Air Separation Case Study
An air separation plant located in Sarnia, Canada had maintenance issues with their existing plant 22,000 CFM Centrifugal Compressor and it warranted an overhaul. This could entail shutting the unit down for up to 3 months during the overhaul, and that was not an option as the plant uses the compressed air to produce nitrogen based on its contractual obligation to neighboring plants. So, they had to weigh the risks of continuing to run the compressor and risk an unplanned outage because of a failure or explore a temporary option during the overhaul.
The typical rental option available to them was to bring in 15 x 1500 CFM diesel compressors and all of the accompanying accessories that would take up an enormously large footprint. Additionally, they would have to account for the increased emissions at the plant and how that would affect their site-wide permit, fuel deliveries and increased chance of a spillage on site, and of course increased maintenance costs. Another option would be to bring in 15 x 1500cfm electric units, but depending on where they can place that many units, where the electrical and air tie in would be, it could present a whole other set of challenges. And these challenges don’t even take in to account the reduced efficiency of the rental rotary screw compressors vs their existing centrifugal compressor, which are significant. At the end of the day when factoring in the cost, reliability, space available, emissions and efficiency, they needed to find a safer and more cost-effective option.
Since Critical Rental Solutions had worked with some of their sister plants throughout the US, we were recommended as an option to consider. After some discussions around the needs and challenges of this project, CRS’s engineering group came up with a solution that involved placing a single 22,000cfm centrifugal compressor on site with a minimal footprint and the ability to fully integrate the compressors control system into existing plant controls. This allowed for the plant to operate as if their existing unit was still online and give them the comfort in their ability to provide the air required for their processes. There were also some challenges with obtaining the correct approvals to getting the unit into Canada, but CRS has crossed that bridge before and was able to supply the certifications required to operate.
In the end, the project lasted a little longer than anticipated as there was unforeseen work that was required on the plants existing compressors, but they could rest easy and continue their operation uninterrupted as they had a reliable alternative.
