Dust, lead accumulation rates

Ozone is a toxic unstable gas that in the presence of catalysts such as hydrogen, iron, copper, and chromium is subject to unstable decomposition. The presence of hydrocarbons, dust particles and high velocities may also lead to explosive decomposition. This reaction is exothermic and releases 136 BTU/mole (143 kJ/mole). Areas subject to ozone releases should be ventilated at a minimum rate of 10 air changes per hour. Ozone is 60 percent heavier than air and will tend to accumulate in low areas. 

It is of particular importance to predict zones of coke accumulation because the associated deactivation of the catalyst reduces the local endothermic effect leading to overheating of the reactor tube under the effect of the heat flux from the furnace to the reacting mixture. The formation of whisker coke is particularly detrimental because it can be blown off the catalyst under the high flow rates encountered in steam reformers. The dust is then blown out of the reactor into downstream equipment, like heat exchangers or compressors, where it can be particularly damaging. 

---