Ethylene | Increasing Yield by Just 1.5% Equates to $12.6M/Year Additional Revenue

As global Plastic demands continue to increase, so do the pressures on Ethylene production. With ever-increasing production targets and a highly competitive Market- our customers are telling us that Improving Reliability, maximizing process Yield and throughput are becoming more and more challenging.

Challenges:

How your system responds during process disturbances could be costing you millions.

Ethylene Process challenges include:

• Increased process resistance reduces compressor speed ultimately impacting throughput
• Furnace trips creating a sudden loss of suction pressure to the Cracked Gas Compressor can lead to process trips or unplanned shutdowns
• Propylene refrigeration train and the interactions between front-end process changes are difficult to optimize and results in wasted energy

Solution:

Increase Throughput – CCC’s control system helps you maintain higher compressor speed when you would otherwise be pressure limited.  Advanced algorithms limit overshoot and provide tight control allowing the system to operate at higher pressure limits and at a higher compressor speed.  Throughput is maximized by optimizing the pressure set points.

Achieve Design Yields – How your system responds during process disturbances may be the difference between keeping your process from running or causing a trip.  When a single furnace trips, the suction pressure drops.  CCC takes only to 2 minutes to stabilize pressure under the largest of typical disturbances versus a general purpose control may take up to 15 minutes to stabilize pressure in a similar situation.  Robust control algorithms minimize control margins and allow for control at lower CGC suction pressure.  Reducing this CGC suction pressure by 14kPa results in an estimated 0.5% increase in yield.

Decrease Energy Costs – Optimizing the Propylene compressor train’s energy usage is nearly impossible with out advanced and integrated controls on the compressor and its driver.  CCC’s full integration of suction pressure control and antisurge control systems can allow for significantly expanded operating envelop for each compressor section without recycle.

Results:

Process optimization for a 600,000 MT/A ethylene plant can achieve the following gains:

• 1% increased throughput = $8,400,000/ Year
• 1.5% increased yield         = $12,600,000/ Year
• Avoiding Process Trips    = $2,000,000/ Day
• Shaft power savings of up to 9%