An experimental study of the inhibiting effect of chlorine in a fluidized bed combustor

Journal Article · Mon Mar 01 04:00:00 EST 1999 · Combustion and Flame

DOI:https://doi.org/10.1016/S0010-2180(98)00057-1· OSTI ID:308191

Gokulakrishnan, P; Lawrence, A D ^[1]

---

1. Queen`s Univ., Kingston, Ontario (Canada). Dept. of Chemical Engineering

The effect of chlorine on CO, NO{sub x} and N{sub 2}O emissions has been studied in an electrically heated bed of fluidized sand. Pyridine (C{sub 5}H{sub 5}N) was burnt as a model compound in a mixture of O{sub 2} and N{sub 2} to produce CO, NO, and N{sub 2}O. The experiments were done at temperature 750, 825, or 900 C. The concentrations of O{sub 2} and pyridine in the fluidizing gas were maintained a 3.2 or 11.6 mol%, and 500, 1500, or 2000 ppm, respectively. When pyridine was burnt in the fluidized bed, the concentrations of CO, NO{sub x}, and N{sub 2}O were measured continuously in the freeboard. Chlorine was introduced to the fluidized bed as HCl. The addition of HCl to the fluidizing gas mixture decreased the concentration of NO{sub x} and either decreased or increased the concentrations of N{sub 2}O depending on the temperature. At 750 C, the addition of HCl reduced the concentration of N{sub 2}O, while it increased the concentration at 825 and 900 C. Temperature has a significant impact on the effect caused by the addition of HCl on the formation of NO{sub x} and N{sub 2}O. On the other hand, the concentrations of pyridine and O{sub 2} do not have a significant effect on the percentage decrease or increase in the concentrations of NO{sub x} caused by HCl. During pyridine combustion, combustion radicals (H/OH/O) play a major role in converting HCN and NCO to NO{sub x}. Thus, the decrease in NO{sub x} caused by HCL is due to the suppression of O, H, and OH radicals. Again the increase in the concentration of N{sub 2}O at 825 and 900 C due to the suppression of H and OH radical by HCl. However, the decrease in N{sub 2}O at 750 C is probably due to the inhibition of pyridine combustion by HCl.

• OSTI ID: 308191
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 4 Vol. 116; ISSN 0010-2180; ISSN CBFMAO
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CARBON MONOXIDE
CATALYTIC EFFECTS
CHEMICAL REACTION YIELD
CHLORINE
COMBUSTION KINETICS
FLUIDIZED-BED COMBUSTION
NITROGEN OXIDES
NITROUS OXIDE
PYRIDINE
RADICALS