Conversion was low because if more air is used to increase conversion
it is difficult to ensure that the air is intimately mixed with the hydrocarbon, and high local concentrations cause unwanted by-products to be
formed. If a better method of mixing air and hydrocarbon can be found
then conversion can be increased; one possible method would be to mix
them under conditions in which reaction cannot occur and then change
conditions so that reaction becomes possible. For example, they could be
mixed at a temperature too low for reaction to occur and then heated