Modelling and Construction of a Deep Well Aqueous Phase Oxidation Process

Abstract

Aqueous phase oxidation is the process in which organic material is oxidized in the liquid phase with gaseous oxygen under elevated temperature and pressure. The VerTech-process uses a vertical subsurface oxidation vessel consisting of two concentric tubes with a length of approximately 1 200 metres. The advantages of which are: an ideal plug flow regime for a high performance, an efficient heat exchange along the reactor length and a less heavy construction compared to surface techniques. The production of residues is minimal and environmentally sound: off-gas consists mostly of carbon dioxide, solid residue is non teachable and the liquid effluent can be purified easily to a high extent. For the design of the oxidation vessel the use of mathematical models is essential: reaction kinetics, hydrodynamics and heat transfer have been brought in models in such a way that up- and downscaling is possible. On the other hand process conditions may be controlled by the model, once it has been approved. The original model has been tested at the demonstration plant at Longmont, Colorado, USA in 1985. A further development will be tested at the first commercial scale plant at Apeldoorn, the Netherlands. This plant will come into full service as of January 1993.