During fermentation, CO2 is released due to glycolisis along with ethanol and so forth, and Sugar (or rather carbohydrates) are needed for glycolysis to take place so yes more sugar would produce more COs. As for different sweetners, I don't believe it would create more CO2, in terms of Cellular Respiration Im sure there are some sugars which would produce more ATP than others such as Lipids which is much more efficient that carbohydrates but I don't know about CO2, I don't think it does.
