SOx Removal in Fluidized Bed Boiler Plants 1

[jonasinc]

Is it common to have SOx removal (scrubber) for the flue gas of a coal fired fluidized bed boiler? How many plants have a FB boiler with scrubbers?

 

[athomas236]

I always thought that the bed is dosed with limestone which then absorbed the sulphur.

athomas236

 

[jonasinc]

That is why we are wondering if there are other FB plants that have the scrubber installed. It seems unusual and unnecessary, however, we are working with a plant that has one and is having problems with corrosion and deposition downstream of the scrubber.

 

[JEB66]

In the USA, a new CFB boiler will be required to have a dry scrubber installed. That is determined by the EPA as Best Available Controllable Technology.

 

[davefitz]

The fluid bed boiler normally uses limestone as the bed medial, and this will remove 85-03% of so2. However, there are many cases where the bed media is not limestone- it can be sand ( riverbed sand- round edges as opposed to millsand with sharp edges)or other inert media.

These inert media are used if you are burning garbage or other material that would form a eutectic slag if limetone were used. In those cases, a scrubber is used.

 

[fvincent]

When we consider that the Ca/S ratio in the bed increases a lot if higher SOx efficiencies are required then a supplementary FGD might be the best economical solution despite the higher capital cost.

A downstream FGD system can operate with Ca/S ratio as low as 1.1. The furnace bed can operate with Ca/S ratio as high as 2.5 (for very high efficiencies and high S content).

This may be true for very high sulfur fuels as petcoke (up to 7% S)

I think Jacksonville CFB power plant was planned this way.



fvincent