A boiler fired by natural gas has an output of 120kW and is 86% efficient. The analysis by mass of the constituents of the gas is methane 89%, ethane 3.3%, propane 3%, butane 1%, nitrogen 3.45%, and carbon dioxide 0.25%. Net calorific value of the gas is 39MJ/m3. Data Ambient temperature =15C Density of oxygen at ambient condition =1.361kg/m3 Density of air at ambient condition =1.234kg/m3 Given Density of substance =22.28molecularmass Calculate a) Find the stoichiometric volume of air for complete combustion of 1 cubic metre of natural gas. b) Find the actual volume of air assuming 20% excess is needed for complete combustion. c) Find the volumetric air fuel ratio based upon the actual volume of air required. d) Determine the emission of carbon dioxide in the products of combustion when the boiler is working at full load. Assume that the air for combustion has negligible CO2 content. e) The plant runs at an equivalent full load for 939 hours/year, how much CO2 would this plant produce annually