Anammox was successfully transited from heterotrophic denitrification and autotrophic denitrification in two upflow biofilm reactors, respectively. The results showed that the volumetric loading rate and nitrogen remo...Anammox was successfully transited from heterotrophic denitrification and autotrophic denitrification in two upflow biofilm reactors, respectively. The results showed that the volumetric loading rate and nitrogen removal efficiency in the reactor transited from heterotrophic denitrification were higher than that in its counterpart. When the hydraulic retention time was 12 h or so, the total nitrogen loading rate was about 0.609 kg N/(m3·d), and the effluent ammonia and nitrite concentrations were less than 8.5 mg/L and 2.5 mg/L, respectively. The upflow anammox biofilm reactor was capable of keeping and accumulating the slow-growing bacteria efficiently. During operation of the reactor, the biomass color was gradually turned from brownish to red, and the ratio of ammonia consumption, nitrite consumption and nitrate production approached the theoretical one. These changes could be used as an indicator for working state of the reactor.展开更多
The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the ge...The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the geometry, the operating parameters and the physical properties of the liquid phase on gas hold-up and mass transfer coefficient were measuered. Compared with other types of gas-liquid reactor, D-JLR shows higher mass transfer coefficient and lower energy dissipation rate, the optimum diameter ratio was found to be about 0.42-0.6. A model for gas hold-up in D-JLR with Newtonian and non-Newtonian fluids has been developed on the basis of the equation of motion and the concept of average mixing length. The prediction of gas hold-up with the model agreed with the experimental results of this work.展开更多
Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) w...Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.展开更多
In order to extend the operating cycle of the upflow reactor for resid hydrotreating, the Re- search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has develo...In order to extend the operating cycle of the upflow reactor for resid hydrotreating, the Re- search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor. The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals, sulfur and carbon residue from the re-siduum to provide improved oil for the following fixed-bed reactor. In the meantime, the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years, resulting in minimization of losses caused by refinery downtime.展开更多
基金TheNationalNaturalScienceFoundationofChina (No . 30 0 70 0 1 7) theScienceandTechnologyFoundationforKeyProjectofZhejiang
文摘Anammox was successfully transited from heterotrophic denitrification and autotrophic denitrification in two upflow biofilm reactors, respectively. The results showed that the volumetric loading rate and nitrogen removal efficiency in the reactor transited from heterotrophic denitrification were higher than that in its counterpart. When the hydraulic retention time was 12 h or so, the total nitrogen loading rate was about 0.609 kg N/(m3·d), and the effluent ammonia and nitrite concentrations were less than 8.5 mg/L and 2.5 mg/L, respectively. The upflow anammox biofilm reactor was capable of keeping and accumulating the slow-growing bacteria efficiently. During operation of the reactor, the biomass color was gradually turned from brownish to red, and the ratio of ammonia consumption, nitrite consumption and nitrate production approached the theoretical one. These changes could be used as an indicator for working state of the reactor.
文摘The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the geometry, the operating parameters and the physical properties of the liquid phase on gas hold-up and mass transfer coefficient were measuered. Compared with other types of gas-liquid reactor, D-JLR shows higher mass transfer coefficient and lower energy dissipation rate, the optimum diameter ratio was found to be about 0.42-0.6. A model for gas hold-up in D-JLR with Newtonian and non-Newtonian fluids has been developed on the basis of the equation of motion and the concept of average mixing length. The prediction of gas hold-up with the model agreed with the experimental results of this work.
基金Supported by the National Natural Science Foundation of China (No.: 29676042)
文摘Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.
文摘In order to extend the operating cycle of the upflow reactor for resid hydrotreating, the Re- search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor. The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals, sulfur and carbon residue from the re-siduum to provide improved oil for the following fixed-bed reactor. In the meantime, the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years, resulting in minimization of losses caused by refinery downtime.
