Composting in Qatar

compost-qatarQatar has one of the highest per capita waste generation rates worldwide. In 2012, Qatar generated 8,000 tons of solid waste daily (excluding construction and demolition waste which amounts to 20,000 tons additional waste per day).  This number is predicted to reach 19,000 tons/day in 2032, with an annual growth rate of roughly 4.2%.

Most of these wastes end up in landfills – in 2012, more than 90% of Qatar’s solid waste were sent to landfills although the government is intensifying its efforts to reduce this amount. This percentage is extremely high compared to many industrialized countries in Europe and Asia (e.g. Austria, Denmark, Netherlands and Japan) where less than 10% of solid waste are disposed of in landfills.  These countries have high recycling rates, have invested in technologies that convert waste into energy, and apply composting process to their organic waste, especially food wastes. In some of these nations, as much as 40% of their wastes are composted.

Composting in Qatar

Currently, composting in Qatar is mainly done at the Domestic Solid Waste Management Centre (DSWMC) in Mesaieed, which houses the largest composting facility in the country and one of the largest in the world.  The waste that enters the plant initially goes through anaerobic digestion, which produces biogas that can power the facility’s gas engine and generators, followed by aerobic treatment which yields the final product.

Two types of compost are generated: Grade A (compost that comes from green waste, such as yard/park trimmings, leftovers from kitchen or catering services, and wastes from markets) and Grade B (compost produced from MSW).  The plant started its operation in 2011 and when run at full capacity is able to process 750 tons of waste and produce 52 tons of Grade A compost, 377 tons of Grade B compost, liquid fertilizer which is composed of 51 tons of Grade A compost and 204 tons of Grade B compost, and 129 tons of biogas.

This is a significant and commendable development in Qatar’s implementation of its solid waste management plan, which is to reduce, reuse, recycle and recover from waste, and to avoid disposing in landfills as much as possible.  However, the large influx of workers to Qatar in the coming years as the country prepares to host the World Cup in 2022 is expected to substantially increase solid waste generation and apart from its investments in facilities like the composting plant and in DSWMC in general, the government may have to tap into the efforts of organizations and communities to implement its waste management strategy.

Future Outlook

Thankfully, several organizations recognize the importance of composting in waste management and are raising awareness on its benefits.  Qatar Green Building Council (QGBC) has been actively promoting composting through its Solid Waste Interest Group.  Last year, they were one of the implementers of the Baytna project, the first Passivhaus experiment in the country.

This project entails the construction of an energy-efficient villa and a comparative study will be performed as to how the carbon footprint of this structure would compare to a conventional villa.  The occupants of the Passivhaus villa will also be made to implement a sustainable waste management system which includes composting of food waste and garden waste, which is meant to lower greenhouse gas emissions compared to landfilling.

Qatar Foundation is also currently developing an integrated waste management system for the entire Education City and the Food Services group is pushing for composting to be included as a method to treat food and other organic waste.  And many may not know this but composting can be and has been done by individuals in their own backyard and can even be done indoors with the right equipment.

Katrin Scholz-Barth, previous president of SustainableQatar, a volunteer-based organization that fosters sustainable culture through awareness, skills and knowledge, is an advocate of composting and has some great resources on how to start and maintain your own composting bin as she has been doing it herself.  A simple internet search will also reveal that producing compost at home is a relatively simple process that can be achieved with minimal tools.  At present, very few families in Qatar are producing their own compost and Scholz-Barth believes there is much room for improvement.

As part of its solid waste management plan as stated in the National Development Strategy for 2011-2016, Qatar aims to maintain domestic waste generation at 1.6 kg per capita per day.  This will probably involve encouraging greater recycling and reuse efforts and the reduction of waste from its source.  It would also be worthwhile to include programs that will promote and boost composting efforts among institutions, organizations and individuals, encouraging them with the fact that apart from its capability of significant waste diversion from landfills, composting can also be an attractive source of income.

Note: The article is being republished with the permission of our collaborative partner EcoMENA. The original article can be viewed at this link.

Biomass Energy Scenario in Southeast Asia

The rapid economic growth and industrialization in Southeast Asian region is characterized by a significant gap between energy supply and demand. The energy demand in the region is expected to grow rapidly in the coming years which will have a profound impact on the global energy market. In addition, the region has many locations with high population density, which makes public health vulnerable to the pollution caused by fossil fuels.

Another important rationale for transition from fossil-fuel-based energy systems to renewable ones arises out of observed and projected impacts of climate change. Due to the rising share of greenhouse gas emissions from Asia, it is imperative on all Asian countries to promote sustainable energy to significantly reduce GHGs emissions and foster sustainable energy trends. Rising proportion of greenhouse gas emissions is causing large-scale ecological degradation, particularly in coastal and forest ecosystems, which may further deteriorate environmental sustainability in the region.

The reliance on conventional energy sources can be substantially reduced as the Southeast Asian region is one of the leading producers of biomass resources in the world. Southeast Asia, with its abundant biomass resources, holds a strategic position in the global biomass energy atlas.

There is immense potential of biomass energy in ASEAN countries due to plentiful supply of diverse forms of wastes such as agricultural residues, agro-industrial wastes, woody biomass, animal wastes, municipal solid waste, etc. Southeast Asia is a big producer of wood and agricultural products which, when processed in industries, produces large amounts of biomass residues.

palm-kernel-shell-uses

Palm kernel shells is an abundant biomass resource in Southeast Asia

According to conservative estimates, the amount of biomass residues generated from sugar, rice and palm oil mills is more than 200-230 million tons per year which corresponds to cogeneration potential of 16-19 GW. Woody biomass is a good energy resource due to presence of large number of forests and wood processing industries in the region.

The prospects of biogas power generation are also high in the region due to the presence of well-established food processing, agricultural and dairy industries. Another important biomass resource is contributed by municipal solid wastes in heavily populated urban areas.

In addition, there are increasing efforts from the public and private sectors to develop biomass energy systems for efficient biofuel production, e.g. biodiesel and bioethanol. The rapid economic growth and industrialization in Southeast Asia has accelerated the drive to implement the latest biomass energy technologies in order to tap the unharnessed potential of biomass resources, thereby making a significant contribution to the regional energy mix.

Municipal Waste Management in Poland

waste-dump-warsawMunicipal waste management in Poland has changed dramatically since the early ’90s when, as part of Poland’s privatisation program, municipal authorities were freed of their waste management obligations. The combined Polish recycling rate for dry recyclables and organic waste has increased from 5% in 2004 to 21% in 2010, according to a Copenhagen Resource Institute (CRI) study Municipal Waste Management in Poland (2013). Another source provides similar, corroborating statistics, putting the dry recycling rate in Poland at 14% and the composting rate at 7%.

The latest Eurostat data (for 2011) shows that the upward trend continuing, with the total recycled and composted reaching 28%. That is rapid rate of improvement, but leaves Poland well below the latest EU-27 average of 40% (25% recycled and 15% composted) – so what prospect is there of Poland reaching the EU’s mandatory 50% target by 2020?

Responsibility for waste disposal shifted to householders, who were left to individually contract any waste collection company of their choice. In the hard economic climate a ‘cheaper-the-better’ mentality prevailed, which did little to encourage sustainable practices. There wasn’t even an obligation on householders even to sign up for waste collection.

Landfilling was – and remains – the most common way of handling waste, but accompanying reporting and tracking methods were inadequate. Statistically, quantities of waste produced were usually larger than those collected, with the missing tonnages usually being dumped in forests or burned in domestic boilers to avoid waste disposal costs. As a result, waste management became largely uncontrolled, with a 2011 report concluding that ‘’waste management is one of the most badly neglected and at the same time one of the most urgent environmental issues for Poland.’’

Waste Management Legislation

Even after joining the EU in 2005, Poland didn’t rush to introduce reforms to improve practices and help to meet recycling targets. Only recently has Poland introduced several pieces of new waste related legislation, including:

  • Act on maintaining cleanliness and order in municipalities (2012);
  • Act on Waste (2012); and
  • Act on management of packaging and packaging waste (2013).

The first of these was revolutionary in that it gave responsibility for municipal waste collection and disposal back to municipalities. Now they are required to organise garbage collection and the separate collection of biodegradable waste and recyclable materials such as paper, metal, glass and plastic. It is expected that the new law will improve waste management control measures on a local level and greatly reduce the illegal dumping and trash burning.

The Act on Waste helps tackle the previous ‘free for all’ amongst collectors – it obliges waste handlers to act in a manner consistent with waste management principles and plans adopted at national level (by the Council of Ministers), regional level (Voivodeship) and local level (Municipality).

Poland has also this year adopted a new National Waste Management Plan, which states that an essential step towards improving the recycling rate in Poland is to increase landfill fees for recyclable, compostable or recoverable material. If acted upon, this could greatly increase the incentive to divert important municipal waste streams from landfill. The Polish market is clearly responsive to cost: in 2008 after landfill tax was significantly raised, there was a substantial reduction in waste being landfilled.

Declaration of bin-dependence

Although Polish citizens have always had to pay directly for waste collection, the new legislation has made some substantial changes to the payment system. There are now three different calculation methods. Each household is subject to a standard fee, which is then adjusted to reflect either:

  • The number of people living in a household;
  • The number of square metres covered by the property; or
  • The number of cubic metres of water used by the household per month.

The first of these options seems to be the most reasonable and has proven the most popular.

Municipalities are left to determine the standard collection fee, which as a result varies from region to region. Some municipalities charge at little as 3 Polish Zloty (around £0.56) per household, per person, per month, while some charge 20 Zloty (around £3.75).

The standard charge is also affected by a declaration made by the householder regarding waste segregation. If a property owner declares that they have separated out recyclable materials then they pay considerably lower fees. In some municipalities, this could be as low as 50% of the usual charge. Only those who declare that they don’t want to recycle pay full price. It’s rare that people do so: who would pick the most expensive option?

The problem is that some householders declare that they recycle their waste while in reality they don’t. Unfortunately, abusing the system is easy to get away with, especially since the new scheme is still in its early stages and is not yet stable. Monitoring recycling participation in order to crack down on such abuses of the system represents quite a challenging task.

Future Perspectives

Transformation periods are always hard and it is common that they bring misunderstanding and chaos. It isn’t surprising that there are problems with the new system which require ironing out, and the new legislation is nevertheless welcome. However, there is still much work to be done to provide sufficient and sustainable waste management in Poland. This will include such measures as educating the population, improving waste separation at source and securing waste treatment capacity.

Perhaps most importantly, Poland needs to take immediate action to develop its municipal waste treatment capacity across the board. If the 2020 recycling target is to be met, the country will require material recovery facilities, anaerobic digestion and in vessel composting sites, and household waste and recycling centres; and if more waste is to be diverted from landfill it will also need energy from waste (EfW) incinerators and mechanical biological treatment facilities.

According to Eurostat, only 1% of waste in Poland was incinerated in 2011. It has been confirmed so far that an EfW plant will be developed in each of Poland’s 11 biggest cities. Fortunately for Poland, the development of waste treatment installations is quite generously funded by the EU, which covers up to 80% of the total cost: EU subsidy agreements have already been signed for three of the planned EfW plants. The remaining cost will be covered by central, regional and local government.

The CRI paper presents three different scenarios for the future recycling rate in Poland. One of them is very optimistic and predicts that Poland has a chance to meet the 2020 recycling requirements, but each is based simply on a regression analysis of recent trends, rather than an analysis of the likely impact of recent and planned policy measures. What it does make clear, though, is that if Poland continues to progress as it has since 2006, it will reach the 2020 target. How many EU countries can claim that?

Note: The article is being republished with the kind permission of our collaborative partner Isonomia. The original version of the article can be found at this link.

Pyrolysis of Municipal Wastes

Pyrolysis-MSWPyrolysis is rapidly developing biomass thermal conversion technology and has been garnering much attention worldwide due to its high efficiency and good eco-friendly performance characteristics. Pyrolysis technology provides an opportunity for the conversion of municipal solid wastes, agricultural residues, scrap tires, non-recyclable plastics etc into clean energy. It offers an attractive way of converting urban wastes into products which can be effectively used for the production of heat, electricity and chemicals.

Pyrolysis of Municipal Wastes

Pyrolysis process consists of both simultaneous and successive reactions when carbon-rich organic material is heated in a non-reactive atmosphere. Simply speaking, pyrolysis is the thermal degradation of organic materials in the absence of oxygen. Thermal decomposition of organic components in the waste stream starts at 350°C–550°C and goes up to 700°C–800°C in the absence of air/oxygen.

Pyrolysis of municipal wastes begins with mechanical preparation and separation of glass, metals and inert materials prior to processing the remaining waste in a pyrolysis reactor. The commonly used pyrolysis reactors are rotary kilns, rotary hearth furnaces, and fluidized bed furnaces. The process requires an external heat source to maintain the high temperature required. Pyrolysis can be performed at relatively small-scale which may help in reducing transport and handling costs.  In pyrolysis of MSW, heat transfer is a critical area as the process is endothermic and sufficient heat transfer surface has to be provided to meet process heat requirements.

The main products obtained from pyrolysis of municipal wastes are a high calorific value gas (synthesis gas or syngas), a biofuel (bio oil or pyrolysis oil) and a solid residue (char). Depending on the final temperature, MSW pyrolysis will yield mainly solid residues at low temperatures, less than 4500C, when the heating rate is quite slow, and mainly gases at high temperatures, greater than 8000C, with rapid heating rates. At an intermediate temperature and under relatively high heating rates, the main product is a liquid fuel popularly known as bio oil.

Wide Range of Products

Bio oil is a dark brown liquid and can be upgraded to either engine fuel or through gasification processes to a syngas and then biodiesel. Pyrolysis oil may also be used as liquid fuel for diesel engines and gas turbines to generate electricity Bio oil is particularly attractive for co-firing because it can be relatively easy to handle and burn than solid fuel and is cheaper to transport and store. In addition, bio oil is also a vital source for a wide range of organic compounds and specialty chemicals.

Syngas is a mixture of energy-rich gases (combustible constituents include carbon monoxide, hydrogen, methane and a broad range of other VOCs). The net calorific value (NCV) of syngas is between 10 and 20MJ/Nm3. Syngas is cleaned to remove particulates, hydrocarbons, and soluble matter, and then combusted to generate electricity. Diesel engines, gas turbines, steam turbines and boilers can be used directly to generate electricity and heat in CHP systems using syngas and pyrolysis oil. Syngas may also be used as a basic chemical in petrochemical and refining industries.

The solid residue from MSW pyrolysis, called char, is a combination of non-combustible materials and carbon. Char is almost pure carbon and can be used in the manufacture of activated carbon filtration media (for water treatment applications) or as an agricultural soil amendment.

Municipal Wastes in Saudi Arabia

Saudi Arabia has been witnessing rapid industrialization, high population growth rate and fast urbanization which have resulted in increased levels of pollution and waste. Solid waste management is becoming a big challenge for the government and local bodies with each passing day. With population of around 29 million, Saudi Arabia generates more than 15 million tons of solid waste per year. The per capita waste generation is estimated at 1.5 to 1.8 kg per person per day.

Solid waste generation in the three largest cities – Riyadh, Jeddah and Dammam – exceeds 6 million tons per annum which gives an indication of the magnitude of the problem faced by civic bodies.  More than 75 percent of the population is concentrated in urban areas which make it necessary for the government to initiate measures to improve recycling and waste management scenario in the country.

In Saudi Arabia, municipal solid waste is collected from individual or community bins and disposed of in landfills or dumpsites. Saudi waste management system is characterized by lack of waste disposal and tipping fees. Recycling, reuse and energy recovery is still at an early stage, although they are getting increased attention. Waste sorting and recycling are driven by an active informal sector. Recycling rate ranges from 10-15%, mainly due to the presence of the informal sector which extracts paper, metals and plastics from municipal waste.

Recycling activities are mostly manual and labor intensive. Composting is also gaining increased interest in Saudi Arabia due to the high organic content of MSW (around 40%).  Efforts are also underway to deploy waste-to-energy technologies in the Kingdom. All activities related to waste management are coordinated and financed by the government.

The Saudi government is aware of the critical demand for waste management solutions, and is investing heavily in solving this problem. The 2011 national budget allocated SR 29 billion for the municipal services sector, which includes water drainage and waste disposal. The Saudi government is making concerted efforts to improve recycling and waste disposal activities.

Waste Management in Qatar

Waste management is one of the most serious environmental challenges faced by the tiny Gulf nation of Qatar. mainly on account of high population growth rate, urbanization, industrial growth and economic expansion. The country has one of the highest per capita waste generation rates worldwide of 1.8 kg per day. Qatar produces more than 2.5 million tons of municipal solid waste each year. Solid waste stream is mainly comprised of organic materials (around 60 percent) while the rest of the waste steam is made up of recyclables like glass, paper, metals and plastics.

Municipalities are responsible for solid waste collection in Qatar both directly, using their own logistics, and indirectly through private sector contract. Waste collection and transport is carried out by a large fleet of trucks that collect MSW from thousands of collection points scattered across the country.

The predominant method of solid waste disposal is landfilling. The collected is discharged at various transfer stations from where it is sent to the landfill. There are three landfills in Qatar; Umm Al-Afai for bulky and domestic waste, Rawda Rashed for construction and demolition waste, and Al-Krana for sewage wastes. However, the method of waste disposal by landfill is not a practical solution for a country like Qatar where land availability is limited.

Solid Waste Management Strategy

According to Qatar National Development Strategy 2011-2016, the country will adopt a multi-faceted strategy to contain the levels of waste generated by households, commercial sites and industry – and to promote recycling initiatives. Qatar intends to adopt integrated waste hierarchy of prevention, reduction, reuse, recycling, energy recovery, and as a last option, landfill disposal.

A comprehensive solid waste management plan is being implemented which will coordinate responsibilities, activities and planning for managing wastes from households, industry and commercial establishments, and construction industry. The target is to recycle 38 percent of solid waste, up from the current 8 percent, and reduce domestic per capita waste generation.

Five waste transfer stations have been setup in South Doha, West Doha, Industrial Area, Dukhan and Al-Khor to reduce the quantity of waste going to Umm Al-Afai landfill. These transfer stations are equipped with material recovery facility for separating recyclables such as glass, paper, aluminium and plastic.

Domestic Solid Waste Management Centre

One of the most promising developments has been the creation of Domestic Solid Waste Management Centre (DSWMC) at Mesaieed. This centre is designed to maximize recovery of resources and energy from waste by installing state-of-the-art technologies for separation, pre-processing, mechanical and organic recycling, and waste-to-energy and composting technologies. At its full capacity, it will treat 1550 tons of waste per day, and is expected to generate enough power for in-house requirements, and supply a surplus of 34.4 MW to the national grid.

Future Outlook

While commendable steps are being undertaken to handle solid waste, the Government should also strive to enforce strict waste management legislation and create mass awareness about 4Rs of waste management viz. Reduce, Reuse, Recycle and Recovery. Legislations are necessary to ensure compliance, failure of which will attract a penalty with spot checks by the Government body entrusted with its implementation.

Improvement in curbside collection mechanism and establishment of material recovery facilities and recycling centres may also encourage public participation in waste management initiatives. When the Qatar National Development Strategy 2011-2016 was conceived, the solid waste management facility plant at Mesaieed was a laudable solution, but its capacity has been overwhelmed by the time the project was completed. Qatar needs a handful of such centers to tackle the burgeoning garbage disposal problem.

Solid Waste Management – History and Future Outlook

The disposal of municipal solid waste is the second most major concern for public health in developing countries because of population explosion, rampant poverty and high urbanization rates combined with poor government funding to curb waste management. Factors such as waste composition, technologies and lack of infrastructure have been found to set apart the good management of solid wastes in developing nations. Municipal waste is mainly comprised of paper, vegetable matter, plastics, metals, textiles, rubber and glass. In some countries (developing as well as developed), municipal solid waste is mixed with medical wastes and this may pose health risk to waste handlers and general public.

Burying the wastes has become most preferred method for waste management in many countries. This method is still used in many more countries. Tackling environmental issues has become more important and more preferred than pollution and consumption of unsustainable utilization of resources. Most importantly, the primary objective of waste management is to put emphasis on protecting the people and environment from potentially harmful effects of waste.

Methods of Solid Waste Management

Depending on the types of wastes generated, four methods of solid waste management has been used throughout the history, i.e. dumping, incineration, recycling and waste prevention. Waste generated from household is much different from industrial waste, agricultural waste, medical waste or mining wastes.

When wastes contain any hazardous component, or it has capability to become hazardous with time, poses very serious threat to environment and health. Hazardous wastes generated needs to be handled very carefully, with special techniques. This is one of the major reasons of open landfills are getting replaced with sanitary landfills.

At a landfill, wastes are covered with thick layer of soil. By the late 1950, this practice was very common for waste management across the world. Earlier landfills had considerable sludge and methane emissions, which were harmful to the environment as well as animal and human health. But these issues have been resolved largely by modern disposal methods, which were developed around 20 years ago. Modern landfills are equipped with thick layer of clay followed by plastic sheets. This method was practiced by some nations and still going on.

In 1930-1940, many cities in USA adopted new technology to curb waste issues by burning at high temperature, this method is known as incineration. During initial years, this method was not very efficient and emit very large amount of poisonous gasses, this is the major reason of incinerators shut down during that period. During mid-1970s, scientists modified incinerators to generate energy, which are known as waste to energy plants. But after around a decade, it has become major issue to build these plants, again because of emission issues.

With development of technology, waste burning in advanced form of incinerators became common in 1970s, researchers across the world bet on incinerators or waste to energy plants for solution to energy crisis in 1973. However, with realisation of impact on environment and air quality, it become very difficult to find location to build any waste to energy plants, mainly because of public opposition. Another issue with incinerator is production of ashes, which contain huge amount of heavy metals, toxic and inorganic compounds.

waste-to-energy-plant

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

Future Outlook of Solid Waste Management

The overall concept of wastes needs to be considered economically, it will be more considered as economically viable product if waste is considered as an inefficiency of the production process not as rejected residue of waste product. A permanent rejection or heavy restriction into products which produces waste that cannot be accumulated back into the environment safely.

The major challenge in waste management is to persuade people/community to consider waste as a resource, rather than a liability on society, which can be created with more innovation and technological development of manufacturing industry, waste processing industry and new business model and plans.

This planning system will create circular economy where product value created by inputs (e.g. energy, materials, labour etc.) is extended by enabling a material that goes into circular economy, beyond product life. We go from mineral to metals to product then back to minerals/metals. By understanding economic cycle of waste, people will understand the creation of opportunities to more sustainable product in future with limited resources.

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, 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.

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 proper 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.

Biomass Energy in Vietnam

Vietnam is one of the few countries having a low level of energy consumption in the developing world with an estimated amount of 210 kg of oil equivalent per capita/year. Over half of the Vietnamese population does not have access to electricity. Vietnam is facing the difficult challenge of maintaining this growth in a sustainable manner, with no or minimal adverse impacts on society and the environment.

Being an agricultural country, Vietnam has very good biomass energy potential. Agricultural wastes are most abundant in the Mekong Delta region with approximately 50% of the amount of the whole country and Red River Delta with 15%. Major biomass resources includes rice husk from paddy milling stations, bagasse from sugar factories, coffee husk from coffee processing plants in the Central Highlands and wood chip from wood processing industries. Vietnam has set a target of having a combined capacity of 500 MW of biomass power by 2020, which is raised to 2,000 MW in 2030.

Rice husk and bagasse are the biomass resources with the greatest economic potential, estimated at 50 MW and 150 MW respectively. Biomass fuels sources that can also be developed include forest wood, rubber wood, logging residues, saw mill residues, sugar cane residues, bagasse, coffee husk and coconut residues. Currently biomass is generally treated as a non-commercial energy source, and collected and used locally. Nearly 40 bagasse-based biomass power plants have been developed with a total designed capacity of 150 MW but they are still unable to connect with the national grid due to current low power prices. Five cogeneration systems selling extra electricity to national grid at average price of 4UScents/kWh.

Biogas energy potential is approximately 10 billion m3/year, which can be collected from landfills, animal excrements, agricultural residues, industrial wastewater etc. The biogas potential in the country is large due to livestock population of more than 30 million, mostly pigs, cattle, and water buffalo. Although most livestock dung already is used in feeding fish and fertilizing fields and gardens, there is potential for higher-value utilization through biogas production. It is estimated that more than 25,000 household biogas digesters with 1 to 50 m3, have been installed in rural areas. The Dutch-funded Biogas Program operated by SNV Vietnam constructed some 18,000 biogas facilities in 12 provinces between 2003 and 2005, with a second phase (2007-2010) target of 150,000 biogas tanks in both rural and semi-urban settings.

Municipal solid waste is also a good biomass resource as the amount of solid waste generated in Vietnam has been increasing steadily over the last few decades. In 1996, the average amount of waste produced per year was 5.9 million tons per annum which rose to 28 million tons per in 2008 and expected to reach 44 million tons per year by 2015.

Gasification of Municipal Wastes

utishinai-gasification-plantGasification of municipal wastes involves the reaction of carbonaceous feedstock with an oxygen-containing reagent, usually oxygen, air, steam or carbon dioxide, generally at temperatures above 800°C. The process is largely exothermic but some heat may be required to initialise and sustain the gasification process. The main product of the gasification process is syngas, which contains carbon monoxide, hydrogen and methane. Typically, the gas generated from gasification has a low heating value (LHV) of 3 – 6 MJ/Nm3.The other main product produced by gasification is a solid residue of non-combustible materials (ash) which contains a relatively low level of carbon. Syngas can be used in a number of ways, including:

  • Syngas can be burned in a boiler to generate steam for power generation or industrial heating.
  • Syngas can be used as a fuel in a dedicated gas engine.
  • Syngas, after reforming, can be used in a gas turbine
  • Syngas can also be used as a chemical feedstock.

Gasification has been used worldwide on a commercial scale for several decades by the chemical, refining, fertilizer and electric power industries. MSW gasification plants are relatively small-scale, flexible to different inputs and modular development. The quantity of power produced per tonne of waste by gasification process is larger than when applying the incineration method. The most important reason for the growing popularity of gasification of municipal wastes has been the increasing technical, environmental and public dissatisfaction with the performance of conventional incinerators.

Plasma Gasification

Plasma gasification uses extremely high temperatures in an oxygen-starved environment to completely decompose input waste material into very simple molecules in a process similar to pyrolysis. The heat source is a plasma discharge torch, a device that produces a very high temperature plasma gas. It is carried out under oxygen-starved conditions and the main products are vitrified slag, syngas and molten metal.

plasma-gasification

Vitrified slag may be used as an aggregate in construction; the syngas may be used in energy recovery systems or as a chemical feedstock; and the molten metal may have a commercial value depending on quality and market availability. The technology has been in use for steel-making and is used to melt ash to meet limits on dioxin/furan content. There are several commercial-scale plants already in operation in Japan for treating MSW and auto shredder residue.

Advantages of Gasification

There are numerous solid waste gasification facilities operating or under construction around the world. Gasification of solid wastes has several advantages over traditional combustion processes for MSW treatment. It takes place in a low oxygen environment that limits the formation of dioxins and of large quantities of SOx and NOx. Furthermore, it requires just a fraction of the stoichiometric amount of oxygen necessary for combustion. As a result, the volume of process gas is low, requiring smaller and less expensive gas cleaning equipment.

The lower gas volume also means a higher partial pressure of contaminants in the off-gas, which favours more complete adsorption and particulate capture. Finally, gasification generates a fuel gas that can be integrated with combined cycle turbines, reciprocating engines and, potentially, with fuel cells that convert fuel energy to electricity more efficiently than conventional steam boilers.

Disadvantages of Gasification

The gas resulting from gasification of municipal wastes contains various tars, particulates, halogens, heavy metals and alkaline compounds depending on the fuel composition and the particular gasification process. This can result in agglomeration in the gasification vessel, which can lead to clogging of fluidised beds and increased tar formation. In general, no slagging occurs with fuels having ash content below 5%. MSW has a relatively high ash content of 10-12%.