Selection of transformation process
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I don’t know much about conversions; for now, I only know that conversion catalysts include Fe-Cr series, Cu-Zn series, and sulfur-resistant conversion catalysts. However, it is not clear as to how this is applied in industry at present. According to available information, there are levels such as medium-low, low-low, and fully low; it is unknown whether there are conversion processes that use only Cu-Zn-based catalysts, and what the corresponding conversion temperatures and pressures are Please give me some advice, thank you!
The temperature depends on the catalyst’s activity temperature and activity pressure; it is around 500 degrees for temperature and around 3.0 MPa for pressure
Is the temperature mentioned upstairs the reaction temperature of the Cu-Zn series shift catalyst? From what I understand, it’s in the range of 190~280°C I’m not quite sure; can someone give me some guidance?
Our factory uses fully low-voltage transformers of the cobalt-molybdenum type; the temperature remains below 400 degrees, which is also acceptable
Our plant uses a medium-low-low shift process for methanol production; the choice of shift process is determined based on the actual conditions of our plant. If more methanol is desired, a full low-shift process is employed.
The Fe-Cr series belongs to high (medium) shift catalysts, featuring high activity temperatures but poor sulfur resistance. The copper-zinc-aluminum and copper-zinc-chromium series belong to low-shift catalysts; although they have good activity at low temperatures, their range of effective operation is narrow, and they are also very sensitive to sulfur (180–260°C). Sulfur-resistant shift catalysts were developed in the late 1950s as catalysts that are resistant to sulfur and have a wider range of optimal activity temperatures. (180–500°C)
The Fe-Cr series belongs to high (medium) transformation catalysts, while the Cu-Zn series belongs to low transformation catalysts. Due to their high sensitivity to sulfur, Cu-Zn-based low-temperature shift catalysts are generally used in three-catalyst (shift, purification, synthesis) processes that utilize natural gas as a feedstock, and many systems of such processes are still in use today. Generally, in ammonia synthesis plants that use coal as raw material, even when low-temperature shift processes are employed, Co-Mo-based low-temperature shift catalysts are mostly selected. The active temperature of Cu-Zn series low-activation catalysts is generally between 180 and 240 degrees, and they can be used at pressures ranging from atmospheric pressure to 3.0 MPa.