Reuse, Reduce, Recycle and Recover. A transition from conventional waste management system to one based on sustainable practices is necessary to address environmental concerns and to foster sustainable development in the region.

Obstacles in Implementation of Waste-to-Energy

The biggest obstacle to the implementation of Waste-to-Energy (or WTE) lies not in the technology itself but in the acceptance of citizens. Citizens who are environmentally minded but lack awareness of the current status of waste-to-energy bring up concerns of environmental justice and organize around this. They view WTE as ‘dumping’ of pollutants on lower strata of society and their emotional critique rooted in the hope for environmental justice tends to move democracy.

An advocate of public understanding of science, Shawn Lawrence Otto regrets that the facts are not able to hold the same sway. Some US liberal groups such as the Center for American Progress are beginning to realize that the times and science have changed. It will take more consensus on the science and the go ahead from environmental groups before the conversation moves forward, seemingly improbable but not without precedent.

Spittelau Waste-to-Energy Plant

The Spittelau waste-to-energy plant is an example of opposition coming together in consensus over WTE. It was built in Vienna in 1971 with the purpose of addressing district heating and waste management issues. Much later awareness of the risks of dioxins emitted by such plants grew and the people’s faith in the technology was called into question. It also became a political issue whereby opposition parties challenged the mayor on the suitability of the plant. The economic interests of landfill owners also lay in the shutting down of the WTE facility. The alternative was to retrofit the same plant with advanced technology that would remove the dioxins through Selective Catalytic Reduction (SCR).

Through public discussions it appeared that the majority of the people were against the plant altogether though thorough studies by informed researchers showed that the science backs WTE. The mayor, Helmut Zilk eventually consulted Green Party members on how to make this technology better perceived in the eyes of the people, and asked the famous Austrian artist Freidensreich Hundertwasser, who was a green party member to design the look of the plant. Freidensreich Hundertwasser after carefully studying the subject wrote a letter of support, stating his belief as to why WTE was needed and accepted Mayor Helmut Zilk’s request. Later public opinion polls showed that there were a majority of people who were either in favor of or not opinionated about the plant, with only 3% in outright opposition of the plant.

Polarized Discussion

Waste-to-Energy or recycling has kept public discourse from questioning whether there may not be intermediate or case specific solutions. This polarization serves to move the conversation nowhere. For now it can be agreed that landfills are devastating in their contribution to Climate Change and must be done away with. The choice then, of treatment processes for municipal solid waste are plentiful. If after recovery of recyclable materials there remains a sizeable waste stream the option of waste-to-energy can be explored.

Primary Considerations

  • Environmental implications (i.e. CO2 emissions vis-à-vis the next best fuel source) given the composition of the local waste stream. If the waste stream consists of a high percentage of recyclables the more sustainable waste strategy would be to ramp up recycling efforts rather than to adopt WTE,
  • Likely composition and variation of the waste stream and the feasibility of the technology to handle such a waste stream,
  • Financial considerations with regards to the revenue stream from the WTE facility and its long term viability,
  • Efforts at making citizens aware of the high standards achieved by this technology in order to secure their approval.

Note: This excerpt is being published with the permission of our collaborative partner Be Waste Wise. The original excerpt and its video recording can be found at this link

Anaerobic Digestion of Animal Manure

Animal manure is a valuable source of nutrients and renewable energy. However, most of the manure is collected in lagoons or left to decompose in the open which pose a significant environmental hazard. The air pollutants emitted from manure include methane, nitrous oxide, ammonia, hydrogen sulfide, volatile organic compounds and particulate matter, which can cause serious environmental concerns and health problems. In the past, livestock waste was recovered and sold as a fertilizer or simply spread onto agricultural land. The introduction of tighter environmental controls on odour and water pollution means that some form of waste management is necessary, which provides further incentives for biomass-to-energy conversion.

Anaerobic digestion is a unique treatment solution for animal manure as it can  deliver  positive  benefits  related  to  multiple  issues,  including  renewable  energy,  water pollution, and air emissions. Anaerobic digestion of animal manure is gaining popularity as a means to protect the environment and to recycle materials efficiently into the farming systems. Waste-to-Energy (WTE) plants, based on anaerobic digestion of cow manure, are highly efficient in harnessing the untapped renewable energy potential of organic waste by converting the biodegradable fraction of the waste into high calorific gases.

The establishment of anaerobic digestion systems for livestock manure stabilization and energy production has accelerated substantially in the past several years. There are thousands of digesters operating at commercial livestock facilities in Europe, United States,  Asia and elsewhere. which are generating clean energy and fuel. Many of the projects that generate electricity also capture waste heat for various in-house requirements.

Important Factors

The main factors that influence biogas production from livestock manure are pH and temperature of the feedstock. It is well established that a biogas plant works optimally at neutral pH level and mesophilic temperature of around 35o C. Carbon-nitrogen ratio of the feed material is also an important factor and should be in the range of 20:1 to 30:1. Animal manure has a carbon – nitrogen ratio of 25:1 and is considered ideal for maximum gas production. Solid concentration in the feed material is also crucial to ensure sufficient gas production, as well as easy mixing and handling. Hydraulic retention time (HRT) is the most important factor in determining the volume of the digester which in turn determines the cost of the plant; the larger the retention period, higher the construction cost.

Process Description

The fresh animal manure is stored in a collection tank before its processing to the homogenization tank which is equipped with a mixer to facilitate homogenization of the waste stream. The uniformly mixed waste is passed through a macerator to obtain uniform particle size of 5-10 mm and pumped into suitable-capacity anaerobic digesters where stabilization of organic waste takes place.

In anaerobic digestion, organic material is converted to biogas by a series of bacteria groups into methane and carbon dioxide. The majority of commercially operating digesters are plug flow and complete-mix reactors operating at mesophilic temperatures. The type of digester used varies with the consistency and solids content of the feedstock, with capital investment factors and with the primary purpose of digestion.

Biogas contain significant amount of hydrogen sulfide (H2S) gas which needs to be stripped off due to its highly corrosive nature. The removal of H2S takes place in a biological desulphurization unit in which a limited quantity of air is added to biogas in the presence of specialized aerobic bacteria which oxidizes H2S into elemental sulfur. Biogas can be used as domestic cooking, industrial heating, combined heat and power (CHP) generation as well as a vehicle fuel. The digested substrate is passed through screw presses for dewatering and then subjected to solar drying and conditioning to give high-quality organic fertilizer.

Insights into MSW-to-Energy

You know the saying: One person’s trash is another’s treasure. When it comes to recovering energy from municipal solid waste — commonly called garbage or trash— that treasure can be especially useful. Instead of taking up space in a landfill, we can process our trash to produce energy to power our homes, businesses and public buildings.

In 2015, the United States got about 14 billion kilowatt-hours of electricity from burning municipal solid waste, or MSW. Seventy-one waste-to-energy plants and four additional power plants burned around 29 million tons of MSW in the U.S. that year. However, just 13 percent of the country’s waste becomes energy. Around 35 percent is recycled or composted, and the rest ends up in landfills.

Recovering Energy Through Incineration

The predominant technology for MSW-to-energy plants is incineration, which involves burning the trash at high temperatures. Similarly to how some facilities use coal or natural gas as fuel sources, power plants can also burn MSW as fuel to heat water, which creates steam, turns a turbine and produces electricity.

Several methods and technologies can play a role in burning trash to create electricity. The most common type of incineration plant is what’s called a mass-burn facility. These units burn the trash in one large chamber. The facility might sort the MSW before sending it to the combustion chamber to remove non-combustible materials and recyclables.

These mass-burn systems use excess air to facilitate mixing, and ensure air gets to all the waste. Many of these units also burn the fuel on a sloped, moving grate to mix the waste even further. These steps are vital because solid waste is inconsistent, and its content varies. Some facilities also shred the MSW before moving it to the combustion chamber.

Gasification Plants

Another method for converting trash into electricity is gasification. This type of waste-to-energy plant doesn’t burn MSW directly, but instead uses it as feedstock for reactions that produce a fuel gas known as synthesis gas, or syngas. This gas typically contains carbon monoxide, carbon dioxide, methane, hydrogen and water vapor.

Approaches to gasification vary, but typically include high temperatures, high-pressure environments, very little oxygen and shredding MSW before the process begins. Common gasification methods include:

  • Pyrolysis, which involves little to no oxygen, partial pressure and temperatures between approximately 600 and 800 degrees Celsius.
  • Air-fed systems, which use air instead of pure oxygen and temperatures between 800 and 1,800 degrees Celsius.
  • Plasma or plasma arc gasification, which uses plasma torches to increase temperatures to 2,000 to 2,800 degrees Celsius.

Syngas can be burned to create electricity, but it can also be a component in the production of transportation fuels, fertilizers and chemicals. Proponents of gasification report that it is a more efficient waste-to-energy method than incineration, and can produce around 1,000 kilowatt-hours of electricity from one ton of MSW. Incineration, on average, produces 550 kilowatt-hours.

Challenges of MSW-to-Energy

Turning trash into energy seems like an ideal solution. We have a lot of trash to deal with, and we need to produce energy. MSW-to-energy plants solve both of those problems. However, a relatively small amount of waste becomes energy, especially in the U.S.

Typical layout of MSW-to-Energy Plant

This lack may be due largely to the upfront costs of building a waste-to-energy plant. It is much cheaper in the short term to send trash straight to a landfill. Some people believe these energy production processes are just too complicated and expensive. Gasification, especially, has a reputation for being too complex.

Environmental concerns also play a role, since burning waste can release greenhouse gases. Although modern technologies can make burning waste a cleaner process, its proponents still complain it is too dirty.

Despite these challenges, as trash piles up and we continue to look for new sources of energy, waste-to-energy plants may begin to play a more integral role in our energy production and waste management processes. If we handle it responsibly and efficiently, it could become a very viable solution to several of the issues our society faces.

Waste Management in Sweden: Perspectives

Sweden is considered as a global leader in sustainable waste management and in the reduction of per capita carbon footprint. The country consistently works to lower its greenhouse gas emissions, improve energy efficiency and increase public awareness. Over the past 10 years, Sweden developed methods of repurposing waste, so less than one percent of the total waste generated in the country makes it to landfills. To accomplish this, the country changed their perspective of garbage.

Increase Recycling

Recycling is a part of Swedish culture. Residents regularly sort recyclable materials and food scraps from other waste in their homes before disposal. This streamlines the recycling process and reduces the effort required to sort large volumes of waste at larger recycling centers. As another way to promote recycling, the Swedish government created legislation stating recycling centers must be within 1,000 feet of residential areas. Conveniently located facilities encourage citizens to properly dispose of their waste.

Repurpose Materials

Citizens are also encouraged to reuse or repurpose materials before recycling or disposing of them. Repurposing and reusing products requires less energy when compared to the recycling or waste disposal process. As Swedes use more repurposed products, they reduce the volume of new products they consume which are created from fresh materials. In turn, the country preserves more of its resources.

Invest in Waste to Energy

Over 50 percent of the waste generated in Sweden is burned in waste-to-energy facilities. The energy produced by these facilities heats homes across the country during the long winter months. Localized heating — known as district heating — has improved air quality throughout the nation. It’s easier and more economical to control the emissions from several locations as opposed to multiple, smaller non-point sources.

Another benefit of waste-to-energy facilities is that ash and other byproducts of the burning process can be used for road construction materials. As a whole, Sweden doesn’t create enough waste to fuel its waste to energy plants — the country imports waste from its neighbors to keep its facilities going.

In the early 1990’s, the Swedish government shifted the responsibility for waste management from cities to the industries producing materials which would eventually turn to waste. To promote burning waste for energy, the government provides tax incentives to companies which make more economically attractive.

Impact of Waste-to-Energy

Although Sweden has eliminated the volume of trash entering landfills, they have increased their environmental impacts in other ways. Waste-to-energy facilities are relatively clean in that most harmful byproducts are filtered out before entering the environment, though they still release carbon-dioxide and water as their primary outputs. On average, waste-to-energy plants generate nearly 20 percent more carbon-dioxide when compared to coal plants.

 

waste-management-sweden

Coal plants burn and release carbon which is otherwise sequestered in the ground and unable to react with the earth’s atmosphere. Waste-to-energy facilities consume and release carbon from products made of organic materials, which naturally release their carbon over time. The downside to this process is that it frees the carbon from these materials at a much faster rate than it would be naturally.

The reliance on the waste-to-energy process to generate heat and the tax incentives may lower Swedish motivation to recycle and reuse materials. The country already needs to import trash to keep their waste-to-energy plants running regularly. Another disadvantage of this process is the removal and destruction of finite materials from the environment.

Even though Sweden continues to make strides in lowering their environmental impact as a whole, they should reevaluate their reliance on waste to energy facilities.

Waste-to-Energy in Saudi Arabia

waste-jeddahUrban waste management has emerged as a big challenge for the government and local bodies in Saudi Arabia. The country generates more than 15 million tons of municipal solid waste each year with per capita waste production estimated to be 2 kg per day, among the highest worldwide. Municipal waste production in three largest cities – Riyadh, Jeddah and Dammam – exceeds 6 million tons per annum which gives an indication of the enormity of the problem faced by civic bodies.

The Problem of Waste

Municipal waste generation in Saudi Arabia is increasing at an unprecedented rate. Due to high population growth rate, rapid urbanization and fast-paced economic development, MSW generation is expected to cross 30 million tons per year by 2033. More than 75 percent of Kingdom’s population is concentrated in urban areas, and collected garbage is thrown in landfills or dumpsites without any processing or treatment.

Most of the landfills in Saudi Arabia are non-sanitary and prone to problems like leachate, vermin, flies and spontaneous fires, apart from greenhouse gas emissions.  It has become necessary for the Saudi government to devise an integrated waste management strategy, using international best practices and modern technologies, to tackle heaps of garbage accumulating across the country.

Promise of Waste-to-Energy

Waste-to-energy provides a cost-effective and eco-friendly solution to both energy demand and MSW disposal problems in Saudi Arabia. Increasing waste generation, inability of existing solutions to tackle waste and expansion of cities into ex-dump sites are strong drivers for large-scale deployment of WTE systems in the Kingdom.

Saudi Arabia has tremendous waste-to-energy potential due to plentiful availability of good quality municipal waste. Modern waste-to-energy technologies, such as RDF-based incineration, gasification, pyrolysis and anaerobic digestion have the ability to transform power demand and waste management scenario in the country.

A typical 250 – 300 tons per day garbage-to-energy plant can produce around 3 – 4 MW of electricity and a network of such plants in cities around the country can make a real difference in waste management as well as energy sectors.  In fact, such plants also produce tremendous about of heat energy which can be utilized in process industries and district cooling systems, further maximizing their usefulness.

Key Challenges

Around the world, waste-to-energy finds wide acceptance as a tool to manage urban wastes, with more than 1,000 waste-to-energy plants in operation globally, especially in Europe, China and the Asia-Pacific. However, waste-to-energy is struggling to get off-the-ground in Saudi Arabia due to several issues, the main reason being the cheap and plentiful availability of oil which prevents decision-makers to set effective regulations for waste-to-energy development in the country.

Waste-to-Energy is widely accepted as a part of sustainable waste management strategy worldwide.

Waste-to-Energy is widely accepted as a part of sustainable waste management strategy worldwide.

Policy-makers in KSA should consider waste-to-energy as a sustainable waste management solution, rather than as a power-producing industry. Unlike Western countries, waste management services are practically free-of-cost for the waste generators which act as a deterrent for governmental investment in new waste management solutions and technologies, such as waste-to-energy. Infact, waste collection, transport and disposal methods in Saudi Arabia do not match the standards of a developed country.

Future Outlook

Vision 2030, touted as most comprehensive economic reform package in Saudi history, puts forward a strong regulatory and investment framework to develop Saudi waste-to-energy sector. An ambitious target of 3GW of energy from waste is to be achieved by 2025.  A methodical introduction of modern waste management techniques like material recovery facilities, waste-to-energy systems and recycling infrastructure can significantly improve waste management scenario and can also generate good business opportunities.

To sum up, environmental issues associated with non-sanitary landfills, ineffectiveness of prevalent waste management model and rising energy demand are key drivers for development of waste-to-energy sector in Saudi Arabia.

Waste-to-Energy in India: An Interview with Salman Zafar

waste-mountainIndia’s waste-to-energy sector, which kicked off in 1987, is still searching for a successful role model, even after tens of millions of dollars of investment. In recent years, many ambitious waste-to-energy projects have been established or are being planned in different parts of the country, and it is hoped that things will brighten up in the coming years. Salman Zafar, CEO of BioEnergy Consult, talks to Power Today magazine on India’s tryst with waste-to-energy and highlights major challenges and obstacles in making waste-to-energy a success story in India.

Power Today: What are the challenges that the Waste to Energy sector faces in the current scenario where there is a rejuvenated interest in clean energy? Do you think the buzz around solar and wind power has relegated the Waste to Energy sector to the back benches?

Salman Zafar: India’s experience with waste-to-energy has been lackluster until now. The progress of waste-to-energy sector in India is hampered by multiples issues including

  1. poor quality of municipal waste,
  2. high capital and O&M costs of waste-to-energy systems,
  3. lack of indigenous technology,
  4. lack of successful projects and failure of several ambitious projects,
  5. lack of coordination between municipalities, state and central governments,
  6. heavy reliance on government subsidies,
  7. difficulties in obtaining long-term Power Purchase Agreements (PPAs) with state electricity boards (SEBs)
  8. lukewarm response of banks and financial institutions and (9) weak supply chain.

Waste-to-energy is different from solar (or wind) as it essentially aims to reduce the colossal amount of solid wastes accumulating in cities and towns all over India. In addition to managing wastes, waste-to-energy has the added advantage of producing power which can be used to meet rapidly increasing energy requirements of urban India. In my opinion, waste-to-energy sector has attracted renewed interest in the last couple of years due to Swachch Bharat Mission, though government’s heavy focus on solar power has impacted the development of waste-to-energy as well as biomass energy sectors.

Power Today: India has a Waste to Energy potential of 17,000 MW, of which only around 1,365 MW has been realised so far. How much growth do you expect in the sector?

Salman Zafar: As per Energy Statistics 2015 (refer to http://mospi.nic.in/Mospi_New/upload/Energy_stats_2015_26mar15.pdf), waste-to-energy potential in India is estimated to be 2,556 MW, of which approximately 150 MW (around 6%) has been harnessed till March 2016.

The progress of waste-to-energy sector in India is dependent on resolution of MSW supply chain issues, better understanding of waste management practices, lowering of technology costs and flexible financial model. For the next two years, I am anticipating an increase of around 75-100 MW of installed capacity across India.

Power Today: On the technological front, what kinds of advancements are happening in the sector?

Salman Zafar: Nowadays, advanced thermal technologies like MBT, thermal depolymerisation, gasification, pyrolysis and plasma gasification are hogging limelight, mainly due to better energy efficiency, high conversion rates and less emissions. Incineration is still the most popular waste-to-energy technology, though there are serious emission concerns in developing countries as many project developers try to cut down costs by going for less efficient air pollution control system.

Power Today: What according to you, is the general sentiment towards setting up of Waste to Energy plants? Do you get enough cooperation from municipal bodies, since setting up of plants involves land acquisition and capital expenditure?

Salman Zafar: Waste-to-energy projects, be it in India or any other developing country, is plagued by NIMBY (not-in-my-backyard) effect. The general attitude towards waste-to-energy is that of indifference resulting in lukewarm public participation and community engagement in such projects.

Government should setup dedicated waste-to-energy research centres to develop lost-cost and low-tech waste to energy solutions

Government should setup dedicated waste-to-energy research centres to develop lost-cost and low-tech waste to energy solutions

Lack of cooperation from municipalities is a major factor in sluggish growth of waste-to-energy sector in India. It has been observed that sometimes municipal officials connive with local politicians and ‘garbage mafia’ to create hurdles in waste collection and waste transport. Supply of poor quality feedstock to waste-to-energy plants by municipal bodies has led to failure of several high-profile projects, such as 6 MW MSW-to-biogas project in Lucknow, which was shut down within a year of commissioning due to waste quality issues.

Power Today: Do you think that government policies are in tandem when it comes to enabling this segment? What policies need to be changed, evolved or adopted to boost this sector?

Salman Zafar: A successful waste management strategy demands an integrated approach where recycling and waste-to-energy are given due importance in government policies. Government should strive to setup a dedicated waste-to-energy research centre to develop a lost-cost and low-tech solution to harness clean energy from millions of tons of waste generated in India.

The government is planning many waste-to-energy projects in different cities in the coming years which may help in easing the waste situation to a certain extent. However, government policies should be inclined towards inclusive waste management, whereby the informal recycling community is not robbed of its livelihood due to waste-to-energy projects.

Government should also try to create favourable policies for establishment of decentralized waste-to-energy plants as big projects are a logistical nightmare and more prone to failure than small-to-medium scale venture.

Note: This interview was originally published in June 2016 edition of Power Today magazine. The unabridged version is available at this link