APC - Prime-D
Specific Application for Prime-D
The Prime-D advanced control package combines Axens' latest generation multivariable controller MVAC, in association with on line inferential reactor model and feed switch technology; it is designed to maximize the benefits from Prime-D process at the lowest operating cost.
As process licensor, catalyst manufacturer and advanced control technology supplier, Axens combines all the necessary expertise for successful Prime-D APC projects.
A six-step control strategy is implemented
- precise control of sulfur in ultra low sulfur products
- adjustment of hydrogen make-up for optimal H2/HC ratio in the 2 reactor beds
- control of reactor bed outlet temperatures
- catalyst deactivation monitoring
- throuput maximization (under catalyst run length and unit constraints)
- if 2 feed available, maximization of lowest value feed
Feed switch technology
- for a new feed, determination of new MV targets, using the reactor model
- rapid ramping to new targets, with constraint protection and sulfur control
Precise sulfur control
- the Prime-D control package uses Axens' on-line ULSD reactor models to estimate the sulfur content of the product at the reactor outlet.
- this technology allows precise sulfur control and fast feed switchover, even when the downstream sulfur on-line analyzer has a measurement lag in the order of 2 hours.
- static gains of APC models are updated on-line, for better control
- Sulfur on spec without give-away
- Minimization of feed switch time
- Catalyst run length maximization
- Reduction of hydrogen make up
- Minimization of energy consumption
- Increased throughput (if feed available)