Over the years, we have delivered many decompression plants that have had the purpose of continuously feeding, for example, an industrial furnace with climate-friendly fossil-free biogas to replace e.g. oil as an energy source. What then happens is that the customer receives filled biomethane mobile gas storages with a pressure of 200-250 bar which needs to be regulated down to the desired pressure, often only a few bars.
When gas is compressed, the distance between the gas molecules decreases and the increased kinetic energy causes the gas to become hot and therefore the gas needs to be cooled down between each compression stage. In the case of pressure reduction, it is exactly the opposite and we instead need to heat the gas between each pressure reduction regulator. This is what we solve with our decompression units, where the gas is regulated down in pressure in a controlled manner and reheated between each step. Of course, that task is made easier by the fact that a relatively even and continuous flow is usually desired.
When we commissioned our new decompression unit for Gasum in Nynäshamn before the summer, the conditions were completely different; instead of a continuous supply, the biomethane would now serve as back-up operation in the event of power cuts and reduce the risk of expensive restarts. We thus had to design the plant to deliver gas with a pressure of 37 bars and a flow of a whopping 4000 kg/h within seconds. The flow alone is enormous as it corresponds to two mobile gas containers per hour and the challenge of being able to start immediately all year round meant great challenges for both our automation technicians and the gas boiler which is responsible for the controlled heating of the gas after each depressurization step.
Thanks to good planning and cooperation with the customer, we were ready on time and now our “Usain Bolt” is standing in the starting blocks waiting for the start signal which may come tomorrow, next week or maybe in a year. And all the time without getting cold or cramping. Do you want to know more about our decompression units? Get in touch and we will be happy to help you!