Showing papers by "Qin Zhong published in 2011"

Study on Ammonium Sulfate Crystallization in the Ammonium Desulphurization Process in a Coal-based Power Plant in the Petrochemical Industry

Abstract: Ammonium sulfate crystallization of ammonia-based flue gas desulphurization was studied. Experiments were conducted to study the influence of pH, temperature, and the fly ash content of the solution on ammonium sulfate crystallization. The fly ash promoted ammonium sulfate crystallization was investigated as well. The results show that the pH has a significant impact on the mean crystal size and the shape of the ammonium sulfate crystals, and it is appropriate to keep pH at 5.0–5.5. The mean crystal size at a temperature of 60°C is larger than that of 70°C, and it will not change significantly from 70 to 90°C. Appropriate concentration of fly ash is helpful to ammonium sulfate crystallization and fly ash acts as a crystal nucleus, while higher fly ash concentration prevented the growth of large-size crystals and surface absorption becomes obvious. The ideal concentration of fly ash for the largest size crystal is about 4 g/L.

Structures and Catalytic Properties of Lithium Phosphates

Abstract: Basic lithium phosphate and stoichiometric lithium phosphate were prepared and their catalytic properties were compared. Using basic lithium phosphate as the isomerization catalyst for propylene oxide led to higher selectivity in allyl alcohol and better propylene oxide conversion than stoichiometric lithium phosphate. The fresh and deactivated basic lithium phosphates were also characterized by X-ray diffraction. Results showed that new phases appeared in the deactivated catalyst. An isomerization mechanism for propylene oxide catalyzed by basic lithium phosphate was proposed. Results of temperature programmed desorption of CO2 showed that the surface basicity of the catalysts had a great effect on their catalytic properties and that the catalyst with pH = 12 had two basic centers and its catalytic properties were the best. Basic lithium phosphate had better catalytic properties for isomerization of propylene oxide to allyl alcohol than stoichiometric lithium phosphate. Results of CO2-TPD showed that surface basicity of the catalysts had much effect on catalytic properties. And a mechanism was proposed.

Ce0.9Sr0.1Cr0.5Mn0.5O3−δ as the anode materials for solid oxide fuel cells running on H2 and H2S

Abstract: Perovskite-type Ce09Sr01Cr05Mn05O3−δ (CSCMn) was synthesized and evaluated as anode for solid oxygen fuel cells based on Ce08Sm02O19 (SDC) The conductivities of CSCMn were evaluated with DC four-probe method in 3% H2-N2 and 5% H2S-N2 at 450–700 °C, respectively The compositions of CSCMn powders were studied by XRD and thermodynamic calculations Meanwhile, sintering temperatures affecting phases of CSCMn is also proposed with XRD, and the analysis is given with thermodynamic calculations CSCMn exhibits good chemical compatibility with electrolyte (SDC) in N2 After exposure to 5% H2S-N2 for 5 h at 800 °C, CSCMn crystal structures change and some sulfides are detected, as evidenced by XRD and Raman analyses The electrochemical properties are measured for the cell comprising CSCMn-SDC/SDC/Ag in 5% H2S-N2 at 600 °C and in 3% H2-N2 at 450 and 500 °C The electrochemical impedance spectrum (EIS) is used to analyze ohm and polarization resistance of the cell at various temperatures

The Effect of Different Co-Mo Ratios as Anode Electro-catalysts on an H2S Fuel Cell with Proton Conductors

Abstract: The performance of a H2S solid oxide fuel cell with proton conductor electrolyte, which is constructed by Co-Mo metal sulfide as an anode electro-catalyst, was tested at different Co/Mo ratios. The results indicate that the maximum power output, 6.0 mW · cm−2, was obtained at Co:Mo = 2:3, the next is 5.2 mW · cm−2 at Co:Mo = 1:1, and the minimal is 4.5 mW · cm−2 at Co:Mo = 2:1. However, the obtained power output value is not consistent with the sequence of conductivity of anode materials, which results from the fact that the performance of solid oxide fuel cells are greatly affected by anode electro-catalytic activity. The electro-catalyst tests by the cyclic voltammetry method were designed to conform it. The electrical energy obtained from H2S solid oxide fuel cell is dependent on the Co/Mo metal sulfide as an anode at different atom ratios.