The next generation of steam super-heating in ammonia and methanol production lines

摘要

The heat recovery equipment in Ammonia processes downstream the secondary reformer, as well as in Methanol production, typically consists of a process gas cooler operating as steam generator and a steam super-heater. Those heat exchangers are major contributors to the overall process efficiency and reliability. The steam super-heater is especially important as the working horse in this heat recovery package. Depending on the licensor and process, the super-heated steam temperature is in the range of 330°C to 470°C and in a pressure range 100 bar to 130 bar. For a typical application the so called U-type steam super-heater was developed and established by SCHMIDTSCHE SCHACK and also a limited number of other heat transfer equipment suppliers about 15 years ago. The SCHMIDTSCHE SCHACK U-type has special features, which enable a robust mechanical design and good temperature control capability for the process gas as well as for the super-heated steam. However, based on the process flow schema, the U-type is close to the mechanical threshold when gas and steam temperatures in the upper range are applied. Since the steam super-heater is a valuable but critical part in the process chain of Ammonia and Methanol production, SCHMIDTSCHE SCHACK has designed and manufactured a steam super- heater, which allows higher steam parameters up to 540°C / 130bar. This design is a combination of proven features and this apparatus is currently used in a Methanation process, but it can also be installed in Ammonia or Methanol production lines. This new steam super-heater provides the licensor and the customer a further reliable potential for improving the overall process efficiency by either reducing the natural gas consumption in fired heaters or increasing the electricity production.