Petrochemicals
Fouling Mitigation Program Recovers Operating Efficiency and Extends Run Length for Ethylene Plant Oil Quench Tower
Mar 16, 2011
Mike Hong
Extension of system run length and maximizing plant throughput will bring substantial profit to olefin producers. The fouling problem in the oil quench tower of the ethylene plant, however, has become a challenge to achieving long run length goals and has even led to unscheduled shutdown or reduced...
Loss of Downcomer Seal on a Depropanizer During a Plant Start up
Mar 16, 2011
Andre Bernard
The bottom C4’s product specification could not be met on the Depropanizer tower during a plant start up. The olefins unit had been started with a new start up procedure, which involved significant reduction in feed rates to the unit until achieving on spec ethylene. C3 & C4’s product were to...
A New Class of Polymer Inhibitors
Mar 16, 2011
P. N. Ramaswamy
Polymer inhibitors are used within an ethylene plant in locations which are susceptible to aggressive polymer formation i.e. Primary Fractionator, Compressors, Pyrolysis Gasoline Strippers and within the Gas Separation units. Over the years, the use of such additives has been extended to newer...
Enhanced Heat Transfer Technology Proves Beneficial In Cooling Water Driven Condensers
Mar 16, 2011
Michael R. Sobczyk
Cooling water driven condensers utilizing enhanced heat transfer technology deliver technical and economic advantages in both revamp and grassroots applications. Meeting equipment performance demands within the confinement of an existing unit structure can be accomplished with simple tube bundle or...
Improved Ethylene Cracking Furnace Control with Modern Process Mass Spectrometers
Mar 16, 2011
Peter J. Traynor
Whereas process mass spectrometers have been used as an alternative (lower cost) solution to multiple process gas chromatograph installations for many years, their use has been somewhat limited by their complexity - both real and perceived. The latest generation of process mass spectrometers has...
Cracked Gas Compressor Control Tutorial
Mar 15, 2011
Nauman Islam
The market conditions over the couple of years has prompted many end-users to review antisurge control design to help lower their energy index. A number of factors affect antisurge control system design and consequently impact the surge control margins. Cracked/charge gas compressors have evolved...
Objectives of Anti-Surge Control
Mar 15, 2011
W. Brian Piercy
Objectives of Anti-Surge Control Preventing a compressor surge is the primary purpose of an anti-surge controller. However, there are additional requirements that must be met for an anti-surge control package to be effective. It must be stable and reliable, while also keeping energy costs to a...
Increased Fouling Potential and Mitigation Plans for Heavy Sour Crude Oils
Mar 15, 2011
Parag Shah
It is becoming a widespread norm that refineries are processing an increasing quantity of heavy and sour crudes than ever before. The depleting oil reserves of light sweet crudes have resulted in the need for deeper exploration. Considerable finds in the Orinoco belt of Venezuela, California and...
Thoughts about Safety, Staying at Zero
Mar 15, 2011
Rendell Newton
Perfect safety records and perfect environmental records are an “inalienable right”, given to us not by governments, companies, or others. It is a right we give ourselves. It takes different skills and thinking to stay at zero recordable incidents than it does to get to zero recordable incidents...
Practices to Mitigate NOx Risk In Cryogenic Section of Ethylene Plants
Mar 15, 2011
Jennifer L. Bancroft
In May 2010 the Ethylene Producers Committee NOx Safety Sub-Committee sponsored a discussion on practices to mitigate NOx risk in the cryogenic section of ethylene plants. The meeting was attended by representatives of 10 ethylene producers, 4 ethylene contractors and other contractors, 2 additive...
Flare Minimization Via Dynamic Simulation
Mar 15, 2011
Kuyen Li
Flaring in chemical process industry (CPI) is an important method to protect equipment and personnel safety during the process upset and the chemical plant turnaround. However, excessive flaring emits lots of carbon dioxide as well as air pollutants, which cause negative environmental and social...
Practical PID Control: Use Filters for Better Disturbance Rejection and Setpoint Tracking
Mar 15, 2011
Patrick P. Thorpe
Many of the practical problems in achieving high performance feedback control for challenging applications have been addressed by modifications to the basic PID control law. These modifications include set-point filters that allow both load rejection and set-point following objectives to be...
Evaluating the Heat Exchanger Technologies Available for Use In Refinery Pre-Heat Trains
Mar 15, 2011
Graham T. Polley
Fouling behaviour is a crucial consideration in the selection and design of heat exchangers to be used in refinery pre-heat trains. We make the following observations regarding fouling associated with the heating of crude oil: 1. The fouling rate decreases with increase in wall shear stress 2. The...
Improving Ethylene Charge Gas Compressor Performance
Mar 15, 2011
Giorgio Greco
The changing landscape of the ethylene industry requiring more feedstock flexibility and upstream and downstream integration increases the complexity of cracker design and management exacerbating challenges traditionally present in ethylene plant operations such as the fouling phenomena. The...
Consequences of High-Pressure Tube Ruptures In Low-Pressure Liquid-Filled Shell Heat Exchangers
Mar 15, 2011
Claire J. Ennis
Shell-tube type heat exchangers are often used to exchange heat between a high pressure fluid and a low pressure fluid, and the pressure difference between the two fluids could be significantly high. In the event of a partial- or full-rupture of a tube, a problem may arise in that a transient...

