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

Waste-to-Energy in China: Perspectives

garbage-chinaChina is the world’s largest MSW generator, producing as much as 175 million tons of waste every year. With a current population surpassing 1.37 billion and exponential trends in waste output expected to continue, it is estimated that China’s cities will need to develop an additional hundreds of landfills and waste-to-energy plants to tackle the growing waste management crisis.

China’s three primary methods for municipal waste management are landfills, incineration, and composting. Nevertheless, the poor standards and conditions they operate in have made waste management facilities generally inefficient and unsustainable. For example, discharge of leachate into the soil and water bodies is a common feature of landfills in China. Although incineration is considered to be better than landfills and have grown in popularity over the years, high levels of toxic emissions have made MSW incineration plants a cause of concern for public health and environment protection.

Prevalent Issues

Salman Zafar, a renowned waste management, waste-to-energy and bioenergy expert was interviewed to discuss waste opportunities in China. As Mr. Zafar commented on the current problems with these three primary methods of waste management used by most developing countries, he said, “Landfills in developing countries, like China and India, are synonymous with huge waste dumps which are characterized by rotting waste, spontaneous fires, toxic emissions and presence of rag-pickers, birds, animals and insects etc.” Similarly, he commented that as cities are expanding rapidly worldwide, it is becoming increasingly difficult to find land for siting new landfills.

On incineration, Zafar asserted that this type of waste management method has also become a controversial issue due to emission concerns and high technology costs, especially in developing countries. Many developers try to cut down costs by going for less efficient air pollution control systems”. Mr. Zafar’s words are evident in the concerns reflected in much of the data ­that waste management practices in China are often poorly monitored and fraudulent, for which data on emission controls and environmental protection is often elusive.

Similarly, given that management of MSW involves the collection, transportation, treatment and disposal of waste, Zafar explains why composting has also such a small number relative to landfills for countries like China. He says, “Composting is a difficult proposition for developing countries due to absence of source-segregation. Organic fraction of MSW is usually mixed with all sorts of waste including plastics, metals, healthcare wastes and industrial waste which results in poor quality of compost and a real risk of introduction of heavy metals into agricultural soils.” Given that China’s recycling sector has not yet developed to match market opportunities, even current treatment of MSW calls for the need of professionalization and institutionalization of the secondary materials industry.

While MSW availability is not an issue associated with the potential of the resource given its dispersion throughout the country and its exponential increase throughout, around 50 percent of the studies analyzed stated concerns for the high moisture content and low caloric value of waste in China, making it unattractive for WTE processes.

Talking about how this issue can be dealt with, Mr. Zafar commented that a plausible option to increase the calorific value of MSW is to mix it with agricultural residues or wood wastes. Thus, the biomass resources identified in most of the studies as having the greatest potential are not only valuable individually but can also be processed together for further benefits.

Top Challenges

Among the major challenges on the other hand, were insufficient or elusive data, poor infrastructure, informal waste collection systems and the lack of laws and regulations in China for the industry. Other challenges included market risk, the lack of economic incentives and the high costs associated with biomass technologies. Nevertheless, given that the most recurring challenges cited across the data were related to infrastructure and laws and regulations, it is evident that China’s biomass policy is in extreme need of reform.

China’s unsustainable management of waste and its underutilized potential of MSW feedstock for energy and fuel production need urgent policy reform for the industry to develop. Like Mr. Zafar says, “Sustainable waste management demands an integration of waste reduction, waste reuse, waste recycling, and energy recovery from waste and landfilling. It is essential that China implements an integrated solid waste management strategy to tackle the growing waste crisis”.

Future Perspectives

China’s government will play a key role in this integrated solid waste management strategy. Besides increased cooperation efforts between the national government and local governments to encourage investments in solid waste management from the private sector and foster domestic recycling practices, first, there is a clear need to establish specialized regulatory agencies (beyond the responsibilities of the State Environmental Protection Administration and the Ministry of Commerce) that can provide clearer operating standards for current WTE facilities (like sanitary landfills and incinerators) as well as improve the supervision of them.

It is essential that China implements an integrated solid waste management strategy to tackle the growing waste crisis

It is essential that China implements an integrated solid waste management strategy to tackle the growing waste crisis

Without clear legal responsibility assigned to specialized agencies, pollutant emissions and regulations related to waste volumes and operating conditions may continue to be disregarded. Similarly, better regulation in MSW management for efficient waste collection and separation is needed to incentivize recycling at the individual level by local residents in every city. Recycling after all is complementary to waste-to-energy, and like Salman Zafar explains, countries with the highest recycling rates also have the best MSW to energy systems (like Germany and Sweden).

Nevertheless, without a market for reused materials, recycling will take longer to become a common practice in China. As Chinese authorities will not be able to stop the waste stream from growing but can reduce the rate of growth, the government’s role in promoting waste management for energy production and recovery is of extreme importance.

Moving Grate Incineration: Preferred WTE Technology

Incineration is the most popular waste treatment method that transforms waste materials into useful energy. The incineration process converts waste into ash, flue gas, and heat. The type of thermal WTE technology most commonly used worldwide for municipal solid waste is the moving grate incineration. These moving grate incinerators are even sometimes referred to as as the Municipal Solid Waste Incinerators (MSWIs). As of August 2013, of more than 1000 of 1200 Waste-to-Energy plants (among 40 different countries) there is no pre-treatment of the MSW before it is combusted using a moving grate. The hot combustion gases are commonly used in boilers to create steam that can be utilized for electricity production. The excess energy that can’t be used for electricity can possibly be used for industrial purposes, such as desalination or district heating/cooling

Benefits of Moving Grate

The moving grate incineration technology is lenient in that it doesn’t need prior MSW sorting or shredding and can accommodate large quantities and variations of MSW composition and calorific value. With over 100 years of operation experience, the moving grate incineration system has a long track record of operation for mixed MSW treatment. Between 2003 and 2011, it was reported that at least 106 moving grate incineration plants were built worldwide for MSW treatment. Currently, it is the main thermal treatment used for mixed MSW.

Compared to other thermal treatment technologies, the unit capacity and plant capacity of the moving grate incineration system is the highest, ranging from 10 to 920 tpd and 20 to 4,300 tpd. This system is able to operate 8,000 hours per year with one scheduled stop for inspection and maintenance of a duration of roughly one month. Today, the moving grate incineration system is the only treatment type which has been proven to be capable of treating over 3,000 tpd of mixed MSW without requiring any pretreatment steps. Being composed of six lines of furnace, one of the world’s largest moving grate incineration plants has a capacity of 4,300 tpd and was installed in Singapore by Mitsubishi in 2000

Working Principle

Moving-grate incineration requires that the grate be able to move the waste from the combustion chamber to allow for an effective and complete combustion. A single incineration plant is able to process thirty-five metric tons of waste per hour of treatment.

The MSW for a moving grate incinerator does not require pretreatment. For this reason, it is easier to process large variations and quantities. Most of these incineration plants have hydraulic feeders to feed as-received MSW to the combustion chamber (a moving grate that burns the material), a boiler to recover heat, an air pollution control system to clean toxins in the flus gas, and discharge units for the fly ash. The air or water-cooled moving grate is the central piece of the process and is made of special alloys that resist the high temperature and avoid erosion and corrosion.

Working principle of a grate incinerator

The waste is first dried on the grate and then burnt at a high temperature (850 to 950 degrees C) accompanied with a supply of air. With a crane, the waste itself is emptied into an opening in the grate. The waste then moves towards the ash pit and it is then treated with water, cleaning the ash out. Air then flows through the waste, cooling the grate. Sometimes grates can also be cooled with water instead. Air gets blown through the boiler once more (but faster this time) to complete the burning of the flue gases to improve the mixing and excess of oxygen.

Suitability for Developing Nations

For lower income and developing countries with overflowing landfills, the moving grate incinerator seems suitable and efficient. Moving grate incineration is the most efficient technology for a large-scale mixed MSW treatment because it is the only thermal technology that has been able to treat over 3,000 tons of mixed MSW per day. It also seems to be considerably cheaper than conventional technologies.

Compared to other types of Waste-to-Energy technologies, this type of system also shows the highest ability to handle variation of MSW characteristics. As for the other incineration technologies like gasification and pyrolysis technologies, these are either limited in small-scale, limited in material for industrial/hazardous waste treatment, requiring preprocessing of mixed MSW before feeding, which make them not suitable for large-scale mixed MSW treatment.

Conclusion

For the reduction of significant waste volume, treatment using a moving grate incinerator with energy recovery is the most commonly used form of waste-to-energy (WTE) technology. The moving grate’s ability to treat significant volumes of waste efficiently, while not requiring pre-treatment or sorting is a major advantage that makes this suitable for developing countries. This technology could provide many other benefits to such nations. Implementing moving grate incinerators is most suitable for developing nations because not only will it reduce waste volume, but it would also reduce the demand for landfills, and could recover energy for electricity.

References

 “A Rapidly Emerging WTE Technology: Circulating Fluid Bed Combustion”. Huang, Qunxing, Yong Chi1, and Nickolas J. Themelis. Proceedings of International Thermal Treatment Technologies (IT3), San Antonio, TX, October 2013. Columbia University. Available: http://www.seas.columbia.edu/earth/wtert/sofos/Rapid_Emerging_Tech_CFB.pdf accessed on 29 March 2016.
“Incineration.” Waste Management Resources. Waste Management Resources. Available: http://www.wrfound.org.uk/articles/incineration.html accessed on 29 March 2016.
Kamuk, Bettina, and Jørgen Haukohl. ISWA Guidelines: Waste to Energy in Low and Middle Income Countries. Rep. International Solid Waste Association, 2013. Print.
“Municipal Solid Waste Management and Waste-to-Energy in the United States, China and Japan.” Themelis, Nickolas J., and Charles Mussche. 2nd International Academic Symposium on Enhanced Landfill Mining, Houthalen and Helchteren, Belgium, 4-16 October 2013.  Enhanced Landfill Mining. Columbia University. Available: http://elfm.eu/Uploads/ELFM/FILE_73D907E9-8225-4B93-91F8-10F71F59B793.PDF accessed on 29 March 2016.
“Review of MSW Thermal Treatment Tecnologies.” Lai, K.C.K., I.M.C. Lo, and T.T.Z. Liu. Proceedings of the International Conference on Solid Waste 2011- Moving Towards Sustainable Resource Management, Hong Kong SAR, P.R. China, 2 – 6 May 2011. Hong Kong SAR, P.R. China. 2011. 317-321. Available: http://www.iswa.org/uploads/tx_iswaknowledgebase/10_Thermal_Technology.pdf. accessed on 14 April 2016.
UN-HABITAT, 2010. Collection of Municipal Solid Waste in Developing Countries. United Nations Human Settlements Programme (UN-HABITAT), Nairobi. Available:
http://www.eawag.ch/fileadmin/Domain1/Abteilungen/sandec/E-Learning/Moocs/Solid_Waste/W1/Collection_MSW_2010.pdf.
World Bank, 2012. What a Waste: A Global Review of Solid Waste Management. Urban Development Series Knowledge Papers. Available: http://documents.worldbank.org/curated/en/2012/03/16537275/waste-global-review-solid-wastemanagement. accessed on 14 April 2016.

Solid Waste Management in Pakistan

Karachi-Garbage-DumpSolid waste management situation in Pakistan is a matter of grave concern as more than 5 million people to die each year due to waste-related diseases. In Pakistan roughly 20 million tons of solid waste is generated annually, with annual growth rate of about 2.4 percent. Karachi, largest city in the country, generates more than 9,000 tons of municipal waste daily. All major cities, be it Islamabad, Lahore or Peshawar, are facing enormous challenges in tackling the problem of urban waste. The root factors for the worsening garbage problem in Pakistan are lack of urban planning, outdated infrastructure, lack of public awareness and endemic corruption.

Contributing Factors

Being the 6th most populated country in the world; there is a lot of consumerism and with it a great deal of waste being produced. Like other developing countries, waste management sector in Pakistan is plagued by a wide variety of social, cultural, legislative and economic issues.  In the country, more waste is being produced than the number of facilities available to manage it. Some of the major problems are:

  • There is no proper waste collection system
  • Waste is dumped on the streets
  • Different types of waste are not collected separately
  • There are no controlled sanitary landfill sites. Opening burning is common.
  • Citizens are not aware of the relationship between reckless waste disposal and resulting environmental and public health problems

As a result of these problems, waste is accumulating and building up on roadsides, canals, and other common areas and burning trash is common, causing hazardous toxins to be exposed thereby threatening human and environmental health. Among the already few landfill sites that are present, even fewer are in operation. Even within Pakistan’s capital, Islamabad, there are no permanent landfills to be found.

The waste on the roads allows for an ideal environment for various flies to thrive which effects both human health and the health of the environment for other species. The poor solid waste management in Pakistan has caused numerous diseases and environmental problems to rise.

Waste Management Situation in Lahore

In Lahore, the capital of Punjab and the second largest city in Pakistan, there are currently no controlled waste disposal facilities are formal recycling systems, though roughly 27% of waste (by weight) is recycled through the informal sector, Lahore does not have very high performing governmental management in the waste management situation. Instead, the City District Government Lahore established the Lahore Waste Management Company and left the responsibility of the Solid Waste Management in Lahore to them. Beginning in 2011, Lahore Waste Management Company strives to develop a system of SWM that ensures productive collection, recovery, transportation, treatment and disposal of the waste in Lahore.

Lahore Waste Management Company (LWMC) has over 10,000 field workers involved in waste collection and disposal. Though the LWMC is working in phases, 100% collection rates are not seen yet. Lahore currently only has three disposal sites which are no more than dumps, where illegal dumping and trash burning is common. However, there is some resource recovery taking place. It is estimated that 27% of dry recyclables are informally recycled within the city. Additionally a composting plant converts 8% of waste into compost.

In general, the governance over the Waste Management in Lahore is hardly present. Though there are current projects and plans taking place, by the Lahore Waste Management Company for example, in order to achieve a productive and sustainable system in the city it is necessary for all service providers (formal, private, and informal) to take part in decisions and actions.

Current Activities and Projects

According to the United Nations Environment Program, there are six current activities and plans taking place towards an efficient Waste Management System. These current activities are as follows:

  • Solid Waste Management Guidelines (draft) prepared with the support of Japan International Cooperation Agency (JICA), Japan.
  • Converting waste agricultural biomass into energy/ material source – project by UNEP, IETC Japan.
  • North Sindh Urban Services Corporation Limited (NSUSC) – Assisting the district government in design and treatment of water supply, sanitation and solid waste management
  • The URBAN UNIT, Urban Sector Policy & Management Unit P & D Department, Punjab. Conducting different seminars on awareness of waste water, sanitation & solid waste management etc.
  • Lahore Compost (Pvt.) Ltd. only dealing with the organic waste with the cooperation of city district government Lahore, Pakistan. The company is registered as a CDM project with UNFCCC.
  • Different NGOs are involved at small scale for solid waste collection, and recycling.

Additionally, in November 2013 a German company, agreed to invest in the installation of a 100 megawatt power plant which generates energy from waste from Lahore. Progress is being made on the country’s first scientific waste disposal site in Lakhodair. With this in mind, the Lahore Waste Management Company considered other possible technologies for their Waste-to-Energy project. They opened up applications for international companies to hire as the official consultant for LWMC and their project. The results of the feasibility study results showed that the power plant has the potential to process 1035 tons of municipal waste daily, and generate 550 megawatt electricity daily.

The Way Forward

Although SWM policies do exist, the levels at which they are implemented and enforced lack as a result of the governmental institutions lacking resources and equipment. These institutions are primarily led by public sector workers and politicians who are not necessarily the most informed on waste management. For improvements in municipal solid waste management, it is necessary for experts to become involved and assist in the environmental governance.

Due to the multiple factors contributing to the solid waste accumulation, the problem has become so large it is beyond the capacity of municipalities. The former director of the Pakistan Council of Scientific and Industrial Research, Dr. Mirza Arshad Ali Beg, stated, “The highly mismanaged municipal solid waste disposal system in Pakistan cannot be attributed to the absence of an appropriate technology for disposal but to the fact that the system has a lot of responsibility but no authority.” Laws and enforcement need to be revised and implemented. The responsibility for future change is in the hands of both the government, and the citizens.

Waste practices in the Pakistan need to be improved. This can start with awareness to the public of the health and environment impacts that dumped and exposed waste causes. It is imperative for the greater public to become environmentally educated, have a change in attitude and take action.

References

http://www.aljazeera.com/indepth/features/2014/08/solid-waste-pakistan-karachi-2014867512833362.html

http://www.iamcivilengineer.com/2014/04/solid-waste-disposal-and-collection.html

http://epd.punjab.gov.pk/solid_waste

http://www.aljazeera.com/indepth/features/2014/08/solid-waste-pakistan-karachi-2014867512833362.html

http://www.iamcivilengineer.com/2014/04/solid-waste-disposal-and-collection.html

https://www.researchgate.net/publication/264629066_An_assessment_of_the_current_municipal_solid_wastemanagement_system_in_Lahore_Pakistan

http://www.lwmc.com.pk/about-us.php

https://www.researchgate.net/publication/264629066_An_assessment_of_the_current_municipal_solid_wastemanagement_system_in_Lahore_Pakistan

http://www.unep.org/ietc/Portals/136/Events/ISWM%20GPWM%20Asia%20Pacific%20Workshop/Pakistan_Presentation.pdf

http://www.dawn.com/news/1081689

http://www.lwmc.com.pk/waste-to-energy.php

http://thinkbrigade.org/asia/pakistan-waste-management/index.html

Peeping into the Future of Waste

Waste management is an important tool for curbing climate change and for keeping our environment clean and healthy. Methane generated from biodegradable wastes is a powerful greenhouse gas, and when it’s not captured and used as a fuel it contributes to rapid warming of the atmosphere. Estimates suggest that biodegradable waste in dump sites and uncapped landfill sites are contributing far more methane to the atmosphere than previously thought. What’s more, urban food waste is predicted to increase by 44% from 2005 to 2025, and with no proper management in place, will significantly add to global greenhouse gas emissions.

Worryingly, 38 of the world’s 50 largest dumps are close to the sea, contributing to marine and coastal pollution. The accumulation of plastics in the marine food chain is causing global concern. While we don’t yet know how to clean the oceans, stemming the flow of waste into marine environments would be a step in the right direction.

Wasted health

40% of the world’s waste ends up in open dumps. These aren’t even what you’d call “landfill”. They don’t have any impervious lining to prevent noxious leachate from entering the surrounding environment, nor are they capped to prevent the spread of disease. In fact, in India, the Philippines and Indonesia, the health risk from open dumping of waste is greater than the risk of malaria[i].

3.5 billion people in the world lack access to proper waste management. That figure is expected to grow to 5 billion by 2050. Respiratory diseases, gastrointestinal diseases and occupational health risks add to the misery experienced by the 50,000+ people living from open dumps.

Waste is any material that is no longer wanted for its original purpose. The owner doesn’t have a need for it, and so discards it. Even valuable items can and do end up as waste purely because someone has thrown them away. The recent (and rather brilliant) BBC programme Hugh’s War on Waste shone the spotlight on attitudes towards disposable fashion. A look through the bins of a typical street uncovered a startling amount of clothing that had been thrown away, despite it still being in perfectly good condition. This highlights a simple fact: there is plenty of value in waste.

  • Estimates suggest there are 40 million people globally who are making their living from waste – half of these are working informally.
  • During the last recession in the UK, the waste management sector was one of the only industries to keep growing, resulting in it being termed the “Green Star of the Economy”.
  • Showing people how to turn a waste stream into something valuable isn’t rocket science. There are lots of examples of informal, community-based, grassroots recycling and upcycling projects that generate wealth for the poorest in society.
  • Internet is allowing simple waste processing techniques to be replicated all over the world, and helping make that information accessible is one of the most fulfilling aspects of my career.

Business skills

“Give a man a fish and he can eat for a day. Show a man how to fish and he can eat for the rest of his life.” Teaching people how to make valuable products from waste is important. But just as important, is passing on the business skills to be able to identify a market, factor in costs, check out the competition, market their products and run a successful business.

Development work in the waste arena needs to address both sides of the coin, and in doing so will enable people to start up their own businesses, in their own communities, and generate wealth organically. That’s far more valuable than delivering aid in a ready-made package (which incidentally rarely works – there’s a great TED Talk on this topic by Ernesto Sirolli, called “Want to help someone? Shut up and listen”).

Why closing dumps isn’t a silver bullet

The proliferation of megacities, particularly in developing countries, is causing a health crisis. Decent waste management is an indicator of good governance – that is, if a council or government can collect taxes and provide a waste management service, then it most likely isn’t (very) corrupt. However, in many places where corruption or other forms of bad or weak governance prevail, top-down solutions are notoriously difficult to implement.

Often, when the world’s attention turns to an open dump, the government responds by closing it and the journalists go home. This is what happened with Smokey Mountain dumpsite in the Philippines (and many others around the world). All that happens is another open dump emerges nearby, and the scavengers move to the new site.

The problem is that if there is no alternative solution in place, people will discard of their waste in the only ways available – dumping it or burning it; and the poor will follow the waste.

Replacing an open dump with a government-controlled waste management system isn’t a silver bullet either. The losers, again, are the hundreds, and sometimes thousands of men, women and children who live from scavenging from the dump. It may seem horrific to many of us, but the truth is that if you take that opportunity to earn a paltry living away from the poorest in society, they will starve. Solutions need to be inclusive.

Power to the people

To close dump sites, you need to have a workable alternative solution in place. You need to have regular waste collection taking place, and you need somewhere to take it. Building materials recovery facilities alongside existing open dumps is one idea. Informal waste pickers who are currently working in dangerous conditions on the dumpsite can gain employment (or better still, form a cooperative) sorting recyclable materials and reducing the amount of real “waste” that needs to be disposed of.

For example, Wecyclers in Lagos, Nigeria employs people to cycle around collecting recyclable materials from households. In return for their source-separated waste, the householder receives a small reward.

In Bangalore, IGotGarbage has harnessed the power of phone apps to enable people who were previously waste pickers to be called directly to a house to collect the waste materials. Solutions like this work because they continue to provide livelihoods for people, while taking waste off the streets.

The need for appropriate technology

There will always be something left though: the stuff that really has little value other than the energy embodied in it. In industrialised countries, energy-from-waste incinerators have become popular. Seen as a clean alternative to landfill, these facilities burn the waste, release the energy, and convert it into heat, electricity and ash. Some of that ash (from the air pollution control system) still needs to be disposed of in specially-prepared hazardous waste landfill sites. The remainder, being fairly benign, can be used to make concrete building blocks.

However, incinerators are fairly technology-heavy, rendering them unsuitable for many developing country contexts.

A problem that we’ve witnessed is that waste management companies from industrialised nations try to wholesale their technology in developing countries. The technology is usually unaffordable, and even if the capital can be raised to procure a facility, as soon as something breaks down the whole solution can fall apart.

There is a need for information about simple waste processing technologies to become more open-sourced. Smart future-thinking businesses could capitalise on selling blueprints rather than entire prefabricated facilities. Most of the time it’s far cheaper to fabricate something locally, and also means that when something breaks it can be fixed.

The continuing need for landfill

The fact is that in most cases, a standard, lined landfill site with landfill gas capture is still the most appropriate answer for non-recyclable waste. Add to that a well-organised, low-cost waste collection service with source separation of recyclable materials and biodegradable waste, and you have a relatively affordable solution that is better for the climate, better for health, better for the local economy, and contributes to a more sustainable future.

Landfill may seem very unfashionable to those of us who work in the recycling sector, but nevertheless it will remain a necessity both in developed and developing countries for the foreseeable future.

Joining forces and stepping stones

The success of the Sustainable Development Goals and potential Climate Change Agreement depend on developed and developing countries working together. Miguel Arias Cañete, the EU climate commissioner, said the Climate Coalition alliance showed that developed and developing countries could work together with a common interest. “These negotiations are not about them and us. They are about all of us, developed and developing countries, finding common ground and solutions together. We urge other countries to join us. Together we can do it.”

Necessity is the mother of invention, and we are facing a waste crisis of unprecedented proportion. The potential for waste management in reducing GHG emissions has never been more pertinent. Waste and development practitioners, academics and entrepreneurs around the world are working together more and more to help bring about the change we want to see, which will benefit the billions of people suffering from poor waste management, and the rest of us who share a warming planet – and share the burden of climate change and poverty.

By sharing knowledge through platforms such as beWasteWise and ISWA, and through initiatives like WasteAidWASTE and Wiego, we can start making a dent in this very large problem.

No silver bullets, but lots of small stepping stones in the right direction.

Note: The original and unabridged version of the article can be found at this link. Please visit http://zlcomms.co.uk/ for more information about the author.

Trends in Waste-to-Energy Industry

The increasing clamor for energy and satisfying it with a combination of conventional and renewable resources is a big challenge. Accompanying energy problems in almost all 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 up to 18 billion tonnes by year 2020. Ironically, most of the wastes are disposed of in open fields, along highways or burnt wantonly.

Size of the Industry

Around 130 million tonnes of municipal solid waste (MSW) are combusted annually in over 600 waste-to-energy (WTE) facilities globally that produce electricity and steam for district heating and recovered metals for recycling. The global market for biological and thermochemical waste-to-energy technologies is expected to reach USD 7.4 billion in 2013 and grow to USD 29.2 billion by 2022. Incineration, with energy recovery, is the most common waste-to-energy method employed worldwide. Since 1995, the global WTE industry increased by more than 16 million tonnes of MSW. Over the last five years, waste incineration in Europe has generated between an average of 4% to 8% of their countries’ electricity and between an average of 10% to 15% of the continent’s domestic heat.

Advanced thermal technologies, like pyrolysis, and anaerobic digestion systems are beginning to make deep inroads in the waste-to-energy sector and are expected to increase their respective market shares on account of global interest in integrated waste management framework in urban areas. Scarcity of waste disposal sites coupled with growing waste volumes and solid waste management challenges are generating high degree of interest in energy-from-waste systems among policy-makers, urban planners, entrepreneurs, utility companies etc.

Regional Trends

Currently, the European nations are recognized as global leaders of waste-to-energy movement. They are followed behind by the Asia Pacific region and North America respectively. In 2007 there are more than 600 WTE plants in 35 different countries, including large countries such as China and small ones such as Bermuda. Some of the newest plants are located in Asia. China is witnessing a surge in waste-to-energy installations and has plans to establish 125 new waste-to-energy plants during the twelfth five-year plan ending 2015.

Incineration is the most common waste-to-energy method used worldwide.

The United States processes 14 percent of its trash in WTE plants. Denmark, on the other hand, processes more than any other country – 54 percent of its waste materials. As at the end of 2008, Europe had more than 475 WTE plants across its regions – more than any other continent in the world – that processes an average of 59 million tonnes of waste per annum. In the same year, the European WTE industry as a whole had generated revenues of approximately US$4.5bn.

Legislative shifts by European governments have seen considerable progress made in the region’s WTE industry as well as in the implementation of advanced technology and innovative recycling solutions. The most important piece of WTE legislation pertaining to the region has been the European Union’s Landfill Directive, which was officially implemented in 2001 which has resulted in the planning and commissioning of an increasing number of WTE plants over the past five years.

Description of a Biogas Power Plant

A biogas plant is a decentralized energy system, which can lead to self-sufficiency in heat and power needs, and at the same time reduces environmental pollution. The components of a modern biogas (or anaerobic digestion) plant include: manure collection, anaerobic digester, effluent treatment, biogas storage, and biogas use/electricity generating equipment.

Working of a Biogas Plant

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 Cleanup

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.

Utilization of Biogas

Biogas is dried and vented into a CHP unit to a generator to produce electricity and heat. The size of the CHP system depends on the amount of biogas produced daily.

Treatment of Digestate

The digested substrate is passed through screw presses for dewatering and then subjected to solar drying and conditioning to give high-quality organic fertilizer.  The press water is treated in an effluent treatment plant based on activated sludge process which consists of an aeration tank and a secondary clarifier. The treated wastewater is recycled to meet in-house plant requirements.

Monitoring of Environmental Parameters

A chemical laboratory is necessary to continuously monitor important environmental parameters such as BOD, COD, VFA, pH, ammonia, C:N ratio at different locations for efficient and proper functioning of the process.

Control System

The continuous monitoring of the biogas plant is achieved by using a remote control system such as Supervisory Control and Data Acquisition (SCADA) system. This remote system facilitates immediate feedback and adjustment, which can result in energy savings.