Gas Purification Catalysts

Synthetic air, N₂, O₂, H₂, noble gases, etc. are typical industrial gases which are often required in high purities.

By using HeraPur^® catalysts all common impurities, such as H₂, O₂, CO and hydrocarbons can be removed efficiently even at low temperatures. In many cases the residual concentrations of the impurities amount to only a few ppb.

Catalyst recommendation for the removal of impurities (examples):

Compared with purely thermal oxidation, catalytic combustion is an economically attractive variation. It functions at considerably lower temperatures and it is less demanding on the materials. Also, it gives longer service lives of the equipment components due to lower thermal loads.

HeraPur^® catalysts based on precious metals and/or non-precious metals guarantee the reliable purification of complex pollutant compositions and also those containing FCHC. The catalysts are used in various industrial processes, e.g. in chemical production, printing shops, paint shops, the electronics and food processing industries, and also in the purification of waste and ground water.

Catalyst recommendation (examples)

The public discussion in the climate debate is focussing more and more on N₂O emissions: N₂O is 310 times more effective as a greenhouse gas than CO₂.

N₂O emissions arise, for example, in the production of nitric acid and other large scale technological processes and also in medical applications. Without any problems, HeraPur^® catalysts decompose N₂O into its harmless components nitrogen and oxygen. For this there is a choice between two alternatives:

• Special doped Rhenium catalysts – for the highly efficient treatment of dry, low-oxygen gas streams
• Palladium support catalysts – for the treatment of moist and oxygen-rich volume streams.

Inert gases are used in the thermal post-treatment of polymer raw materials, for instance in the SSP process (Solid State Polycondensation) for polyester materials. The impurities, which are enriched in the inert gas, are organic compounds, such as aldehydes, glycols and oligomers.

These impurities are removed from the inert gas in circulation by means of catalytic oxidation. Heraeus catalysts can be used in this process with a minimum (stoichiometric) excess of oxygen. The purified gas can be fed back into the circulation immediately after a subsequent drying step.

Also, Heraeus catalysts are used in the purification of exhaust gases in PTA equipment.

Catalyst Options:

It is not only the food processing industry which is showing an increasing demand for CO₂ of highest purity but also many other markets. Both CO₂ from natural sources and industrial CO₂ often contain a large number of impurities such as CO, methane and aromatics which must be removed before further use.

By using HeraPur^® catalysts high degrees of purity can be achieved specifically to meet the quality requirements of the food processing industry.

Catalyst recommendation: