Summary
The recovery or disposal of wastes containing organic contaminants requires the application of increased safety measures. In addition to solvents, waste paint, enamelling wastes and waste oil, wastes of this type include emulsions, sewage sludge and residues generated by the decontamination of abandoned industrial sites and military properties.
- In terms of the recovery of materials, the objective was to achieve the conversion of organic contaminants into high-energy gases. The project therefore included the experimental investigation of the following: the thermocatalytic gasification of organic compounds using hydrogen in a nickel-doped calcium aluminate catalyser;
- the calcium aluminate coating of silicon carbide as a self-heating carrier material.
Results:
For 1.)
Using the thermocatalytic steam reforming process, organic contaminants have been converted into hydrogen, carbon monoxide and carbon dioxide using a nickel-doped calcium aluminate catalyser and steam.
From the conversion of various model hydrocarbons, it emerged that nitrogen has no significant influence upon the activity of the catalyser. Chlorine compounds produced corrosion in the heat exchanger, thereby reducing the conversion capacity of the catalyser to 82%. The complete catalytic gasification of sulphurous contaminants is only possible using nickel-free calcium aluminate catalysers.
For 2.)
The direct coating of silicon carbide with calcium aluminate does not appear to be possible. A more promising option would be the production of a self-heating catalyser from a triple combination of SiCl/Al2O3/calcium aluminate, with aluminium oxide as the intermediate layer.
