A cyclometallated phosphorescent iridium-based probe to detect CN– was prepared through a cyanide alcoholize reaction based on the C^N type main ligand and N^N type ancillary ligand (2-phenyl pyridine and 1,10-phenanthroline-5-carboxaldehyde, respectively). The efficient probe exhibited good sensitivity in response to CN– in an CH3CN and H2O (95/5) mixture within a 1.23 μM detection limit. The response of PL is directly in line with the concentration of CN– from 0 to 2.0 equiv. The PL investigation of other reactive anions proved the great selectivity to CN–. Additionally, upon adding 1.0 equiv. of cyanide, the formation of cyanohydrin was correctly elucidated in 1H NMR, FT-IR, and mass spectra studies. The conspicuous results indicate that the iridium complex has the potential possibility of application in other biosystems related to CN–.
The optimization of flow control devices (FCDs) for a T-type five-strand billet caster tundish was carried out by water modeling and numerical simulation. In water modeling experiments, flow characteristics of the bare tundish and tundish configurations with designed U-type baffles and a round turbulence inhibitor were analyzed using residence time distribution (RTD) curves. Mathematical models for liquid steel in the real plant tundish were established using the fluid dynamics software package Fluent. The flow field, the temperature field, and the RTD curves of liquid steel in the proposed tundish configurations were obtained. The results of numerical simulation and water modeling were validated with each other by the predicted and experimental RTD curves. The results of flow field and temperature field were used to reflect the actual state of a real plant tundish and to choose the optimal FCD. Finally, from the whole performance of the multi-strand tundish, the optimal scheme was determined by combining the results of water modeling and numerical simulation. With the optimal tundish equipped with U-type baffle with deflector holes and round turbulence inhibitor, not only was the flow characteristic of each strand improved, but also the difference of flow characteristics between multiple strands was smaller.
In recent years, with the development of hydrogen energy economy, there is an increasing demand for hydrogen in the market, and hydrogen production through biomass will provide an important way to supply clean, environmentally friendly and highly efficient hydrogen. In this study, cow dung was selected as the biomass source, and the efficiency of the biomass to hydrogen reaction was explored by coupling high temperature pyrolysis and water vapor gasification. The experimental conditions of gasification temperature, water mass fraction, heating rate and feed temperature were systematically studied and optimized to determine the optimal conditions for in situ hydrogen production by gasification of cow dung. The relationship of each factor to the yield of hydrogen production by gasification of cow dung semi-coke was investigated in order to elucidate the mechanism of the hydrogen production. The experiment determined the optimal operating parameters of in situ gasification: gasification temperature 1173 K, water mass fraction 80%, heating rate 10 K/min and feed temperature 673 K. The semi-coke treatment separated high temperature pyrolysis and water vapor gasification, and reduced the influence on gasification of volatile substances such as tar extracted from pyrolysis. The increase of semi-coke preparation temperature increases the content of coke, reduces the volatile matter and improves the yield of hydrogen; the small size of semi-coke particles and large specific surface area are beneficial to the gasification reaction.
25 June 2022 in Journal of Colloid and Interface Science
In this research, Australian fine iron ore is reduced by pressured carbon monoxide in a fluidized bed. This research aims to obtain the influence law of gas linear velocity, reduction pressure, reduction temperature, particle size, and reduction time on the reduction effect and the economic, convenient, and effective operating parameters, as well as clarify the effect of the pressurized decarbonization of CO, which inhibits the adhesion of fine iron ore particles during the reduction process. The experimental results show that the preferable operating parameters are a linear velocity of 0.8 m/s, reduction pressure of 0.2 MPa, reduction temperature of 1023 K, and particle size of 0.18 mm–0.66 mm. The graphite produced by the carbon precipitation reaction of carbon monoxide hinders the diffusion of iron atoms and avoids the direct contact between the iron atoms, thereby effectively controlling the sticking.