PLANTSERV® – Learn how flexible an ASU can be
When product demand shifts, your ASU can adapt. Learn how process know-how enables flexible ASU output with minimal investment and downtime.
Designed for efficiency – but not for change
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.
A plant no longer aligned with market demand
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.
Adapting the ASU with process know-how
Many of the obvious solutions would have required major modifications to equipment such as machinery or the coldbox and were therefore not feasible within the available budget. Instead, LINDE experts applied their process know-how to adapt the existing plant.
By increasing the air inlet flow and extracting gaseous oxygen before liquefaction, LIN production could be increased without using LOX as a cooling agent. With targeted adjustments to pressures, temperatures and flow rates, the plant met the new LIN and GAN demand using the existing equipment. This approach allowed the operator to avoid a major revamp, downtime and CAPEX – while realigning the plant with current market needs.
