Plant to produce SO2 for pulp plant cooking liquor

[Raakesh]

I'm in the process of evaluating different types of sulphur burners. One has molten sulfur sprayed by a gun, into a reactor where it combines with air to form SO2, this is the Cellchem type. The 2nd type is one that I haven't been able to find much info on, it's a "film-type" sulphur burner. Can someone shed more light on the pro's and con's of both these units, maybe someone who's had similar experience. Also, are there any preferred ways for off-loading molten sulphur.

Thank you

 

[butelja]

The atomizing spray burner gives better control of what's going on, and has the significant benefit of reduced startup emissions. I believe it has replaced the falling film type in sulfonation units.

The "falling film" type burner I'm familiar with is in our SO3 sulfonation unit. It is a refractory lined vessel that has a cube shaped stack of checker brick. Air flows up through the checker brick and molten (burning) sulfur flows down. It is essentially a bonfire with forced draft. The high startup emissions stem from how the unit must be started up. A propane fired heater is used to heat the refractory significantly above the sulfur autoignition temperature. During this heatup, any residual sulfur in the burner eventually burns and causes SO2 emissions. With a spray fired unit, the burner co-fires sulfur and natural gas, with gas being used for a very short time period vs. ~12 hrs with a falling film type.

As for unloading, the most reliable method is gravity unloading into a below ground sulfur storage pit.