$($a$)$ Fresh ginger enters a drier with $35\%$ moisture and leaves at $10\%.$ The feed rate to the drier is $1180kgh{r}^{-1}.$

$($i$)$ Draw a flow diagram of the process and use the algebraic method to determine the rate at which dried ginger is produced and the amount of water removed.

$($ii$)$ Repeat the calculation in part $($i$)$ above using the tie element procedure.

$($b$)$ A distillation feed comprising $40\%$ ethanol and $60\%$ water is fed to a column at a rate of $18,500kgh{r}^{-1}.$ The vapours leaving the still enter a condenser and after cooling, contain $93\%$ ethanol, and flows at a rate of $13,700kgh{r}^{-1}.$ A portion of the condensed vapour $(V)$ is returned to the column as reflux $($R$)$ and the rest is withdrawn as distillate $($D$).$

If the stream entering the condenser has the same composition as the reflux and distillate streams, and the bottoms contain $94\%$ water, draw a diagram of the operation and determine:

$($i$)$ the rate at which distillate is withdrawn from the system and the reflux ratio, $\frac{R}{D}$;

$($ii$)$ the amount of ethanol that is lost to the waste.

$($iii$)$ The process engineer plans to decrease the recycle$-$to$-$product ratio. Do you agree with this approach? Explain how this action will impact the production rate, product quality and the overall process efficiency.