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Za zniževanje izpustov škodljivih onesnažil se v procesih zgorevanja pogosto vpeljuje visoke deleže recirkuliranih izpušnih plinov. Sestavljeni so iz ogljikovega dioksida, vode, dušika ter posameznih komponent v sledeh, ki zajemajo tudi dušikov oksid (NO). Temeljne raziskave so razkrile, da NO vpliva na kinetiko zgorevanja in s tem na časovno in prostorsko porazdelitev sproščanja toplote, kar potencialno vpliva na proces zgorevanja in tudi nadaljnjo tvorbo izpustov onesnažil. Za prvo aplikativno potrditev teh hipotez naloga analizira proces zgorevanja zemeljskega plina v motorju z notranjim zgorevanjem in prisilnim vžigom ob različnih koncentracijah NO, ki so dozirane v vstopni zrak. Na podlagi poteka tlaka v valju, sproščanja toplote, temperatur ter izpustov onesnažil je v posameznih obratovalnih intervalih mogoče zaznati vpliv že izrazito nizkih koncentracij NO. Učinek NO na zgorevanje je močno odvisen od temperature in sestave gorljive zmesi. Največja občutljivost je opažena pri temperaturah med 1600 in 1900°C ter revnih zmeseh. Pri višjih dodanih koncentracijah NO deluje kot promotor vžiga, saj pospeši tvorbo reaktivnih OH in O radikalov. NO spreminja tudi kinetiko tvorbe izpustov škodljivih snovi, saj rezultati potrjujejo znaten vpliv na dodatno tvorbo NO predvsem v območjih nizkih temperatur. Naloga na ta način predstavlja prvo aplikativno potrditev temeljnih hipotez in predstavlja izhodiščno delo za nadaljnje študije v realističnih procesih zgorevanja. High proportions of recirculated exhaust gases are often introduced in combustion processes to reduce emissions of harmful pollutants. They consist of carbon dioxide, water, nitrogen and individual components in traces, which also include nitric oxide (NO). Fundamental research has revealed that NO has a potential effect on combustion kinetics and thus on the temporal and spatial distribution of heat release, which potentially affects the combustion process as well as the further formation of pollutant emissions. For the first applied confirmation of these hypotheses, this thesis analyzes the process of natural gas combustion in an internal combustion engine and forced ignition at different concentrations of NO doped into the intake air. Based on the pressure trace in the cylinder, heat release, temperature and pollutant emissions, the influence of already extremely low doped NO concentrations can be detected in individual operating intervals. The effect of NO on combustion is strongly dependent on the temperature and composition of the combustible mixture. The highest sensitivity is observed at temperatures between 1600 and 1900 ° C and lean mixtures. At higher added concentrations, NO acts as an ignition promoter as it accelerates the formation of reactive OH and O radicals. NO also changes the kinetics of the formation of emissions of harmful substances, as the results confirm a significant impact on the additional formation of NO, especially in areas of low temperatures. The thesis represents the first applied confirmation of the basic hypotheses and represents initial work for further studies in realistic combustion processes.