A packed column is used to absorb $\mathrm{SO}_{2}$ from flue gas using an ethanol amine solution. The column is $4 \mathrm{ft}$ in diameter and has a packed height of $20 \mathrm{ft}$ and is packed with $2 \mathrm{in}$. plastic Pall rings. The flue gas is at a temperature of $180^{\circ} \mathrm{F}$ and has an average molecular weight of