In order to realize the waste biogas recycled as reburning fuel in industrial boilers aims to reduce nitrogen oxides （NOx） high efficiency

which can achieve resource recovery and NOx emission reduction. Characteristics of industrial boiler bed and furnace were simulated by combining FLIC and FLUENT software

and the effects of CH4/NO molar ratio

biogas dilution and biogas nozzles arrangement on in-furnace NOx emission were investigated. The results showed that the CH4/NO molar ratio and the degree of mixing between the two were the main factors affecting the reduction of NOx

and NOx reduction efficiency increased with CH4/NO molar ratio and biogas dilution ratio increasing in general. When the CH4/NO molar ratio was small

the dominant factor influencing NOx reduction efficiency was the mixture degree of them. When biogas was diluted to a certain degree

which could guarantee possessing sufficient momentum to mix well with the main flow

the dominant factor influencing NOx reduction efficiency was CH4/NO molar ratio. At the same time

increasing of biogas dilution ratio was beneficial to reduce the loss of gas incomplete combustion. To realize of NOx high efficiency reduction

the biomass nozzles should be arranged at the front wall

and the position should not be too low. This paper could provide some reference of biogas for industrial boilers combustion and NOx reduction.