It is not uncommon to arrive for a standard tank cleaning job to discover the contents are not as predicted. The challenge is to quickly react to get the project completed as safely, quickly and cost effectively as possible.
This is precisely what happened when TriStar PetroServ, a division of TriStar Global Energy Solutions, was called on to de-inventory and clean a standard Gulf Coast alkylation tank. Prior to the start of the project, it was discovered the contents were not as expected. In addition to alkyl, the tank contained a conglomeration of pyrophoric sludge, water and reddish oil at the top that could indicate acid soluble oil (ASO). Upon further evaluation, it was determined the pH of the sludge was 7.0 and the water was 5.9. In addition, there was 6 PPM of fluoride present as well as 3-percent pyrophoric iron sulfide (FeS). Due to these findings, the likely presence of hydrofluoric acid immediately raised the level of safety concern. Hydrofluoric acid is extremely dangerous, having the ability to not only burn but also penetrate to the bone.
To undertake this new challenge, TriStar PetroServ was able to call on its affiliated company, Zyme-Flow® Decon Technology, for additional technical support. Working with the head scientist on staff, they engineered a highly specialized plan unique to the situation. The proposed two-step solution used both patented chemistry (Zyme-Flow UN657) and advanced cleaning equipment, without having to call on a secondary vendor. The main objective was to first neutralize the extremely hazardous hydrofluoric acid, and eliminate both the pyrophoric iron sulfide (FeS) and hydrogen sulfide (H2S). Only after this neutralization was achieved could the tank be de-inventoried and cleaned. Additionally, due to the corrosive nature of the contents, all pumps, nozzles and metal surfaces had to be stainless steel or natural rubber.
After the approval was received from the operating committee overseeing the project, the job was carried out in two stages. The first step was the distribution of Zyme-Flow chemistry using two high-pressure cannons. The contents were then circulated to completely neutralize the H2S and FeS. The second stage used the cannons to add a neutralizing solution that converted the hydrofluoric acid to harmless fluoride salts. Once neutralized, the tank was considered safe and nonhazardous allowing the de-inventory and final cleaning.
The project was very closely monitored, having both a full-time safety technician and a Zyme-Flow Decon service technician on site. This specific tank proved incredibly dangerous, but by developing such a unique solution, the tank was cleaned with zero injuries or incidents of any kind. The entire process, including the use of chemistry, was labeled a best practice for this situation.
What started as a normal tank cleaning job turned into a highly specialized cleaning and decontamination project. This challenge was successfully completed by taking advantage of the technical expertise and product offerings that fall under TriStar Global Energy Solutions.
For more information, contact TriStar PetroServ at (281) 484-2223 or info@tristarpetroserv.com or TriStar Global Energy Solutions at (281) 484-2201 or sales@tristarges.com.
