Abstract: The utilization of fossil fuels causes serious negative impacts on the environment and human life.To mitigate greenhouse gases and other pollutants, a novel combustion process-the nonflame combustion technology with a thermal cyclic carrier of molten salt is introduced.In this technology, a whole combustion is divided into two steps, i.e., the section of producing oxide and the section of combustion.In the first step, oxygen is separated from air, and pure N₂ is simultaneously formed which is easily recovered.In the other step, the fuels react with lattice oxygen in the oxides formed in the first step, and at the same time, thermal energy,CO₂ and H₂O vapor are produced.It is noted that the CO₂ is easily separated from water vapor and ultimately captured.Theoretically, there are no environmental-unfriendly gases such as CO₂, NO_x and SO₂ discharged in the whole combustion process.Some metal oxides scattered into molten salts play the roles of oxygen carriers in the combustion system, and they can constantly charge and discharge oxygen element from air to fuels during the combustion process.A nonflame combustion system with Li₂CO₃+K₂CO₃+Na₂SO₄ as the molten salt system, CH₄ as the fuel and CuO as the catalyst was experimentally investigated.The experimental results show that the combustion process proceeded as it was theoretically analyzed, and CO₂ with a high volume fraction of 77.0%_95.0% and N₂ with a high volume fraction of 91.9%_99.3% were obtained.The high concentration of CO₂ is favorable for capturing and storing subsequently.Therefore, the potential of reducing CO₂ emissions of this nonflame combustion technology is huge.

Key words: Nonflame combustion technology, Molten salt, Thermal cyclic carrier, Greenhouse gas reduction