Discussion on sulfur recovery issues
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Our process gas heat exchangers used for sulfur recovery often get clogged. During cleaning, it was found that black solid particles were blocking the pipes that carry liquid sulfur from the process gas heat exchangers to the overflow tank. The acidic gas we purify contains a high level of methanol, with a hydrogen sulfide content of around 50% (by volume). What is the cause of this phenomenon? How to solve it?
Is it a blockage in the liquid sulfur pipeline or in the heat exchanger? Overflow tank or liquid sulfur tank?
Reply 2# Clauspolunit is the liquid sulfur pipeline of the heat exchanger
Reply to 3# zyx2255: Are you referring to a gas-to-gas heat exchanger or a condenser? Blockages in the liquid sulfur pipeline may be caused by catalyst dust, detached lining, and other impurities entering the pipeline. In typical design, to prevent the aforementioned problems, the sulfur outlet is placed about 10 mm above the bottom of the equipment. I wonder if there are any issues with your design?
In acidic gas streams, methanol can easily lead to insufficient air supply. The phenomenon is that when there is a large amount of methanol present, insufficient air supply leads to a noticeable increase in furnace temperature. If this phenomenon occurs frequently in your device, it may be due to incomplete combustion of methanol, resulting in some carbon deposition reactions. Active participation
Reply to 4# Clauspolunit: Teacher, does the sulfur outlet need to be this much higher after lining the condenser? I really haven’t observed this before
Reply to 4# Clauspolunit: What I meant is that the heat exchanger is a gas-to-gas heat exchanger, and the sulfur outlet should be about 10 mm above the bottom of the equipment; this has not been taken into account in our design
The blockage of the process gas heat exchanger is caused by the temperature of the hot gas stream being lower than the dew point temperature, resulting in the precipitation of liquid sulfur； This can be avoided by raising the inlet temperature of the converter, so that the outlet temperature of the hot gas is above the dew point temperature.
A hydrogen sulfide content of 50% in your acidic gas is preferable; relatively speaking, this results in higher yields and conversion rates of sulfur. The heat exchanger pipeline you mentioned is likely the last heat exchanger. To further increase the sulfurization yield, the outlet temperature of the final condenser is kept very low, slightly above the solidification temperature of sulfur. If this temperature isn’t controlled properly, blockages can easily occur.