Following to the tightening of emission limit values complex, multi-stage plants have been installed for the gas cleaning downstream waste incinerators.
The Chemisorption with particle conditioning offers such a procedure. It mainly comprises the component parts additive powder injection (CaO/ Ca(OH)2, AC), reaction chamber, fabric filter and multiple particle re-circulation with wetting of recycled particulate prior to reinjection into reactor. This system allows the simultaneous separation of particles, heavy metals, incl. mercury and mercury compounds, acid crude gas components such as HF, HCl, SOx as well as dioxins / furans. Especially the approx. 50fold particle re-circulation combined with the wetting of the recycled particulate grants the high effectiveness of this system with regard to the separation capacity and the additive powder consumption.
The efficiency is described on the basis of several application examples out of the field of waste incinerators. The presentation includes among other things the degrees of separation and the emission limit values in comparison with definitely more complex scrubbing systems.
The process is in addition provided with an up-to-date control device for the additive powder injection. Based on crude gas measurements of the acid crude gas components HCl and SOx as well as on measurements of the volume flow, the additive powder is injected in dosed quantities in accordance with a given stoichiometric factor. The control concept is explained by means of a practical example.
Furthermore, results will be presented, showing the advantages of the Chemisorption with particle conditioning relating to the expenses for consumable supplies, compared to a conventional spray sorption for the separation of acid crude gas components.