A natural gas analyzes N2, 20.0 percent and CH4, 80.0 percent. It is burned under a boiler and for the production of dry ice most of the CO2 is scrubbed out of the flue gas. The exit gas from the scrubber analyzes O2, 4.9 percent; CO2, 1.2 percent; and N2, 93.9 percent. Estimate the Percentage of the CO2 absorbed and Percent excess air used.