Collection, Compression, and Sequestration of Plastic Waste
A solution to the global crisis in food packaging management
Plastic pollution is a serious and rapidly growing global environmental threat with potential implications for human health. In much of the world, mismanaged municipal solid waste levels are high, resulting in considerable levels of open dumping and burning. Globally, plastic recycling is hindered by low collection rates, high costs, and an inability to handle most resin types, laminates, mixed streams or contamination. A wide variety of chemical recycling technologies and novel biomaterials are being developed but are still experimental and years away from utilisation at a meaningful scale. The transition to a fully functioning circular economy for plastic packaging waste will likely take several years and will have to overcome strong opposition from industry.
Thus, there is an immediate need for a stopgap solution to the environmental plastic waste crisis; one that can effectively scale quickly and widely, and without pushback from governments, industry or the public. We believe such a solution exists.
- Citizens around the globe are paid a bounty to collect non-recyclable plastic film and packaging waste from their own households and the local environment.
- The waste is brought to dedicated landfills for plastic, heat-compressed into interlocking blocks and sequestered on-site, either permanently or re-introduced into the economy at a later date as chemical or energy feedstock.
- The incentivization (bounty) is through the introduction of a novel universal coupon, redeemable at, and continuously circulating among environmentally-committed businesses and citizens willing to accept it.
- For example, a citizen delivers 5 kg of unrecyclable film waste and receives a 5 kg coupon, which is redeemed for a 5% discount at a merchant, who then uses it to buy stock from a supplier, who passes it on to reward a staff member, who gifts it to a friend, who uses it at a merchant…
- The coupons themselves are polymer (i.e. not digital), similar to bank notes. The unit is the kilogram, and the value is set by any retailer willing to accept them.They have no expiry date and cannot be cashed out for legal tender.
- The coupons can also be purchased, with the money raised providing the incentivization for collectors in places (such as emerging markets) where a cash system may be more effective.
- Resistance will be minimal as interests are aligned for all the main actors, including governments, Big Oil, manufacturers, retailers, consumers, and waste workers. Participation is voluntary, without contractual obligations of any kind.
- The system can have an immediate impact, scale quickly, and be easily adjusted as externalities become known.
- Expected global outcomes include reductions in: marine plastic pollution, air pollution, landfill stress, urban flooding, vector-borne disease, and poverty.
The Global Plastics Problem
Globally, 464 million tonnes (MT) of plastic were produced in 2018, of which 50% was used once (mostly as food and beverage packaging) and then immediately discarded, with serious repercussions for the natural environment. In 2016 an estimated 19–23 MT of plastic waste entered the aquatic environment (1). Economic losses in marine ecosystem services alone are thought to be USD 500 billion to 2.5 trillion annually (2). The implications for human health are unknown at present but likely not trivial. Mismanaged plastic waste creates air pollution and CO2 when burned, and can degrade in the open environment to form the greenhouse gases methane and ethylene (3). It is a major contributor to urban flooding (via blocked drainage and irrigation canals), and to the persistence of vector-borne diseases such as malaria and dengue (due to increased standing water).
A recent model (1) suggests we are presently on pace to emit 62 MT of plastic waste into the aquatic environment annually by 2030, and that an extraordinary effort would be required to get down to the (still dangerous) 2010 level of marine-bound plastic (8 MT / y). Since the majority of plastic waste consists of single-use food and beverage packaging, the useful life of many products is short compared to their environmental persistence, resulting in increasing interest in creating a circular economy for plastic (4,5). This new thinking focuses on elimination of unnecessary products and the re-design of useful ones; the development of reusable, recyclable, biodegradable, and compostable products; and the circulation of all plastic within the economy.
However at present we are far from realising a truly circular economy in plastic and it’s unclear how realistic such a goal is in the near term. Only PET and some polyethylene are recycled to any great extent today (representing 9% and 37% of all plastics manufactured) and only about 1% of the remaining waste is recovered at all. At present, global recycling rates are low: 14% of packaging waste is collected for recycling (of which 4% is lost, 8% is processed to lower value products, and only 2% by closed-loop recycling). The remaining plastic packaging waste is incinerated (14%), consigned to landfill (40%), or dumped into the open environment (32%). Bioplastics such as poly-lactic acid (PLA) break down very slowly under natural conditions and would require significant farmland to produce at scale: for example, 11% of global arable land would be needed for 400 MT of plastic production (6). Chemical recycling technologies, plasma pyrolysis, plasma gasification and pyrolysis with in-line reforming show great promise but are very energy intensive, and are mostly still experimental (7).
Through some combination of consumer behavioural change, innovative packaging design, novel biomaterials, improved waste-to- energy and chemical recycling technology, and Extended Producer Responsibility beyond lip service, a day will come when we are much closer to a truly circular economy for plastic. That day however may be 10–20 years down the road. In the meantime, global plastic production is increasing 3.5–3.8% per year; investment in plastics infrastructure is rising ($203 billion in the USA since 2010); aquatic plastic pollution is increasing by 19–23 MT per year; and municipal solid waste generation is rising rapidly in the very countries where the majority of mismanaged plastic waste is generated; countries with poor solid waste management infrastructure and weak regulatory regimes with neither the funds nor political will to undertake the rapid improvements urgently needed.
Clearly a stopgap is required while technology, awareness and political will catch up to an expanding plastic pollution crisis.
A New Approach
We propose putting a bounty on difficult-to-recycle plastic film waste (bags, pouches, multi-laminates, food packaging), which will be collected, heat-compressed into blocks and subsequently stored in a network of resource depots (plastics-only landfills) distributed locally. A modest premium for thin film plastic waste would incentivise citizens to undertake proper waste separation at home, as well as reduce visible litter in their local communities. The blocks can be safely sequestered permanently, diverting significant tonnage from landfills, eliminating the potential for leakage to the environment, and preventing the illicit export of plastic waste as “recyclables” to other countries where it can cause significant morbidity to local populations. Alternatively, the blocks can be mined out at any time in the future when appropriate (clean, energy-efficient) technologies become available that can utilise them as chemical or energy feedstock.
Regional depots can be set up on small parcels of land in or near urban areas. The footprint required to service (100%) film waste collection for 100,000 residents for 10 years is 102 x 102 x 5 meters. Compared to traditional landfills, a plastics depot should have significantly less associated traffic-related noise and pollution, (only 14.3 cubic meters of waste delivered per day), and negligible leachate, odour, vermin, and fire issues (pending testing). In addition, the formation of microplastics will be minimized. All waste plastic (landfilled or not) degrades at varying rates into micro- and nanoplastic particles due to natural processes (wind, water, UV radiation) resulting in high levels of soil and groundwater contamination (microplastics, heavy metals, plasticizers) around dumps and landfills where leachate is untreated (i.e. most of them)(8) . The depots described here are composed of tightly integrated solid blocks that are impermeable to gas and liquids. Compressing film waste into block form reduces exposed surface area by several thousand fold, greatly reducing the potential for microplastics and leachate formation. For example, 1 cubic meter of interlocking blocks has a surface area of 6 square meters, but may contain 100,000 grocery bags with a total surface area of 54,760 square meters.
Once full, a depot can be expanded, relocated, or reintegrated into the urban environment in which it sits (parkland, sports fields). However, we expect that in the mid-term (5–15 years) effective recycling technologies will become available allowing the resource to be re-incorporated into the manufacturing economy, facilitating the continuous use of the depot in perpetuity.
A more ambitious system envisions an extensive network of mini-depots with a footprint of 12 x 12 x 3.6 meters each, servicing a local neighbourhood of 1000 residents. Such mini-depots can be turned into EcoParks, functioning as collection, processing and storage points for the local neighbourhood. They can provide a block-making appliance, storage space, and be a social hub for the exchange of resources and information on sustainable living for each community. If permanent sequestration is desired, each EcoPark can accommodate 365 tonnes of plastic; equivalent to 10 years storage at 100 g per person per day.
In the case of Toronto (population density 4334 / km2), 4 such mini-depots would be needed per square kilometre, facilitating easy access (walking distance) for the majority of residents, and providing storage space for 985,000 tonnes collected over 10 years. This would significantly contribute to the City’s Waste Strategy goal of 70% landfill diversion (150,000 tonnes per year) for residential waste by 2026 (9).
The depot system does not affect regular waste collection or recycling practices, and thus can function at any scale from niche (one neighbourhood) to city-wide. Due to its technical and conceptual simplicity, low implementation cost, and rapid set-up the system can very quickly be expanded to cover whole municipalities. However, it should be noted that the system is not reliant on government-run regional depots or an EcoPark network at all. Private citizens, civic organisations, rotary clubs and religious groups can purchase their own block-making device and set up depots on private property.
The system can work in any municipality in the world, but with some key differences (incentivization scheme, collection mechanism) depending on local municipal waste management quality, poverty levels, and climate, as described below.
High Income Countries (HIC’s)
In municipalities with high standards of living, good waste management, and high levels of environmental awareness, our system asks interested citizens to separate out their unrecyclable household plastic film waste and carry it down to the neighbourhood EcoPark (perhaps once a month) where they can exchange it for a universal coupon (described below). Each park may also provide (on a volunteer basis) various resources on sustainable living as determined by community needs (e.g. seminars, workshops, tool library, used goods exchange, repair kiosks). The waste is processed on site into interlocking blocks and either given back to the citizen (for storage in their own home depots), or stored (underground or warehoused) at the EcoPark itself. The blocks can easily be moved to other storage sites, sold off as feedstock, or sequestered permanently in situ. The depot can be any size, expanded or shrunk at will, closed down and reincorporated into the urban environment, or completely mined out at any time in the future. The coupon (which we have dubbed ES) will be used to incentivise plastic waste collectors, EcoPark staff, and privately established depots. It will be redeemable at participating businesses truly committed to environmental protection or merely interested in leveraging PR and marketing opportunities. Unlike traditional coupons or shopping/mileage points cards ES will circulate continuously among any establishments or citizens willing to accept it for any product or service rendered.
The benefits of such a distributed, dedicated (plastics-only) depot network include:
- reduction of plastic leakage into the local environment;
- prevention of illicit international exportation of waste;
- reduced strain on landfill and waste collection infrastructure;
- availability of an easily mined, energy dense resource (80–85% carbon by weight);
- safe, compact and permanent carbon storage (if not re-integrated into the economy);
- increased waste separation at the household level;
- high accessibility to information and resources on sustainable living;
- more responsibility given to waste generators (consumers);
- ability to start small (1 park), identify and fix inefficiencies, and improve while scaling up;
- technical simplicity; can be set up quickly and cheaply at any scale;
- no impact on standard recycling and waste collection procedures for other materials;
- can also be used for contaminated recyclables rejected at transfer stations (30% of Blue Box contents currently rejected in Toronto).
If larger, regional depots are preferred, it may be more efficient for standard waste collection procedures to continue as is, and have transfer stations separate out all the unrecylable and contaminated waste for compression into blocks. Such a system maintains most of the benefits listed above.
One of the most significant benefits of our system is the prevention of low-value waste exportation, legal or otherwise, to places with poor waste management infrastructure. In Canada in 2016, 4.67 million tonnes (MT) of plastic was introduced into the economy and 3.27 MT of waste plastic was generated, 1% of which (29,000 T) ended up as environmental pollution (litter), 4% incinerated for energy recovery, 9% recycled and 86% landfilled (9,10). Thus at a global level Canada (and the OECD in general) does not seem to be a major contributor to the plastic crisis. However in 2018 China stopped taking on the bulk of the world’s plastic waste (dropping from 50% of globally exported waste to 1%), and ever since, recyclers everywhere have been overwhelmed with unsold product piling up in their facilities. Much of this waste is making its way (often illegally) to processors in South and South-East Asia where, after the valuable bits have been removed, the remainder is burned or dumped locally, causing widespread distress, respiratory disease, and livestock and crop damage. The main offenders include Germany, the UK, Australia, the USA, and Canada (11,12). Our system facilitates local sequestration of plastic waste in HIC’s, precluding its illegal export to places with inadequate waste management.
Low and Middle Income Countries (LMIC’s)
A more impactful way that interested citizens in HIC’s can participate in our system is by purchasing ES coupons directly. The revenue raised will be used to support the establishment of the system in our target countries; areas with concomitant poor waste management and high levels of poverty. In effect, by buying ES, rich-country consumers will be paying for (or forcing corporations to pay for) environmental remediation in poorer places while alleviating poverty at the same time. While a coupon system may work well in many parts of LMIC’s, cash incentivization may be more useful for areas with high levels of poverty.
Our initial target countries include 5 of the top 8 global sources of marine plastic pollution. (Table 1, Fig 1,2). Indonesia is the second biggest source of marine plastic pollution (after China), emitting about 1.3 MT per year, or 10% of the global total. While the country is now part of the upper middle income group, it continues to struggle with effective municipal waste management due to a lack of funding, a high level of mismanaged waste (83%), and weakly enforced regulations. Here is how our system might look on the island of Lombok, Nusa Tenggara Barat, Indonesia (a potential pilot location we are looking at).
We propose paying a bounty of 2,500 Indonesian rupiah ($0.18 USD) per kilogram of any plastic film waste, and processing it into blocks stored in a local depot. We expect interested citizens to not only separate their household waste, but to pick up any visible (and accessible) waste in local streets, beaches, illegal dumps, and irrigation canals. In addition, we will hire workers (initially recruiting them from the population of informal waste pickers) to collect from households on a fixed weekly schedule. We will pay these collectors 1500 IRp / kg and the household 1000 IRp / kg to incentivise both groups.
The typical collector in Mataram (the provincial capital) would visit 24 households a day covering 1.3 hectares with a pushcart (Fig 3), collecting 61 kilograms. By collecting on foot, accessibility is greatly improved (especially in informal settlements) as municipal waste collection vehicles can’t access areas with narrow (or no) roads. The collectors would earn about 6 times the national poverty-line wage. It should be noted that the national poverty line for Indonesia is unusual in that it varies by region, but is generally much lower than the international standard. For example the national level in the relatively poor eastern province of Nusa Tenggara Barat is $0.94 USD per person per day. At this level, 17% of the population fell below the poverty line in 2018. However if we use the common international standard ($3.10 USD), 45% of the population were considered poor. In Mataram our collectors will earn twice the international level. In our scenario, total cost of collection on Lombok is $6.43 USD per capita per year for the sequestration of 128,000 tonnes of plastic waste. Employment will be provided for 7050 collectors. (See Table 2 for the data, sources and assumptions used).
Notwithstanding the high levels of poverty and plastic pollution, Lombok (the island on which Mataram sits) is poised for a massive tourist boom as the government has recently declared it one of 4 super-priority tourism destinations (Jakarta Post). Thus environmental remediation here (and in many similar islands throughout the tropics) can have outsized economic impact.
Similar to HIC’s, the blocks can be stored or reintegrated into the economy as seen fit. However for places with non-sanitary landfills (i.e. open dumps) situated close to human settlements, we recommend that the blocks be used for barrier walls. This would protect against landslides, increase dump capacity, and provide a visual/odour/vermin barrier for the surrounding settlements (Fig 4,5). In addition, the blocks can be used for flood protection walls around residences (Fig 6,7), or even low lying parts of islands.
At some point as new uses (structural or as feedstock) are found for the blocks it may be possible to reduce or even remove the bounty as local market mechanisms will ensure the continuation of the system. This will free up resources for expansion into other regions similarly burdened with poor waste management and high levels of poverty.
Local benefits (in addition to those noted for HIC’s) include:
Reduced Environmental Plastic
- improved tourism potential
- reduced blockage in urban drains (less flooding)
- fewer standing water traps (fewer mosquitoes reduces vector-borne disease)
- improved local aesthetics
- improved health of fisheries, coral reefs
- reduced damage to shipping
- reduced air pollution (less incineration of waste)
- waste management at pollution source
- near 100% collection possible
- re-deployment of informal waste pickers to formal economy (safer, higher salary, better social integration)
- improved awareness and use of waste banks (recycling centers) for recyclables
Blocks as Construction Material
- development of new products, markets and entrepreneurial ecosystem
- housing improvements: flooring, flood protection walls
- property fences, sheds, animal pens, walkways
- river bank protection (erosion, flood control)
- landfill barrier (increased vertical capacity, waste avalanche protection, vermin control)
- sea walls
ES: The Universal Coupon
A new type of universal coupon will be introduced to incentivise waste separation at the household level in HIC’s, and to generate funds (via direct sales) for environmental remediation in the target countries (LMIC’s). While thousands of alternative currencies have come and gone over the years (including mileage and loyalty cards), our ES will have a unique collection of features not found in any other.
The main distinguishing features are:
- It isn’t local. ES can be used over a wide geographical, multinational expanse at any establishment or by any person willing to accept it.
- There is no demurrage (negative interest). ES maintains its value permanently. The value itself is solely determined by any retailer, service provider or citizen willing to accept it.
- It is not officially exchangeable with fiat currencies and thus can never be cashed out.
- The unit is the kilogram, representing sequestered plastic and emotionally connecting the user to environmental remediation.
- It isn’t virtual. High quality polymer bank note technology will be used to create notes similar to Canadian dollars, with robust anti-counterfeit measures and tear resistance. Notes are also washable in soapy water.
- Because the notes must be physically exchanged, they can only be used for in-person transactions. This will have the effect of stimulating local economies, especially small businesses, farmers markets and other in-person services. Keeping transactions non-web based will prevent the siphoning-off of community wealth and protects consumer privacy.
A New Economy
As ES starts accumulating among the public and as awareness of the system spreads, a network of businesses and citizens willing to accept the currency for goods and services rendered will grow organically. By accepting ES at some level, brands in the consumer goods sector will compete for market share by positioning themselves as responsible corporate citizens. By using ES, shoppers can maintain their present consumption levels guilt-free, as they pass on some of the cost of pollution to companies. Such companies will naturally find clever ways to reduce their financial exposure while taking full advantage of the marketing opportunity available.
In addition to simply raising prices, retailers could decide to accept ES
- only during non-peak times
- only on selected goods (slow-moving products, last year’s fashions)
- to a maximum level per purchase (e.g. 10%)
- only on designated days
- only in designated shops
- only to a maximum annual limit (e.g. 0.01% of sales)
- only for purchase of a book of traditional coupons for their branded products
Our system requires no government regulations, industry promises or contracts of any kind. Any entity is free to accept or reject participation at their discretion, and is free to set their own conditions of usage. While completely voluntary, we expect significant corporate buy-in due to increasing public pressure and awareness, and due to the availability of significant marketing opportunities to enhance (and in some cases rehabilitate) corporate image.
- The value of the note is set by each retailer.
- ES can replace some existing sales, coupons, and introductory offers.
- Unlike coupons and loyalty points ES can be recycled by using it to pay suppliers, give staff bonuses, or reward regular customers.
- ES can be used to soak up unused capacity for live events or shows. For example a half-empty cinema can accept ES once the movie has started. Marginal cost to the venue is zero.
- Governments can accept ES for taxes, fines, entrance fees to parks and galleries, continuing education, public transportation.
From the perspective of the consumer our system provides:
- an easy way to participate in environmental remediation without altering shopping behavior;
- a way to make corporations pay for cleanup and global poverty reduction;
- a strong psychological benefit.
This last point is speculative, but when we consider that mere possession of an ES 5 kg note represents 5 kg of plastic waste that will never harm the environment (assuming permanent sequestration) either by clogging the oceans or by contributing to global warming, we can imagine the thoughtful consumer experiencing deep satisfaction. The satisfaction is doubled when the note is foisted on a corporation. Since ES can only be created by the physical sequestration of environmental plastic waste, it is essentially born in virtue. In addition to feeling good about protecting the environment and making corporations pay for it, ES users will also be aware of their contribution to global poverty alleviation.
Our system can function on a micro scale; a handful of neighbours cleaning up the local beach and being rewarded by the local ice-cream shop. While it may very well remain niche, there is potential for massive and rapid scaling to a global level. Once a critical mass of ES is circulating, major corporations will start to see the advantages of being an early adopter as they are feeling increasing consumer pressure to be more proactive regarding their environmental footprint. They will also fear being out-competed by their peers. A virtuous marketing spiral may result, bringing added attention to the system, drawing in competitors and spreading throughout the consumer goods sector: big box stores, supermarkets, fashion, electronics, cosmetics, luxury goods, cars; every brand with an image to maintain and market share to protect.
The ameliorative effect on poverty can be considerable. The areas that generate the most plastic pollution are often the areas of highest poverty. By providing cash directly to targeted groups for the remediation of their local environment (and by extension, the total environment), we all win.
Published Nov 13, 2020
copyright Michael T. MacKay
OTHER ESSAYS IN THIS SERIES
The Ocean Cleanup: Barking Up the Wrong Tree
The Heat-Compressed Blocks
Ideally, only low-to-zero value thin film plastic waste will be used, including bags, pouches, sachets, and food wrappers. Any type (mixed resins, laminates) or physical condition (residue contamination, UV degradation, biofilm, salt, paper labels, adhesives, dyes) should be tolerated to a relatively high degree. The block maker will rely on simple hand compression and induction heating, require little electricity and produce little waste. It will be robust, portable, cheap to manufacture, and made available at cost (or free) to any interested party.
A family can set up a home depot in the yard, garage, basement or any available space of about a square meter. The figure on the left illustrates a depot of dimensions 1.05 x 1.12 x 1.8 meters, which can accommodate 10 years of plastic waste (1460 kg) for a family of 4, at 100 g per person per day.
Mixed Plastic Compressed Disc
The calculations in this essay assume a block density of 0.7 g/cc. Simple bench-top testing has yielded densities of around 0.78 g/cc. A variety of food packaging and bags were heated at 250 degrees C for 15 minutes and then hand-compressed, resulting in the 1 cm thick discs below.
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Fig 1: Manila Waterway, https://www.straitstimes.com/asia/se-asia/plastic-wasteland-asias-ocean-pollution-crisis
Fig 2: Citarum River Java, https://designyoutrust.com/2014/02/the-most-polluted-river-in-the-world/
Fig 3: Waste Collector, https://www.bennettpics.com/asia/indonesia/bali-recycling/
Fig 4: Waste Avalanche, https://www.dailymail.co.uk/news/article-2032012/Garbage-landslide-Five-people-missing-rubbish-floods-city-dump-site-walls-collapse-Typhoon-Nanmadol.html?ito=feeds-newsxml
Fig 5: Dump Barrier Wall, www.strataindia.com/Vapi_GreenEnvo_Casestudy.html
Fig 7: Flood Protection Wall, https://www.researchgate.net/publication/276905679_Mobile_Flood_Protection_Walls