Thank you for a very interesting conversation today. Per your request, I have jotted down some notes about our technology and its application to wastes such as those at Sydney Tar Ponds, which I hope are helpful to you.
GPCR is a NON-incineration technology that uses hydrogen to reduce the contaminants down to their basic components. In the case of chlorinated hydrocarbons (such as PCBs), the basic components are methane and hydrochloric acid. Because hydrogen is used, rather than oxygen (as in incineration processes), there is no risk of forming dioxins and furans during the GPCR reactions. Contaminants that have been removed from the sediment using the thermal desorption step are conveyed into the GPCR reactor, which has a hydrogen atmosphere (no oxygen) and is at a temperature of about 875°C. This breaks down the contaminants into methane and hydrochloric acid. The methane is used to refuel the system, or can simply be burned.
Before we do this, however, we make very sure that the methane gas does not contain any of the original contaminants. The hydrochloric acid is neutralized and exits the system as a salty water. As we discussed, though, our GPCR technology is for the destruction of contaminants (i.e. PCBs, PAHs, etc.). If the contaminants are bound to soil or sediment, as is the case of the Tar Ponds material, then they must first be taken out of the sediment by some means. One common way to do this is to use thermal desorption, which heats the soil and "vapourizes" or "volatilizes" the contaminants off of the soil. The gas containing the contaminants can then be captured and cooled, into a liquid. It is this liquid that would then be treated using GPCR. So another way of looking at it is that we are a post-treatment technology to thermal desorption: thermal desorption gets the contaminants out of the soil, and then we destroy the concentrated contaminants using GPCR.
I know that in the "Considering Technologies" fact book, the JAG cover thermal desorption quite well, and state that the residual material (i.e. the contaminants taken out of the soil) can be treated by a number of other means, including incineration, pyrolysis, hydrogen reduction (i.e. GPCR), etc. I should also point out that solvent washing the sediment is another way of getting the contaminants out of the sediment. But the result is the same - a liquid is created that contains all of the contaminants that were taken out, and will require some kind of post-treatment. Again, the document refers to various methods of doing this, and GPCR is certainly one option.
I've not mentioned the fate of the metals in the sediment, but should do so. The majority of the metals will stay with the treated sediment in the thermal desorption device. Depending on the concentration of metals in the treated sediment, the material may require some kind of post-treatment step to stabilize the metals. But by this time, there will be significantly less material to deal with, as all of the organics (including organic contaminants) and water will be taken out. I don't believe this metals post-treatment reuqirement is unique to GPCR or thermal desorption. I believe other technologies (incineration) will need to stabilize the metals in the treated sediment in some way too.
I note in some of the articles that the consultants are stressing that the technologies they've recommended are proven, and that they don't want Sydney to be subjected to experimental technologies. I think this is a very wise decision, especially with a project of this magnitude. But I would like to point out that nothing of what I've described above - that is, thermal desorption followed by GPCR - is experiemental. There are numerous thermal desorption technologies out there that have done work on large soil and sediment contamination projects, so that is a well-proven technology. And while we ourselves have not handled a large soil or sediment project, that is not really what we would be doing in Sydney anyway! What we would be doing is taking a highly contaminated liquid that is created from thermal desorption, and treating it in our GPCR reactor.
We did this kind of work for several years in Australia, treating high-strength PCB oil, high-strength hexachlorobenzene, high-strength liquid and solid (powder) pesticides - there is absolutely nothing experimental about the ability of GPCR to treat the concentrated, contaminated residue from Thermal Desorption.
It is possible that the consultant's concern over the "experimental" nature of GPCR comes from our original approach from a few years ago. I have already explained to you that at that time, we had envisioned sending the gases from thermal desorption directly into the GPCR reactor for destruction (i.e. not condensing the gases first and feeding them as a liquid). This "coupled" system was experimental - although both technologies have a wealth of experience doing their particular job (i.e. getting contaminants out of soil, in the case of thermal desorption, and destroying high-strength contaminants in the case of GPCR), we had never coupled the two technologies together.
In the past several months we have rethought our approach of coupling the technologies, and realise that an "uncoupled" system, where the two technologies operate separately (although they can be located at the same place), is a much more sensible and economically viable approach. And also, there is no experimental aspect. As I said, with our new approach there is absolutely nothing experimental about using thermal desorption followed by GPCR for treatment of the Sydney Tar Ponds waste.
Also, I believe we can do the job within the cost ranges and timeframes indicated for the different approaches recommended by the consultant. Our approach is to partner with firms that do have experience with large projects such as Sydney Tar Ponds, to offer them our technology for use at the site - we would never undertake a project such as this without strong partnerships.
I hope the above information has helped clarify our technology and its approach.
Please feel free to contact me again at the number below if necessary.