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[cruam]

Dear All

I'm trying to simulate an absorber tower for SO2 removal of a flue gas consist of 12%v co2 , 74% N2, O2 and 800-1000 ppm SO2 with a Soda ash soebent(a packed column with soda ash spraying)
how can I find some specific information about Soda ash inlet temperature, concentration; flue gas inlet temparature; tower pressure to run absorber column.

please gide me!!

Thanks all

[kkala]

I'm trying to simulate an absorber tower for SO2 removal of a flue gas consist of 12%v co2 , 74% N2, O2 and 800-1000 ppm SO2 with a Soda ash sorbent(a packed column with soda ash spraying)
how can I find some specific information about Soda ash inlet temperature, concentration; flue gas inlet temperature; tower pressure to run absorber column. please guide me!!

Not having specific experience on flue gas desulfurization, I can only say my opinion on some points and hopefully someone else will offer comments or more help. Soda ash (Na2CO3) is assumed to be in a form of solution.
1. Use of soda ash does not seem common, at least according to some rather old books on Gas Purification. Nonhebel (1972) does not report it. Kohl & Riesenfeld (1974) just make a short mention (less than half page), referring absorption temperatures of 35-55 oC and desorption at 70-120 oC (Sulfur Dioxide - Recovery Processes based on Absorption in solutions of Alkali Metal compounds), generally for sodium or potassium hydroxide, carbonate, bicarbonate. Difficulty/complexity of regeneration is pointed out in general (not specifically for Na2CO3), leaving the impression that deposits could be a problem.
2. Soda ash temperature in: No reason to be different to ambient.
3. Flue gas temperature in: 15 oC above flue gas acid dew point (according to a practice) to avoid condensation upstream of the tower. Flue gas acid dew point (probably in the order of 140 oC) can be estimated (goggle "acid dew point" to find a lot of estimates, including the thread of 1 Aug 08 in "Refining, Hydrocarbons, Oil and Gas" Forum of Cheresources).
4. Tower pressure in (concerning flue gases): For gases just upstream stack absolute pressure is practically atmospheric; the tower will be placed there, so pressure of gases into it will get ΔP (gauge), where ΔP=pressure drop through tower, probably 0.3 in H2O/ft of packed depth; this means ΔP=500 mm H2O for (arbitrarily say) 20 m height of packing, that is 0.05 at. Assume atmospheric pressure of flue gases for your calculations.
Note. Main part of the tower design seems to be: selection of packing type & size, column diameter, L/G, height of packing; then calculation of ΔP. Simulator usually does not have all necessary data in sufficient detail; in this case consultancy is needed from a packing supplier.
5. Soda ash concentration in: I do not know optimum value; search literature for it and recommended "blow down".Risk of deposits may influence it, among others.
Note. Concentrations in the liquid circulating through the sprays (containing also SO3 anions), if specified, could result in definition of the feeding "soda ash concentration in" (water balance around tower).
6. It is noted that flue gases (of, say, 140 oC) will be cooled in the tower, following the wet-bulb temperature line up to saturation (dew point). Contact time between flue gases and solution is usually adequate to justify this assumption (simulator is expected to find exit gas temperature), so temperature of soda ash solution in (2) is not significant (does not practically affect exit gas temperature).