Burning Liquid Fuels In CFB (Circulating Fluid Bed)

[ericvd]

I am researching the suitability of burning liquid fuels in a CFB combustor. Our clinet has process waste from a coke plant that they would like to utilise for inceneration and power generation. This is char plant tar, liquor (97% water) and off-gas. Coal will be added at times to boost output.

Info from the 20th International Conference on CFB indicate that this (burning liquids in CFB's) has up to date only been done on lab and pilot scale, and the suitability for large scale projects are questionable and not proven....

Does anybody know if that have been done somewhere?

Regards

 

[rmw]

Paper Mill sludge has been burned in CFB boilers successfully for years now, but that is a fairly thick fluid, if it can be classed as a fluid at all. Is there any way to concentrate your fuel stream to make it more suitable for this type of combustion process?

rmw

 

[ericvd]

Well, the tar is 70% naphtalene, 10% gasolene and 10% carbon (by wieght) so not much to do about it. except if we mix it with coal beforehand and add it as a wet solid or sludge...hmmm.....

The liquor is basicly contaminated water that needs to be incinerated. But this have very little suplur so I guess it could be sprayed into the combustion chamber without getting in contact with the sorbent...

problem is the boiler contractor we are working with are not willing to quote on something they havn't done before
:-(

I think doing this might be possible but will probably require some sort of lab testing first...

Regards
Eric

 

[davefitz]

wastewater sludge has been successfully burned in bubbling bed combustors, but in general they are limited in size to less than 300 MWth input. As I recall, the fuel must be less than 50% water by wt.

It may be worth directly contacting a CFB supplier ( Metso, Alstom, FW Oy) to get their opinion- maybe the liquid fuel could be introduced in the fines recycle stream ( cyclone drains loop back to main combustor)?