$17.$ Calculating Air Demand for Fluidized Bed:

A fluidized bed combustion system requires $15$ m$^3$ of air for every kg of biomass burned. If the system processes $1000$ kg of biomass per hour, calculate the total volume of air needed per hour.

$18.$ Energy Output from an Oil Stoker:

An oil stoker system burns oil with a calorific value of $38$ MJ$/$kg at a rate of $300$ kg$/$hr$.$ If the combustion efficiency is $80\%,$ calculate the effective energy output per hour in MJ and convert it to kWh$.$