Know About Popular Waste to Energy Conversion Routes

Waste-to-energy is the use of combustion and biological technologies to recover energy from urban wastes. There are three major waste to energy conversion routes – thermochemical, biochemical and physico-chemical. Thermochemical conversion, characterized by higher temperature and conversion rates, is best suited for lower moisture feedstock and is generally less selective for products. On the other hand, biochemical technologies are more suitable for wet wastes which are rich in organic matter.

Teesside-WTE-plant

Thermochemical Conversion of Waste

The three principal methods of thermochemical conversion of waste 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 household 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.

WTE_Pathways

Combustion technology is the controlled combustion of waste with the recovery of heat to produce steam which in turn produces power through steam turbines. Pyrolysis and gasification represent refined thermal treatment methods as alternatives to incineration and are characterized by the transformation of the waste into product gas as energy carrier for later combustion in, for example, a boiler or a gas engine. Plasma gasification, which takes place at extremely high temperature, is also hogging limelight nowadays.

Biochemical Conversion of Waste

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. Anaerobic digestion is the natural biological process which stabilizes organic waste in the absence of air and transforms it into biofertilizer and biogas.

Anaerobic digestion is a reliable technology for the treatment of wet, organic waste.  Organic waste from various sources is biochemically degraded in highly controlled, oxygen-free conditions circumstances resulting in the production of biogas which can be used to produce both electricity and heat.

anaerobic_digestion_plant

In addition, a variety of fuels can be produced from waste resources including liquid fuels, such as ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and gaseous fuels, such as hydrogen and methane. The resource base for biofuel production is composed of a wide variety of forestry and agricultural resources, industrial processing residues, and municipal solid and urban wood residues. Globally, biofuels are most commonly used to power vehicles, heat homes, and for cooking.

Physico-chemical Conversion of Waste

The physico-chemical conversion of waste involves various processes to improve physical and chemical properties of solid waste. The combustible fraction of the waste is converted into high-energy fuel pellets which may be used in steam generation.

RDF pellet

The waste is first dried to bring down the high moisture levels. Sand, grit, and other incombustible matter are then mechanically separated before the waste is compacted and converted into fuel pellets or RDF.

Fuel pellets have several distinct advantages over coal and wood because it is cleaner, free from incombustibles, has lower ash and moisture contents, is of uniform size, cost-effective, and eco-friendly.

Role of Food Waste Disposers in Food Waste Management

Food waste is a global issue that begins at home and as such, it is an ideal contender for testing out new approaches to behaviour change. The behavioural drivers that lead to food being wasted are complex and often inter-related, but predominantly centre around purchasing habits, and the way in which we store, cook, eat and celebrate food.

food-waste-management

Consumer Behavior – A Top Priority

Consumer behaviour is a huge priority area in particular for industrialised nations – it is estimated that some western societies might be throwing away up to a third of all food purchased. The rise of cheap food and convenience culture in recent years has compounded this problem, with few incentives or disincentives in place at producer, retail or consumer level to address this.

While it is likely that a number of structural levers – such as price, regulation, enabling measures and public benefits – will need to be pulled together in a coherent way to drive progress on this agenda, at a deeper level there is a pressing argument to explore the psycho-social perspectives of behaviour change.

Individual or collective behaviours often exist within a broader cultural context of values and attitudes that are hard to measure and influence. Simple one-off actions such as freezing leftovers or buying less during a weekly food shop do not necessarily translate into daily behaviour patterns. For such motivations to have staying power, they must become instinctive acts, aligned with an immediate sense of purpose. Click here to see what steps you can take to tackle this issue. The need to consider more broadly our behaviours and how they are implicated in such issues must not stop at individual consumers, but extend to governments, businesses and NGOs if effective strategies are to be drawn up.

Emergence of Food Waste Disposers

Food waste disposer (FWDs), devices invented and adopted as a tool of food waste management may now represent a unique new front in the fight against climate change. These devices, commonplace in North America, Australia and New Zealand work by shredding household or commercial food waste into small pieces that pass through a municipal sewer system without difficulty.

The shredded food particles are then conveyed by existing wastewater infrastructure to wastewater treatment plants where they can contribute to the generation of biogas via anaerobic digestion. This displaces the need for generation of the same amount of biogas using traditional fossil fuels, thereby averting a net addition of greenhouse gases (GHG) to the atmosphere.

Food waste is an ideal contender for testing new approaches to behaviour change.

The use of anaerobic digesters is more common in the treatment of sewage sludge, as implemented in the U.K., but not as much in the treatment of food waste. In addition to this, food waste can also replace methanol (produced from fossil fuels) and citric acid used in advanced wastewater treatment processes which are generally carbon limited.

Despite an ample number of studies pointing to the evidence of positive impacts of food waste disposer, concerns regarding its use still exist, notably in Europe. Scotland for example has passed legislation that bans use of FWDs, stating instead that customers must segregate their waste and make it available curbside for pickup. This makes it especially difficult for the hospitality industry, to which the use of disposer is well suited.

The U.S. however has seen larger scale adoption of the technology due to the big sales push it received in the 1950s and 60s. In addition to being just kitchen convenience appliances, FWDs are yet to be widely accepted as a tool for positive environmental impact.

Note: 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

Waste Management Challenges in Developing Nations

Waste is the result of collective failure from public, legislative rules, lack of funds and technical support. Public awareness and proper knowledge of waste management and end use of different types of waste, health effects, environmental problems and economic issues that are related to waste management is very important for successful execution of any waste management related practices. Everyone needs to get better knowledge, proper understanding of waste management issues and their practices to curb it. Basic training needs to be initiated from governments in this regard, which can be very effective. Poor knowledge can make the best planned technique questionable.

The increasing cost of waste disposal is a cause of major concern in developing nations

In developing countries, participation level of most citizens in waste management is very low, with residents in urban areas are not actively involved in the process of waste management. Even though it’s low, but very beneficial for future prospect and for more meaningful involvement of majority of public in waste management practices.

People should be educated about sorting out waste based on their type e.g. recyclable waste, hazardous waste, green waste etc. Majority of people across the world are not aware of waste as recycling material, amazingly most of them think plastic is recyclable waste. Involving people who are unaware of waste management practice is extremely difficult.

In developing countries, practices of waste management are usually carried by poor, for their survival. It has been estimated that 2% of population in Asia, Latin America and Africa are dependent on waste for their livelihood. Family organized, or individual manual scavengers are often involved with waste management practices with very limited supportive network and facilities with increased risk of health effects. Also, this practice prevents their children from further education.

iraq-wastes

Despite the bad consequences, it should be kept in mind that this practice keeps them employed and provide livelihood in countries with high unemployed population. But measure need to be taken to provide their better lifestyles, social behaviour towards people involved in waste management practices, provide them with facilities to reduce their health-related risk and increase their working efficiency.

In developing countries, where government support for waste management is scarce, people need to come strongly against their local municipal office or government if they see things are not changing and stacks of waste are piling up. They should protest to protect their environment, health and keep living secure and healthy for their children.

Biomass Resources from Sugar Industry

Sugarcane is one of the most promising agricultural sources of biomass energy in the world. It is the most appropriate agricultural energy crop in most sugarcane producing countries due to its resistance to cyclonic winds, drought, pests and diseases, and its geographically widespread cultivation. Due to its high energy-to-volume ratio, it is considered one of nature’s most effective storage devices for solar energy and the most economically significant energy crop.

The climatic and physiological factors that limit its cultivation to tropical and sub-tropical regions have resulted in its concentration in developing countries, and this, in turn, gives these countries a particular role in the world’s transition to sustainable use of natural resources.

Sugarcane_Biomass

According to the International Sugar Organization (ISO), Sugarcane is a highly efficient converter of solar energy, and has the highest energy-to-volume ratio among energy crops. Indeed, it gives the highest annual yield of biomass of all species. Roughly, 1 ton of Sugarcane biomass-based on Bagasse, foliage and ethanol output – has an energy content equivalent to one barrel of crude oil.

Sugarcane produces mainly two types of biomass, Cane Trash and Bagasse. Cane Trash is the field residue remaining after harvesting the Cane stalk and Bagasse is the milling by-product which remains after extracting sugar from the stalk. The potential energy value of these residues has traditionally been ignored by policy-makers and masses in developing countries. However, with rising fossil fuel prices and dwindling firewood supplies, this material is increasingly viewed as a valuable renewable energy resource.

Sugar mills have been using Bagasse to generate steam and electricity for internal plant requirements while Cane Trash remains underutilized to a great extent. Cane Trash and Bagasse are produced during the harvesting and milling process of Sugarcane which normally lasts 6 to 7 months.

Around the world, a portion of the Cane Trash is collected for sale to feed mills, while freshly cut green tops are sometimes collected for farm animals. In most cases, however, the residues are burned or left in the fields to decompose. Cane Trash, consisting of Sugarcane tops and leaves can potentially be converted into around 1kWh/kg, but is mostly burned in the field due to its bulkiness and its related high cost for collection and transportation.

bagasse-cogen

On the other hand, Bagasse has been traditionally used as a fuel in the Sugar mill itself, to produce steam for the process and electricity for its own use. In general, for every ton of Sugarcane processed in the mill, around 190 kg Bagasse is produced.

Low pressure boilers and low efficiency steam turbines are commonly used in developing countries. It would be a good business proposition to upgrade the present cogeneration systems to highly efficient, high pressure systems with higher capacities to ensure utilization of surplus Bagasse.

Management of Construction Wastes

A wide variety of wastes are generated during construction projects which may be classified into four categories – excavated wastes, demolition wastes, construction wastes and mixed wastes. Construction wastes are also known Construction and Demolition (C&D) wastes. Excavated materials is made up of soil, sand, gravel, rock, asphalt, etc. while demolition wastes is comprised by  concrete, metal, roofing sheets, asbestos, brick, briquette, stone gypsum, wood material. Waste materials generated from construction activities are concrete, dry wall, plastics, ceramics tiles, metals, paper, cardboards, plastics, glass etc. In addition, mixed wastes, such as trash and organic wastes, are also produced in construction projects. A great way to get rid of all the construction waste is to hire a company that handles everything for you. For instance, if you need a south Philadelphia roll-off dumpster, you will find many options, make sure to select a reliable company that can offer you an excellent service and advises you along the way.

construction-wastes

 

Almost 90 percent of construction wastes are inert or non-hazardous, and can be reused, reclaimed and recycled and reused. The non-recyclable, non-hazardous and hazardous waste materials constitute the remaining 10 percent. The non-inert materials include trees, green vegetation, trash and other organic materials while and the hazardous construction waste materials include contaminated soil, left over paints, solvent, aerosol cans, asbestos, paint thinners, striping paint, contaminated empty containers.

Sustainable management of construction wastes uses number of strategies and is based on the typical waste hierarchy: Avoid/ eliminate, reduce, reuse, recycle, treat and dispose.

Avoidance / Source Reduction

Avoidance or source reduction is considered as the best strategy for waste management and is the most economic way to reduce waste and minimise the environmental impacts of construction wastes. This can be done by avoiding use of hazardous materials such as asbestos-containing materials or chromated copper arsenate treated timber or through green purchasing of materials. This includes purchasing of non-toxic materials, pre-cut timbers and ordering materials of desired dimensions.

Reuse

Although source reduction and elimination are preferred options in the waste management hierarchy, it is always not possible to do so. In this case consider reuse, donation and salvage options to companies or people who need those. Reuse option lengthens the life of a material. Reuse strategy can be used in two ways.

Building Reuse – It includes reusing materials from existing buildings and maintaining certain percentages of building structural and non-structural elements  such as interior walls, doors floor covering and ceilings.

Material Reuse – This is one of the most effective strategies for minimising environmental impacts which can be done by salvaging, refurbishing and reusing materials within the same building or in another building.

Many of the exterior and interior materials can be recovered from existing buildings and reused in new ones. Such materials will include steel, walls, floor coverings, concrete, beams and posts, door frames, cabinetry and furniture, brick, and decorative items. Reuse of materials and products will help to reduce the demand for virgin materials and reduce wastes.

Recycle

There is very good potential to recycle many elements of construction waste. Recycling involves collecting, reprocessing and/ or recovering certain waste materials to make new materials or products. Often roll-off containers are used to transport the waste. Rubble can be crushed and reused in construction projects.

Waste wood can also be recovered and recycled. Many construction waste materials that are still usable can be donated to non-profit organizations. This keeps the material out of the landfill and supports a good cause.

Treat and Dispose

This option should be considered after all other options are exhausted. The disposal of construction materials should be carried out in appropriate manner through an approved contractor. For examples, certain components of construction waste such as plasterboard are hazardous once landfilled. Plasterboard is broken down in landfill conditions releasing hydrogen sulfide, a toxic gas.

Zero Waste Trends in the United States

Most people don’t see what happens to their trash. They throw it in a black plastic bag, toss the bag into a dumpster and the trash man collects it once a week and makes it disappear. Magic, right?

Wrong.

Most of our trash ends up in a landfill where it is buried and mixed in with decades-worth of junk. Certain items will break down over time while others are essentially just stored there, in a graveyard of forgotten items and a mountain of garbage.

In the year since China banned the import of other countries’ plastic recyclables, the global recycling industry has been in flux, resulting in plastics ending up in landfills, incinerators and littering the environment. This is causing countries and citizens across the globe to reexamine their recycling systems and highlights the need for zero waste practices.

Zero waste is the concept of eliminating the amount of trash thrown away by only purchasing reusable items. That’s a significant shift from the 4.4 pounds of trash that the average American tosses every day. But certain trends are helping make the idea of zero waste a reality in the United States. Let us have a look:

Replace Single-Use Packaging With Reusable Materials

Way too many plastic items that we use every day are meant to be used only once. And the amount of packaging that goes into shipping one box, that will simply get tossed in the garbage after the parcel is unwrapped, is astounding. In fact, 40 percent of plastic produced is packaging, which is thrown away after it arrives at your doorstep.

Plastic bag and straw bans are on the rise across the globe. Consumers are becoming more conscious of how their use of these items contributes to the trash crisis. Recent data shows that customers are more likely to buy products from brands that promote sustainable business practices.

biodegradeable-packaging

Reduce Energy Waste By Choosing Renewable Options

Many industries are opting to reduce energy waste by pursuing renewable energy sources. U.S. manufacturers account for 30 percent of the nation’s energy consumption, which means manufacturers must take the lead in reducing fossil fuel consumption and energy waste.

The U.S. is the leader in energy waste. Americans spend $350 billion on energy costs each year, yet three-quarters of that energy goes to waste. One way to reduce the burden on our power grid — and our wallets — from all that lost energy is by switching to renewable energy sources.

Air compressors are vital to the upkeep of a successful farm, and many producers in the agricultural sector are also reducing waste by switching to high-powered air compressors that, when properly maintained, can reduce energy usage and cut costs.

Eliminate Food Waste

About 94 percent of food waste ends up in landfills, which contribute to methane gas emissions. Reducing food waste not only helps the environment, but it also decreases the amount you have to spend at the grocery store. It also helps to conserve energy, as less power is needed to grow and produce food if less is wasted.

Individual consumers can help eliminate food waste by freezing leftovers to preserve them and composting uneaten food, as opposed to tossing in the trash.

Restaurants can use these tactics and others to cut down on food waste, such as donating leftovers and properly training staff to get on board with waste reduction. They can also hire auditors to help them identify ways to reduce waste and streamline business practices.

Never Too Late to Make a Change

Though the statistics may seem disheartening, the reality is that it’s never too late to make a change in your individual or business habits to help cut down on waste and work toward the goal of accomplishing zero waste. Following these trends and implementing others is just one way to do your part to eliminate waste and protect the environment.

Generating Electricity from Municipal Solid Waste

We live in a throwaway society that accumulates vast quantities of waste every day. While this comes with pressing challenges, there are also opportunities for professionals including electrical engineers to process at least some of the waste to produce much-needed renewable energy.

According to the U.S. Energy Information Administration (EIA), in 2018 a total of 68 U.S. power plants generated around 14 billion kilowatt-hours of electricity from 29.5 million tons of combustible municipal solid waste (MSW). Biomass, which comes from plants and animals and is a source of renewable energy, was responsible for more than half (about 51%) of the electricity generated from waste. It also accounted for about 64% of the weight of the MSW used. The rest of the waste used was from other combustible materials including synthetic materials made from petroleum and plastics. Glass and metal are generally not noncombustible.

WTE_Plant_Belgium

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

Municipal Solid Waste in the U.S.

Burning MSW is not only a sustainable way to produce electricity, it also reduces the volume of waste that would inevitably end up in landfills. Instead, the EIA estimates that burning MSW effectively reduces waste volumes by about 87%.

But, while more than 268 million tons of MSW are generated in the United States every year, in 2017, only 12.7% of it was burned to recover energy. More than half (52.1%) went to landfill, about a quarter (25.1%) was recycled, and the rest (10.1%) was used to generate compost.

According to a U.S. Environmental Protection Agency (EPA) fact sheet on sustainable materials management published in November 2019, the total MSW generated in 2017 by material, comprised:

  • Paper and paperboard, primarily containers and packaging 25%
  • Food 15.2% (see below)
  • Plastics 13.2% (19.2% of the total materials that ended up in landfill were plastics)
  • Yard trimmings 13.1% (most of this type of waste is composted)
  • Rubber, leather and textiles 9.7%
  • Metals 9.4%
  • Wood 6.7%
  • Glass 4.2%
  • Other 3.5%

Indicating tremendous human waste in its worst form, 22% of the material that ended up in landfill was classified as food. Trashed food was also the product category with the highest landfill rate, at an alarming 75.3%. Nearly a quarter (22%) of materials that were combusted with energy recovery were food, and overall, food was also the highest product category to recover energy, with a rate of 18.4%.

The total MSW combusted to generate energy was made up of the following materials:

  • Food 22%
  • Plastics 16.4%
  • Rubber, leather, and textiles 16.1%
  • Paper and paperboard 13.2%
  • Wood 8.4%
  • Metals 8.6%
  • Yard trimmings 6.2%
  • Glass 4.3%
  • Other 4.3%

Generating Electricity from MSW

There are a variety of technologies for generating electricity from municipal solid waste, but in the US the most common system involves mass burning of MSW in a large incinerator that has a boiler that produces steam, and a generator that produces electricity. Another entails processing MSW into fuel pellets for use in smaller power plants.

Waste materials destined to be processed to generate electricity

Generating electricity in mass-burn WTE plants is remarkably straightforward and follows seven basic steps:

  1. The MSW is dumped out of garbage trucks into a large pit.
  2. A crane with a giant claw attachment is used to grab the waste and dump it into a combustion chamber.
  3. The waste, which now becomes the fuel, starts to burn, releasing heat.
  4. The heat that is released turns water in the boiler into high-pressure steam.
  5. The steam turns the turbine generator’s blades and produces electricity.
  6. The mass-burn plant incorporates an control system to prevent air pollution by removing pollutants from the combustion gas before it is released through a smoke-stack.
  7. Ash is inevitably produced in the boiler and the air pollution control system, and this has to be removed before another load of waste can be burned.

While the volumes burned as fuel in different plants vary, for every 100 pounds of MSW produced in the US, potentially, more than 85 pounds could be burned to generate electricity.

Of course, the USA isn’t the only country that uses waste-to-energy plants to generate electricity from MSW. And in fact, when compared to a lot of other countries, the percentage of MSW burned with energy recovery in the U.S. is minimal. At least nine countries are named by the EIA as bigger producers of electricity from municipal waste. In Japan and some European countries, for instance, there are fewer energy resources and not much open space available for landfills. So generating electricity from MSW is an obvious opportunity.

The four leading nations identified by the EIA as burning the most MSW with energy recovery are:

  • Japan 68%
  • Norway 54%
  • Switzerland 48%
  • France 35%
  • The United Kingdom 34%

One thing’s for certain, the percentages are all set to continue increases globally as the move towards sustainability gains momentum. And U.S. percentages are going to increase too.

Plastic Wastes and its Management

Plastic seems all pervasive and unavoidable. Since the 1960s our use of plastic has increased dramatically, and subsequently, the portion of our garbage that is made up of plastic has also increased from 1% of the total municipal solid waste stream (household garbage) to approximately 13% (US Environmental Protection Agency).

Plastic products range from things like containers and packaging (soft drink bottles, lids, shampoo bottles) to durable goods (think appliances, furniture and cars) and non-durable goods including things from a plastic party tray to medical devices. Sometimes marked with a number and a chasing arrow, there is an illusion that all plastics are recyclable, and therefore recycled. But there are a number of problems with this assumption.

plastic-wastes

While use and consumption of plastic is increasingly high, doubts about viable options for reuse, recycling and disposal are also on the rise. Complications such as the increasing number of additives used alter the strength, texture, flexibility, colour, resistance to microbes, and other characteristics of plastics, make plastics less recyclable. Additionally, there is very little market value in some plastics, leading municipalities to landfill or incinerate plastics as waste. Based on figures from the EPA (2011 data) only 8% of plastic materials are recovered through recycling.

Another major concern about plastics in the waste stream is their longevity and whether or not they are truly biodegrade. It is estimated that most plastics would take 500-1000 years to break down into organic components. Because of this longevity and the low rate of recycling, much of our plastic waste ends up in landfills or as litter. Some of this plastic waste makes its way via rivers and wind to the ocean. Garbage barges, and the trans-continental transport of recyclable materials also lead to an increasing amount of plastics in our oceans and waterways.

Plastic waste directly and indirectly affects living organisms throughout the ecosystem, including an increasingly high impact on marine life at a macro and micro scale. According to United Nations, almost 80% of marine debris is plastic. Policy enforcement remains weak, global manufacture of plastics continues to increase, and the quantity of plastic debris in the oceans, as well as on land, is likely to increase.

With limited sustainable recovery of plastics, there is a growing global movement to reduce the generation of plastic. Certain types of plastic may be ’safer‘ for the environment than others, however, there are troubling issues associated with all of them, leading to the conclusion that action is needed to remove plastic waste, and stricter controls are required to limit new sources of plastic pollution.

biodegradable-plastics

Efforts such as light weighting of packaging and shifts to compostable plastics are options. Many people use eco-friendly bags for the sake of green living. Policies limiting the use of plastics such as bottle bills and bag bans are other ways to decrease the production and consumption of plastics.

Mining the debris fields in our oceans and turning plastic waste into usable materials, from socks made of fishing line to fuel made from a variety of plastic debris, is one way to mitigate the current situation. You can do your part by using renewable cotton bags.

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

Solid Waste Management – India’s Burning Issue

For the first time in the history of India, the year 2012 saw several public protests against improper solid waste management all across India – from the northernmost state Jammu and Kashmir to the southernmost Tamil Nadu. A fight for the right to clean environment and environmental justice led the people to large scale demonstrations, including an indefinite hunger strike and blocking roads leading to local waste handling facilities. Improper waste management has also caused a Dengue Fever outbreak and threatens other epidemics.

In recent years, solid waste management has been the only other unifying factor leading to public demonstrations all across India, after corruption and fuel prices. Public agitation resulted in some judicial action and the government’s remedial response, but the waste management problems are still unsolved and might lead to a crisis if this continues for too long without any long term planning and policy reforms.

Solid-Wastes-India

Hunger Strike in Kerala

The President of Vilappilsala Village Panchayat went on a hunger strike recently, against her counterpart, the Mayor of Thiruvananthapuram. Thiruvananthapuram is the state capital of Kerala, and Vilappilsala is a village 22 km away.

Since July 2000, about 80% of the waste generated in Thiruvananthapuram is being transported to a waste composting plant and a dumpsite in Vilappilsala village. Since the same month, respiratory illnesses reported in Vilappil Primary Health Center increased by 10 times from an average of 450 to 5,000 cases per month. People who used to regularly swim in the village’s aquifer started contracting infections; swarms of flies have ever since been pervasive; and a stigma of filth affected households throughout the community. This was a source of frustration as locals who, as Indians, prize the opportunity to feed and host guests, found them unwilling to even drink a glass of water in their homes. Currently, there is not a single household which has not experienced respiratory illnesses due to the waste processing plant and the adjoining dumpsite.

On the other hand, Thiruvananthapuram’s residents had to sneak out at night with plastic bags full of trash to dispose them behind bushes, on streets or in water bodies, and had to openly burn heaps of trash every morning for months. This was because the waste generated was not being collected by the City as it could not force open the composting plant and dumpsite against large scale protests by Vilappilsala’s residents. This is why in August – 2012, about 2,500 police personnel had to accompany trucks to the waste treatment plant as they were being blocked by local residents lying down on the road, and by some, including the village’s President, by going on an indefinite hunger strike.

Municipal Commissioner Replaced in Karnataka

In response to a similar situation in Bengaluru, the state capital of Karnataka, where the streets were rotting with piles of garbage for months, the municipal commissioner of the city was replaced to specifically address the waste management situation. Against the will of local residents, a landfill which was closed following the orders issued by the state’s pollution control board in response to public agitation had to be reopened soon after its closure as the city could not find a new landfill site.

Mavallipura landfill in Bangalore

Population density and the scale of increasing urban sprawl in India make finding new landfill sites around cities nearly impossible due to the sheer lack of space for Locally Unwanted Land Uses (LULUs) like waste management.

Dengue Outbreak in West Bengal

Even if partially because of improper waste management, Kolkata, state capital of West Bengal and the third biggest city in India experienced a Dengue Fever outbreak with 550 confirmed cases and 60 deaths. This outbreak coincides with a 600% increase in dengue cases in India and 71% increase in malarial cases in Mumbai in the last five years.

Accumulation of rain water in non biodegradable waste littered around a city act as a major breeding environment for mosquitoes, thus increasing the density of mosquito population and making the transmission of mosquito related diseases like dengue, yellow fever and malaria easier.

Rabies in Srinagar

Rabies due to stray dog bites already kills more than 20,000 people in India every year. Improper waste management has caused a 1:13 stray dog to human ratio in Srinagar (compared to 1 per 31 people in Mumbai and 1 per 100 in Chennai), where 54,000 people were bitten by stray dogs in a span of 3.5 years. Municipal waste on streets and at the dumpsite is an important source of food for stray dogs.

The ultimate solution to controlling stray dogs is effective waste management. The public has been protesting about this stray dog menace for months now with no waste management solutions in sight, but only partial short term measures like dog sterilization.

Waste-to-Energy Sector in China: Perspectives

China is the world’s largest waste 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.

garbage-china

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.