In recent years, several refiners have announced plans to convert their operations to renewable fuels production to remain viable as global economies try to reduce carbon emissions.

Process equipment designed to refine crude oil products will now be faced with new chemical compositions, pressures and temperatures. Free fatty acid corrosion, sulfidation, wet chloride corrosion, carbonic acid corrosion and stress corrosion cracking can all detrimentally affect existing carbon steel, stainless steel or internally clad reactors, drums and other process equipment.

One refinery in Eastern Canada has approached the issue of future corrosion by upgrading the metallurgy in their reactors and drums at a fraction of the cost typically associated with weld overlay.

The refinery was performing a site-wide conversion in preparation for firing renewable fuels instead of oil. The Canadian government was partly financing the conversion. Using sustainable aviation fuel results in an up to 80% reduction in carbon emissions compared to the traditional jet fuel it replaces over the lifecycle of the fuel.

Image credit: IGS.

Two reactors and two drums required a metallurgy upgrade due to new operating conditions. With renewables processing, reactors are susceptible to high temperature free fatty acid (FFA) corrosion, sulfidation, wet chloride corrosion, and stress corrosion cracking.

The drums had possible damage mechanisms including wet CO2 corrosion, wet chlorides and potential NH4HS and NH4CL.

Upgrading the metallurgy can be achieved via automated welding or high velocity thermal spray (HVTS).

Selecting the solution

Image credit: IGS.

The refinery in conjunction with their EPC have elected to go with the Integrated Global Services (IGS) HVTS solution. Jason Lynn, IGS HVTS subject matter expert, said: “I would say that they probably saved half of their cost comparing to automated welding. In terms of time, they saved a third of their time, so that was important.”

Integrated Global Services, Inc. (IGS) is an international provider of efficiency and reliability solutions. They focus on solving metal wastage and reliability problems in mission-critical process equipment.

“Another reason why they didn’t choose automated welding, was the fact that IGS doesn’t have to preheat the material for the HVTS application. This was important as the facility is in Arctic conditions.”

“The facility appreciated the fact that IGS could work turnkey. They didn’t want to have multiple vendors performing different tasks with one group doing preheating, another group welding with a third group potentially doing the post weld heat treatment.”

IGS worked turnkey and performed blasting, provided ventilation, applied thermal spray and inspection services.

Furthermore, much higher deposition rates, without dilution or needed “butter” / intermediate layers to achieve surface chemistry, make HVTS a better choice over welding applications.

HVTS vs welding

Credit: IGS.

Material science

IGS designed and specified two different alloys for the drums and the reactors. NiCroMoXX type material has been specified for the reactors due to its excellent resistance to chloride corrosion, SCC and sulfidation. For the drums, a NiCroMoWXX material was specified for its proven corrosion and erosion resistance.

Image credit: IGS.

Prequalifying the solution

The EPC, asset owner and the licensor required a comprehensive pre-qualification and adherence to a tight engineering standard to govern the quality of the cladding applied and ensure that the HVTS protection would hold up against the new harsh corrosion mechanisms. Tests were performed in the IGS state-of-the-art laboratory in Richmond, Virginia, to alleviate any concerns.

Iain Hall, the chief technology officer at IGS, said: “While material selection is important, it is only a small part of the technical package required to ensure durable long-term performance in claddings systems. Careful attention to surface preparation and accessibility, utilization of High Velocity process and critical parameter control is necessary to ensure homogenous alloy cladding with the right mechanical properties. It also takes more than a coupon to qualify an application. Management of environmental conditions and monitoring of field quality control with real time production test plate assessments is also required.”

IGS delivered an engineering package, including the project plan, method statement, inspection test plan, project safety analysis, risk mitigation plan and the job specific safety data sheets. The whole project was completed in 29 days.

To learn more about IGS and how their corrosion solutions could save your firm money, download this free whitepaper.