Problems during sulfur plant startup
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During the heating-up phase of my sulfur production facility, the SO2 and O2 analyzers installed at the chimney were put into use. The sulfur production furnace used dry gas to drive Reactors 1 and 2 as well as the hydrogenation reactor; during the heating-up of the dry gas, the SO2 level remained above 1000 mg/m3, while the O2 level was between 10% and 14%. Measures were taken to reduce these two values, but without success. In order to lower the oxygen level, both the air flow rate to the sulfur production furnace and that to the exhaust furnace was reduced significantly, yet the oxygen level at the chimney still did not decrease. I urge everyone to actively discuss and analyze this issue – points will be awarded for helpful suggestions. Thank you
Is the high sulfur dioxide content due to the gas not having been desulfurized?
Theoretical gas equivalent combustion can reach around 2000 degrees, so in order to control the temperature, the flue gases must be oxygen-rich. I’m not sure what the temperature of the furnace in front of you is
Sulfur production furnace: over 1,000 degrees; exhaust gas furnace: over 500 degrees
The oxygen content of yours is still within the range indicated by the spectrum; based on the calculations using our gas composition, the oxygen content reaches 12% at 1000 degrees, and 17% at 500 degrees.
The ratio of air to acid gas should be between 1.2 and 1.6; please calculate the ratio again to see if it’s appropriate
If it is for upgrading to the first or second stage, once the furnace temperature reaches the required level, 200–300 cubic meters of nitrogen can be supplied in front of the furnace as a heat carrier. The dry gas components need to be burned in an equivalent manner, and the air supply volume must be high. After operating for some time, when the amount of acidic gases increases, this situation should be able to be alleviated. Additionally, the accuracy of the ratio meter plays an important role, as does the method of sampling; I have encountered such issues before as well
How can there be SO2 if there is no acidic gas during the heating process? Could it be that the fuel gas contains sulfur? Is it your first time driving, or wasn’t the sulfur scrubbed when you parked last time? If sulfur was not swept during the last parking, the SO2 emissions should decrease after driving for about a day; during this time, an increase in temperature should be observable in the catalyst bed. If it’s the first time driving, and the fuel gas analysis shows no sulfur content, then the instrument is inaccurate; it needs to be checked, calibrated, and adjusted. For high O2 levels, you can analyze the components of the fuel gas, calculate the air-fuel ratio, and then adjust the air volume accordingly. In incinerators, the oxygen content in the supplied air is generally not more than 200%, while the O2 level in the exhaust gases is usually between 10% and 3%. If the burner does not go out, increasing the fuel gas supply or reducing the air flow will definitely lead to a decrease in the O2 content in the exhaust gases. If there is no decrease, it means that the air flow hasn’t been reduced enough, or the oxygen analyzer is faulty. Analyzers that use zirconia probes are prone to failure, with a lifespan of only two to three months.
Either you haven’t changed the catalyst, resulting in a high sulfur content in the system, or there is sulfur buildup in the exhaust lines, especially near the inlet of those lines at the rear of the furnace, which has caused ignition; or else the SO2 meter is not accurate. Dry gas certainly can’t contain that much sulfur.