Recently, Refined Technologies used its patented and proprietary Vaporganic® process and QuikTurn® chemical to clean both the shell and tube sides of 14 large series-connected heat exchangers. Before they were opened to the atmosphere, pyrophoric iron sulfides – known to be present on the shell side of each exchanger – were converted to iron sulfate using the Permanna® chemistry.
In the past, this large Gulf States refinery has had a problem performing maintenance on a series of 14 large, feed/effluent exchangers connected in series on their hydrocracker unit. The bank of exchangers are double stacked and installed across 100 linear yards of the refinery. The bundles are difficult to access and include a great deal of interconnecting pipe. To complicate the effort, pyrophoric iron sulfide on the feed (shell) side of each exchanger would combust as each bundle was exposed to oxygen. The combination of large volumes of hard to remove sludge, difficult access and pyrophoric combustion made conventional cleaning methods dangerous and ineffective.
Refined Technologies developed a plan to use QuikTurn and the Vaporganic process to clean all of the bundles and interconnecting pipe and deactivate the pyrophoric iron sulfide in less than 18 hours. The plan included written instructions and detailed drawings that were reviewed with refinery staff well before the project began. This documentation was used to identify and resolve potential problems, train people involved in the project, communicate information during the project and review after the project to identify opportunities for future improvement.
The cleaning and pyrophoric deactivation process involved these generalized steps:
- De-inventory the unit using standard procedures. No light cycle oil wash is necessary.
- Steam the exchangers to achieve a minimum temperature.
- Inject QuikTurn into the tube side of all exchangers at four points.
- Inject QuikTurn into the shell side of all exchangers at four points.
- Rinse both sides of all exchangers with water.
- Inject Permanna into rinse water going to the shell side and perform colorimetric test for pyrophorics.
The project began with injection of QuikTurn at 2pm on Sunday. Rinse water was applied at 2am on Monday, and the Permanna rinse was complete at 7:30am on Monday. The turnaround manager was very pleased with the cleaning project. There were no residual solids, no pyrophoric issues and no need to hydroblast the channel heads.
Refineries are using Refined Technologies’ patented products and services to gain a strategic advantage in the marketplace. In your daily operations meetings we encourage you to consider Strategic Chemistry®: the timely use of chemistry and planning, designed to improve Client operating margins.