The combustion of methane (CH4) in a lime kiln typically produces carbon dioxide (CO2) and water vapor (H2O) as the main products. Nitrogen (N2) is also present in the kiln's atmosphere, but it remains largely unreacted during the combustion process. Therefore, the waste gases from a lime kiln burning methane primarily consist of CO2 and H2O, with trace amounts of other gases such as sulfur dioxide (SO2) and nitrogen oxides (NOx) depending on the specific fuel and process conditions.