Question 10.6: The emission stream inlet HAP concentration is 1000 ppmv wit...
The emission stream inlet HAP concentration is 1000 ppmv with a control requirement of 95\%. Determine the adsorption cycle time, regenerative cycle time, and the steam requirement for carbon regeneration.
The air emission stream inlet HAP concentration is 1000 ppmv and a control requirement is 95\% or 50 ppmv outlet concentration. From Table 3, at an adsorption cycle time of 2 h, a regeneration cycle time of 2 h, and 0.3 lb of steam/lb of carbon, the regeneration rate will provide an outlet concentration of about 70 ppmv, or slightly less than 95\% of the control efficiency. This assumes that the bed does not get close to breakthrough. For the examples in this handbook, these values will suffice.
| Table 3 Carbon Adsorber System Efficiency Variables |
||
| Steam requirement for regeneration, St (lb steam/lb carbon) | ||
| 0.3 | 1.0 | |
| Outlet HAP concentration, HAP_{o} (ppmv) | 70 | 10–12 |
| Adsorption cycle time,^{a} θ_{ad} (h) | 2 | 2 |
| Regeneration cycle time,^{a} θ_{reg} (h) | 2 | 2 |
_{}^{a}\textrm{In } some instances, cycle times may be considerably longer than the values given here. The values in this table are approximate, not definitive.