PELLETISED CARBON FUEL – AQUAFORM ™: AN ADVANCED ASPHALTENE PELLETISATION PROCESS.
The implementation of new clean fuel specifications in South Africa will cause the value of oil refinery residues to drop to levels significantly lower than today’s. New value added opportunities for this material have already been identified and these can now be developed, provided the product can be turned into a free-flowing solid carbon format, thereby reducing cost of transport, storage and utilisation. Such technology is available through Kellogg Brown & Root, a company within the Halliburton group of America. A full module plant has been installed at the Engen refinery in Durban to evaluate and test this process and market acceptance of the product in South Africa.
What is Aquaforming?
Aquaforming is a process that converts bitumens into free-flowing particles (prills) roughly spherical in shape and with a size between 1 and 5mm. This product is clean and easy to handle at ambient temperature, which removes the need to store and ship the bitumen as a hot (180°C) liquid.
Bitumen is pumped through a trim heat exchanger (to maintain constant viscosity) to a mechanically driven prilling head located in the top of a closed vessel. Water is sprayed into the vessel to contact and solidify the falling prills. These drop into a heel of water in the vessel, from where both prills and water are withdrawn to a de-watering screen. The water is cooled and recycled to the prilling vessel and the prills are removed for storage.