Elevated temperature separation chemistry

In the previous section we dealt with the surface area per unit weight or unit volume required to achieve technically acceptable conversions. The conclusion was that porous catalyst particles must usually meet the demands both of pressure drop (fixed bed catalysts) or of viability of separation (suspended catalyst particles) and of the extent of the catalytically active surface area. When the catalyst must be thermally pretreated, the active surface area should not severely drop as a result of sintering of the active particles. Although solid catalysts in fine-chemistry operations are usually employed in liquid phases, i. e. not at highly elevated temperatures, sintering of the active component(s) should not occur during the reaction. 

The corrosion coupons are 31.75 mm diameter discs 3.175 mm thick and with a hole in the centre to fit over an insulated stainless steel rod. Plastic insulators separate individual coupons. The coupons are not preoxidized at elevated temperature in water but have the normal air formed oxide. This condition should make them more sensitive to any water chemistry changes. Four basic types of corrosion coupon are being tested in the L basin and RBOF water environments ... 

---