Advanced Materials Research Vols. 512-515

Abstract: In this paper, NiCo₂O₄ nanoparticles were synthesized by three different methods. The applied preparation methods in this research are thermal decomposition of a mixed oxalate precursor, combustion synthesis and hydrothermal method. The crystalline phase, morphology and specific surface area (BET) of the resultant samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and nitrogen physical adsorption, respectively. The research found that the hydrothermal method is a promising method to prepare NiCo₂O₄ nanoparticles.

Abstract: Under reducing conditions, H₂S, which will result in the high temperature corrosion of fireside water wall, is predominant sulfur compounds discharged from the coal. Influences of temperature and oxygen on the transformation mechanism of H₂S were studied by chemical kinetics. It is concluded from the study that the main productions of H₂S vary with the reaction conditions, COS is mainly produced in highly reducing conditions and SO₂ is dominant production under oxidizing atmosphere. Peak concentration of S₂ only can be obtained at mildly reducing conditions and moderate temperature; meanwhile, most of H₂S is oxidized to SO₂ when the temperature is above 1300K. A turning point is found when the concentration of O₂ is about 2%, and simulation results comply with experimental measurements.

Abstract: The paper mainly introduces the desulfurization technology before coal combustion and gives a brief analysis of principles , advantages and disadvantages of the three current coal desulfurization technologies: physical desulfurization, chemical desulfurization and biological desulfurization . Finally, this paper puts forward some views on the development trend of coal desulfurization technology.

Abstract: With the rapidly development of natural gas production, storage and transportation, the requirement for safety monitoring on natural gas industry are continuously increasing. This paper analyzes the application of WSN (wireless sensor network) in natural gas industry safety monitoring, and proposes a layered structure for large scale WSN based safety monitoring system, which can be used in collecting various kinds of safety information in natural gas industry, and sending them to surveillance center for data analyzing and early warning of abnormal situation. In the structure, we discuss the deployment of sensor nodes, sink nodes and e-sink nodes, and proposed the layered data fusion model and query model.

Abstract: Concentration model of indoor flammable leakage gas is established and simplified. The relations between indoor gas concentration and leakage time, leaking intensity, the rate of ventilation, room volumes are analyzed comprehensively. Point out that leakage gases concentration of the entire space and the partial regions should be considered simultaneously to adopt the measures to reduce the concentration when gases leakage accidents are occurred.

Abstract: In this paper, the desulfurization of LA (Lu,an) coal was carried out by combining the method of ultrasonic and microwave irradiation. The effect of microwave time and combination of ultrasonic and microwave irradiation on the desulfurization of LA coal was investigated. The results showed that the sulfur removal effect of microwave irradiation time is obvious. The removal rate of organic sulfur increased with the microwave irradiation time increased. The effect of ultrasonic before microwave irradiation on desulfurization was greater than simply microwave method. The sulphur form was investigated systematically using X-ray photoelectron spectroscopy (XPS). After microwave and ultrasonic co-enhanced oxidative desulfurization of coal, the content of sulfur in coal was decreased by the XPS analysis.

Abstract: The removal of sulfur in coal before its combustion can reduce its environmental pollution, and microbial desulfurization should have good application prospects. Some species of bacteria have been used in the process of coal desulfurization, and our previous study demonstrated that mixed culture should be more efficient than pure culture by shaking cultivation. In this study, column leaching was investigated, due to its similarity to the industrial heap leaching. The mixed culture consisted of three strains of bacteria, which were Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans respectively. The ratio of the three strains of bacteria was 1: 1: 1. The column (50 cm height, 650 mm Inner Diameter) bioleaching experiments were carried out at ambient temperature. After desulfurization for 18 days, the ultimate desulfurization rate was 28.66% for total sulfur, which was higher than the previous study of J.Cara (with total sulfur desulfurization rate for 24% after 125 days). This study showed that ferric ions should be in proper concentration, and Leptospirillum ferrooxidans might be in lower ratio for reducing the precipitation of jarosite and improving the efficient of coal desulfurization.

Abstract: This article refers to the status quo of liquified natural gas (LNG) in China, the anylisis of LNG’s risks, and the discussion of fire-fighting design specifications related to LNG gasification stations at home and abroad. In this text, safety measures are also proposed being aimed at the fire-fighting design of gasification station in the aspects of site selection, overall layout, building structure, safety devices, electric instruments, fire-extinguishers and fire-fighting strategy etc.

Abstract: Nuclear power is clean, safe, but not zero risk, which has been evidenced by the history of nuclear power development. Nuclear accident emergency response is the final barrier of depth defense to reduce the potential risks that may arise from nuclear power development, which must be enhanced. The accident emergency preparedness in China and China responses to Fukushima accident are presented. Learning lessons from past nuclear power accidents (the Three Mile Island, Chernobyl and Fukushima), China would be keeping confidence in nuclear power development and advancing further improvement of emergency response capabilities to insist on the safety-first principle for nuclear power development.

Abstract: The paper studies the flame spread characteristics of the diesel with safety performance by schlieren technology. The flame of fire spreading of the diesel includes flash fire flame which is blue and main flame which is orange. The main flame spread forward in the reciprocating and pulsatile pattern, while the flash fire flame spread with the level discontinuous pulsatile pattern. The water content in the diesel has notable restriction effect on the speed of the flame spreading, which is decreased with the increasing of the water content. But the micro-emulsified diesel can’t effectively restrain the spread speed when water content is below 3%. The microemulsified diesel whose water content being in the range of 3%~12% could be used in engine.