I spent a couple of days in a class going over this process and equipment, as we expect it to be nationwide someday.
Donaldson is making after market kits for the heavy trucks and off road machinery in CA that are forced to install this equipment on ALL diesel engines. The kits run from $8500 - $14000 based on the size of the engine... This is for soot only... . the EGR system to lower nox is another matter... . These sales are slow as there is a huge court case going on... its like back in the late 50's and early 60's when you had to retro all cars with the PCV systems from the old breather systems...
Most other states are looking at the CA law and I assume that in a few years they will follow... so all the off road machinery, Cats, Loaders, Graders, Logging, Track Hoe's etc with these 8-12 L engines will get cleaned up... . CA feels this is a huge problem now that the cars and trucks are clean.
The Donaldson system is a cartridge that can be removed from the truck... . its put through an oven first to turn all the soot in the cartridge to ash and than the ash is blasted with air while the unit is in a shaker to remove the ash...
The Donaldson system is not designed to be re-generated. But its a much larger cartridge and is designed to have a catalyst in front of the cartridge to do some of the burn off with the excess fuel. It's design is to run 100,000 miles before cleaning.
As soot, it will hang onto any surface and you'll get that oily feeling when you rub your fingers in it... as ash it sort of floats off the part... .
We use a oven in our cleaning operation to clean brake shoes and clutch cores... any dirt, grease that is on the part burns off in the oven... . the oven is set for 700-800 with a separate afterburner chamber that runs at 1300... . so any oils and grease that burn off will vaporize at the higher afterburner temperature so that the smoke stack is clean...
Once through this process the ash goes in the garbage... as it has no heavy metals such as lead, zinc, chromium etc... Other states have different rules... but here in WA they take samples of the ash and monitor the oven...
I think this answers most of the questions...