Xiaoying Hu

Product gas combustion in fluidized bed for N 2 O reduction

The experimental research on removing N2O with biomass gas was carried out in a small-fluidized bed reactor tube. The decomposition rate of N2O and the production rate of NO impacted by reaction temperature, residence time, reburning position, rate of fuel, initial oxygen content of flue gas and the height of material bed were researched. The results showed that the decomposition rate of N2O was more than 99% with some biomass gas and residence time was 0.32 sec in the reducing zone. The decomposition rate of N2O was increased with the increasing of the distance from air distributor, was decreased with the increasing of the initial oxygen fraction, and was in direct proportion to the height of material bed and the fraction of ejected biomass gas.

Modeling the Effect of Particle Flow on Erosion in CFB

Fly ash may cause serious erosive wear on steel surfaces along the flow path in a circulating fluidized bed (CFB) boiler. In this paper, erosion model and MFIX software were used to evaluate gas-solids flow on erosion rate. The effects of the particle size and density on the erosive wear were compared quantitatively.

Mechanism Study on N2O Reduced with Biomass Gas

The reduction of N2O by adding biomass gas as reburning fuel is studied on a small-scale vertical reactor tube and experimental results are analyzed using the theory of chemical kinetics. The result showed that for the flue gas containing a certain concentration of N2O, when the biomass gas contained H2, CH4, CO and CO2 was used, the reburning fuel ratio should be more than 1.4%. The decomposition of N2O is caused by free radicals, including H and OH in the process.

The Effect of CaO on N2O emission during the Biomass gasification gas Reburning Process

The effects of desulfurizer CaO with a diameter of 415 ?m on N 2 O reduction with biomass gasification gas reburning at a reactor temperature of 850°C was researched on a small-scale fluidized bed in this paper, and the main mechanisms of the effects caused by the desulfurizer CaO were analyzed. The results of the experiment showed that the N 2 O decomposition rate was improved by ejecting biomass gasification gas reburning and arranging the bed material CaO on the distributor; the NO formation rate was enhanced with biomass gasification gas reburn and was decreased with the effect of desulfurizer CaO.

Simulation of Dense Gas-Solid Fluidized Bed Based on Two-Fluid Model

Numerical simulation of gas-solid flow in fluidized bed has been carried out based on two-fluid model (TFM) in the paper. The influence of different height of bed material, superficial velocity, restitution coefficient of granular elasticity, drag model and time step calculated on phase mixing and bubbles appeared was analyzed and investigated. The results showed that by using the same drag model, the fluidization was improved along with the increase of bed material, superficial velocity and restitution coefficient of granular elasticity; different bubble diameter size can be obtained by using different drag force model; the effect of time step calculated on the diameter of bubbles in bed was slightly. Keywords-gas-solid fluidized bed; TFM; drag coefficient; restitution coefficient

Kinetics simulation of N 2 O reduced with combustible gas CO

The reduction machinism and kinetics characteristic of the reaction of carbon oxide (CO) and Nnitrous oxide (N2O), which contained the influence of reaction time on the reactants and products, were studied in the paper. The radical reaction of CO and N2O was assumped in a ideal reactor with a high temperature and a constant pressure, and was analyzed with chemical reaction kinetics theory. The result showed that the reduction effect of CO on N2O could be forecasted and simulated by the model built under certain temperature and pressure, of which the mechnism contained 3 elements, 12 components and 26 reactions.