Despite the fossil fuel are still dominant source of primary energy in the word, the natural gas is generally used in many branches in industry. The interest in natural gas is caused by new production technologies (shale gas). This situation leads to take an interest in natural gas combustion technologies, especially low-emission combustion. In spite of many advantages of natural gas, it is also a source of nitrogen oxides generated during combustion in high temperature processes. The knowledge of the mcchanisms of the formation of NOx allows to modify the combustion process. There are two ways of Iow emission combustion processes leading to reduce pollutants: "primary and secondary methods". This paper presents the primary low-emission com...