Energy from waste: the pros and cons of advanced gasification vs incineration
With rising volumes of waste, and the drive towards sustainable energy sources, producing energy from waste has the potential to be the perfect solution for both problems. However, not all technologies that produce energy from waste are equal.
They vary in terms of efficiency, environmental impact, and economic viability. This article compares and contrasts incineration – by far the most widely used waste to energy technology – with advanced gasification, to highlight why the latter is the more sustainable and economically viable choice.
Waste management is becoming more challenging
It’s well known that waste production is increasing. According to the World Bank, we produce 2.01 billion tonnes of municipal solid waste globally every year. Even in high income countries, daily per capita waste volumes are predicted to increase by 19% by 2050.
At the same time, European Union countries generated 487kg of waste per person in 2017.
As a result of these sobering numbers, public concern and government policy have combined to impose more restrictions on how waste is managed.
In March 2020, the European Union adopted its Circular Economy Action Plan – one of the main pillars of the region’s Green Deal. This plan includes a binding target to reduce landfill to 10% of total municipal waste by 2030 — from an EU average of 23% in 2018. Other parts of the world are heading in the same direction.
Sustainable energy is an essential part of energy policy
At the same time, climate change concerns are driving the EU’s Green Deal target of becoming carbon neutral by 2050.
The European Commission’s recently published clean energy investment agenda seeks to drive the transformation of its energy system “which accounts for 75% of the EU’s greenhouse gas emissions”.
Producing energy from waste can solve the waste problem AND the energy problem by applying thermal processes to convert that waste into energy. However…
Not all energy from waste technologies are the same
- Incineration applies oxygen and high temperatures to waste, effectively burning the waste to convert it into heat, ash, and flue gas. The flue gas must be cleaned of polluting gases and particles before being released into the atmosphere.
- Advanced gasification works by thermochemically transforming waste feedstocks using temperatures in excess of 700℃ and a highly controlled supply of oxygen or steam — without using combustion. The process creates a synthetic gas (syngas), which can then be used for a wide variety of applications.
Pros of incineration
- Tested technology that’s been proven at commercial scale
Incineration is certainly a tried and tested technology. The total number of incineration plants in Europe is over 500 and the Confederation of European Waste to Energy Plants represents around 410 of these in 23 countries. The amount of waste incinerated in Europe more than doubled to 58 million tonnes between 1995 and 2018.
- An easy way to manage waste
Incineration can burn up to 90% of all solid waste generated, making it an extremely convenient way to manage waste, especially when compared with landfill.
- It reduces landfill
According to the European Environment Agency, the share of total waste disposed of in landfill decreased from 29% to 24% between 2010 and 2016, and it is continuing to fall.Some of that decrease is due to the rise of incineration. In the UK, for example, incineration will soon account for more than half of all waste disposal – a direct result of government efforts to reduce landfill.
- It generates energy
The heat produced by incineration can be used as an energy source, as well as a means to generate electricity
Cons of incineration
- Negative environmental impact
Incineration produces greenhouse gases, including CO2. The ash it produces includes fly ash, which contains toxins such as sulphur dioxide, hydrogen fluoride, nitrogen oxide, silicon dioxide and more. Fly ash may also contain mercury, arsenic, ammonia, cadmium, cobalt, lead and chromium – all poisonous.
- It requires emissions treatment systems to capture pollutants
Incinerator plants need extensive flue gas treatment for them to meet environmental compliance regulations.
According to a research note from Arden Equity Research:
- Some countries now have excess incineration capacity
For example, the UK is facing incineration overcapacity of up to 9 million tonnes, according to pressure group UKWIN.
- It’s often expensive and takes a long time to recoup investment costs
“Building and operating waste processing plants such as incinerators requires long contract periods to recover initial investment costs, causing a long-term lock-in.”
This adds an extra element of risk, especially in light of the EU’s decision in 2019 to phase out subsidies to incineration plants.
- Regulatory pressure means it may not remain economically viable
In December 2019, it was reported that the European Commission agreed to “exclude incineration from its list of activities that advance climate change mitigation… stating that minimising incineration and avoiding disposal of waste will contribute to the circular economy”.
Given that the growth of incineration relies largely on being promoted by governments, this official decision that incineration does not mitigate climate change presents a significant risk to the future financial viability of such projects.
Pros of advanced gasification
- Tested technology that’s been proven at commercial scale
At EQTEC, we have over 125,000 cumulative – and independently audited – engine operating hours at our 6MWe plant in Movialsa, Spain. On top of this, the universities of Lorraine, France, and Extremadura, Spain have conducted extensive R&D in facilities based on our advanced gasification technology.
- It doesn’t rely on subsidies and is economically viable
“Plant economics are attractive and do not require subsidies,” according to the Arden Equity Research note, which adds:
- It can be designed and built for specific applications
EQTEC technology can be adapted for a huge range of applications and locations, because of our modular approach, meaning we can size projects for any capacity from 1MWe to 25MWe.
- Flexible implementation allows for a smaller carbon footprint
This flexibility allows us to work with waste operators to site modular waste gasification plants closer to the source of waste, minimizing the carbon impact of transporting waste longer distances.
- It does not pollute and doesn’t need any emissions treatment
Due to the fact that advanced gasification is a non-combustible process – and the purity, reliability and efficiency of our syngas – our technology creates 25-30% lower greenhouse gas emissions than incineration. It also produces no fly ash or other pollutants.
- When used with biomass waste, it qualifies as a renewable energy source
Where gasification is used to convert organic material – such as biomass waste – into synthesis gas, it can be considered a renewable energy source.
- It can be used to generate green hydrogen cheaply and efficiently
Thanks to an increased focus at the 2019 G20 summit and 2020’s EU Hydrogen Strategy, hydrogen has attracted a lot of support as a practical solution to decarbonize the global economy. But the challenge remains of how to produce more “green” hydrogen, whose production is currently prohibitively expensive.
Advanced gasification offers a cheaper alternative. From our extensive commercial scale experience and research and development, we know that the synthesis gas we produce from wood contains 42% hydrogen, on average. This hydrogen can then be separated and purified for use as an energy source.
This process is 100% green, and far less expensive than the process of water hydrolysis.
- As well as hydrogen, it is proven to produce a large range of valuable outputs
At EQTEC, we can also use our syngas to produce:
Electricity, for capitve industrial use or to sell to the national electricity grid
Heat/steam, for industrial process applications
Liquid biofuels, by applying a Fischer-Tropsch gas-to-liquids module
Synthetic Natural Gas, via a methanation process, to sell to the national gas grid
As a byproduct we can generate Biochar – which in turn can be used as a fertilizer for soil, an additive to remove or absorb contaminated soils, a filtering material for clearing heavy metals from waste-water, or as an additive in cosmetic products.
It is proven to be able to process a huge range of waste and feedstocks
At EQTEC, we have commercial operation data and years of research and development testing the results of gasifying over 50 different types of waste feedstocks, including:
- Olive stones
- Nut shells
- Grape bagasse
- Pine cones
- Forestry clipping
- Demolition rubble
- Municipal solid waste – also know as refuse-derived waste
As well as many more too numerous to list.
- Advanced gasification is around 25-30% more efficient than incineration
Again according to Arden Equity Research, “production of energy from a typical EQTEC advanced gasification plant is 930 kWh per MT [metric tonne] of feedstock material, 69% higher than the 500 kWh per MT of feedstock, produced by a typical energy-from-waste incineration plant”.
Cons of advanced gasification
- It is a misunderstood technology
The one serious issue with advanced gasification is that many in the marketplace do not understand it.
Due to some high profile failures of gasification projects – especially in the UK – there are some who believe that the technology doesn’t work at commercial scale, or on certain kinds of waste feedstock. Others don’t think the technology is viable.
All of these assumptions are incorrect, however.
Advanced gasification — the perfect energy from waste solution?
Depending on your waste management and energy needs, advanced gasification is the best choice to future-proof your energy from waste projects.
It can be implemented in a flexible, modular fashion, which means plants are faster to build and require lower capex. It offers a huge amount of flexibility with regards to the kinds of waste feedstocks it can process, as well as a great diversity of output. All of which makes it suitable for managing many different kinds of waste and offering a variety of high-value revenue streams.
As a waste management solution, advanced gasification is far more environmentally-friendly than either landfill or incineration. This is an important consideration when incineration is likely to face stricter emissions controls and possible restrictions on new projects in the next few years.
Advanced gasification is the cleanest, greenest, most flexible and most economically viable energy from waste technology currently available. Its adoption is only likely to grow.
By David Palumbo, CEO, EQTEC plc