APC - Sulfur Removal
A tailored application for Sulfur Removal Units
The SRU advanced control package uses Axens' latest generation multivariable controller MVAC.
It is designed to achieve optimum operation of the SRU, often a difficult to control process, in an environment with frequent composition and flowrate variations of the multi-component feed.
Poor operation can easily result in emission violations, SRU shutdown or costly constraints for upstream plant operations.
As a catalyst manufacturer and an advanced control technology supplier, Axens combines all the necessary expertise for successful SRU APC projects.
A four-step control strategy
- Tail gas ratio control: H2S / SO2, by adjustment of air flow for optimal conversion
- Catalytic reactor inlet temperature control, to monitor hot spots, control catalyst bed dew-point and prevent sulfur laydown on the catalyst
- Thermal reactor temperature control, by adjustment of the feed split, to promote complete oxidation of amine compounds in the acid gas feed
- Compensation for dead time variation, generated by significant changes in the flowrate.
On-line analyzers are recommended for tail gas and acid gas in order to allow feed-back and feed-forward actions.
Axens' inferential technology is used for on-line estimation of main fractionator product qualities.
- Reduction of sulfur compounds emissions (meet emissions limits)
- Reduction of operating problems (sulfur blockage,…)
- Reduction of unscheduled downtime (constraints for upstream units)
- Increase of sulfur recovery ( + 2%)
- Extended catalyst bed life
- Reduction of energy consumption