A combustion unit is burning RDF consisting of 85% organics, 10% water, and 5% inorganics (inerts) at a rate of 1000 kg/h. Assume the heat value of the fuel as 19,000 kJ/kg on a moisture-free basis....

A combustion unit is burning RDF consisting of 85% organics, 10% water, and 5%
inorganics (inerts) at a rate of 1000 kg/h. Assume the heat value of the fuel as
19,000 kJ/kg on a moisture-free basis. Assume the facility is refractory lined with
no water wall and no heat recovery. Assume that the air flow is 10,000 kg/h and
that the under- and overfire air contributes negligible heat. Assume further that 5%
of the heat input is lost due to radiation and that 10% of the fuel remains uncombusted in the ash, which exits the combustion chamber at 800ºC. The specific heat
of ash is 0.837 kJ/kg/ºC, and the specific heat of air is 1.0 kJ/kg/ºC. What is the
temperature of the stack gases?