Part 1: Fuel and Feedstock Resource Recovery - Energy Carriers from Waste

In our previous articles entitled Waste-to-Wealth Initiatives – Aerobic and Anaerobic digestion waste projects¹ we stated that we would consider fuel and feedstock² in the next article in the Waste-to-Wealth Initiatives Series, including to address the importance of understanding composition and quantity of fuel and feedstock for the purposes of councils and municipalities contracting for, and increasingly, the private sector, developing, resource recovery projects.

Since the publication of the articles on Aerobic and Anaerobic digestion, there has been a healthy increase in debate and engagement on waste
policy, in particular on how to address certain plastics.³ The debate about plastics needs to be placed in the context of waste generally, and waste in the context of greenhouse gas (GHG)⁴ production.⁵ In doing so, we continue to illustrate that the macro issues in relation to resource recovery correlate directly with the micro issues for each resource recovery project, specifically projects that derive or produce fuel and feedstock. In this context, the United Nations estimates that through sustainable waste management practices, it should be possible to reduce 15% to 20% of anthropogenic GHG emissions. As with many facts and statistics, this estimate captures the attention. Placing plastics in this context, it is estimated that the life cycle of plastics accounts for 3.8% of anthropogenic GHG emissions. As such, responding to certain plastics as a part of sustainable waste management practices could make a material difference over time. Also, progress on plastics may be regarded as easier to achieve than progress on other waste management practices. It is important that plastics are viewed holistically as plastics are part and parcel of our daily lives. Not all plastics are “at large” in oceans, waterways, or buried in landfills, many of them are to be found in our homes and workplaces.

In this article we consider fuel and feedstock that can be derived from waste, rather than waste that is used as a fuel or feedstock. As such, this article does not cover the use of fuel or feedstock to fire waste-to-energy/energy from waste projects. Until relatively recently, “waste-to-energy” and “energy from waste” have been used interchangeably to refer to projects that use waste delivered directly from collection (or possibly via a transfer station) as fuel or feedstock to generate electricity or to produce heat, or both. Increasingly, the phrase “energy from waste” (or EfW) is being used by policy makers to refer to and include the processing and treatment of waste to derive or to produce materials (energy carriers) that can themselves be used as fuel or feedstock. Energy carriers include gas (biogas⁶ and synthetic gas⁷), liquid fuel and feedstock (including from refining of dry organics) and solid fuel (for example, biomass and PEF, RDF and SRF). In the lexicon of some policy makers waste to energy has become a subset of energy from waste. For the purposes of this article, we do not conflate wasteto- energy and energy from waste, rather we consider the derivation and production of energy carriers, which are themselves fuel or feedstock, in contrast to the use of waste as fuel or feedstock.⁸ Given the breadth of the current debate, particularly as it relates to plastics, the co-authors decided to make this a two-part article.

Part 1 of this article covers:

• in section 2.2, the continued importance (some may say the increased importance) of effective policy for deriving and producing energy carriers, and more broadly to increase resource recovery;
• in sections 2.3 to 2.6, the feedstock that may be used to derive or produce fuel and feedstock from waste (including the means of derivation and production to achieve a closed loop); and
• in section 3, the key commercial and legal issues in the derivation and production of energy carriers, including the Four Cs.⁹

Part 2 of this article will cover the means of deriving and producing energy carriers (critically the technologies that are used), including the technologies used for each feedstock, and the commercial and legal issues that arise in respect of each feedstock. In doing so, we will consider Fuel Crops, which are crops grown specifically as fuel or feedstock. The co-authors will consider the convergence of technologies, including those to derive/produce hydrogen from waste and include comparison to the refining industry.

Also Part 2 of this article includes details of the means used to recycle plastics, typically shredding to create shredded plastics or granules, which are dried and then melted with the resulting molten plastics separated, higher value to lower value.¹⁰ We will also consider plastics in detail: certain plastics do more harm, have lower life cycles, release methane more readily than others and/or have little or no value; some plastic bags fit all of these characteristics and, perhaps surprisingly, so do “compostable plastics” arising in a region without access to the necessary industrial recycling facilities.¹¹ In addition, some plastics are difficult to recycle and have lower values. For example, rigid plastics including those containing calcite, which may add rigidity to the plastic but subtracts from value (because calcite affects recyclability). Part 2 of this article looks at these issues in more detail and, taking our theme of macro to micro, the types of technologies that need to be used in resource recovery projects to achieve the sought for policy outcomes.

While the “facts and stats” about plastics can be sobering, and, for some, resulting in a conclusion that it is all too hard, the awareness and debate about plastics is starting to have a positive effect: in 2019 Finland re-cycled plastics within two to three times the rate of 2018, and large consumer products corporations (such as Nestle) are acting to respond on plastics.

1. Outline of this Article

With the increased debate around waste policy, certain plastics have come to the fore in discussion.¹² The frame within which resource recovery from waste is considered has consequentially become clearer and more concise: certain plastics pollute waterways and oceans¹³ and, depending on the environment in which they are disposed, release carbon dioxide and methane as they degrade.¹⁴ The production of plastics depletes hydrocarbons in an energy-intensive process¹⁵ which generates GHGs. Disposing of plastics to landfill contributes over time to the release of landfill gas (LFG)¹⁶ emissions (although not to the same extent as putrescible waste because the degradation of plastics takes considerably longer): it is important to understand that landfilling plastics does not constitute the creation of a “carbon sink” for plastics as may be implied and as some have asserted.

Furthermore, as plastics degrade, depending on the environment and their chemical composition, they can leach into groundwater and soil as a result of comprising part of the leachate from landfill.¹⁷ Part 2 of this article will consider plastics (including compostable plastics) and resulting micro-plastics.¹⁸ This said, while the increased awareness of plastics is good, we need to continue to increase awareness on climate change. Plastics contribute around 3.8% of anthropogenic GHGs, we need to continue to have regard to the other 96.2% of anthropogenic GHGs.

While the fuller narrative is more nuanced, this understanding frames how policy may (and should) develop. While market solutions may be preferred, they cannot be relied upon. In particular they cannot be relied upon to place value on the collection and recovery of waste (including plastics): our experience informs our perspective, which is that market solutions arise within a policy framework that places value on and maximises resource collection and recovery. This framework should consider how to reduce, and over time how to avoid, producing plastics that cannot be, or will not be, recycled, thereby maximising collection and recovery (and therefore processing and treating) of recyclable plastics. Importantly, any reduction or avoidance of plastics production must occur in the context of their being replaced by a sustainable alternative, being an alternative that is both sustainable environmentally and affordable.

This will allow more plastics to be recycled, processed and treated before or at the “end of life” to derive or produce products which will, in turn, reduce hydrocarbon depletion and encourage movement towards alternatives to plastics with improved recyclability. Ultimately, though the move to any sustainable alternative is the likely policy outcome, this outcome must be balanced with the need to abate GHG production.¹⁹ Similar policy issues arise with all waste streams, not just plastics. There is however a balance to be struck; the private sector is developing new uses for recycled plastics, including for use in structural building products (to displace steel and timber) and for use in the motorvehicle industry. The investments made by the private sector to increase levels of recycling need to be encouraged, in particular if the net effect is a reduction in hydrocarbon use and GHG production.

Helpfully, the debate about waste policy is increasingly being framed in balanced terms across the resource recovery sector generally, including with regard to the need to achieve closed loops²⁰ (within circular economies)²¹ and higher order waste management hierarchy outcomes, characterised by a movement towards “zero waste” policy outcomes.²² It is important, however, to have in mind that no matter how efficient resource recovery becomes, there will always remain residual material from resource recovery, and as such there will always be a need to dispose of that residual material. Applying the logic of the waste management hierarchy, residual material should be treated using a waste-to-energy facility (WtE Facility), rather than being disposed of to landfill.

Increased granularity in this debate facilitates more informed decision-making, including to increase awareness of the need for balanced policy so as to achieve the policy trifecta: first, to reduce and to avoid waste over time; second, to achieve resource recovery and the derivation or production of products in a manner that avoids or minimises the production of GHGs; and third in all stages (production, collection, processing and treatment, and disposal) to maximise resource recovery and avoid or minimise adverse environmental and health and safety impacts.

2. Overview of Fuel and Feedstock From Waste

2.1 Waste as fuel and waste as feedstock for the derivation/production of fuel and feedstock

Deriving and producing fuel and feedstock from waste continues to be an area in which progress is made, both in terms of increased activity and technology options.

Figure 1 summarises at a high level the key types of primary waste from which fuel and feedstock may be derived and produced. In this context we are considering the fuel and feedstock that can be produced from waste when it is processed (i.e. the products produced after processes in a facility). This is distinct from the use of waste as the primary fuel or feedstock used for the purposes of waste-to-energy projects.

It appears to us that progress has been accelerating and is likely to continue with increased understanding of the waste streams from which energy can be recovered and from which fuel and feedstock can be derived and produced, and the implications of doing so. One reason for this progress is the ever-increasing awareness of the actual and potential adverse impacts of waste production, collection, processing and treatment. However, the key reason for this progress is the development and implementation of policy, including in the form of grants, subsidies and tax incentives, and landfill/waste levies (and other means of ensuring that the costs of disposal, rather than resource recovery, are imposed and calibrated), as well as policies that give value to different parts of the waste stream.

2.2 Facts and statistics: a starting point

How much plastic is out there?

Some information contains compelling facts and statistics. For example, it is estimated that more than 8 billion metric tonnes of plastics have been produced, and that more than 6.2 billion metric tonnes of plastics have been thrown away. These are estimates, and given current facts and statistics on the rates of current production of plastics, it may transpire that these are underestimates and the co-authors suspect this to be the case: the current best estimate appears to be that around 0.3 billion metric tonnes of plastic are produced each year, and that the rate of production is increasing. What should be clear however is that the best part of 2 billion metric tonnes of plastics remain in use, including in our homes and workplaces, motor vehicles, and so on. There is more certainty as to current plastic production. This is a good thing, because it is possible to capture these plastics.

The issue is how to capture and to control the life cycle of plastics (both existing and those to be produced), not the production of plastics as such. It is estimated by The World Economic Forum that around 30% of plastics “leak” from collection and recovery systems in the sense that they are unaccounted for, and as such may be assumed to be at large in the environment or landfilled. Given the level of resource recovery of plastics, we suspect this figure may be higher.

Some plastics are more likely to leak than others. It is estimated that 1 million plastic bottles are purchased every minute. Coca-Cola makes 200,000 bottles every minute.²³ A key issue is how many of these bottles are collected and recovered for recycling and having been recovered how many are made from recycled plastic (and in due course how many of the bottles made from recycled plastics, will themselves be recycled). An estimated 24.2 billion pairs of shoes were made in 2018, a fair proportion of them manufactured from plastics. An estimated 1 billion tooth brushes were thrown away in the United States in 2019.²⁴ These are examples of every day products made from plastic that are difficult to re-cycle, and in respect of which over time sustainable alternatives, and respect of which there is no current waste management system solution to re-cycle.

It is estimated that between 9% and 9.5% of all plastics produced have been recycled. This estimate appears to be reflected in some current statistics, with less than 10% of plastic bottles being currently recovered as a resource for recycling. In jurisdictions with developed waste collection and management systems, the levels for recovery of plastics for recycling can be within the 10% to 15% range.²⁵ Even in jurisdictions in continental Europe with the most developed waste collection systems, the rate of collection/recovery of plastics hovers around the 30% mark.

Perspective is needed

Some compelling facts and statistics need further analysis to avoid overstatement, in particular the contribution of plastics producers to GHGs. This analysis is important to ensure that policy is calibrated appropriately. Critically, there is also a need to concentrate on “difficult” plastics, particularly those used in food packaging (and packaging generally), coloured plastics and hard plastics.

This is not a petrochemical industry issue it involves all industries.

Close to home, plastics is an issue for the food industry (agricultural farming, wholesale and retail), and consumer goods industry, specifically it is an issue that goes to the balance each industry seeks to achieve - to be environmentally responsible and to deliver food/consumer goods at a price and of a quality acceptable to consumers. Of particular focus in seeking to achieve this balance is the relevance of packaging to the plastics debate. While there is increased consumer awareness, ultimately the use of containers and packaging is a choice and cost issue, at its most basic, whether consumers will pay for alternatives. The introduction of and access to sustainable alternatives requires the support of policy to require or to incentivise payment for them. Furthermore, it is a not a simple substitution in any instance. For example, replacing plastics with aluminium or glass for beverages and drinks is not as simple a solution at it may appear, because aluminium cans and glass bottles are both energy intensive, in production and transportation. As we note above, there is a need for balance, and over time this is a renewable and sustainable solution.

It is important to note that the building and construction, and the motor vehicle and IT industries as large users of plastics have a key role to play in the use of plastics that can be recycled, and in some ways the motor vehicle and IT industries may have a residual value role to play in the context of the recycling of vehicles and IT hardware produced by industry participants. 

Policy and the Waste Management Hierarchy

The Waste Management Hierarchy suggests that we move toward avoiding the production of plastics. This requires time, although in some jurisdictions such a move is underpinned by law in respect of some plastics. For example, the phasing out of single use plastics (being plastics that are used once before disposal by the user).²⁶ Also, it is important that policy does not result in all plastics being used as feedstock to derive or to produce energy carriers: again applying the logic of the Waste Management Hierarchy, ideally, policy will result in the production of plastics being avoided, as sustainable (and as such affordable) alternatives to plastics are developed over time. Plastics will continue to be produced and ideally policy will promote maximisation of recycling and reuse prior to being used as feedstock to derive or to produce energy carriers. 

Plastics at large in the environment

While many facts are compelling, they do not of themselves allow us to understand the quantity of plastics that may be recovered from the environment (including oceans and waterways) and, following recovery, the quantity of that plastic that may be processed and treated.

For example, it is estimated that the mass of the “Great Pacific Garbage Patch”, being the mass of plastic floating in the Pacific Ocean (covering an area estimated to be twice the size of Texas), is around 87,000 metric tonnes. This mass is less than is required as feedstock each year for some energy carrier resource recovery projects to produce liquid fuel from plastic²⁷.

In contrast, Unilever²⁸ produces 700,000 metric tonnes of new plastics a year. If Unilever increases its use of plastics derived from recycled plastics and is able to create a closed loop of all its plastics, we move to a policy framework that may be described as “capturing the life cycle of plastics”.

This is not to say that the plastic constituting the Great Pacific Garbage Patch (and other plastic pollution) should not be recovered. It should be. Of the 300 million metric tonnes of plastic is produced each year, it is estimated that between 8 to 15 million metric tonnes of plastic finds its way into waterways (and some ultimately into oceans), with the majority of this comprising plastic containers and packaging. But the recovery of plastics from waterways and the oceans, it a small (albeit important) part of the broader capture of plastics²⁹.

The role of policy and the market

It is logical to conclude from these facts that policies are needed to increase the collection and recovery rates for plastics so that this does not eventuate. The recovery of plastics from our oceans and waterways must be an effort driven by policy makers to limit further environmental harm, as the market is not well positioned to address this issue. By seeking to “capture the life cycle of plastics”, policy makers will also recapture the material value of plastics which is lost to the economy after their first use.

This framework will allow market solutions to develop in the form of recycling facilities and facilities to produce liquid fuels as captive plastics reach the optimal point in their life cycle. But this framework does not ensure that all plastics that are collected and recovered will be delivered for recycling or to produce liquid fuels. As yet, legal and policy frameworks are not sufficiently developed in any jurisdiction to ensure that all plastics collected and recovered are delivered for recycling or the production of liquid fuels³⁰. Some jurisdictions have policies to increase collection and recovery rates. Policies of this kind need to be “bookended” with legal and policy frameworks that ensure that plastics that are collected and recovered remain captive, rather than being delivered into landfill.

If the challenges identified with plastics are to be addressed, it is apparent from the above that two distinct steps are required:

• first, the recovery and collection of plastics from our waterways and oceans to address environmental and public health, safety and welfare concerns, and
• secondly, “capturing the life cycle of plastics” to ensure that plastics do not find their way into our waterways and oceans and are not delivered to landfill, so as to create a closed loop for plastics.

In addition to “capturing the life cycle of plastics” (and ensuring that plastics remain captive), ideally the policies to achieve this will give value (which is both an absolute and relative issue) that will be recognised by the market so as to encourage:

• the delivery of plastics to recycling facilities or liquid fuel producers (to realise the benefits of scale); and
• the derivation and production of products, including liquid fuel produced from plastics,

which will, in turn, increase the rate of collection and recovery of plastics by the market.

The increasing debate promotes discussion about a broad range of policies. In addition to policies that give value to encourage outcomes, polices are being suggested that require the manufacturers and the major users of plastics to be directly responsible for the life cycle of the plastics that they sell, or to be indirectly responsible through the payment of a levy to fund the collection and recovery of plastics and subsequent recycling of those plastics. Others have enlivened the idea of imposing fines and penalties on those that frustrate collection and recovery, from households to commercial and industrial enterprises.

Each jurisdiction has its own circumstances, but as a general statement, “giving value”³¹ will lead to market solutions, and the market will extract and maximise value. Over time and given the right signals, the market will develop alternatives to plastic.³²

2.3 Resource Recovery

It is possible to assess waste arising and resource recovery in a number of ways. We have chosen to assess these matters in the context of an urban environment (section 2.4) and non-urban environment (section 2.5).

In doing so, we seek to emphasize the importance of transportation, both for processing and treatment and then onto market. Transportation is both a cost issue and a GHG issue. 

2.4 Waste arising in urban setting

(a) The urban ore body

As we stated in the first article in this series (entitled Waste Projects), “waste provides a resource that can be “mined”³³ and otherwise used to avoid or to reduce contamination and emissions – effectively “an urban ore body””. But what does this mean in practice? In the context of an increasing population and urbanisation (and increased disposable income and consumption), urban populations give rise to large amounts of waste of different kinds. In jurisdictions that have reached peak urbanisation and which possess more developed waste collection systems, the proportion of the waste arising that is collected and recovered is generally highest. Collection and recovery of waste allows it to be processed and treated.³⁴ 

The greater the level of collection and recovery of waste, the greater the opportunity to process and treat waste to achieve the desired policy outcomes, including Zero Waste outcomes. The quality of what is collected (and its level of contamination of it) is key. The segregation/separation at source is also key: experience has shown that the greater the value ascribed to plastics (and containers generally) the greater the level of collection, and the higher the quality of the plastics (and containers) collected. If the waste collected and recovered is disposed of to landfill, to the extent that the waste comprises organic material that material will decompose, and as it decomposes will give rise to fugitive LFG emissions (comprising predominately carbon dioxide and methane, the principal GHGs). These emissions will escape to the atmosphere and, depending on the engineering of the landfill and the geology on which it is located, leachate may contaminate soils and groundwater. To the extent that the waste delivered to landfill contains plastics, these plastics will break down over time and will release methane. While increasingly effective systems have been developed to capture LFG from landfill, even the most advanced systems do not recover the majority of LFG produced, and as such in most instances considerably more than half of the LFG is released as fugitive emissions contributing to GHG emissions.

There are many means to ensure collected and recovered waste is reused and recycled or, where this is not possible (including where plastics have reached the end of their life cycle), treated and processed to derive useful products. For example, if the waste collected is organic and therefore not capable of reuse or recycling, it can be treated to derive other products including gas³⁵ or mixed organic material. Other types of waste not capable of reuse or recycling can be treated, for example, thermally in a WtE Facility. The resulting bottom ash can be used as a base for road and construction materials and the fly ash can be used in construction materials, including to increase the performance of concrete. 

(b) Categories of waste in urban environments

(i) What are the waste streams?

A number of waste streams arise in urban environments, principally municipal solid waste (MSW),³⁶ commercial and industrial waste (C&I Waste)³⁷ and construction and demolition waste (C&D Waste).³⁸ Each waste stream has a different composition and different fractions of waste within it. Depending on the country in which the waste arises, typically MSW is often the smallest proportion of the waste arising, next C&I Waste, with C&D Waste making up to two thirds of waste (and in some countries more) arising (by mass) in some countries.
It is estimated that globally between 7 to 10 billion metric tonnes of MSW, C&I Waste and C&D Waste arises each year, with by far the greatest percentage by mass being C&D Waste.³⁹ In Part 2 of this article, we will take a more detailed look at a number of jurisdictions to consider the fractions of waste arising, and how this correlates to the technologies used in that jurisdiction.

The processing and treatment of these three categories of waste is critical. Of the other categories of waste arising in urbanised areas, Events Waste⁴⁰ and Green Waste⁴¹ can be processed and treated using technologies used to recover resources from MSW and C&I Waste. 

E-Waste⁴² is increasingly being addressed through prescribed processes and treatment. Of the jurisdictions collecting and recovering e-Waste, the quantities being collected and recovered are increasing. This said, only around 20% to 22% of e-waste is being collected and recovered. By 2021, a projected 52 million metric tonnes of e-waste will be generated globally each year.⁴³

Within MSW and C&I Waste, there will also be Food Cycle Waste,⁴⁴ principally from the preparation and consumption of food (giving rise to Food Organics).⁴⁵ Food Organics contains a wet/wetter organic fraction comprising organic matter that is predominantly derived from the preparation and consumption of food, which may be used as feedstock for production of biogas⁴⁶ (using anaerobic digestion (AD) technology), but given the risk of contamination it may be regarded as unlikely that MSW and C&I Waste that is not predominantly organic will be used as a source of feedstock for AD. 

(ii) Energy from urban waste streams

The production of biogas is more likely from a single source of biomass,⁴⁷ although sometimes from multiple sources (called codigestion) ⁴⁸ that are not derived from MSW or C&I Waste. This said, C&I Waste comprising a separated wet organic waste stream may offer opportunities for the production of biogas. Garden Waste⁴⁹ (a sub-set of Green Waste) may be comprised in MSW or separated at source (in the “green bin”). Garden Organics comprise a dry/drier organic fraction which may be used as feedstock for production of compost or mixed organic material,⁵⁰ which may be used as feedstock for compost⁵¹ or blended to produce solid fuel. MSW and C&I Waste will also contain recyclables⁵² including card, paper, textiles and wood, and plastics. 

Depending on the quality of the feedstock, solid fuel may be produced. Solid fuel includes refuse derived fuel (RDF),⁵³ process engineered fuel (PEF),⁵⁴ and solid recovered fuel or specific recovered fuel (SRF).⁵⁵ RDF tends to describe a lower calorific value solid fuel (that is not processed) that may be used as a substitute for, or may be blended with, coal. PEF and SRF tend to be used to describe a higher calorific value solid fuel that have been processed to produce such calorific value and in some instances well defined specifications, including as to calorific value, chlorine content, ash and moisture content, and particle size, for use in cement kilns. 

Within MSW, C&I Waste and C&D Waste there is likely to be a dry organic fraction comprising timber and wood. Increasingly, this organic fraction is being considered as a possible source of feedstock for the production of syngas from which liquid fuel may be derived, and projects are being developed for this purpose. At the moment there is a limited number of jurisdictions in which production of fuels and feedstock from timber and wood may be regarded as viable, being jurisdictions in which policy incentives reward this production, and allow the relatively high levels of capital investment to earn an appropriate rate of return. This said, we are aware of a number of corporates considering use of timber and wood residue to derive feedstock. Given that this dry organic fraction is within existing waste streams, depending on the waste stream, integration into a dirty/wet MRF or a dry MRF may be required to extract this fraction, C&D Plants may recover wood waste. While there are established technologies to derive syngas and liquid fuel from waste, those technologies are able to progress
to full commercialisation in jurisdictions with appropriate policy settings. 

There will also be a plastic fraction within MSW, C&I Waste and C&D Waste. In developed waste management systems, recyclables (including plastics) may be separated at source by households and individual businesses or otherwise at a sorting facility. If waste is separated at source, the plastics collected and recovered may be recycled mechanically to produce feedstock to derive recycled plastics, or may be treated chemically to derive liquid fuel or liquid feedstock, for example, synthetic crudes (syncrudes) that can be used for the production hydrocarbon products, including new plastics, and heavier hydrocarbon derived products. If there is no separation at source, plastics will be found in the MSW, C&I Waste, and C&D Waste. MTs and MBTs (with dirty/wet MRFs) are able to sort plastics. C&D Plants are able to recover the plastics (typically conduits and pipes, but also fittings). 

(iii) Waste arising in urban environments and WtE Facilities

MSW and C&I Waste are the primary fuel source/feedstock for many thermal treatment WtE projects, and increasingly the dry organics from C&D Plants provide feedstock for wood waste projects, which we considered in detail in an earlier article in the series (entitled Waste-to-energy Projects).

WtE projects are able to process and to treat the broadest range of waste arising in an urban environment. In the context of the increasing global population and increasing urbanisation, WtE projects may be regarded as offering a relatively cost-effective means of addressing adverse outcomes and avoiding uncontrolled GHG emissions.

In the context of the Waste Management Hierarchy, there is a balance to be struck between resource recovery and the use of WtE projects. This gives rise to a number of issues, including cost and affordability of other resource recovery projects when compared to WtE projects, which can be more cost-effective. In some jurisdictions, WtE projects may be preferred to landfill for the disposal of residual material discarded by other resource recovery technologies, or the disposal of materials from which it is not possible or cost-effective to recover resources.

(c) Municipal Solid Waste

By 2025, it is estimated that between 2.2 billion metric tonnes and 2.4 billion metric tonnes of MSW will arise globally each year (or between approximately 6 million metric tonnes and 6.6 million metric tonnes a day).⁵⁶

It is also helpful to understand and to reflect that it is estimated that the world will not reach the peak urbanisation and as such peak MSW arising until the twenty-second century. Given experience gained in developing waste collection systems, the ability to separate at source, and the ever increasing range of technologies available to recycle, process and treat MSW means that well before the twenty-second century, it is likely that we will be able to achieve policy objectives such as Zero Waste on a consistent basis. Our assessment is that with increasing urbanisation globally, the most pressing need is for the increased and effective collection and recovery of MSW.

Effective collection and resource recovery requires effective, and ever improving, waste management systems. It is estimated (conservatively we suspect) that currently, in respect of 2 billion people worldwide, there is no waste management system at all and, in respect of 3 billion people, that there are no effective controlled waste facilities.

The absence of sufficient waste facilities is not an abstract concept. In Lebanon in 2015, the management of MSW reached crisis point, with waste collection being suspended and waste not collected (and piling up) around the Beirut and Mount Lebanon region because of the closure of the Naameh landfill. Although the Naameh landfill was established in 1997 as a temporary waste solution, it reached capacity prior to its closure in 2015 and a long term controlled waste facility or other solution was not developed in the interim. An ineffective waste management system continues to plague Lebanon, with a similar situation arising in northern Lebanon in 2019 with the closure of the unregulated Aadoueh dumping site and citizens resorting to burning waste to control overflows, despite the enactment of a national law in October 2018 prohibiting the practice. 

(d) Commercial and Industrial Waste⁵⁷

In the context of the increased disposable income and consumption attendant on increased urbanisation, the quantities of C&I Waste arising are increasing. For the purposes of comparison with MSW, in many jurisdictions C&I Waste gives rise to a higher proportion of waste than MSW in the urban environment. 

Commercial and industrial enterprises produce waste (often in environments in which it is possible to control the collection and recovery of waste) and consume directly and indirectly recycled products (and energy carriers). Given these factors, commercial and industrial enterprises have an increasingly critical role to play in the collection and recovery of waste, and deriving value from resources recovered from that waste.

From a policy (and practical) perspective, commercial and industrial enterprises are probably best placed to put in place and to implement best practice collection and recovery waste management systems to increase collection and recovery rates, and as importantly to pass on to consumers the costs of implementing those best practices. This will lead to the creation of closed loops (including through the use of recycled products). Commercial and industrial enterprises are well placed to impose contractual obligations on contractors that collect and deliver waste to ensure that the waste is not delivered to landfill, including by imposing obligations to trace and to verify the use to which the recovered resources are put. If these costs are passed on to all consumers, they will be negligible for each consumer. 

In the context of the production of energy carriers, the dry organic and non-recyclable plastic fractions of C&I Waste (and possibly C&D Waste) may provide feedstock for the production of solid fuel (in the case of dry organics) and liquid fuel and feedstock (in the case of dry organics and plastics).

(e) Construction and Demolition Waste

With increased urbanisation the demand for extractive resources (from quarrying and mining) continues to grow. In some jurisdictions there are shortages of construction materials and the costs of transportation is high given the mass of these materials (and attendant GHG creation). In this context, the market has  provided construction and demolition recycling plants, to allow recycling of C&D Waste.

In most instances, C&D recycling plants are located close to the demand for the recovered resources to address (at least in part) the transportation cost issue. From an environmental perspective, effective recycling of C&D Waste (in the urban setting) avoids or reduces the risk of run-off into natural water courses and waterways and into storm water systems. In countries prone to flooding, this is a public health, safety and welfare issue. 

Given that C&D Waste is recoverable and is predominantly dry and has value, increased levels of recycling and reuse are both achievable and sustainable. The challenge is the cost of
transportation to the point of recycling, and from the point of recycling to the point of reuse, in comparison to the cost of sourcing new extractive resources and the transportation of them to the point of use. As with C&I Waste, the producers of C&D Waste are more often than not consumers of the recycled products. Policy makers are able to incentivise the use of recycled products in a number of ways and mandate use of recycled resources through building laws and regulations. When governments or government corporations and enterprises are procuring the construction of infrastructure including bridges, roads and tunnels, they are able directly to influence the development of the C&D Waste recycling industry, as they do with local and national content requirements on procurements.

In the context of the production of energy carriers, the organic fraction of C&D Waste (timber and wood) may be recovered to provide feedstock to produce liquid fuel (from the production of syngas) it may be combined with other higher calorific material to produce solid fuel. The plastic fraction of C&D Waste may be recovered to provide feedstock for chemical processing to derive liquid fuel or feedstock. 

(f) Wastewater

Wastewater is a phrase describing water used in the home, business or in an industrial process, and, in an urban area, stormwater collection and management. In urban areas, the effective collection and management of Wastewater is a critical environmental and public health issue, with the need to treat used water and sewage. In respect of sewage, the effective
treatment of bio-solids allows the capture of biogas (and avoid the release of methane and carbon dioxide), manage pollution, and avoid and manage the risk to public health, safety and welfare. There is a number of similarities between Water Projects and Waste Projects. In future InfraRead articles, Michael Harrison and Richard Guit will explain the key commercial and legal issues arising from Water Projects, including Wastewater Projects.

2.5 Non-urban ore body

(a) Resources to be recovered

While there are towns and some cities in agricultural, farming and forestry areas, and each of MSW, C&I Waste and C&D Waste arises, these three categories of waste may not arise in quantities large enough to encourage the market and provide solutions as are available in urban areas. Depending on the size of these communities and distances between them, transportation costs may also be such that the unit costs consolidating the quantities of waste arising for processing and treatment is not affordable or sustainable without policy to provide the necessary funding or gap funding. In the context of C&D Waste, the level of construction and demolition activity in non-urban areas is substantially less, and the nature of that activity different, such that it is most unlikely that the market will provide a solution in the form of a C&D Waste recycling plant.

As with urban areas, Food Waste and Green Waste arises, although not on the same scale as in urban areas. It follows that a market solution in an urban area may not work in a non-urban area, and vice versa.

Non-urban areas in which agricultural, farming and forestry activities are undertaken grow biomass, and produce biomass as waste from those activities. Biomass is a word used in many contexts.⁵⁸ In the context of resource recovery, biomass refers to organic matter that has become waste, and on recovery may be used as feedstock for processing and treatment to produce compost using aerobic digestion technology, to produce biogas using anaerobic digestion technology to process biomass in its wetter form (and possibly to produce bio-fertiliser from the digestate), and for some forms of biomass in their dry (or drier form) to use it as feedstock for biomass to energy projects (BtE) (which feedstock includes residue from forestry and husbandry activities and from the production of certain crops, for example, bagasse from sugar cane production) and possibly in dry (or drier) form as feedstock for pyrolysis⁵⁹ to produce liquid fuel.

As a general statement (and without wishing to oversimplify), for the purposes of recovering gas, liquid and solid fuels and feedstock from biomass, it is helpful to understand that biomass can be categorised as lignocellulosic⁶⁰ organic material and nonlignocellulosic⁶¹ organic material.

In Figure 4, the italicised biomass comprises predominantly lignocellulosic organic material, the non-italicised biomass comprises predominantly non-lignocellulosic organic material.

Wet/wetter biomass is not suitable as the principal feedstock for BtE (to generate electricity). Dry biomass (that is lignocellulosic) is suitable for BtE and may provide feedstock for
the productionof syngas.

Certain non-lignocellulosic material provides some of the highest methane yielding feedstock for anaerobic digestion (AD), and as such is an ideal feedstock for the production of biogas. The feedstock⁶², and the AD technology used to process that feedstock, will affect the quantity of biogas derived from the organic material used as the feedstock, and the methane content of the biogas. Although, generally, non-lignocellulosic material does not provide an appropriate feedstock for the production of syngas.

(b) Categories of waste arising

In non-urban areas, the principal categories of waste arising are Agricultural and Farming Waste, Forestry Residue, Food Waste and Green Waste

Agricultural and Farming Waste describes all biomass arising from agricultural and farming activities. Figure 4 below describes what may be regarded as the predominant sources of biomass: there are others and we will consider them in further detail in Part 2 of this article.

Agricultural and Farming Waste provides a “non-urban resource body” for the derivation of biogas and bio-fertiliser using wet/wetter organic material that is predominantly nonlignocellulosic material, and dry/drier material as a source of solid fuel for BtE projects. Using dry organic material that is predominantly lignoceollulosic may provide feedstock for the production of liquid feedstock to be further refined to produce bio-diesel/bio-fuel.

Forestry Residue describes waste arising from forestry, typically comprising the organic material removed from trees as they are forested (including bark and branches, tree stumps, and in some nstances, sawdust). Forestry Residue is a source of solid fuel for BtE projects and as a possible feedstock for the production of liquid feedstock for further refining to produce bio-diesel/bio-fuel. 

(c) Fuel Crops

For the purposes of Part 1 of this article, we do not consider Fuel Crops, being crops that are grown for the purpose of the production of fuel or feedstock. For example, the production of
bio-fuel, principally bio-ethanol (using such crops as cassava, corn, potato and sugarcane). Part 2 of this article will consider Fuel Crops, the technologies used to the produce them and the associated commercial and legal issues. 

2.6 Non-recyclable/Non-renewable waste

There are some organic and inorganic materials that cannot be recycled, and from which it is not possible to derive or to produce energy carriers from waste. For the purposes of this article, we have not addressed Chemical Waste, Medical Waste (waste arising from medical and pharmaceutical activities), Mega Waste (waste arising from breaking of mega structures, including oil rigs and vessels), Mining and Quarrying Waste (waste arising from extractive industries, both from extraction and from processing) or Nuclear (Radioactive) Waste (waste arising from nuclear power plants and nuclear processing, and testing, facilities). This is because these waste streams are not suitable for the derivation or production of fuel or feedstock. The overriding policy outcome in respect of these waste streams is the safe collection, processing and treatment and disposal or storage of them so as to avoid environmental harm and any adverse impact on public health, safety and welfare. As such, the collection, processing and treatment and disposal or storage of these waste streams is
heavily regulated in many jurisdictions. 

3. Key Commercial and Legal issues

(a) Background

In this section 3, we introduce the key commercial and legal issues that need to be assessed and addressed in the context of recover projects producing fuel and feedstock. We will address these in greater detail in Part 2 of this article.

As noted previously, assuming that collection and recovery has occurred, the key issues in the context of any resource recovery project are the Four Cs: Compatibility, Contamination, Composition and Capacity.⁶⁵ Before considering the development or developing any resource recovery project to derive/produce fuel or feedstock, Collection (and the resulting recovery) needs to be considered as does Community Engagement (and the resulting social license) – the Pre-Decision Considerations.

(b) Key Issues

• Quality of waste as fuel/feedstock: The Composition of the fuel/feedstock will be key to Compatibility for the resource recovery technology and, as such, the Capacity of the resource recovery facility to process and treat waste to derive/produce gaseous, liquid or solid fuel or feedstock. Also, the level of Contamination67 contained or likely to be contained in the waste needs to be understood, as does its impact on the resource recovery technology, and on the quality of the fuel or feedstock derived or produced.
• Quantity of waste collected/recovered: The quantity of waste arising within the catchment area of resource recovery facility is critical, both to understanding the likely use of Capacity (if all waste rising within that catchment area is to the delivered) and also how much more waste may be available for collection and recovery. In the context of resource recovery projects to derive/produce fuel and feedstock, this is likely to be a risk that the resource recovery project takes.
• Quality and Quantity of waste: Quality and Quantity come together in the context of the Capacity of the resource recovery facility (including whether it achieves the required performance characteristics and tests) and the quantity of fuel and feedstock that may be derived/produced (Output). Output is one half of the revenue equation, the other half is the price that the market is prepared to pay for the fuel or feedstock. The price of biogas and syngas (used a fuel, not feedstock) will be a function of the cost of substitute fuels, and may be priced to reflect fluctuations in substitute fuels. The price of syngas used as feedstock for further refining and the liquid fuel derived/ produced will be a function of the world prices for those liquid fuels. The price of solid fuel/feedstock will be a function of its use: if the solid fuel is to fire a BtE facility or is blended to produce RDF, PEF or SRF, the price will tend to be fixed (by reference to an existing off-takers). If the solid feedstock is to be used as a feedstock to produce liquid fuel, the price will reflect the world prices for the fuel to be produced.
• Cost Certainty – Delivery Solution: This issue is not unique to resource recovery projects, nor is the criticality of the technology. Many technology providers are not comfortable with or suited to undertaking the role of EPC contractor: technology providers will not provide an EPC solution, and an EPC contractor will not provide a risk adjusted price that is workable on the basis that it will take technology risk. As such, both have to take responsibility for the design and build interfaces working. This is a critical area for the management of the capital cost and performance of each resource recovery facility, particularly in respect of resource recovery facilities that are using technologies sensitive to Composition and Contamination, and that are using established technologies but in a new or relatively new combination.
• Cost of Collection/Recovery (including transportation costs): This is both a front end issue (the cost of collection/recovery and delivery to the resource recovery facility) and a back end issue (the cost of delivery of derived fuel and feedstock to customer/market, and the cost of transportation and disposal of material that is not Compatible or that is Contaminated and of residue material following processing and treatment). There are variables in respect of all of these costs (including escalating collection and recovery costs and variable fuel costs).
• Cost Certainty – Operation and Maintenance: This issue is not unique to resource recovery projects. In the context of any resource recovery facility it is more likely than not that the risk of cost and performance will rest with the project sponsors (at least outside proven cost and performance parameters), unless the EPC contractor, or a related entity of it, is the O&M contractor. In addition to the project sponsors assuming cost and performance risk, if an O&M contractor is retained even within proven cost and performance parameters, the O&M contractor will not agree to be liable on an open-ended basis for escalating costs or for damages and losses incurred by the project sponsors for breach of contract.
• Costs of off-takers from resource recovery facility: Depending on the off-taker of the gaseous, liquid or solid fuel or feedstock derived or produced by a resource recovery facility, it is possible that the off-takers may incur costs (short, medium or long-term costs) as a result of the quality of the fuel or feedstock. While resource recovery projects will seek to avoid or to limit liability for the consequences of delivering offspecification or out of specification fuel or feedstock, it is possible that it will not be possible to do so, and liquid feedstock refiners will deal specifically with the consequences of off-specification or out of specification fuel or feedstock, both by price adjustment and recovery of increased costs.
• Change in law risk: As will be apparent from all of the Ashurst Waste to Wealth articles, change in law is a key commercial and legal risk. A change in law is able to undermine a resource recovery project if some or all of the resource recovered cannot be marketed or, in order to be capable of being marketed, must be subject to further or new processing and treatment. If a resource recovery project is being paid for the acceptance and processing and treatment of waste, risk of change in law may be something that it is able to pass to its customer or customer through an increase in the gate fee/waste processing fee. If a resource recovery project, is a merchant project its ability to pass on the cost consequences of Change in Law is a function of the elasticity of price changes.
• Market change/disruption risk: The regulatory changes introduced by the Peoples’ Republic of China in late 2017 have demonstrated that market change and disruption can occur as a result of a regulatory change in another jurisdiction. Prior to late 2017, China provided value for recyclables not offered by any other jurisdiction. Many jurisdictions were therefore able to avoid the need to introduce policies to give value to recyclables. After late 2017 there has been disruption to the global market for recyclables, and dislocation of collection and recovery of recyclables as a result. In this context, the increasingly healthy debate around policy may be regarded as having been fuelled by that disruption.
• Feedstock change and technology change/disruption risk: Over time it is likely that changes in law and perspectives will result in the decreased production of plastics. This does not seem to be a short or medium term issue, but in the longer term there may be less plastic available as fuel or feedstock. The medium to long term future of energy businesses (including oil and gas companies) is likely to involve the production of hydrogen which, depending on the feedstock, is renewable. In this context, resource recovery projects that derive or produce fuel or feedstock from renewable resources (and in so doing serve an environmental and public health, safety and welfare function and GHG abatement function) may be regarded as less susceptible to risk of feedstock change and technology change. 

Conclusion

The healthy increase in debate around plastics has resulted in an invigorated policy debate about resource recovery (and GHGs), much of which is helpful and informed. To the public and resource recovery industry professionals alike, we appear to be at a point of inflection – the fulcrum of a tipping point if you will. In the context of certain plastics, for policy makers there is an ever increasing range of solutions, and for councils and municipalities an apparently wide range of technologies on offer, and to choose from.

In this context, a balance must be maintained between addressing plastics (by increasing levels of collection/recovery (and recycling), encouraging avoidance and reducing production over time) while also ensuring the continued reduction and abatement of GHGs in the context of reduction over time of the production of plastics.

In the context of waste management practices generally, we see a golden opportunity for policy makers, councils and municipalities and the private sector to come together to maximise resource recovery by achieving the benefits of scale by combining and colocating to develop facilities and plants that in combination offer multiple solutions. This is particularly the case in larger urban areas.

In Part 2 of this article we will consider the broad range of policies and technologies being used and considered, but also we will provide a sense of realism and responsibility that needs to prevail to collect and to process waste so as to maximise resource recovery, while seeking over time to reduce waste arising.

The co-authors would like to thank Francesca Arciuli and Charlotte Britton for their keen editing skills.

1. One of these articles was general, the other article was Queensland specific. The aerobic and anaerobic articles were published in June and January 2019 respectively.

2. In the context of resource recovery, waste provides a feedstock for the derivation and production of fuel (in the case of fuel that can be used without further processing or treatment) or feedstock which following initial processing and treatment will require further refining to derive or to produce fuel. For example, the use of dry organics as feedstock to produce a crude liquid fuel that is then subject to refining to derive differing hydrocarbon fractions.

3. In the Ashurst article Waste-to-Wealth Initiatives – Have We Reached a Tipping Point, we stated that a tipping point had been reached in respect of certain plastics – specifically single use plastics. In this context, we noted that the onus rests on policy makers to formulate policies to avoid waste arising, and to maximise resource recovery from waste arising. Ideally, the increased debate will result in policy better suited to achieving these outcomes. Both parts of this article, continue this theme.

4. Greenhouse gases (GHGs) are those gases in the atmosphere that absorb thermal radiation emitted from the surface of the earth, and through absorption of that thermal radiation lead to an increase in the temperature of the atmosphere (not the earth), hence the use of the phrase “global warming”. The most prevalent GHG is water vapour (approximately 0.4% of the atmosphere). Water vapour is not increasing at a dramatic rate (as is the case with other GHGs, and as such does not have the same global warming impact as other GHGs.)
Ozone is a potent GHG, but like water vapour, it is not increasing at a dramatic rate (rather the debate focuses on too little ozone). What may be regarded as the principal GHGs and their estimated contribution to global warming and global warming potential (based on the measurement of CO2e, being one metric tonne of carbon dioxide equivalent), are set out below:

5. The production of materials that become waste and the recycling of that waste (including to derive/produce fuel and feedstock), does not produce at many GHGs as transportation, but the production of GHGs is significant.

6. Biogas is a gas comprised predominantly methane and carbon dioxide, which is produced by the anaerobic digestion, or putrefaction, of organic matter.

7. Synthetic Gas or Syngas is a gas comprising of predominantly carbon monoxide and hydrogen produced from conversion from waste as a result of thermal processing.

8. In the Ashurst article Waste-to-Wealth Initiatives – Waste-to-energy projects, we covered waste-to-energy projects in detail, including the waste streams used as fuel.

9. The Four Cs is a term coined by Ashurst in 2018 in the context of key aspects of each resource recovery project: Compatibility, Contamination, Composition and Capacity. These concepts are considered in more detail in the Waste-to-Wealth Initiatives articles, “Have we reached a tipping point?” and the two “Aerobic and Anaerobic digestion waste projects” articles. In 2019, Ashurst coined the concept of two additional Considerations (or Two Additional Cs): Collection and Community Engagement to achieve social license.

10. Briefly, plastics can be: recycled mechanically following collection/recovery (involving cleaning, sorting, shredding and pelletising), with the pelletised plastics used to make recycled plastics or processed and treated chemically to derive a liquid fuel, or more likely a liquid feedstock (as an energy carrier), for refining and blending with other hydrocarbon derived products to produce fuel.

11. Many plastics badged as “compostable” break down only in industrial composters, that maintain the required conditions for decomposition (i.e. heat). Compostable plastics which are made from or include bio-plastic components, including polylactic acid (PLA), are often relegated to the “red” bin (general waste being MSW) in the absence of necessary industrial facilities and will be destined for landfill. If plastics containing PLA find their way into waterways and oceans, they will contribute to plastic pollution as PLA does not degrade in sea water. Compostable plastics will be considered further in Part 2 of this article.

12. This debate has included the quantity of plastics that remain in the environment, including in our oceans and waterways, and as such the quantity of plastics that are not collected or recovered for recycling, and whether the production of liquid fuel from plastics provides a means to address these issues.

13. In addition to what policy makers have had to say about plastics, key opinion formers in business are adding thought leadership and action to addressing the issue of plastics. For example, Andrew Forrest (Chair of Fortescue Metals Limited, one of the world’s largest producers of iron ore) has provided detailed thought leadership as to how policy may be introduced to give value to plastics. The result of giving value to plastic will be an increased level of collection and recovery, and increased levels of recycling and ultimately recovery of energy carriers from waste. The co-authors agree with the need to give value to plastics.

14. When exposed to heat including sunlight, plastics degrade and release methane, although the amount released and rate of production depends on the type and age of the plastic. For example, a study showed that virgin low-density polyethylene (LDPE) exposed to sunlight emits 500 nmol g-1 over a 212-day incubation period with production rates increasing over time, while aged LDPE emits 700 nmol g-1 over the same period at a relatively steady rate. While this amount of methane is relatively small, the scale of certain plastic production supports increased resource recovery and the environmental agenda to address marine plastic pollution.

15. The production of new plastics requires the production (extraction, processing and treatment) of hydrocarbons, transportation of hydrocarbons, and the production of the plastic from those hydrocarbons.

16. LFG is gas produced from the putrefaction of organic matter disposed of to landfill. LFG contains biogas, ammonia and sulphides (including H2S).

17. As plastics degrade and react with material in landfill, carbon dioxide (in the presence of oxygen) and methane is released (albeit not in great quantities). The extent of this release depends on the environment in which the plastics are degrading. Plastics also leach chemicals contained within them as they degrade, including chlorine, phthalates and Bisphenol A (BPA), harmful to animal and human health and likely to pollute soil and groundwater. We note that the European Commission has recommended banning oxo-degradable plastics because of the concern of the degradation into micro-plastics.

18. Micro-plastics and nano-plastics arise from many sources (including unsuspected sources such as cosmetics and from washing clothing (otherwise known as microfibres)) and the degradation of plastic materials over time. Micro-plastics are pieces of plastic less than 5mm long, and may be that size before entering the environment or otherwise break down to that size after entering the environment. Nanoplastics are plastics ranging from 1 to 100 nm and arise from the degradation of plastics in their manufacture and use, and as they age. These find their way into the environment in many ways. In the context of waste disposal and resource recovery, micro-plastics and nanoplastics arise from waste disposed of to landfill and also arise from the application of sludge (after treatment in a wastewater facility) to agricultural land as fertilizer.

19. Large producers of plastic bottles (such as Coca-Cola) are moving towards increased recycling of plastics as a step towards sustainable alternatives to plastics. This does not mean that there will be a switch to the production of aluminium cans or glass, because this is more GHG-intensive than the recycling of plastics.

20. In the context of closed loops, a progressive move towards the production of plastics that do not have adverse impacts on the environment and welfare, health and safety should be the policy objective. If this is not achievable on a sustainable basis, policy can appropriately encourage or prescribe avoidance of waste, in the context of promoting the production of sustainable alternatives to those plastics.

21. The concept of a circular economy (in contrast to a linear economy) is an economy in which waste that arises is collected and recovered and processed and treated to maximize resource recovery so that the collected and recovered resources can be recycled and reused for as long as possible. At the moment, we may be regarded as some distance from achieving circular economies. There is no “one size fits all” blue print for a circular economy, but the key is increasing the quantity of resources collected and recovered, and formulating policies that send the right messages and “give value” to resource collection and recovery so that they are collected and recovered: for example, container deposit schemes. As rates of collection and recovery increase, the quantity of waste available for processing and treatment at resource recovery projects increases, including the recovery of fuel and feedstock from waste. With this increase, the scale of resource recovery projects will increase and as such the unit costs of recovery will decrease. 

22. While many jurisdictions have had Zero Waste objectives for a number of years, after the publication by the United Nations of the 17 Sustainable Development Goals in 2015 (as part of the 2030 Agenda for Sustainable Development), there has been a marked increase in the number of jurisdictions developing plans that allow implementation of Zero Waste. The term Zero Waste is used in two contexts: (1) principally, zero waste diverted to landfill (although this needs to be viewed by the percentage of waste collected and resources recovered from the waste collected); and (2) increasingly, moving to an economy that is circular. Others use the term as shorthand for avoiding the production of waste.

23. Coca-Cola (like other major users of plastics) is committed to increasing its use of recycled plastics to make plastic bottles.

24. It is said that the vast majority of the toothbrushes made since the 1930’s remain at large in the environment, principally in landfill.

25. In Australia it is estimated that between 12% and 15% of plastics are recycled. In Canada it is estimated that between 9% and 11% of
plastics are recycled. By comparison, in 2016 the EU recycled 30% of its plastic waste (while 31% was landfilled and 39% subject to thermal treatment). As ever, one has to look beyond raw numbers in any jurisdiction to understand what percentage of the plastics are recyclable or can be used to derive and to produce energy carriers from waste, because if there is no market/value for the particular plastic, the market will not recover it. This returns to the central and continuing theme that policy is required to place value on the collection and recovery of plastic and the products that can be derived or produced from it.

26. The single use plastic which policy makers are taking action to phase out are lightweight plastic bags, which are often made from resourceintensive low-density polyethylene (LDPE) plastic. Countries which have banned or imposed taxes/charges on the sale of lightweight plastic bags in an effort to phase out use include Afghanistan, Bangladesh, Cambodia, Cameroon, Chile, Denmark, France, Italy and South Korea. Other countries including Australia, Argentina, Brazil and Indonesia have regional policies (some of which prohibit sales) in certain states and provinces. Enforcement remains an issue in many jurisdictions and the banning of the production and import of lightweight plastic bags is therefore important.

27. By some estimates, by 2050 we will have produced approximately 50 billion tonnes of plastic. Given the estimates of plastics produced so far, and the estimated plastic production each year, if this figure is correct we would appear to have been underestimating the mass of plastics produced so far, and predicting an acceleration in the rate of plastics production in the 30 years to 2050.

28. The United Kingdom’s largest food producer and one of the largest consumer pharmaceutical products companies.

29. For those seeking to reconcile the estimated mass of plastics comprising the Great Pacific Garbage Patch, and the quantity of plastics entering the oceans each year, some of our plastics would appear to be “missing plastics”: it is estimated that approximately 1% of plastics remain on the surface, rather they sink and decompose, and are likely to be ingested by marine life. This said, by some estimates, up to 90% of plastics remain within a 100 kilometre zone off shore, and in many instances is closer, and as such there is an opportunity to capture it.

30. In many jurisdictions, recyclables collected and recovered (including in jurisdictions in which container deposit schemes provide for payment for the collection and recovery of plastics (and other recyclables) to increase collection and recovery rates) are not delivered to recycling facilities or to facilities for the production of liquid fuels.

31. Value can be given by the introduction of policy, for example, a container deposit scheme giving value to containers that are collected, imposing a levy on the manufacturers/producers of containers that is recoupable on the collection and recycling of them, and imposing a levy on the retailers of containers which is recovered by the person that collects, recycles and tracks them.

32. Being options that use less non-renewable energy to produce plastics, and that are sourced from renewable resources.

33. In this context, we do not mean the mining of an established landfill for waste, rather we mean the collection of waste and resource recovery from it.

34. This does not mean that waste that is collected and recovered is processed and treated. As noted below, plastics may be delivered to landfill, including by the private sector seeking to maximise net revenue. In addition, there are examples of jurisdictions in which plastics are delivered to landfill because councils/municipalities have chosen to do this or have been forced to do so. For example, in the disarray that has affected the plastics market since late 2017 (and the broader recycling market), councils and municipalities in some jurisdictions have delivered recyclables to landfill. This is an interim measure while policy makers consider how best to create or to recalibrate policy.

35. And if the process is continued to produce fertiliser or compost conversion of nitrogen in its unstable form as ammonia into a stable form: chemically nitrogen in fertiliser or compost is stable and as such released slowly.

36. MSW or municipal solid waste, is waste arising from the general public and consists of reusable, recyclable, organic, incompatible, contaminated and other fractions. We discussed MSW in detail in the first article the Waste to Wealth series, entitled Waste Projects.

37. C&I Waste is used to describe waste arising from commercial and industrial activities. Depending on the composition of C&I Waste, the dry organic fraction may be used as feedstock for pyrolysis to produce syngas, to be combusted for the purposes of a waste-to-energy project or to be separated (by refining technology) to produce liquid fuel. C&I Waste may be used as feedstock for waste-to-energy projects, in particular mass combustion (in particular using moving grate technologies).

38. C&D Waste comprises a varied range of material (from organic and inorganic sources), including bricks and rubble (comprising stones for the most part, including granite, marble, and sandstone, cement (including in cement plaster), cinder blocks, concrete, gypsum, glass, metals (copper and steel predominantly), plastics, clay, rock, sand and soil (principally from excavation during construction), steel, conduits and pipes (including iron/steel and plastic) and electrical fittings (including plastics and non-ferrous metals).

39. From research that we have undertaken, it seems likely that the quantity is higher than this because of the quantity of C&D waste appears understated.

40. Events Waste is a phrase used to describe waste arising from entertainment and public events, including music concerts and festivals, demonstrations and parades, and sporting events. Events Waste comprises predominantly recyclables (which will be collected and sent to a dry MRF) and Food Organics (which can be collected and sent to an MT or MBT facility to produce mixed organic output, or to a waste to energy facility). The Food Organics fraction of Events Waste may provide a feedstock for the production of biogas using AD technology.

41. Green Waste is a phrase used to describe organic material collected from domestic green bins and by councils and municipalities in managing vegetation (including parks and gardens, topping and lopping trees, and management of vegetation in the vicinity of roads). Green Waste tends to be used as feedstock for the production of compost or possibly mixed organic output using aerobic technology (often as part of an MBT or MT resource recovery project or as a FOGO resource recovery project). Green Waste does not tend to be used as feedstock for the production of energy carriers from waste on the basis that separation at source allows the production of compost. This said, Green Waste may be in part for RDF production (a solid fuel).

42. E-Waste is a phrase used to describe waste arising from electronic products. An ever increasing number of jurisdictions around the world are developing specific E-Waste collection and processing systems. These systems recognise the importance of processing and treating E-Waste effectively to avoid any adverse impact on the environment and health and welfare: providing for the recovery of resources comprising the E-Waste. E-Waste is not used as feedstock for the production of energy carriers from waste. E-Waste contains precious metals (including copper and gold, palladium and platinum and silver), and ferrous (iron) and non-ferrous (cobalt and lithium) metals, and recyclable plastics. Each year, it is estimated that up to 330 metric tonnes of gold is recovered from E-Waste, approximating to around 10% of the total global production of gold.

43. In 2020, an E-Waste article will be published by Ashurst (on the Ashurst website). The recovery of E-Waste is of particular interest to one of
the co-authors of this article.

44. Food Cycle Waste is a phrase used to describe waste arising from the growth, collecting and harvesting, production, and preparation and consumption of food. The dry organic fraction derived from collection and harvesting of crops may be used as feedstock for the production of compost or as feedstock for a biomass waste to energy project, and possibly as feedstock for the production of liquid fuel.

45. Food Organics is a phrase used to describe waste arising from the production and consumption of food. Food Organics can be used as feedstock for processing and treating using AD technologies to produce biogas, and bio-fertiliser.

46. Biogas (like LFG), comprises predominantly methane and carbon dioxide, and will have traces of other gases, including hydrogen sulphide (which is toxic) and nitrous oxide NOX (which is a fundamental measure of air quality). Depending on the composition of the feedstock, the biogas may comprise between 50% to 80% methane and between 20 to 50% carbon dioxide.

47. In the context of resource recovery, biomass refers to organic matter that has become a waste, and on recovery, and among other things, may be used as feedstock for processing and treatment to produce compost using aerobic digestion technology or to produce biogas (and possibly to produce bio-fertiliser from the digestate) using anaerobic technology.

48. Co-digestion refers to the use of more than one feedstock to achieve anaerobic co-digestion of differing feedstocks using the same anaerobic digestion technology.

49. Garden Organics describes a subset of Green Waste, in particular in the context of Food Organics and Garden Organics (FOGO) projects. Garden Organics are used as feedstock for the production of compost (using aerobic technology). Garden Organics do not provide feedstock for energy carriers from waste production.

50. The mixed organic output (effectively an organic product) derived from processing and treatment of the organic fraction of MSW (using mechanical treatment (MT) or mechanical biological treatment (MBT)) derived from an aerobic environment (typically, a composting and drying hall) can provide a feedstock (possibly blended with our resources) to produce solid fuel. Depending on the policy framework in the applicable jurisdiction, this mixed organic output can be used as compost medium (for some agricultural uses) or as rehabilitation medium (for use in the mining industry and for freeway/motorway central reservations or verges).

51. The production of compost requires taking the organic fraction (or more accurately part of the organic fraction) from the waste stream, processing to it produce organic matter in the (more) stable form of compost; the compost is derived from the process breaking down at a slower rate than the organic matter in the waste stream from which it is derived, and which may otherwise have been disposed of to landfill.

52. Recyclables are materials that may be recovered from the waste stream and recycled, for example, cardboard, paper (including newspapers and magazines), liquid paperboard (LPB), glass bottles, plastic bottles and containers, high density polyethylene (HDPE), mixed plastics, polyethylene terephthalate (PET), drink cans (aluminium), and food cans (comprising ferrous metals) and steel, the recycling of which will require the use of energy.

53. RDF or refuse derived fuel is solid fuel derived from waste used to fire industrial facilities, including cement kilns, being a fuel from waste.

54. PEF or process engineered fuel is fuel derived from waste used to fire industrial facilities, including cement kilns, being a fuel from waste.

55. SRF or solid/specific fuel recovery is solid fuel derived from waste used to fire industrial facilities, including cement kilns, being a fuel from waste, more often than not blended to produce a specific specification, i.e., a specific calorific value/heating value.

56. It is estimated that the highest rates of growth in MSW arising will occur in Africa and Asia, in particular South and South East Asia.

57. C&I Waste is sometimes separated (and analysed) into commercial waste (being waste arising from commercial activities, including commercial enterprises, such as restaurants and shops, and offices (private and public sector)) and industrial waste (being waste arising from industrial activities, including manufacturing and production processes). For the purposes of this article, and generally, we prefer to combine.

58. In the broadest (and most accurate) sense, biomass describes the total mass of living organisms on earth, comprising humans, animals (domesticated and non-domesticated), crops and forests and other vegetation (including estuaries and wetlands).

59. Pyrolysis involves deriving gas (and char and tar) form the sublimation of feedstock at high temperatures in the absence of oxygen with the gas to provide energy combusted or separated to derive liquid fuel.

60. Lignocellulosic material is organic material that has certain characteristics, critically in the context of anaerobic digestion, organic material that is resistant to enzymatic hydrolysis, tends to have limited water content and takes a fibrous form. Furthermore, lignin resists microbial digestion. Because of these characteristics, the use of lignocellulosic material feedstock for anaerobic digestion tends to result in higher levels of residual digestate. This does not mean that lignocellulosic material cannot be used as a feedstock to produce biogas, but its use does not result in optimal yields of biogas, and can impact operations.

61. Non- ignocellulosic material is organic material that is not resistance to microbial digestion.

62. The potential biogas yield of a feedstock is dependent on the total solids and volatile solids, each expressed as a percentage: a lower total solids percentage results in a lower biogas yield. Also the nature of the solids allows the prediction of methane yields, including fat and
protein content. The presence of cellulose/lignocelluloses (ie from lignocellulosic material) will reduce the biogas production/yield.

63. In addition, it is possible to derive fats from abattoir waste, and those fats can be blended with other feedstock to produce blended bio-fuel.

64. Vinasse is a by-product of sugar processing which can be processed, among other things, to produce ethanol.

65. These concepts are considered in more detail in the Waste-to-Wealth Initiatives articles Have we reached a tipping point? and the two Aerobic and Anaerobic digestion waste project articles.

66. In this article or context, Contamination does not mean that the waste is hazardous, rather that it is waste that if processed or treated will result in the fuel or feedstock being derived or produced not being within the required specification.