A biomass fuel has the following ultimate analysis: This fuel is used in steam g
ID: 918284 • Letter: A
Question
A biomass fuel has the following ultimate analysis: This fuel is used in steam gasifier to produce CO_2 and H_2. The fuel enters the gasifier at 298 K. while the steam enters at 400 K (the steam may be treated as an ideal gas, so do not use the steam tables). These are the only two streams into the gasifier, and only CO_2 and H_2 are present in the products. The products following the gasifier are cooled to 298 K. The HHV of the fuel is measured to be 22 MJ/kg. The reaction is endothermic, so heat must be supplied to the system. Find the amount of heat that must be added to the gasifier/gas cooler combination (kJ/kg biomass).Explanation / Answer
Given:
To find:
The amount of heat that must be added to the gasifier in kJ/kg.K.
Conversion:
1 MJ/kg = 1000 kJ/kg
Solution:
The energy balance equation to find the amount of heat to be added,
Hprod (T) = Hreact + Qin +Qout
HHV = 22 MJ/kg which is nothing but 22000 kJ/kg.
Hprod = 22000 + (298+400) + 298
Hprod = 22996 kJ/kg.K
The amount of heat that must be added to the gasifier is 22996 kJ/kg.K.