Changqing Dong

The Resistivity Property of Nikel Loaded Winter Wheat Straw Char

In this paper, the effects of nickel ions concentration (4.0 wt%, 4.5 wt%, 5.0 wt%), carbonization temperature (700°C, 800°C, 900°C), heating rate (5°C/min, 15°C/min, 20°C/min) and particle size (0.1-0.2 mm, 0.2-0.3 mm, 0.3-0.38 mm) on resistivity of char derived from winter wheat straw were studied. The result showed that when nickel loading is 5.0 wt%, carbonization temperature is 900°C, heat rate is 5°C/min and particle size is 0.2-0.3 mm, the resistivity is lower and its value is 1.5 �·cm.

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.

Research on the Reactivity of Oxygen Carrier Fe2O3 for Chemical Looping Combustion (CLC)

Chemical looping combustion (CLC) was a promising combustion technology with inherent separation of CO 2 . In this paper, thermodynamic equilibrium approach was used to investigate the reactions between CO or biomass gas and oxygen carrier Fe 2 O 3 , and experiments were carried out in a laboratory fluidized bed reactor. The results showed that when temperature was below 1000 K, the carbon deposition on oxygen carrier was serious. When CO was used as fuel, the highest gas yield of CO to carbon dioxide reached to 99.5% at 1153 K. And when biomass gas was used as fuel, the highest gas yield of biomass gas to carbon dioxide was almost 75% at 1113 K.

Numerical Modeling of Gas Flow in a 48t/h Biomass-fired Boiler

A numerical model of the flow field of a 48t/h grate-fired boiler was presented in this paper. The air distributions in the furnace under different air supply ratio were considered in order to get the optimum air ratio. The three-dimensional Reynolds averaged Nervier-stokes equation with the Standard k-epsilon Model was solved. The result showed that the airflow ratio played a significant role on the air distribution of the furnace and the optimum airflow ratio of R PA : R SA : R IA = 4:4:2.

The Fate of Trace Elements in the Co-combustion of Municipal Solid Waste and Sludge based on Thermodynamic Equilibrium Calculation Approach

Thermodynamic equilibrium calculations were performed to determine the distribution of potentially toxic elements in the co-combustion of waste and sludge. The effects of temperature, pressure and atmospheres on equilibrium composition were evaluated. The results showed that: Under oxidizing conditions, HCl was a key factor influencing the distribution of trace element besides temperature. The participation of HCl served to decrease the retention in ash of Zn and Cu. Hg and Pb were released at lower temperatures in gas atmosphere containing HCl. The participation of SO 2 served to increase the retention in ash of Ni. Sludge moisture content had little effect on the release of trace elements.

Notice of Retraction Simulation of Co-combustion of Waste with Sludge for Power Generation by Aspen Plus

The process of co-combustion of municipal solid waste with sludge for power generation was simulated by ASPEN PLUS in this paper. Thermodynamic analysis was carried out according to the simulation results later. The results showed that: Using exhaust gas as heat source to dry the sludge could improve the generation efficiency; The exhaust flue gas of 423 K could decrease the sludge moisture content from 72% to 62%, subsequently the generation efficiency and exergy efficiency improved 2%, 0.58% respectively, further drying had little contribution to efficiency.

First-Principles Study of Ni Adatom Adsorption on Graphene for Ni-Catalyzed Carbonization of Wood as Electromagnetic Shielding (EMS) Materials

The functionalization and electric properties of graphene by the addition of transition metal atom of Ni to its surface had been investigated computationally using density functional theory with the generalized gradient approximation. The stable geometry adsorption position, binding energy, band gap, density of states, charge transfer of Ni adsorbed on graphene at two different coverages were calculated. The hollow site was the most stable adsorption site with the largest binding energy. The local density of states showed that carbon 2p orbital (Â? bonded states) hybridized strongly with the 3d orbital of the Ni atom. Mulliken population showed the net charge (e) transferred from the Ni metal atom to the graphene was 0.87 of the (2Ax972) supercell and 1.05 of the (4Ax974) supercell respectively. All these changes of electric properties resulted in the band gap getting smaller and showing stranger conductivity after Ni adsorbed on the graphene.

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 Nn 2nO 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 Nn 2nO 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.

A Density Functional Investigation on C Atom Adsorbed on Ni (111) Surface in the Steam Reforming of Acetic Acid

The adsorption modes of C on the clean Ni (111) surface had been investigated by first principles Density Functional Theory (DFT) within a periodic slab model and the generalized gradient approximation. The threefold hep and fee hollow sites on Ni (111) surface were preferred to be adsorbed strongly by the C atom with chemisorptions energy of-6.89 eV and -6.81 eV. The calculated binding energies had been compared with the previous experimental and theoretical results and good agreement was found. The local density of states (LDOS) showed that the formation of adsorption bonding was mainly due to the mixing between the carbon 2p and Ni 3d orbitals. The analysis of charge density difference and Mulliken population suggested that there were a net charge flow of electrons from the Ni surface to C atom induced by the adsorption.

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