An integrated oxy-combustion turboexpander process including producing an enriched carbon dioxide product stream, by combusting a compressed synthetic air stream, including an oxygen-enriched stream and a carbon dioxide recycle stream, with a fuel stream and expanding the combustion stream thereby producing the carbon dioxide recycle stream and an enriched carbon dioxide product stream; producing an essentially pure carbon dioxide product stream, by processing the enriched carbon dioxide product stream into a deoxo methane combustor.