A gas mixture containing $10$ mol$\%$ SO$2$ and $90$ mol$\%$ air at latm total pressure and $30$C is to be scrubbed with water to remove $97\%$ of the SO$2$ in a tower packed with $25$ mm ceramic Raschig rings. The feed gas rate is $1500$kg$/$hr$.$ Calculate the minimum liquid rate. Equilibrium data for SO$2$water system at $30$C is The Colbum$-$Drew volumetric mass transfer coefficients at the given conditions are: KOL.a $=1\mathrm{.}25$ kmol$/$m$3.$s $($x$)$ Kog.a $=0\mathrm{.}075$ kmol$/$m$3.$s $($y$)$