The ‘hierarchy of waste’ is a well-known principle for considering how to deal with waste, with versions ranging from the simple ‘Prevent – Reduce – Reuse – Recycle – Recover – Dispose’ mantra to more complex approaches that break these steps down into multiple operations and markets in use in the waste industry.  As a society, we need to prioritise our actions at the higher parts of the hierarchy (i.e. prevention, reduction and reuse of wastes, and closed-loop recycling), however, as we move increasingly towards a lower-waste (or even a zero-waste) economy, energy recovery from waste will become increasingly important.  This view is shared by WRAP – the UK’s Waste and Resources Action Programme (see here).

Enter ‘Waste to Energy’ (WtE or W2E) approaches – also referred to (more correctly in my view) as ‘Energy from Waste’ (EfW).

Energy from waste is all about taking otherwise unusable waste streams and turning them into a useable form of energy – this can include electricity, heat and even transport fuels (e.g. diesel).  Much of the attention in EfW is focused on ‘residual waste’, that is to say waste that is left over when all the recycling that is ‘possible’ has been done (generally taken to mean that the environmental and economic costs of further separating and cleaning the waste are greater than any potential benefit of doing so).  This category of waste includes a mixture of different things – part will come from products made from oil (e.g. plastics) and part from things that were recently (i.e. in the last hundred years or so) growing and are biodegradable (e.g. food, paper, wood, etc.).  The energy generated from the recently-grown materials in the mixture is generally considered renewable, and hence energy from residual waste is therefore partially a renewable energy source and is generally considered a low-carbon energy source.  In addition to potentially contributing to decarbonising energy generation, EfW is a valuable energy source, contributing to energy security:  A WtE plant with a 1,500t capacity has a power capacity equivalent to 40,000kW and can provide electricity to nearly 40,000 homes.  Furthermore, it has the added advantage that it is non-intermittent, and therefore can complement other (intermittent) renewable energy sources such as wind or solar power.

Most EfW is currently produced in the form of electricity, however there is a growing proportion that is used to generate heat, with many developments including combined heat and power (CHP).  More innovative technologies have the potential to also transform waste into other products such as transport fuels or substitute natural gas (SNG).

A report published by US-based market research and consultancy company Grand View Research (GVR) in November (see here) valued the market for WtE at $25 billion in 2015, stating that the market size “will experience significant growth out to 2024”, reaching approximately $45 billion, driven by a worldwide shift towards energy security, coupled with decreasing landfill capacity and environmental concerns.  Regulatory drivers – e.g. tax benefits and incentives – will positively influence the growth of the WtE market.  GVR identified the ‘Europe segment’ (including CIS countries in their methodology) as accounting for the largest share of the global market for WtE in 2015 (over $10 billion), and this is projected to grow at a CAGR of 6.2% between 2016 and 2024, primarily driven by stringent regulations to minimise industrial waste.  Germany, Austria and the Netherlands have adopted WtE technologies to utilise industrial waste.  The ‘Asia Pacific segment’ (i.e. Indian subcontinent, Japan, China, SE Asia and Oceania in their methodology) – accounting for around $9 billion of the 2015 market size – is expected to grow at an even higher CAGR (7.2%) over the same period, with countries such as India and China having huge potential owing to increasing industrial and residential waste arisings.  The ‘North America segment’ (USA, Canada and Mexico) and the ‘MEA segment’ account for much smaller proportions of the total market (~$3 billion and ~$2 billion respectively in 2015), with only a relatively small amount of activity in the ‘Central & South America segment’ (less than $1 billion).

The technologies involved in EfW are predominantly ‘thermal treatment’ technologies – primarily incineration, but also so-called ‘advanced thermal treatment’ (ATT) technologies based on gasification and pyrolysis of the wastes – with ‘biological treatment’ technologies (i.e. anaerobic digestion of waste to produce vehicle fuels or biogas for use in gas engines or turbines to produce heat and/or electricity).  GVR, in their recent report, estimate that thermal treatment WtE plant accounted for around 80% of the $25 billion market size in 2015, but commented that they expect to see significant growth in biological treatment WtE plant over the 2016-2024 period (accounting for 21.53% of the market by 2024), due to its potential in developing markets.

While thermal treatment methods involve relatively simple processes coupled with ease of operations, health concerns due to flue gas emissions have presented major challenges to the EfW industry in the recent past.  R&D to address such health aspects, ways of reducing costs of installation and efficiency of waste conversion, are expected to positively impact the market for WtE plant in the next 5-10 years.

So, with the utilisation of fossil fuels for power generation and industrial processes in decline in many parts of the world, perhaps the IFRF should pay increased attention to this already substantial – and growing – market opportunity for combustion technology…  Perhaps a TOTeM on thermal treatment technologies for waste to energy is needed!