Abstract: In a process for operating an ammonia plant, a gas mixture comprising nitrogen, hydrogen and ammonia is conveyed cyclically in a synthesis circuit with a conveying device which comprises at least a first compressor, nitrogen and hydrogen are converted at least partly into ammonia in a converter, the gas mixture is cooled in a cooling device in such a way that ammonia condenses out of the gas mixture, and hydrogen is provided at least partly by electrolysis. In this process, the utilization of fluctuating renewable energies can be integrated into existing plant designs, for the provision of hydrogen; for this reason, a master controller is provided and the master controller keeps at least the pressure in the synthesis circuit approximately constant via at least one control loop, on the basis of the anticipated amount of hydrogen. For this, the apparatus comprises a first bypass line for circumventing the first compressor, and a second bypass line for circumventing the cooling device.

Abstract: A memory system for an automatic door, the memory system being capable of recording for a specified length of time all relevant operational parameters according to the first-in/first-out principle.