TDP was sold by Changing World Technologies as a tech that turns any waste into oil by reacting it with water. A cursory inspection reveals that this cannot work out chemically, and it didn't in practice.
The press releases contained scarce details, but did drop a few hints at what's actually going on: Stuff that can hydrolyse, will hydrolyse. This turns fat into fatty acids and glycerol, and protein into amino acids. The second stage decarboxylated the organic acids. In practice, that means fats became "crude oil", proteins became mixtures of amino compounds, and everything else pretty much remained unchanged. They even made up the bullshit term "fertilizer grade amino acids" to hide the fact that this byproduct was worthless and simply dumped. I suspect, the complaints about smell were caused by the amines in the waste stream.
In summary, TDP never worked, and it was oversold. It's not coming back.
MSO is different. The conditions in a molten carbonate are much harsher, so everything breaks down to simple molecules. Dissolved oxygen radicals can oxidize everything, including carbon black. There is no question whether MSO works, it has been positively evaluated for the destruction of very difficult wastes, including explosives and chlorinated pesticides. The question is whether it can be economical for general mixed wastes.
On the other hand my understanding is that MSO is used today actively to deal with e.g. chemical weapons disposal etc.
I'm not qualified to give a detailed answer.
MSO happens at much higher temperatures than TDP but doesn't require pressurization, whereas TPD is essentially a pressure cooker.
Essentially you "burn" the waste within a molten salt bath and get "synthesis gas" (mix of CO and H2) out. https://en.wikipedia.org/wiki/Syngas Feed that through a water column to get CO2 and more H2, send the CO2 to greenhouses or algae and the H2 to fuel cells.
> Molten salt oxidation is a non-flame, thermal process that destroys all organic materials while simultaneously retaining inorganic and hazardous components in the melt. It is used as either hazardous waste treatment(with air) or energy harvesting similar to coal and wood gasification(with steam). The molten salt of choice has been sodium carbonate (m.p 851°C), but other salts can be used. Sulfur, halogens, phosphorus and similar volatile pollutants are oxidized and retained in the melt. Most organic carbon content leaves as relatively pure CO/CO 2/H2/H2O gas (depending on the feed conditions, whether steam or air is used), and the effluent only requires a cold trap and a mild aqueous wash (except mercury-containing wastes). It has been used for safe biological and chemical weapons destruction, and processing waste such as scrap tires where direct incineration/effluent treatment is difficult. The major downside of the process compared to direct incineration is the eventual saturation of the melt by contaminants, and needing reprocessing/replacement.
https://en.wikipedia.org/wiki/Molten_salt_oxidation