HF Alkylation Troubleshooting & Benchmarking Studies

Improve HFA Unit Safety and Reliability

Equity is among the few independent engineering companies to achieve an international recognition for its expertise in the understanding of corrosion in HF Alkylation (HFA) Units. We have also developed a benchmarking process to review HFA units with the specific intent of improving unit reliability.

Equity’s Jon Dobis, P.E. is a recognized expert in the field of HFA and the effects of operating parameters on corrosion in HFA units. He has authored or coauthored 19 technical publications, including five in the area of HFA.

We have shown that it is possible to identify the relationship between specific operating parameters, including maximum levels of feed contaminants, to help define an operating envelope. Significant damage to equipment can occur when operating parameters drift outside recommended limits. In order to accomplish this, we help establish operating, inspection and maintenance guidelines to improve HFA Unit safety and reliability.

We utilize a benchmarking study to help identify opportunities for improvement. The benchmarking methodology has been used to help maintenance and inspection groups gain a better understanding of the manner in which corrosion is directly affected by operating parameters.

The overall goal is to help minimize corrosion and fouling problems in HFA Units. Important factors affecting unit reliability are discussed, with particular emphasis on the importance of feed treating practices, and the effect of feed contaminants and operating conditions on corrosion and damage to the unit.

Typical examples of the activities and areas of interest include:

• Identify key process parameters and help define an operating envelope to minimize corrosion, fouling, and other forms of damage in HF service (temperature limits, acid strength, water, etc)
• Effects of contaminants such as oxygen, sulfur, arsenic, ethylene and others
• Operating and maintenance guidelines to minimize corrosion and fouling
• Materials of construction selection criteria and limitations
• Common damage mechanisms found in piping and equipment in HF service (e.g., corrosion, HIC, SOHIC, blistering, dealloying, etc.) and the factors that contribute to this damage
• Inspection methods for various damage mechanisms
• Best-in-class inspection programs including methods and frequencies (e.g., flange face inspection, vents and drains, heat exchangers, safety valves, etc.)
• Corrosion monitoring
• Chemical cleaning and neutralization