What is RDF?
Refuse Derived Fuel is a type of fuel made from the combustible components of your general, everyday rubbish. Typically, this waste is taken from industrial or commercial sites, before being dried out, shredded, baled, and then later burned as a fuel type to produce electricity. Some believe that RDF is the final chance for waste to be a renewable energy source, as it avoids the landfill. Others believe that this waste should have been better sorted and recycled instead of burned – that debate rumbles on.
How does it work?
The waste that has been dried, baled, and shredded is then burned for its calorific value in a huge cement kiln. The heat produced then kick-starts a process at the end of which electricity is produced. By being burned for energy, this waste reduces our national dependence on fossil fuels, such as coal, which can be seen as a huge positive. Some RDF facilities only accept certain types of waste, such as tyres (TDF), for example, and have the specialist technology to get the maximum energy return from these materials.
Some of the other processes that are involved include:
- Size screening
- Coarse shredding
- Bag splitting
- Magnetic separation
- Refining separation
How does RDF affect you?
As mentioned above, RDF affects our relationship with both waste management and energy production, though it’s debated in some circles whether this is in a positive or negative way.
When making the case that RDF is negative, it’s quite easy to tarnish it with the same brush as other waste-burning technologies, for these reasons:
- It traditionally produces both greenhouse gases and toxic ash, which are harmful to the environment. However, more modern facilities can prevent this.
- It is low on the waste hierarchy, meaning opportunities for reuse and recycling have been missed, and the embedded carbon of production is lost.
- Recycling rates suffer in a time when we should be seeking to be more resourceful and take more care to separate our waste.
- RDF is pro-incineration at a time when we need to be pro-prevention. If people believe that their waste can be burned for energy, it does little to discourage them from generating unnecessary waste.
- Much of the RDF is wet and requires extra fuel to get it burning. The calorific content of RDF is very low, to begin with, so this paints a picture of inefficiency.
- If not done carefully and closely following guidelines, burning RDF will violate many international laws and policies. Openly burning rubbish is forbidden in most developed countries, so RDF must be used in professional facilities that take precautions to minimise damage to the environment, public health, and local communities.
What are the challenges with RDF?
RDF is one small ‘solution’ to the global problem of what to do with our waste. As it piles up, struggles to be recycled and dealt with, and as it filters into our waterways, oceans, and landfills, there have to be some tough decisions made. Populations will continue to expand, creating more waste and heaping even greater pressure onto the situation.
RDF was once seen as an innovative solution to this problem, but it is not entirely true. If anything, burning waste is the oldest way to deal with it, far detached from modern technology. Governments around the world once invested heavily into incineration, RDF, kilns, WtE plants, and other forms of combustion, but all to arrive at the same result – waste is not great for burning, you are left with toxic ash, it doesn’t deal with the root of the problem, it is bad for the environment, it is a poor way to manage resources, it negatively affects recycling, and it has an adverse effect on human health.
What are the benefits of RDF?
If you can look past all of the challenges that RDF must overcome in order to be seen as beneficial, then you might see that it does present a good way to make use of non-recyclable plastics, labels, and corrugated materials. As long as good resources are not being burned for energy, then the energy that is being made from items would serve no better purpose, especially not by sitting in a landfill. This is a double-edged sword, as you may ask why we continue to produce non-recyclable plastics, and on the other side, it produces energy to support our national dependence whilst dealing with unusable waste.
Is RDF an alternative to the landfill?
If you’re going by the waste hierarchy, you could argue that RDF is a precursor to landfill. It is the stage before landfill, but in most cases, the toxic ash produced by incinerating RDF will end up in a specialist landfill anyway.
Currently, the UK exports a great deal of its waste overseas, which is more environmentally friendly in carbon terms according to this report from Eunomia, than incineration. On home soil, our RDF efforts are not that impressive, but having read this article and knowing what you know now, would you advocate for more RDF facilities, or support more sustainable technologies and prevention awareness? It’s a tough call as waste piles grow.
July 26, 2019