Dr. Uri Stoin, Head of Chemistry at MOG, about his supposedly crazy research and the unexpected magic of synthetic superoxidation.
Dr. Stoin, please tell us something about your career. Why chemistry?
That is a very boring story [laughs]. No, seriously, I already loved chemistry in school. I always found it exciting, because there were always experiments during which almost anything could happen. I wanted to do this all the time, so it was an easy choice for me to enroll for a major in chemistry in Jerusalem. After my graduation at the Hebrew University, I started my PhD thesis about this new kind of chemical reaction we call Green Catalysis. Since the nineties, the scientific community and environmental authorities have developed the concept of Green Chemistry. Its goal is to design environmentally friendly processes to reduce pollution, without using or producing hazardous chemicals or by-products.
What was the initial question behind your research?
When we started, we were looking into ways to synthetically produce an extremely strong oxidant. This later led to the superoxidation process we patented as NHS+, which is now MOG’s core procedure to decompose any kind of carbon material.
In a sense, we were dusting off a research field that had been neglected by chemical science since the early eighties. Back then, the potential applications seemed to be very limited, so the attempts to synthetically reproduce the superoxidation process had been abandoned.
What is superoxidation, and why was it an interesting field for your research?
The superoxide radical is one of the strongest known radicals inside the human body. It is deployed by the immune system to kill invading microorganisms. Its synthetic production has been very inefficient so far. In addition, until we started our research, there had only been a few applications in synthetic chemistry. They were very limited and expensive. They also proved to be problematic concerning the solubility and explosiveness of the chemical components and their reaction. We were facing a scientific challenge, which of course made it interesting for us as researchers. We decided to develop a whole new way to synthetically generate and stabilize this material. If we were to succeed, we would later decide what to do with it.
It was only later, after having gathered a lot of material from scientific experiments, that we came up with the idea to use the method for soil cleaning. That was about three years ago, when we learned that near our institute a huge military property had been heavily contaminated by military production facilities. We decided we would try to clean it with our strong oxidation process. We took the soil to the laboratory, and tests were successful. At this point, both the positive environmental effect and the business potential of our method became obvious.
Why is better than existing solutions? What is the competitive advantage?
There are two major approaches for soil decontamination on the market. First, there is the biological treatment. Second, there is the chemical treatment.
Both theoretically work in situ, i.e., on the spot to be cleaned, and ex situ, when the contaminated soil or substrate is excavated and treated somewhere else.
The biological solutions have some disadvantages: They are slow and not very efficient, because there is no reasonable way to use them in situ, even though some people claim the opposite. You have to dig out the soil to clean using bacteria. If it is contaminated with oil, the remediation can take months, or even years. This method is also highly dependent on the right temperature, and the soil has to be taken care of during the process. You cannot just inject the bacteria and wait. It is cheaper but does not really meet the practical needs of a marketable solution, partly because biological treatment hardly reaches the desired degrees of decontamination.
Since we were using chemicals, we compared it to the most widely used chemical solutions. We discovered that our solution is faster, cheaper and more efficient. The other solutions are limited in terms of the range of hydrocarbons they decompose. Our radical is different. It can decompose almost any kind of hydrocarbon. It is only a matter of time and concentration.
Where you surprised by the results?
Indeed, my notion throughout almost all of our experiments was: This is too simple to be true! Over time, however, we found more and more evidence that it is actually true [laughs]. We did something very unexpected. Up to that point, the main drawback with superoxide radicals had been that they are not stable in wet environments. They just decompose when they come in contact with water. In the past, all research had been done in water-free contexts. The idea of adding water to the process of superoxidation had long been abandoned. It seemed nonsensical, so no one did it. We decided to try and check whether we could stabilize it. And it worked.
Because you tried what everyone else thought of as a waste of time.
Well, yes, somehow. It was just a way of thinking differently and trying a rather unorthodox approach. If you are trying to solve a problem, you always have the obvious way and maybe one or two crazy ways. Since all obvious approaches had been tried before—by brilliant scientists—we decided to do it the crazy way.
Now that you have proven it to be not at all crazy and have even patented the procedure, how does it work outside the lab, when used in cleaning railway track beds, for instance?
Actually, in exactly the same way as when we tested it on contaminated soil. The main idea is still to attack any kind of organic material with the superoxide radical. If the radical touches hydrocarbons on the surface of the gravel stones, it will destroy them. The advantage with railway ballast is that we can easily repeat the procedure by reapplying the reagents to almost completely decompose the contamination.
To improve the results, you can use high pressure pumps to apply the components and, even more importantly, you can adjust the mixture, the ratio and the amount of water exactly to the degree of pollution and the depth of the track bed you want to reach. This all applies to the in-situ treatment, in which the ballast remains in the track bed. If you dig the ballast out and treat it in landfills or even on conveyors during track maintenance or renewal, NHS+ works even more efficiently.
We were speaking of Green Chemistry. What is so green about NHS+, given it is based on chemical components?
Firstly, there is no production of by-products. Secondly, the original chemical components are so simple that their decomposition only produces very simply structured natural molecules such as oxygen, water and sodium bicarbonate, also known as baking soda; obviously, very green leftovers.
Even if the reaction does not take place, because there are no hydrocarbons to destroy, the original components will decompose by sun exposure and added water.
What is your favorite area of application for NHS+?
That is a tough question, because the solution can be used for many kinds of contamination in different environments and markets. Decomposing crude oils or fuels is just one application. In many cases, especially around industrial facilities, we are dealing with pollutants such as organic solvents, chlorinated materials, herbicides, for example, with PCBs and other toxic hydrocarbons. Simply put: the wider the range of pollutants we can attack at one time, the more helpful our solution will become.
In terms of market opportunities, our track bed cleaning solution seems very convincing to me. I only recently learned about the need and the legal obligation to clean the ballast. From a business perspective, I really appreciate the prospect of helping the railway companies, because our technology works perfectly there. The market is huge, and the timing seems just perfect.
Actually, I think our railway solution is brilliant, because there is no other method so far that includes all of the advantages we can provide. I am very happy about this amazing opportunity. We never thought of it when we started our research in the first place.