Rate of increase in system resistance
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Our company has a sulfuric acid production plant, with the ash content of pure sulfur at 10 ppm. What is considered a normal rate of increase in catalyst resistance?
It’s hard to say by how much the resistance increases, but for a single-layer catalyst in a converter, a pressure difference of no more than 2000 Pa is considered normal; if it exceeds this value, there may be some problems.
There should be no problem with the refined sulfur ash content, but the rate of increase in catalyst resistance is also related to factors such as the method of temperature rise (direct or indirect) and moisture levels.
Catalysts have high mechanical strength and are not prone to pulverization; therefore, the increase in resistance is slow. This increase also depends on factors such as the acid mist and moisture levels in the system, as well as the quality of sulfur, so it is impossible to determine the exact rate at which resistance increases. Those in charge of the technology should regularly check for changes in resistance.
During normal production, the catalyst resistance is primarily related to the following factors: 1. Quality of refined sulfur: mainly including the ash content, moisture content, and acidity of refined sulfur； 2. Furnace gas quality: includes moisture, acid mist, ash, etc., in the furnace gas. If the sulfur content in the ash can be reduced to around 10 ppm and the quality of the furnace gas meets the requirements, then the catalyst screening cycle should be able to last three years.
Apart from system-related factors, the quality of the catalyst also matters; domestic ones are slightly inferior!
There is also the case where resistance increases due to the extensive shedding of iron oxide scale from the stainless steel surface; there are discussions on this topic in this section, so please search using the relevant keywords.