Automation of Distillation Columns has always been one of the most challenging subjects for a control engineer due to its complex nature, multiple options for degrees of freedom and slow dynamics of the process. We at Control Solutions have extensive experience in handling a variety of distillation applications in refineries, petrochemical, chemical, pharmaceutical and specialty chemical industries. This includes batch stills, both packed & tray columns, multi-pressure, atmospheric and vacuum-based systems, different configurations of reboiler or direct steam spargers, side stream draws, single or multiple condensers, columns having internal reference or external reflux conditions, choices of accumulators, etc.
Some of the common control techniques include:
- Steam pressure control
- Steam flow control
- Feed flow control
- Column pressure/vacuum control
- Condenser controls
- Reflux ratio controls
- Reflux & distillate controls using accumulator level
- Specialized control techniques for azeotropic mixtures
- Column temperature controls
- Bottom level controls
- Composition controls
A well-designed state-of-the-art control solution can provide the following benefits:
- Maintaining column equilibrium
- Optimization and consistency of product purity and yields
- Substantial savings on energy consumption
- Enhanced operational efficiency
- Safety
- Increased product throughput
