Regenerative Thermal Oxidiser (RTO) with downstream SCR-DeNOx
for Carbon Fibre production

Posing the task

A world-wide producer of Carbon fibres has extended the production capacity at his site in Scotland.
Experiences with existing Regenerative Thermal Oxidisers (RTOs) have shown, that a single unit is not able to meet the low emission levels, especially for Hydrogen Cyanide (HCN) and Ammonia.
Therefore a new concept / technology was required.

Solution / Highlights

Based on the rather low VOC concentrations, the Regenerative Thermal Oxidiser technology has still be selected as the most economic solution for destruction of organic compounds in terms of running costs.
Due to the content of HCN and Ammonia, NOX will be generated during thermal oxidation within the RTO. To meet the low emission requirements of Scottish Environment Protection Agency (SEPA), a downstream SCR DeNOX system (Selective Catalytic Reduction) for reduction of NOX, HCN and Ammonia has been installed downstream the RTO.
Urea solution has been chosen as reduction agent, as this is quite easy to handle. To provide a sufficient and constant reaction temperature for the catalyst, an air-heating device and heat exchanger have been included between RTO and DeNOX unit.
Stack emission sampling has proved compliance with all the required emission levels.