If you’ve been following this blog or if you’ve poked around Swestep’s websites you’ll have inevitably come across this mouthful- “catalytic pressureless depolymerization” (CPD). Whatever it is, it must be pretty special since Swestep’s entire business seems to depend on it. Yes, Swestep is bringing innovation to the way they are rolling out this technology, making their recycling plants scalable and modular, not to mention what must be countless other important business decisions. Yet it stands, that without the technology that is CPD, Swestep has nothing.
So what exactly is CPD? It is the goal of this multipart series to deconstruct the technical jargon so that you, an investor or lay person with little to no knowledge of chemical engineering, can feel like you can lift the lid on this magical little black box and begin to understand CPD.
Part 1- C is for Catalyst
Before you can even come close to understanding CPD you first need to understand the three bits of jargon that comprise it. By the end of this article you should understand what a catalyst is since for something to be “catalytic” it simply must involve the use of a catalyst. Google “catalyst” and you’ll find a fairly simple technical definition stating that it is “a substance that increases the rate of a reaction without itself undergoing any permanent chemical change”.
Let’s start by taking a closer look that the first part of definition. Basically, catalysts speed up reactions. Who doesn’t like the job to get done faster? But catalysts don’t just hurry things along by a little bit. Typically, catalysts increase the speed of a reaction many thousands, or even millions of times. For example, and perhaps the most well-known use of the word, every modern car is outfitted with a component called a catalytic converter near the end of the exhaust system. Without a catalytic converter, internal combustion engines release a slurry of harmful chemical compounds into the air. It is true to say that these harmful emissions will eventually convert into less harmful stuff. However, considering the vast number of vehicles in operation on this planet and the length of time it takes for this process to occur, we’d have poisoned ourselves long before it would occur. The catalytic converter, typically made of platinum or palladium, so efficiently speeds up this reaction that the exhaust blowing over it is enough to cause the stuff to come out of your tailpipe a whole heck of a lot less toxic.
Here’s an example we can put some numbers to. Ever heard of an enzyme? Enzymes are simply biological catalysts. The millions of reactions that occur in our bodies, and in every other living thing, are all catalyzed by enzymes. Without enzymes we’d all be dead. Take the simple act of transporting the carbon dioxide (CO2) produced in every cell to your lungs for you to breath out. Transporting CO2 through your blood as is doesn’t work since it would form bubbles that would ultimately kill you. Instead CO2 must be combined with water converting into a molecule called carbonate (HCO3–) plus one hydrogen ion. In chemistry equation form the reaction looks like this:
CO2 + H2O → HCO3– + H+
Left alone, without a catalyst, this reaction will occur at the rate of 200 times per hour. Pop in an enzyme, or the biological catalyst known as carbonic anhydrase, and the reaction occurs at a rate of 600,000 times per second. With the catalyst, the same reaction occurs 2.16 billion times faster!
In Swestep’s process the reaction they catalyze is turning plastics and other solid organic waste into renewable diesel. This is a process that can really use some catalysis. Can you imagine staring at a pile of plastic and waiting for it to turn into usable fuel? No way. In fact, this reaction is so slow that without a catalyst and working on a human time scale, it is considered not to occur at all.
Finally, it is important to understand the second half of the definition of a catalyst. Put simply, the catalyst itself is not consumed in the reaction. This is of great benefit since there is never any need to replace or replenish a catalyst. It’s the gift that keeps on giving. The catalysts used in Swestep’s CPD, potassium, sodium, calcium and magnesium aluminum silicates, are no exception.
Now you at least understand the first part of CPD. Whatever pressureless depolymerization is, it happens way faster than it would otherwise, thanks to the presence of a magical little catalyst which can do its job over and over again without ever needing replacing.
Tune it next week to find out what the heck “pressureless depolymerization” is.