Engineering
PLANTSERV® Learn how flexible an ASU can be
Industries are changing at lightning speed. Discover how to adapt your ASU to evolving customer needs.
Most ASUs are optimized to produce a defined product mix in a very narrow range. This set point optimizes efficiency, but it also limits the ability of operators to react to short term fluctuations and even more to a long-term change in customer demand. We receive more and more requests to adjust the output of plants or increase the output flexibility. However, plant managers are often concerned about the downtime and CAPEX of a major revamp and the risk when starting up their plant again; but this must not be the case. In certain cases, even fundamental changes in the output can be realized without major changes to your equipment.
For one project the operator faced a difficult situation. The plant was designed to produce similar levels of LOX and LIN, but the LOX demand was in a long-term decline and the plant was no longer operating efficiently. Thus, the plant manager requested us to explore ways to use the excess LOX in an injection system to liquefy gaseous nitrogen to LIN. Our engineers have developed similar systems in the past, so this didn’t seem to be a challenge. However, liquefying and expanding the same gas just to use it for cooling purposes is not exactly an energy saver. So, our engineers started evaluating alternative options for the plant to increase the LIN production, stop the oxygen liquefaction or even find a new use for the LOX product.
Most of the obvious solutions had a big impact on some of the equipment, especially machinery or coldbox. But with a limited budget those options were off the table. With their experience and process know-how, our LINDE experts found a way to adjust the plant at low investment and without using LOX as a cooling agent. They were able to increase the total air inlet flow, extract a significant amount of GOX prior to liquefaction and redirect this GOX to another offtake process. With adjustments in pressures, temperatures, and flow rates in the coldbox and compressors, the now increased flow of nitrogen can be liquefied with the existing equipment. Thanks to the high flexibility of the installed compressor not even additional throttling is required. With this new case, the plant achieved the required LIN and GAN capacity with high energy efficiency while producing significantly lower amounts of LOX. The plant is now producing in line with the new demand, and the LINDE engineers helped the operator avoid a major revamp, downtime, and CAPEX just with their process know-how.
Linde PLANTSERV®
Performance you can trust
You can trust in our experience and our aim to find the best solution for your plant and your needs. If you must react to changes in your customers’ demand or want to know how you can optimize the overall efficiency of your ASU, contact us now and benefit from our experience from projects in more than 2.000 ASUs.
