How advanced gasification solves the biomass problem in waste to energy

Advanced biomass gasification is an ideal solution for biomass waste management and clean energy production. But it risks being overlooked and underutilised due to a fundamental misunderstanding.

This article explores the reasons for this misunderstanding before going on to show how advanced gasification is already being developed for use on biomass waste in multiple countries in sustainable and low-cost ways.

Under the right circumstances, the technology also offers the ideal solution to managing biomass waste and creating truly clean energy with minimal environmental impact.

The critiques of using biomass waste to produce energy fall into two main categories:

1. Biomass is increasingly being used in coal-fired energy plants as a substitute for coal, extending the life of greenhouse gas-emitting plants.
 
2. A market has developed in which wood pellets are harvested and transported great distances to be used in energy production – again, mainly at coal-based plants. This creates a large carbon footprint both in the harvesting and the transport. It may also contribute to deforestation.
 
Let us briefly explore each of these…

Critique 1: Use of biomass in coal plants

Many coal-fired power plants across Europe “have laid out plans to transition away from burning the emission-heavy fossil fuel by converting their existing facilities to instead cater for biomass – typically wood in the form of small pellets.”
The reason is simple. Burning wood pellets to create energy “can help in reducing the dependence on fossil fuels”, while at the same time, “dumping waste in landfills can be reduced to a major extent by increasing the number of biomass energy plants”. Plants in Finland, Germany and the Netherlands have been most active in this area.
The first problem is that this is expensive, as such coal plant operators are “largely being supported by government subsidies to the tune of $7bn across the European Union each year”.
Environmental groups question whether these subsidies are a price worth paying, as even though the use of biomass in coal-fired plants will reduce the amount of coal used to generate energy, it does allow many of these plants to continue to do so.
Not only that, but because coal-fired plants use combustion to generate power, they are inherently large emitters of greenhouse gases. Even when using biomass.
Many energy, waste management and environmental groups question whether this is the best use of $7bn they believe could be better spent on other green energy initiatives instead. Indeed, as a result of these concerns, the Netherlands recently decided to end such subsidies to its coal-fired plants.

Advanced gasification of discarded waste biomass works differently to the combustion process used in coal plants, making it a renewable energy source.
When implemented in a modular fashion which allows for smaller plants to be built near to the source of the biomass, it also does not rely on subsidies. And when used specifically to process biomass waste, it qualifies as a renewable energy source. We will explore these points in more detail below.

Critique 2: Increasing the carbon footprint and risks of deforestation

Converting coal plants to biomass could fuel climate crisis,” reads a 2019 headline in the Guardian newspaper. The paper highlights a report from climate think tank Sandbag (now renamed Ember) which discusses the current schemes to convert coal plants to biomass production by pointing out:
“Europe’s planned biomass conversion projects would require 36m tonnes of wood pellets every year, equal to the entire current global wood pellet production. This would require forests covering 2,700 sq km to be cut down annually, the equivalent of half the Black Forest in Germany.”
Since the majority of wood pellets are imported from the US and Canada, “there’s a huge added environmental cost in transporting the wood from the other side of the Atlantic” according to report author.

EQTEC uses advanced biomass gasification very differently

Not only is advanced gasification a different, greener process to the combustion used by coal plants, we also design and implement advanced gasification plants to process local waste in a way that promotes the circular economy.

How advanced biomass gasification works

Converted coal plants do not use gasification. Instead, they replicate the combustion process used with coal. Indeed, in many cases plants mix wood pellets in with coal.

They grind wood pellets into tiny pieces which they burn in a furnace. The heat from the furnace is used to create steam, which is used to spin turbines that turn generators.

Even when using wood, the combustion process itself emits greenhouse gases. So although reducing the proportion of coal burned does reduce emissions, it is still not a green energy.

Advanced biomass gasification, by contrast, is a technology which converts organic waste into synthesis gas. Because it doesn’t use combustion in the process, it emits far fewer greenhouse gases and qualifies as a renewable energy source.

Applying advanced gasification to real world biomass waste

The key to using advanced biomass gasification sustainably is to use it with waste biomass rather than virgin sources harvested specifically for energy conversion.

Applying advanced biomass gasification on existing biomass waste – for example, by-products of agricultural production or forestry waste – qualifies it as a renewable source, because this kind of biomass is waste that needs to be managed.

Using forestry waste

Let’s take the example of the plant EQTEC is developing in California. Over the past several years, California has suffered from severe forest fires, often made worse by forest waste. Clearing forest floors of this hazardous forestry waste is essential to good environmental management in the state.

Furthermore, recent laws passed in California have made it illegal to dispose of such waste in landfill. That’s why we are developing advanced gasification projects with partners in California to convert this potentially hazardous biomass waste into high efficiency, clean electricity.

This promotes the circular economy in California by supporting good forestry management and converting existing waste into clean energy the state can use.

Because the plants are being developed on a modular basis, they will be designed and built for this specific purpose and in the location of the waste itself, with minimal impact on the carbon footprint because the waste does not need to be transported over long distances.

Using agri-waste

On a similar note, EQTEC’s 6MWe capacity advanced gasification plant located at Movialsa, in Ciudad Real, Spain, converts local waste olive pomace into synthesis gas (syngas). This syngas is then fed through Jenbacher engines and converted highly efficiently into electricity that powers the plant and is sold to the national energy grid.

Again, the carbon footprint is low because the waste is a by-product of local olive oil production. The energy produced is renewable. And because much of the heat and the electricity generated is used onsite, this is another great example of the circular economy in action.

The right technology and the right application are the keys to creating value from waste biomass sustainably

We could go on with other examples. We are currently also developing an advanced gasification plant in Greece that will process local agri-wastes including densified straw, corn and cotton residues produced by local agricultural activities in three different seasons.

And, as a recent research note from Arden Research makes clear, designing and implementing modular scale plants means EQTEC’s advanced gasification technology produces a “highly efficient supply of electricity, heat or steam… with an attractive rate of return.”  

There are more biomass gasification projects in our pipeline. There are a growing number of waste producers, waste management companies, EPC contractors and other stakeholders who see the benefits of advanced gasification for processing genuine waste biomass in such a way that it promotes the circular economy and produces sustainable energy highly efficiently.

If we all spread the word then surely more people will begin to see the huge potential benefits of this technology for using waste biomass in a cleaner, greener and more efficient way.

Share on twitter
Twitter
Share on linkedin
LinkedIn
Share on email
Email