Corrugated catalyst

A corrugated catalyst uses corrugated ceramic-fibre sheets coated with the active catalytic material, assembled into modules with alternating flat and corrugated layers to form gas-flow channels. The construction is lighter than honeycomb and plate catalysts and is particularly common on tail-end SCR, marine duty and applications where catalyst weight matters.

Where corrugated catalysts fit

Tail-end SCRs downstream of FGD
Marine SCR for shipboard NOx control
Co-generation and industrial duty with weight constraints
Some HRSG installations

Trade-offs

Factor	Corrugated	Honeycomb	Plate
Weight per unit volume	Lowest	Highest	Medium
Mechanical robustness	Lower	Medium	Higher
Surface area	Medium	Highest	Lower
Cost	Variable	Lowest (mature supply)	Medium

Corrugated catalysts are less common in heavy-duty coal and cement SCR but earn their place in specialised duty.

Construction and use

Corrugated catalyst is built from thin corrugated sheets or fibre-reinforced plates that create parallel gas passages. The active catalytic material is applied to or incorporated into the sheet structure. The result is lighter than many ceramic honeycomb blocks and can be packaged into modules for SCR reactors with limited support capacity.

It is common in applications where low weight, moderate pressure drop and resistance to thermal cycling are important. Tail-end SCR, marine engines, gas turbines and some industrial processes may use corrugated designs depending on dust loading and temperature.

Strengths and limitations

The open corrugated geometry can tolerate some thermal movement and may be easier to handle than brittle monolithic blocks. However, thin sheets can be damaged by rough handling, high-velocity ash, water washing or mechanical cleaning. If passages deform, gas distribution and catalyst surface exposure change.

Compared with large-pitch plate catalyst, corrugated catalyst may be less tolerant of coarse particulate. Compared with honeycomb, it can offer lower weight and different pressure-drop behaviour. The correct choice depends on ash properties, required activity, reactor geometry and service temperature.

Cleaning implications

Cleaning must avoid crushing or tearing the catalyst sheets. Sonic horns are attractive where fine dust or ammonium salts form a surface layer because they provide non-contact energy across the face. Heavy pluggage, oil contamination or cemented salts may still require outage cleaning or module replacement. The cleaning plan should be agreed with the catalyst supplier because acceptable methods vary by construction.

Field checks

Corrugated catalyst is inspected for open flute passages, face damage, delamination, ash packing and frame sealing. Its lower mass can make handling easier, but the geometry can also be vulnerable to crushing or deformation if modules are lifted badly or if deposits load one area unevenly. Gas distribution remains critical because local high velocity erodes the exposed corrugations while low-velocity lanes accumulate ash.

Operating teams watch reactor differential pressure, ammonia slip, outlet NOx and temperature distribution. A corrugated layer that stays open can give good low-pressure-drop service, but plugging can progress quickly once a few passages close and flow shifts to the remaining open flutes. Acoustic cleaning is useful when deposits are dry and reachable at the inlet face. It should be set to prevent face packing without causing unnecessary vibration of brittle catalyst media or loose module hardware.