Capturing methane emissions from landfill sites for use as feedstock for fuel, chemicals and plastics makes good environmental sense. In the US, Bob DeMatteis, of RNG Plastics, takes this a step further. What if there was a way to ensure that the non-recyclable fossil fuel plastics in landfills could be converted into renewable natural gas (RNG) and renewable biogas, to enhance the yield from these landfills? According to DeMatteis, with the solution developed by RNG Plastics, it’s not only possible, but it’s happening already.
You’ve developed a solution specifically for landfills, I understand. But why the focus on landfills – how does that mesh with the drive for circularity today?
In the US, the reality is - and the APR recognises this as well – that we're lucky if 10% of the plastics get recycled. Today’s landfills are well-engineered and managed facilities for the disposal of solid waste, with one common type being the municipal solid waste landfill; a landfill designed for the disposal of household waste, and other types of nonhazardous wastes. These landfills are the third-largest source of human-related methane emissions in the United States. Landfill gas (LFG) is a natural byproduct of the decomposition of organic material in landfills. That waste includes food, plastics, paper – anything households throw out. LFG is composed of roughly 50 percent methane (the primary component of natural gas), 50 percent carbon dioxide (CO2) and a small amount of non-methane organic compounds.
Now, in the US, there is something called the Landfill Methane Outreach Program (LMOP). It's a voluntary program sponsored by the EPA that encourages the recovery and use of biogas, including methane, generated from organic municipal solid waste in landfills, methane that would otherwise be emitted into the atmosphere, but now instead can become a significant energy resource. It’s already used, for example, heating and cooling in major cities like New York City, Los Angeles, Chicago. These landfills serve over 85% of the United States population.
How does that work? And why not simply reduce the volume of waste being landfilled?
These engineered LMOP landfills function as a biodigester, and there are over 500 LFG conversion plants today. Many of them are RNG conversion plants[1], of which there are about 300 in the U.S. and Canada. By 2050, there will be over 43,000. Most are in agriculture and cattle/dairy operations. Are they trying to reduce the amount that goes into a landfill? Of course they are. There's no question. But that's a different equation.
Here's the process of what happens if something ends up in one of these LMOP landfills: that piece of plastic, or whatever gets buried and sits in the relatively cool environment of the landfill for up to four years. It’s covered and sealed off as long as possible because they don't want anything to degrade while they're loading up the landfill. Then, after four years, they drill extraction wells into the landfill. These have holes in the side, and what that does, is there's some built up gases that have been in that landfill that starts escaping - and something starts happening. The access to oxygen means the landfill starts to heat up, the moisture can move around the microbes start eating. In other words, it’s a classic aerobic digestion process that goes on. This goes on for about a year. Then, a little-known phenomenon occurs: the process changes into anaerobic digestion, which automatically converts it into landfill gas. The methane content of this gas soars. This gas is then piped from the wells to central locations - entire networks been built, including conversion plants to safely capture and convert that methane into renewable biogas or renewable natural gas.
So, your company is called RNG Plastics. What is its role in the process? How do you come into it?
What we’ve done is we’ve developed a technology that will accelerate the conversion of plastic waste in landfills into landfill gas but only after the LMOP biodigester environment is established. We’ve been working on this for over 12 years, and my associates and I have got over 14,000 hours into this. Technically, you could call what we are doing recovery. It meets EPA requirements; as a matter of fact, we are an LMOP partner of the EPA in Washington DC. Our technology increases the yield of the LMOP landfills, creating a renewable resource, a low carbon fuel source (LCFS) which not only can be used for energy purposes but can be turned into organic chemicals and used to make new plastics. You know, in the United States, we don't make plastic out of oil. We make it out of natural gas. So, we're taking it from natural gas and we're putting it right back into renewable natural gas. You won't lose any quality or performance compared to the fossil fuel version – they are interchangeable.
How does your technology work, can you explain a little about that?
We supply a product in a masterbatch - or compound, if you want to call it that. It goes into the fossil fuel plastic when it is being processed. Although we are talking with resin producers about incorporating our technology in their resin production. Right now, we are mainly dealing with brand owners, major retailers, end users and converters.
Well, does this technology use enzymes or some kind of catalyst?
No, we do not use enzymes. No enzymes are approved by the FDA, nor are they approved by the EPA in the United States. This RNG Plastic is FDA approved and organic – there are actually quite a few different substances we can use. One popular one we use is a complex sugar, a polysaccharide – starch, if you will. But not just any one will work. And we use a nanoparticle size, which allows it to be basically 100% bio assimilated - the homogenous blend throughout the plastic provides an even dispersal of the food for the microorganisms.
What is left after the process is finished – are there any toxic residues?
No toxic residue. The only thing left over is a little bit of water vapor and a little bit of biomass. And the biomass is really the [dead] bugs. And they're going to be there anyway. So, from that perspective, that's good because that little bit of leftover biomass is really a very rich soil amendment.
The technology is described as a Polymeric Algorithmic Compound, which is a bit of a mouthful?
I should point out that that's not my description, but it is what my research team came up with as a way to describe this new category of substances that is already becoming quite popular. But, basically speaking, to break it down: polymeric – that obviously refers to the fact of its being a polymer. The algorithmic part refers to what I was explaining earlier about what happens in the LMOP landfill. An algorithm is basically a set of rules or conditions. In this case, the algorithm is to not prematurely biodegrade, release any greenhouse gas or in any way affect any performance qualities – but simply stay dormant in the landfill - until the wells are drilled. Then when the biodigester environment is created, it triggers the process to start.
Lastly, it is a compound, because that's what masterbatches are.
We're actually working on a different application with liquid resins, as well, which is a very attractive market in a way - very vulnerable to contamination. We don't care if it's food contaminated. In fact, we like food contaminated plastics, because that's just more food for the microbes.
So, the reason that the product has no negative effects on material properties, quality, recycling, or anything else is because it only starts to work in this very specific environment?
Right. Basically, when it starts heating up. And even then, it doesn’t happen right away. It has to stay at the higher temperature for a while. Obviously, we have patents pending on this. RNG Plastics Corporation supplies our technology for plastic products used in North America and we may be licensing the technology overseas.
Outside of the United States, for example in the EU, the focus is on reducing the amount of waste that goes to landfill. In fact, the amended EU directive on the landfill of waste specifically states that member states must ‘take the necessary measures to ensure that by 2035 the amount of municipal waste landfilled is reduced to 10 % or less of the total amount of municipal waste generated (by weight)’. Do you have plans to market this technology internationally?
We are focusing on the US and Canada, where the situation is very similar. We’ve specifically tailored the technology for the EPA and the LMOP landfills in the United States of America and Canada. Can we adjust it for other countries and other applications and other biodigester environments? Yes, but we are sticking with the United States and Canada for now. Although that said, we are in discussions with companies who also have interests in Europe. And they're very curious about how Europe might look at this, especially as contaminated plastics are easily dealt with using this technology. Contaminated plastics mean nothing to us. Food, blood or whatever - our plastics are going to be bio assimilated as long as they end up in the biodigester environment of an LMOP-type landfill.
[1] RNG is made from LFG that has been thoroughly cleaned. It can be used interchangeably in existing natural gas pipelines and systems.