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IN2ERT at your Service: Rapid and Effective Treatment of Refinery Equipment
By adding a mist of select chemistry to otherwise, inert nitrogen (N2), Linde offers a cost-effective accelerated cleaning and purging solution for decontaminating refinery process equipment.
Successful execution of maintenance tasks is critical to the reliability of refinery operations, where extended downtime is not an option. Operators need quality results, quickly. With IN2ERT, Linde offers its refinery customers a flexible platform technology for accelerated purging and cleaning of process equipment like reactors, tanks, piping and heat exchangers, that reduces maintenance downtime - not to mention the added benefits of predictability, reliability, safety, and sustainability
Maintenance: Where Time is of the Essence
Take a look inside many refinery vessels and you’ll physically see oil and sludge adhered to the walls. What you won't see are the toxic, flammable gases emitted by these hydrocarbon residues. For anyone entering the vessel to carry out non-routine maintenance and repair work that refinery process equipment periodically requires, this poses a clear safety issue. "Any vessel must be safe for personnel entry in these situations", explains Ashley Zachariah, Technology Expert - Linde Technology. “That means purging the vessel of hydrogen sulfide and volatile organic compounds before any maintenance work is performed."
To this end, inert nitrogen is conventionally used. In a long and often unpredictable process (taking anywhere from 24 hours to several days in some cases), non-combustible nitrogen gas is injected displacing toxic and flammable gases to vent. The problem is, even once purged in this way, surface residues continue to off-gas, and vapor space concentrations creep up to unsafe levels again. This reduces the time window for maintenance work to be safely performed and can result in suspension of activities before completion. "Our customers place tremendous value on time and predictability," says Zachariah. "Time lost on maintenance work translates to lost production and lost revenue."
Customized Chemistry for Customer Needs
Instead of just nitrogen, Linde's IN2ERT solution accelerates purging and cleaning by using chemical-enhanced nitrogen. "Since nitrogen is inert, we can add specific chemicals to it as a mist or foam without worrying about any reactions," Zachariah explains. Specific chemicals to the task at hand that is. "IN2ERT is a fully developed chemical delivery method using nitrogen,” he adds. "If a customer has an issue that requires a specific chemical to interact with a contaminant, we can select and provide a more customized formulation."
In tank purging applications, the IN2ERT chemical mist effectively encapsulates hydrocarbons and neutralizes H2S - and because the formulation coats the surface residue, it also prevents further off-gassing. The vessel is therefore rendered inert in a faster and more predictable process. From a sustainability perspective, the benefits are clear: less time, less nitrogen compared to traditional purging and less harmful gas handling. "That means a lower quantity of gases sent to flare – and thus lower CO2 emissions overall," adds Zachariah.
A heat exchanger cleaning case in point: One Canadian heavy oil processing facility ran a cleaning trial on its fouled heat exchangers. The thick bitumen that had caked the tube surfaces had significantly reduced heat transfer efficiency. Using IN2ERT, Linde Services cleaned one tube bundle in four hours to the point that the customer didn't need to pursue manual cleaning - a long process with elevated safety risks. Comparatively, the tube bundle pulled from the sister heat exchanger took 40 hours of total manual cleaning time to reach the same clean state. 
Richard Kelly, Associate Director - Linde Technology sees the tale of IN2ERT as one of transformation: "We essentially transform nitrogen from an inert but functional gas, typically used pneumatically in industrial services, into a more reactive substance." As in the previously mentioned case study, if cleaning a heat exchanger is the task - i.e. not just purging the vessel but physically removing the surface contamination - then cleaning chemicals are also selected. "The technology platform is the same - we just build the applications based on specific customer needs," says Kelly. In the case of accelerated reactor turnaround services, for example, "the process design is a little more complicated because of the packed catalyst bed. It's not just about the gases and chemistry but setting the right flow rates and managing pressures too." Here Linde can lean on its unrivaled gas handling experience and expertise.
A Solution That Delivers Results. Reliably.
Beyond just the nitrogen, a typical IN2ERT setup includes a chemical injection skid that houses chemical storage and metering equipment, an IN2ERT mixer with safety valves and an optional vapor scrubber. "Linde always offers reliable equipment and nitrogen supply," Zachariah states, "But as well as that, our portfolio of services enables us to offer a single service supplier model." After decontamination for example, Linde Services can also take care of reactor cooldowns and inert support during catalyst change-outs - both using nitrogen gas. "This seamless suite of services simplifies communications and coordination efforts for customers and reduces risks associated with complex temporary setups that can also cause compounded delays".
As one turnaround planner from a refinery located in the midwestern United States who had turned to IN2ERT to service a chloride treater testified: "Having a reliable cleaning process saved other costs including reducing the time on site for our vendor handling the effluent vapor control." On the same job, IN2ERT provided 70%-time savings compared to previous times with nitrogen alone.
Incidentally, the very genesis of the IN2ERT offering was a result of responding quickly to a customer need, as Kelly recalls: "By working in an agile way, we went from idea to first commercial job on a small tank in just 70 days." IN2ERT was quick out of the blocks and continues to accelerate.