Chemical process catalysts: Characteristics
Why one point of selectivity is worth millions
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Buyers judge activity, selectivity, life, pressure drop and poison resistance in their own reactor, backed by supplier guarantees. Small gains in selectivity (EO, methanol) or approach to equilibrium (ammonia) are worth millions a year per plant.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Selectivity | EO high-selectivity silver about 85-90% (indicative) | feed use and CO2 | indicative |
| Catalyst life | about 2-10 years for fixed beds (indicative) | reload frequency | indicative |
| Shape and pressure drop | rings, multi-hole tablets | compressor and fan energy | indicative |
Commercial grades
- Nickel reforming catalyst
- HT and LT shift
- Ammonia synthesis (iron, ruthenium)
- Methanol (Cu-Zn-Al)
- EO silver (high-activity, high-selectivity)
- Sulphuric acid (K and Cs promoted)
- Pt-Rh gauzes and N2O secondary catalyst
- Ziegler-Natta, chromium, metallocene
- PDH (Cr, Pt-Sn)