Operating at a wrong synthesis operating pressure is always a tricky situation for any urea plant operator, knowing that a too high operating pressure will lead to blowing off of the pressure safety valves, which cause not only a significant environmental impact but also a forced shut down of the plant as typically the pressure safety valves do not close anymore properly after blowing. Servicing these valves becomes necessary and because of that not producing any urea can be a costly incident. On the other hand operating at a too low synthesis pressure will lead to lower conversion figures, higher carbamate recycle streams and higher energy costs. Key is to measure the synthesis pressure in a reliable way. Most ideal would be to measure the synthesis pressure as close as possible to the pressure safety valves so in a high pressure carbamate gas line, but crystallization and corrosion risks are the challenge here. Until recently this was not possible and mostly the synthesis pressure has been measured at locations, where these risks are not or less likely present. Now LESER has developed together with SKW Piesteritz a reliable solution to measure the synthesis pressure in the high pressure carbamate gas lines. But what to do when one does not have a reliable synthesis pressure indication ?
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