hi guys, from the web site of star-cd, it said the latest release of star-cd ---3.2 can solve combustion of blend up to 10 type coal and non-coal particle. Now I have a question, in my case that de-sulfur in coal boiler furnace with limestone, there are one kind purverized coal and one kind reactive particle ---CaCO3,

CaCO3(solid)->CaO(solid)+CO2(gas)

I want to simulation the phenomenon of the combination of coal combustion and limestone decomposition, but the limestone decomposition's reaction kinetic is complex (not standard Arrhenius format), I need do it in user subroutine.

would somebody tell me whether the star-cd can solve it?

thanks!

Dear Leo; Thanks for your question. As the web site indicates, STARCD has the ability to model coal blends including limestone injection. The basic coal models assume that for each particle, the devolatilization rate for each component in the particle is the same (i.e., the carbon comes off at the same rate as hydrogen, etc.). For cases with additional surface reactions beyond the C + 1/2O2 => CO or C + H2O => CO + H2, as you've listed for the reaction of limestone CaCO3 + H2S => CaSO4 + CO2 one has to modify the particle reaction rate and other particle properties. This is normally done using one of STARCD's predefined user subroutines such as reactfn.f, or drmast.f. There are also several other subroutines that modify the droplet/particle enthalpy, heat transfer, etc. which may be used as necessary.

In the coal business, SO2 capture is a BIG deal and we are using STARCD at our offices in Tulsa, OK to do this type of work. If you're interested in further discussion, please contact me via email at joseph.smith@us.cd-adapco.com or by phone at 918-280-0200 ext 103.

Regards, Joseph Smith