High-Dust SCR Technology

Operational Experience with Catalytic NOx Abatement

7th International VDZ Congress 2013Düsseldorf, 26 Sept 2013

Detlef EdelkottSchwenk Zement KG

• Aug 2008 - Application for permission and subsidies

• Oct 2008 - Purchase agreed

• until Mar 2010 - Planning, delivery, erection

• Apr 2010 - Start-up

• since May 2010 - Testing & optimisationsupported by in-depth research by VDZ

Project phases

Project Phases

Description of the SCR installation

Exhaust gas system with combined SCR and SNCR

NH3-injection for SNCR

NH3-injection for SCR

SCR

ID Fan

Suspension PreheaterMergelstetten with SCR Installation

Description of the SCR installation

Catalyst

specific requirements:

• fit for high dust contents

• sustainable activity

• low oxidation rate SO2 to SO3

• chemically and mechanically stable

• low pressure drop

Description of the SCR installation

6m

6m

blower

Scheme of a Catalyst Layer Cross-Section

18 catalyst modules

Description of the SCR installation

Process Control Scheme of SCR

Description of the SCR installation

• Apr. 2010 Initial start-up with three active layers in hexagonal honeycomb-design (L = 1.3m) installed and a dummylayer on the top

• Jul. 2010 Active catalyst layer (L = 0.6m) added in place ofdummy layer

• Feb. 2011 Bottom layer replaced with new square grid design layer (L = 0.9m)

• Nov. 2011 Middle layers replaced (1 new, 1 regenerated)

• Sept. 2012 Top layer replaced (regenerated)

• Jun. 2013 Repair of both regenerated layers

Changes of configuration of SCR

Operational results since refit Nov 2011

Operational experience

Operational results since refit Nov 2011

448 days clinker production411 days SCR operation 92 % availability

Operational costs of SCR

Investment and operational costs

- Catalyser replacement

- NH3 consumption24.9% Ammonia solution or 40% urea

- Power consumption

Influence of injection location on reduction agent consumption

Investment and operational costs

refitting ofSCR, SNCR

onlycombinedSCR/SNCR

SCR only

Power consumption of 4 layer SCR

Investment and operational costs

Conclusion• High-Dust SCR is feasible and effective –

emission limits of 200 mgNO2/m³ and 30 mg/m³ NH3 can certainly beachieved. The compressed-air cleaning system must be properlylevelled and maintained

• Availability approx. 92% in 2012 – 100% availability should beachievable

• Deactivation time has been unsatisfactorily low –longer life-cycle is expected with limitation of operation temperature bywater injection into the downcomer (less than 380°C)

• Regenerated catalyser elements were seen to suffer a decrease in mechanical resistance (erosion of weakened elements)

• Injection of either Urea or Ammonia solution show comparable results

Conclusion

…….many thanks!