Study On Low NOx Burning Technologies For Hydrogen-rich Syngas

With the constant economic development of China, energy and environment problems become more and more prominent. In order to solve the problems of low-rate utilization of energy and the severe environment contamination, several types of clean coal generation technology had progressed remarkably in our country, among which, integrated gasification combined cycle (IGCC) power generation is the most conspicuous and potential clean coal power generation technology in the contemporary world, representing the21st century power technology development direction. The main components of fuel syngas are CO and H2, which will produce the environment-contaminated NOx. Syngas dilution, as an effective low-NOx combustion technology, has been applied extensively in clean energy development and IGCC.The study implements syngas dilution combustion experiments using CO2diluent in the25-hole swirl burner, and reviews the variation tendency of NOx emission under the influence of different excess air coefficient, C/H log, heat and power.First, the study focuses the influence of different excess air ratio on flame distribution, furnace temperature, flue gas temperature and emission of CO and NOx in flue gas under the condition of same power ratio, C/H log and heat emission. It is found that as excess air coefficient increases, the CO of tail gas obtains an obvious regulated increase with the growth of excess air coefficient after first decrease, and the emission of NOx doesn’t reveal any obvious relations with the excess air coefficient.Furthermore, the study analyzes the syngas burning flame distribution, furnace temperature, gas temperature and CO and NOx emission of flue gas base on the same power, C/H log and different heat. The study implements experiments focusing on the syngas with different heat7MJ/m3,8MJ/m3,9MJ/m3after diluting the CO2, showing that when heat release is9MJ/m3, that is, diluted concentration of CO2is22%, the emission of NOx possesses the largest amount of tail flue gas after syngas burning; when heat release is MJ/m3, that is, diluted concentration of CO2is40%, the emission of NOx possesses the smallest amount of tail flue gas after syngas burning. The results demonstrate that thermodynamic NOx mechanism is the main factor that influences the NOx emission of syngas. In addition, the study examines the influence of different C/H log on NOx emission after syngas burning. The experiment showed that with the rising C/H log, NOx emission of tail gas will also increase, proving that the ratio of CO in syngas has a proportional relation with NOx emission of tail gas.Finally, the study researches the influence of different power on NOx emission after syngas burning, the experiment proves that the furnace temperature elevates and NOx emission increases with the power growth. When excess air ratio is more than1.4, that is, flammable gas in furnace is close to complete combustion, the trend aforementioned is more obvious.