Question

2. A steady state solid feed consisting of 4 mm (radius) spherical particles enters a rotating kiln-type reactor (assume plug flow) and reacts with gas of uniform composition at a particular T and P. Experimentally it was determined that the time required for complete conversion of the solid particle was 4 h. a) Calculate the time required for 70% conversion of the solid feed to solid product for 2 mm (radius) particles at the same conditions. Assume the SCM is applicable with ash-layer diffusion. b) Calculate the amount of solid required (Ws) if the feed rate (FBO) is 15000 kg h1. Assume t = tg.

Answer 1

Umm - slutions - - - Given. That I u uniform gas comportition gas has uniform Cal l Cag Composition at the I particle, so that under "Reaction control" for Reaction Control time required for complete convenon af N = SB Roi it comes b " where p. Time for complete conversion. - r = 4h: Ig- molar density of 'B' . b- stoicheometric coefficient of B k" Reaction rate Conntart. Gry- Cone of A in gasphase Ro- initial Radios of particle - .) Ro= 4mm > fe Ro > N. & . P . b I" CAY

70% time Converion for complete ... @ Time required for » Firut calculate - Convension, ..r = loro by Co . JB - Comet, : :: ble" Cag I h = mm mm >>. R. = 2mm 1 = N = 1 ) rankis ½ time for 70% Convertion. 3Balc (1-xey's . t= time for 70% Conveni XB = 0.7 (givero) 3) 1 (1-0.7)" It= 0.6611 hr. h Aus (G) 2.hr

6. Amount et solide required CWB; A feed rate RBO = 15000 kg/h sgiven. » we known that to to .. .. =) Ws = . Ebo. Es = (1994)(0.61) ka He = 9916.5 kg to Ans®

6. Amount et solide required CWB; A feed rate RBO = 15000 kg/h sgiven. » we known that to to .. .. =) Ws = . Ebo. Es = (1994)(0.61) ka He = 9916.5 kg to Ans®