Recycling of Polyvinyl Chloride

Polyvinyl chloride is one of the most widely used plastics worldwide. A major problem in the recycling of polyvinyl chloride is the high chlorine content in raw PVC and high levels of hazardous additives added to the polymer to achieve the desired material quality. As a result, PVC requires separation from other plastics before mechanical recycling. PVC products have an average lifetime of 30 years, with some reaching 50 or more years.  This means that more PVC products are reaching the end-of-life and entering the waste stream, and the amount is likely to increase significantly in the near future.

PVC Recycling Methods

Currently, PVC is being recycled by either one of the two ways:

  • Mechanical recycling – This involves mechanically treating the waste (e.g. grinding) to reduce it into smaller particles.  The resulting granules, called recyclate, can be melted and remolded into different products, usually the same product from which it came.
  • Feedstock recycling – Chemical processes such as pyrolysis, hydrolysis and heating are used to convert the waste into its chemical components.  The resulting products – sodium chloride, calcium chloride, hydrocarbon products and heavy metals to name a few – are used to produce new PVC, as feed for other manufacturing processes or as fuel for energy recovery.

In mechanical recycling, because no chemical reaction is involved, the recyclate retains its original composition. This poses a recycling challenge because PVC products, depending on their application, contain different additives.  For example, rigid PVC is unplasticized whereas flexible PVC is added plasticizers because this additive increases the plastic’s fluidity and thus, its flexibility. Even products used for the same application may still differ in composition if they have different manufacturers.

When different kinds of PVC waste are fed to a mechanical recycler, the resulting product’s composition is difficult to predict, which is problematic because most PVC products, even recycled ones, require a specific PVC content.  In order to produce a high-quality recylate, the feed ideally should not be mixed with other kinds of plastic and should have a uniform material composition.Material recycling is therefore more applicable for post-industrial waste than for post-consumer waste.

Feedstock recycling is seen to be complementary to conventional mechanical recycling as it is able to treat mixed or unsorted PVC waste and recover valuable materials.  However, a study showed that feedstock recycling (or at least the two that was considered) incurred higher costs than landfilling, primarily due to the low value of the recovered products. This provides little incentive for recyclers to pursue PVC recycling.  This may change in the future as more stringent regulations to protect the environment are enacted.  Some countries in Europe have already banned PVCs from landfills and PlasticsEurope is targeting a “zero plastic to landfill” in Europe by 2020.

Post-industrial waste is relatively pure and comes from PVC production and installation, such as cut-offs from laying of cables or scraps from the installation of window frames.  These are easily recycled since they can be collected directly from processors or installers or even recycled by producers themselves as raw material to manufacture the same product.

Post-consumer waste contains mixed material and has been used for different applications.  These are products that have reached the end-of-life or are replaced due to damage, like pipes from underground, window frames being replaced for renovation and electric cables recovered from demolition. These would require further sorting and cleaning, adding cost to the recycling process.  The recyclate produced is usually of lower quality and consequently of decreased economic value.

Recent Developments

Europe is leading the way for a more sustainable use of PVC with programs, such as RecoVinyl and VinylPlus, where recycling is advanced as one of the ways to use resources more efficiently and to divert as much waste as possible from landfills. Recovinyl, created in 2003, is an initiative of the European PVC industry to advance the sustainable development of the PVC industry by improving production processes, minimise emissions, develop recycling technology and boost the collection and recycling of waste.

Having been successful in all of its goals, including an increase in recycling of PVC across Europe to over 240,000 tonnes a year, in 2011 the PVC industry redefined the role of Recovinyl as part of the ambitious new ten-year VinylPlus sustainable development programme. VinylPlus works in partnership with consumers, businesses, municipalities, waste management companies, recyclers and converter, as well as the European Commission and national and local governments. The goal is to certify those companies who recycle PVC waste and those accredited converting companies who purchase recyclate to manufacture new products and applications.

Even if some types of PVC recycling are not feasible or economically viable at present, it will likely be reversed in the future as governments, manufacturers, consumers and other stakeholders create programs that innovate and find ways to achieve a sustainable future for the PVC industry.

Pelletization of Municipal Solid Wastes

MSW is a poor-quality fuel and its pre-processing is necessary to prepare fuel pellets to improve its consistency, storage and handling characteristics, combustion behaviour and calorific value. Technological improvements are taking place in the realms of advanced source separation, resource recovery and production/utilisation of recovered fuel in both existing and new plants for this purpose. There has been an increase in global interest in the preparation of RDF containing a blend of pre-processed MSW with coal suitable for combustion in pulverised coal and fluidised bed boilers.

Pelletization of municipal solid waste involves the processes of segregating, crushing, mixing high and low heat value organic waste material and solidifying it to produce fuel pellets or briquettes, also referred to as Refuse Derived Fuel (RDF). The process is essentially a method that condenses the waste or changes its physical form and enriches its organic content through removal of inorganic materials and moisture. The calorific value of RDF pellets can be around 4000 kcal/ kg depending upon the percentage of organic matter in the waste, additives and binder materials used in the process.

The calorific value of raw MSW is around 1000 kcal/kg while that of fuel pellets is 4000 kcal/kg. On an average, about 15–20 tons of fuel pellets can be produced after treatment of 100 tons of raw garbage. Since pelletization enriches the organic content of the waste through removal of inorganic materials and moisture, it can be very effective method for preparing an enriched fuel feed for other thermochemical processes like pyrolysis/ gasification, apart from incineration. Pellets can be used for heating plant boilers and for the generation of electricity. They can also act as a good substitute for coal and wood for domestic and industrial purposes. The important applications of RDF are found in the following spheres:

  • Cement kilns
  • RDF power plants
  • Coal-fired power plants
  • Industrial steam/heat boilers
  • Pellet stoves

The conversion of solid waste into briquettes provides an alternative means for environmentally safe disposal of garbage which is currently disposed off in non-sanitary landfills. In addition, the pelletization technology provides yet another source of renewable energy, similar to that of biomass, wind, solar and geothermal energy. The emission characteristics of RDF are superior compared to that of coal with fewer emissions of pollutants like NOx, SOx, CO and CO2.

RDF production line consists of several unit operations in series in order to separate unwanted components and condition the combustible matter to obtain the required characteristics. The main unit operations are screening, shredding, size reduction, classification, separation either metal, glass or wet organic materials, drying and densification. These unit operations can be arranged in different sequences depending on raw MSW composition and the required RDF quality.

Various qualities of fuel pellets can be produced, depending on the needs of the user or market. A high quality of RDF would possess a higher value for the heating value, and lower values for moisture and ash contents. The quality of RDF is sufficient to warrant its consideration as a preferred type of fuel when solid waste is being considered for co-firing with coal or for firing alone in a boiler designed originally for firing coal.

The Concept of Biorefinery

A biorefinery is a facility that integrates biomass conversion processes and equipment to produce fuels, power, and value-added chemicals from biomass. Biorefinery is analogous to today’s petroleum refinery, which produces multiple fuels and products from petroleum. By producing several products, a biorefinery takes advantage of the various components in biomass and their intermediates, therefore maximizing the value derived from the biomass feedstock.

A biorefinery could, for example, produce one or several low-volume, but high-value, chemical products and a low-value, but high-volume liquid transportation fuel such as biodiesel or bioethanol. At the same time, it can generate electricity and process heat, through CHP technology, for its own use and perhaps enough for sale of electricity to the local utility. The high value products increase profitability, the high-volume fuel helps meet energy needs, and the power production helps to lower energy costs and reduce GHG emissions from traditional power plant facilities.

Biorefinery Platforms

There are several platforms which can be employed in a biorefinery with the major ones being the sugar platform and the thermochemical platform (also known as syngas platform).

Sugar platform biorefineries breaks down biomass into different types of component sugars for fermentation or other biological processing into various fuels and chemicals. On the other hand, thermochemical biorefineries transform biomass into synthesis gas (hydrogen and carbon monoxide) or pyrolysis oil.

The thermochemical biomass conversion process is complex, and uses components, configurations, and operating conditions that are more typical of petroleum refining. Biomass is converted into syngas, and syngas is converted into an ethanol-rich mixture. However, syngas created from biomass contains contaminants such as tar and sulphur that interfere with the conversion of the syngas into products. These contaminants can be removed by tar-reforming catalysts and catalytic reforming processes. This not only cleans the syngas, it also creates more of it, improving process economics and ultimately cutting the cost of the resulting ethanol.

Plus Points

Biorefineries can help in utilizing the optimum energy potential of organic wastes and may also resolve the problems of waste management and GHGs emissions. Biomass wastes can be converted, through appropriate enzymatic/chemical treatment, into either gaseous or liquid fuels. The pre-treatment processes involved in biorefining generate products like paper-pulp, HFCS, solvents, acetate, resins, laminates, adhesives, flavour chemicals, activated carbon, fuel enhancers, undigested sugars etc. which generally remain untapped in the traditional processes. The suitability of this process is further enhanced from the fact that it can utilize a variety of biomass resources, whether plant-derived or animal-derived.

Future Perspectives

The concept of biorefinery is still in early stages at most places in the world. Problems like raw material availability, feasibility in product supply chain, scalability of the model are hampering its development at commercial-scales. The National Renewable Energy Laboratory (NREL) of USA is leading the front in biorefinery research with path-breaking discoveries and inventions. Although the technology is still in nascent stages, but it holds the key to the optimum utilization of wastes and natural resources that humans have always tried to achieve. The onus now lies on governments and corporate sector to incentivize or finance the research and development in this highly promising field.

MSW to Energy at a Glance

MSW-to-Energy is the use of thermochemical and biochemical technologies to recover energy, usually in the form of electricity and steam, from urban wastes. These new technologies can reduce the volume of the original waste by 90%, depending upon composition and use of outputs. The main categories of MSW-to-energy technologies are physical technologies, which process waste to make it more useful as fuel; thermal technologies, which can yield heat, fuel oil, or syngas from both organic and inorganic wastes; and biological technologies, in which bacterial fermentation is used to digest organic wastes to yield fuel.

Components of MSW-to-Energy Systems

  1. Front-end MSW preprocessing
  2. Conversion unit (reactor or anaerobic digester)
  3. Gas cleanup and residue treatment plant
  4. Energy recovery plant (optional)
  5. Emissions clean up

Incineration

  • Combustion of raw MSW, moisture less than 50%
  • Sufficient amount of oxygen is required to fully oxidize the fuel
  • Combustion temperatures are in excess of 850oC
  • Waste is converted into CO2 and water concern about toxics (dioxin, furans)
  • Any non-combustible materials (inorganic such as metals, glass) remain as a solid, known as bottom ash (used as feedstock in cement and brick manufacturing)
  • Fly ash APC (air pollution control residue) particulates, etc
  • Needs high calorific value waste to keep combustion process going, otherwise requires high energy for maintaining high temperatures

Anaerobic Digestion

  •  Well-known biochemical technology for organic fraction of MSW and domestic sewage.
  • Biological conversion of biodegradable organic materials in the absence of oxygen at mesophilic or thermophilic temperatures.
  • Residue is stabilized organic matter that can be used as soil amendment
  • Digestion is used primarily to reduce quantity of sludge for disposal / reuse
  • Methane gas is generated which is used for heat and power generation.

Gasification

  • Can be seen as between pyrolysis and combustion (incineration) as it involves partial oxidation.
  • Exothermic process (some heat is required to initialize and sustain the gasification process).
  • Oxygen is added but at low amounts not sufficient for full oxidation and full combustion.
  • Temperatures are above 650oC
  • Main product is syngas, typically has net calorific value of 4 to 10 MJ/Nm3
  • Other product is solid residue of non-combustible materials (ash) which contains low level of carbon

Pyrolysis

  • Thermal degradation of organic materials through use of indirect, external source of heat
  • Temperatures between 300 to 850oC are maintained for several seconds in the absence of oxygen.
  • Product is char, oil and syngas composed primarily of O2, CO, CO2, CH4 and complex hydrocarbons.
  • Syngas can be utilized for energy production or proportions can be condensed to produce oils and waxes
  • Syngas typically has net calorific value (NCV) of 10 to 20 MJ/Nm

Plasma Gasification

  • Use of electricity passed through graphite or carbon electrodes, with steam and/or oxygen / air injection to produce electrically conducting gas (plasma)
  • Temperatures are above 3000oC
  • Organic materials are converted to syngas composed of H2, CO
  • Inorganic materials are converted to solid slag
  • Syngas can be utilized for energy production or proportions can be condensed to produce oils and waxes
  •  

MSW-to-energy technologies can address a host of environmental issues, such as land use and pollution from landfills, and increasing reliance on fossil fuels. In many countries, the availability of landfill capacity has been steadily decreasing due to regulatory, planning and environmental permitting constraints. As a result, new approaches to waste management are rapidly being written into public and institutional policies at local, regional and national levels.

Anaerobic Digestion of Tannery Wastes

The conventional leather tanning technology is highly polluting as it produces large amounts of organic and chemical pollutants. Wastes generated by tanneries pose a major challenge to the environment. Anaerobic digestion of tannery wastes is an attractive method to recover energy from tannery wastes.

According to conservative estimates, more than 600,000 tons per year of solid waste are generated worldwide by leather industry and approximately 40–50% of the hides are lost to shavings and trimmings. Everyday a huge quantity of solid waste, including trimmings of finished leather, shaving dusts, hair, fleshing, trimming of raw hides and skins, are being produced from the industries. Chromium, sulphur, oils and noxious gas (methane, ammonia, and hydrogen sulphide) are the elements of liquid, gas and solid waste of tannery industries.

Biogas from Tannery Wastes

Anaerobic digestion (or biomethanation) systems are mature and proven processes that have the potential to convert tannery wastes into energy efficiently, and achieve the goals of pollution prevention/reduction, elimination of uncontrolled methane emissions and odour, recovery of biomass energy potential as biogas, production of stabilized residue for use as low grade fertilizer.

Anaerobic digestion of tannery wastes is an attractive method to recover energy from tannery wastes. This method degrades a substantial part of the organic matter contained in the sludge and tannery solid wastes, generating valuable biogas, contributing to alleviate the environmental problem, giving time to set-up more sustainable treatment and disposal routes. Digested solid waste is biologically stabilized and can be reused in agriculture.

Until now, biogas generation from tannery wastewater was considered that the complexity of the waste water stream originating from tanneries in combination with the presence of chroming would result in the poisoning of the process in a high loaded anaerobic reactor.

When the locally available industrial wastewater treatment plant is not provided by anaerobic digester, a large scale digestion can be planned in regions accommodating a big cluster of tanneries, if there is enough waste to make the facility economically attractive.

In this circumstance, an anaerobic co-digestion plant based on sludge and tanneries may be a recommendable option, which reduces the quantity of landfilled waste and recovers its energy potential. It can also incorporate any other domestic, industrial or agricultural wastes. Chrome-free digested tannery sludge also has a definite value as a fertilizer based on its nutrient content.

Potential Applications of Biogas

Biogas produced in anaerobic digesters consists of methane (50%–80%), carbon dioxide (20%–50%), and trace levels of other gases such as hydrogen, carbon monoxide, nitrogen, oxygen, and hydrogen sulfide.  Biogas can be used for producing electricity and heat, as a natural gas substitute and also a transportation fuel. A combined heat and power plant (CHP) not only generates power but also produces heat for in-house requirements to maintain desired temperature level in the digester during cold season.

CHP systems cover a range of technologies but indicative energy outputs per m3 of biogas are approximately 1.7 kWh electricity and 2.5kWh heat. The combined production of electricity and heat is highly desirable because it displaces non-renewable energy demand elsewhere and therefore reduces the amount of carbon dioxide released into the atmosphere.

AD Plant at ECCO’s Tannery (Netherlands)

A highly advanced wastewater treatment plant and biogas system became fully operational in 2012 at ECCO’s tannery in the Netherlands. A large percentage of the waste is piped directly into the wastewater plant to be converted into biogas. This biogas digester provides a source of renewable fuel and also helps to dispose of waste materials by converting waste from both the leather-making processes, and the wastewater treatment plant, into biogas. All excess organic material from the hides is also converted into biogas.

This project enables ECCO Tannery to reduce waste and to substitute virtually all of its consumption of non-renewable natural gas with renewable biogas. The aim is to use more than 40% of the total tannery waste and replace up to 60% of the total natural gas consumption with biogas.

Agricultural Biomass in Malaysia

Malaysia is located in a region where biomass productivity is high which means that the country can capitalize on this renewable energy resource to supplements limited petroleum and coal reserves. Malaysia, as a major player in the palm oil and sago starch industries, produces a substantial amount of agricultural biomass waste which present a great opportunity for harnessing biomass energy in an eco-friendly and commercially-viable manner.

Peninsular Malaysia generates large amounts of wood and’ agricultural residues, the bulk of which are not being currently utilised for any further downstream operations. The major agricultural crops grown in Malaysia are rubber (39.67%), oil palm (34.56%), cocoa (6.75%), rice (12.68%) and coconut (6.34%). Out of the total quantity of residues generated, only 27.0% is used either as fuel for the kiln drying of timber, for the manufacture of bricks, the curing of tobacco leaves, the drying rubber-sheets and for the manufacture of products such as particleboard and fibreboard. The rest has to be disposed of by burning.

Palm Oil Industry

Oil palm is one of the world’s most important fruit crops. Malaysia is one of the largest producers and exporter of palm oil in the world, accounting for 30% of the world’s traded edible oils and fats supply. Palm oil industries in Malaysia have good potential for high pressure modern power plants and the annual power generation potential is about 8,000 GWh. Malaysia produced more than 20 million tonnes of palm oil in 2012 over 5 million hectares of land.

The palm oil industry is a significant branch in Malaysian agriculture. Almost 70% of the volume from the processing of fresh fruit bunch is removed as waste in the form of empty fruit bunches (EFBs), fibers and shells, as well as liquid effluent. Fibres and shells are traditionally used as fuels to generate power and steam. Effluents are sometimes converted into biogas that can be used in gas-fired gensets.

Sugar Industry

The cultivation of sugarcane in Malaysia is surprisingly small. Production is concentrated in the Northwest extremity of peninsular Malaysia in the states of Perlis and Kedah. This area has a distinct dry season needed for cost-efficient sugarcane production. Plantings in the states of Perak and Negri Sembilan were unsuccessful due to high unit costs as producing conditions were less suitable.

The lack of growth in cane areas largely reflects the higher remuneration received by farmers for other crops, especially oil palm. Over the past 20 years while the sugarcane area has remained at around 20 000 hectares, that planted to oil palm has expanded from 600 000 hectares to 5 million hectares.

Other leading crops in terms of planted areas are rubber with 2.8 million hectares, rice with 670 000 hectares and cocoa with 380 000 hectares. Malaysia, the world’s third largest rubber producer, accounted for 1 million tons of natural rubber production in 2012. Like oil palm industry, the rubber industry produces a variety of biomass wastes whose energy potential is largely untapped until now.

Food Waste Management in UK

Food-Waste-UKFood waste in the United Kingdom is a matter of serious environmental, economic and social concern that has been attracting widespread attention in recent years. According to ‘Feeding the 5K’ organisation, 13,000 slices of crusts are thrown away every day by a single sandwich factory which is featured in the figure above. More recently, Tesco, one of the largest UK food retailers, has published its sustainability report admitting that the company generated 28,500 tonnes of food waste in the first six months of 2013. TESCO’s report also state that 47% of the bakery produced is wasted. In terms of GHG emissions, DEFRA estimated that food waste is associated with 20 Mt of CO2 equivalent/year, which is equivalent to 3% of the total annual GHG emissions.

Globally, 1.2 to 2 billion tonnes (30%-50%) of food produced is thrown away before it reaches a human stomach. Food waste, if conceived as a state, is responsible for 3.3 Bt-CO2 equivalent/year, which would make it the third biggest carbon emitter after China and USA. What makes food waste an even more significant issue is the substantially high demand for food which is estimated to grow 70% by 2050 due to the dramatic increase of population which is expected to reach 9.5 billion by 2075. Therefore, there is an urgent need to address food waste as a globally challenging issue which should be considered and tackled by sustainable initiatives.

A War on Food Waste

The overarching consensus to tackle the food waste issue has led to the implementation of various policies. For instance, the European Landfill Directive (1999/31/EC) set targets to reduce organic waste disposed to landfill in 2020 to 35% of that disposed in 1995 (EC 1999). More recently, the European Parliament discussed a proposal to “apply radical measures” to halve food waste by 2025 and to designate the 2014 year as “the European Year Against Food Waste”. In the light of IMechE’s report (2013), the United Nations Environment Programme (UNEP) in cooperation with FAO has launched the Save Food Initiative in an attempt to reduce food waste generated in the global scale.

In the UK, WRAP declared a war on food waste by expanding its organic waste programme in 2008 which was primarily designed to “establish the most cost-effective and environmentally sustainable ways of diverting household food waste from landfill that leads to the production of a saleable product”. DEFRA has also identified food waste as a “priority waste stream” in order to achieve better waste management performance. In addition to governmental policies, various voluntary schemes have been introduced by local authorities such as Nottingham Declaration which aims to cut local CO2 emissions 60% by 2050.

Sustainable Food Waste Management

Engineering has introduced numerous technologies to deal with food waste. Many studies have been carried out to examine the environmental and socio-economic impacts of food waste management options. This article covers the two most preferable options; anaerobic digestion and composting.

In-vessel composting (IVC) is a well-established technology which is widely used to treat food waste aerobically and convert it into a valuable fertilizer. IVC is considered a sustainable option because it helps by reducing the amount of food waste landfilled. Hence, complying with the EU regulations, and producing a saleable product avoiding the use of natural resources. IVC is considered an environmentally favourable technology compared with other conventional options (i.e. landfill and incineration). It contributes less than 0.06% to the national greenhouse gas inventories. However, considering its high energy-intensive collection activities, the overall environmental performance is “relatively poor”.

Anaerobic Digestion (AD) is a leading technology which has had a rapidly growing market over the last few years. AD is a biologically natural process in which micro-organisms anaerobically break down food waste and producing biogas which can be used for both Combined Heat & Power (CHP) and digestate that can be used as soil fertilizers or conditioners. AD has been considered as the “best option” for food waste treatment. Therefore, governmental and financial support has been given to expand AD in the UK.

AD is not only a food waste treatment technology, but also a renewable source of energy. For instance, It is expected that AD would help the UK to meet the target of supplying 15% of its energy from renewable sources by 2020. Furthermore, AD technology has the potential to boost the UK economy by providing 35,000 new jobs if the technology is adopted nationally to process food waste. This economic growth will significantly improve the quality of life among potential beneficiaries and thus all sustainability elements are considered.

Bioenergy Perspectives for Southeast Asia

Southeast Asia, with its abundant bioenergy resources, holds a strategic position in the global biomass energy atlas. There is immense bioenergy potential in Southeast Asian countries due to plentiful supply of diverse forms of biomass wastes such as agricultural residues, woody biomass, animal wastes, municipal solid waste, etc. The rapid economic growth and industrialization in the region has accelerated the drive to implement the latest waste-to-energy technologies to tap the unharnessed potential of biomass resources.

Southeast Asia is a big producer of agricultural and wood products which, when processed in industries, produces large amounts of biomass residues. 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.

Rice mills in the region produce 38 million tonnes of rice husk as solid residue which is a good fuel for producing heat and power. Sugar industry is an integral part of the industrial scenario in Southeast Asia accounting for 7% of sugar production worldwide. Sugar mills in Thailand, Indonesia, Philippines and Vietnam generate 34 million tonnes of bagasse every year.  Malaysia, Indonesia and Thailand account for 90% of global palm oil production leading to the generation of 27 million tonnes of waste per annum in the form of empty fruit bunches (EFBs), fibers and shells, as well as liquid effluent.

Woody biomass is a good energy resource due to presence of large number of forests in Southeast Asia. Apart from natural forests, non-industrial plantations of different types (e.g. coconut, rubber and oil palm plantations, fruit orchards, and trees in homesteads and gardens) have gained recognition as important sources of biomass. In addition, the presence of a large number of wood processing industries also generates significant quantity of wood wastes. The annual production of wood wastes in the region is estimated to be more than 30 million m3.

The prospects of biogas power generation are also high in the region thanks to presence of well-established food-processing and dairy industries. Another important biomass resource is contributed by municipal solid wastes in heavily populated urban areas.  In addition, there are increasing efforts both commercially and promoted by governments to develop biomass energy systems for efficient biofuel production, e.g. bio-diesel from palm oil.

Biomass resources, particularly residues from forests, wood processing, agricultural crops and agro-processing, are under-utilised in Southeast Asian countries. There is an urgent need to utilize biomass wastes for commercial electricity and heat production to cater to the needs of the industries as well as urban and rural communities.

Southeast Asian countries are yet to make optimum use of the additional power generation potential from biomass waste resources which could help them to partially overcome the long-term problem of energy supply. Technologies for biomass utilization which are at present widely used in Southeast counties need to be improved towards best practice by making use of the latest trends in the biomass energy sector.

Behavioral Drivers Behind Food Wastes

food-waste-behaviorBy 2075, the United Nations estimates the global population will peak at 9.5 billion, an extra 3 billion mouths to feed by the end of the century. Meanwhile, while we produce about four billion tonnes of food annually, it is estimated that 30-50% of this never reaches our plates. Of the food that does reach us, some western societies throw away up to a third of all food purchased. This has enormous implications for the global environment, from wasting the water used to grow the food to adverse effects on climate, land and biodiversity.

The drivers behind these phenomenal levels of food waste are complex and include food pricing, logistical and storage issues. However, given the significant level of waste that happens within the households of societies like the UK and US, it is useful and informative to consider those behaviours that drive this level of waste.

The quality of data around food waste, as with much of waste data, has historically been poor. To this end, WRAP commissioned groundbreaking research in the UK in 2006/7 to act as a baseline to their Love Food Hate Waste campaign. This came up with the alarming statistic that 1/3 of food bought by a UK household was thrown away. Until this time, there had been no comprehensive research, either by food manufacturers, retailers or interest groups, suggesting the importance of government, or some other dis-interested party, taking a lead on the issue.

Back to Basics

There may be a link between the amount of time spent preparing food, and the skill and effort that goes into this, and the amount of food waste produced. This has led to a loss of confidence in the kitchen, with individuals losing basic skills that allow them to cook with leftovers, understand food labeling, including Best Before and Use By, even basic storing. WRAP had found little evidence of best practice storage advice so carried out the research themselves – leading the (surprising for many) conclusion that fruit such as apples and pears are best stored in the fridge wrapped in a plastic cover. However, this has masked a larger trend of less time spent in the kitchen, due to demographic changes. This of course begs the question – how should we use this when trying to reduce food waste? Should we encourage people to cook from scratch as a principle?

Although waste prevention and recycling are clearly separated within the waste hierarchy, there are apparent links between the two when considering food waste. There is an urgent need for legislation to enforce separate food waste collections, not only to ensure it was diverted to anaerobic digestion or composting, but also as it led to greater self awareness around food waste. WRAP research has clearly showed a fall in food waste when separate food waste collections were introduced.

Role of Packaging

Historically, packaging has always been a high priority to the public when asked about priorities for reducing waste. However, as awareness of food waste has grown, a more nuanced position has developed among waste managers. While excess packaging is clearly undesirable, and, within the UK for instance, the Courtauld Commitment  has helped reduced grocery packaging by 2.9 million tonnes of waste so far, there is a realization of the importance of food packaging in preserving food and hence reducing food waste.

Making food easily accessible and affordable by many, it could be argued, is one of the crowning achievements of our age. Over the last century, the proportion of household income that is spent on food has plummeted, and there is a direct link to malnutrition and food prices, particularly for children. But does cheap food mean that it is less valued and hence greater wastage? Is the answer expensive food? The evidence from WRAP in the UK is that food waste is still a serious economic issue for households, and underlining the economic case for reducing food waste a major incentive for households, especially as food prices are not entering an era of increase and instability, providing added economic urgency

Political Persuasions

Different political persuasions often differ in the approaches they take to changing behaviours and food waste is no different. In the UK, the Courtauld Commitment is a voluntary agreement aimed at encouraging major retailers to take responsibility mainly for packaging, later growing to encompass food waste, voluntary and so far has seen a 21% reduction in food waste post-consumer.

Meanwhile Wales (in the UK) effectively banned food waste from landfill. Scotland has ensured that businesses make food waste available for separate collection – again it’s only once you see it, you can manage it. Campaigns like the UK’s Love Food Hate Waste have been successful but measuring food waste prevention, as with all waste prevention, is notoriously difficult. But, people are now widely aware of food waste as an issue – we even see celebrity chefs actively talking about food waste reduction and recipes involving leftovers or food that is about to go off.

There is clearly a balance between food waste and food safety, with a commitment to reducing food waste throughout the retail and catering world, not just at home. By engaging environmental health officers to help deliver this, a potentially conflicting message can be delivered in a nuanced and balanced way. Indeed, environmental health officers in Scotland will be responsible for ensuring that Scottish food businesses present their food waste for separate collection.

Role of Communication

It is worth considering how the message should be communicated, and by whom. The community sector are more trusted by the public than government and the private sector are more effective at imparting personal, deeply held beliefs – the sort of beliefs that need to change if we are to see long term changes in attitudes towards consumption and hence waste production.

Furthermore, communications can engage wider audiences that hold an interest in reducing food waste that is perhaps not primarily environmental. The health and economic benefits of issues and behaviours that also result in food waste prevention may be the prevalent message that fits with a particular audience. So whilst the main aim of a training session might be food waste prevention, this is may not be the external message. And this has wider implications for waste prevention, and how we engage audiences around it.

Municipal authorities tasked with waste prevention will need to engage with new groups, in new ways. They will have to consider approaches previously considered to be beyond their powers to engage new audiences – should they be partnering with public health authorities with an interest in nutrition, or social housing providers that are focused on financial inclusion.

Should waste prevention even be a discipline in itself? After all, across material streams it is a motley assortment of behaviours with different drivers. Furthermore, with the knots that one can tie oneself in trying to measure waste that doesn’t get generated, – therefore doesn’t exist – should we integrate waste prevention in to other socio-economic programmes and position it as an “added benefit” to them?

Note: The article is being republished with the permission of our collaborative partner be Waste Wise. The unabridged version can be found at this link. Special thanks to the author Mike Webster.

Municipal Solid Waste Management in Oman

Municipal solid waste management is a challenging issue for the Sultanate of Oman because of its adverse impacts on environment and public health. With population of almost 3 million inhabitants, the country produces about 1.9 million tons of solid waste each year. The per capita waste generation in Oman is more than 1.5 kg per day, among the highest worldwide.

Prevalent Scenario

Solid waste in Oman is characterized by very high percentage of recyclables, primarily paper (26%), plastics (12%), metals (11%) and glass (5%). However the country is yet to realize the recycling potential of its municipal waste stream.

The predominant waste disposal method in Oman is landfilling. Most of the solid waste is sent to authorized and unauthorized dumpsites for disposal which is creating environment and health issues. There are several dumpsites which are located in the midst of residential areas or close to catchment areas of private and public drinking water bodies.

Solid waste management scenario in Oman is marked by lack of collection and disposal facilities, as well as lack of public awareness about waste in the country. Solid waste, industrial waste, e-wastes etc are deposited in very large number of landfills scattered across the country. Oman has around 350 landfills/dumpsites which are managed by municipalities. In addition, there are numerous unauthorized dumpsites in Oman where all sorts of wastes are recklessly dumped.

Al Amerat Sanitary Landfill

Al Amerat landfill is the first engineered sanitary landfill in Oman which began its operations in early 2011. The landfill site, spread over an area of 9.6 hectares, consists of 5 cells with a total capacity of 10 million m3 of solid waste and spread over an area of over 9.6 hectares. Each cell has 16 shafts to take care of leachate (contaminated wastewater).

All the shafts are interconnected, and will help in moving leachate to the leachate pump. The project is part of the government’s initiatives to tackle solid waste in a scientific and environment-friendly manner. Being the first of its kind, Al Amerat sanitary landfill is expected to be an example for the future solid waste management projects in the country.

The Way Forward

Solid waste management is among the top priorities of Oman government which has chalked out a robust strategy to resolve waste management problem in the Sultanate. The country is striving to establish 16 engineered landfills, 65 waste transfer stations and 4 waste treatment plants in different parts of the country.

Modern solid waste management facilities are under planning in several wilayat, especially Muscat and Salalah. The new landfills will eventually pave the way for closure of authorized and unauthorized garbage dumps around the country. However investments totaling Omani Rial 2.5 billion are required to put this waste management strategy into place. Oman is also seriously exploring waste-to-energy as a tool to manage garbage in a sustainable manner.