It is desired to remove \(90 \%\) of the sulfur dioxide in a flue gas stream at \(298 \mathrm{~K}\) and \(1 \mathrm{~atm}\) by countercurrent absorption with pure water at the same temperature, using a packed tower that is \(0.7 \mathrm{~m}\) in diameter. The tower is packed with \(35-\mathrm{mm}\) plastic NORPAC rings. The average gas-pressure drop is \(200 \mathrm{~Pa} / \mathrm{m}\). Equilibrium is described by Henry's law with \(y_{i}=8.4 x_{i}\). If the liquid flow is adjusted so that the driving force \(\left(y-y^{*}\right)\) is constant, calculate the height of the packed section. Flue gases usually contain less than \(1 \mathrm{~mol} \%\) of \(\mathrm{SO}_{2}\), an air pollutant regulated by law. Assume that the properties of the liquid are similar to those of pure water, and that the properties of the flue gases are similar to those of air. Hint: For the driving force \(\left(y-y^{*}\right)\) to remain constant, the operating and equilibrium lines must be parallel, which means that \(A=1\).