The combustion of chlorine-bearing fuels can result in the formation of dioxins, highly toxic pollutants. On...

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The combustion of chlorine-bearing fuels can result in the formation of dioxins, highly toxic pollutants. On the other hand, sulfur in fuel mitigates the formation of dioxin. A rule-of-thumb for preventing dioxin formation is to maintain a sulfur-to-chlorine (S:CI) molar ratio greater than one for fuel mixtures to be burned. 1. Determine whether dioxin emissions might be expected from the combustion of wheat straw 2. Determine the maximum mass fraction of wheat straw that can be blended with bituminous coal in a fuel blend to avoid dioxin emissions. 3. What is the HHV of the blend (determined in (2)) in units of MJ/kg dry 4. It is recommended that fuel alkali content should not exceed 0.34 kg/GJ to prevent ash fouling in combustion systems. Is the above blend (determined in (2)) likely to cause ash fouling? Use the following data for your calculations Fuel Wheat straw Sulfur (S) % dry weight 0.11 Bituminous coal 0.45 Chlorine (CI) % dry weight 0.28 0.1 Alkali % dry weight 1.61 0 HHV MJ/kg dry 18.5 28 The combustion of chlorine-bearing fuels can result in the formation of dioxins, highly toxic pollutants. On the other hand, sulfur in fuel mitigates the formation of dioxin. A rule-of-thumb for preventing dioxin formation is to maintain a sulfur-to-chlorine (S:CI) molar ratio greater than one for fuel mixtures to be burned. 1. Determine whether dioxin emissions might be expected from the combustion of wheat straw 2. Determine the maximum mass fraction of wheat straw that can be blended with bituminous coal in a fuel blend to avoid dioxin emissions. 3. What is the HHV of the blend (determined in (2)) in units of MJ/kg dry 4. It is recommended that fuel alkali content should not exceed 0.34 kg/GJ to prevent ash fouling in combustion systems. Is the above blend (determined in (2)) likely to cause ash fouling? Use the following data for your calculations Fuel Wheat straw Sulfur (S) % dry weight 0.11 Bituminous coal 0.45 Chlorine (CI) % dry weight 0.28 0.1 Alkali % dry weight 1.61 0 HHV MJ/kg dry 18.5 28