超临界汽轮机用1Cr11MoNiW1VNbN不锈钢组织和性能的研究

以超临界汽轮机用1Cr11MoNiW1VNbN不锈钢为研究对象,研究了热处理工艺对其组织和力学性能的影响.研究表明:1Cr11MoNiW1VNbN不锈钢经几种工艺热处理后的组织全部是板条马氏体组织,随着淬火温度的升高,晶粒度逐渐变大;抗拉强度随回火温度的升高而下降,且在660℃以后下降速度快速增加,材料塑性随回火温度的升高而升高,1050℃和1100℃淬火的试样无论是强度还是塑性都比较高;其拉伸断裂时均为脆性断裂,但在同一淬火温度的条件下,随着回火温度的升高,断口的韧性断裂特性逐渐趋于明显;1Cr11MoNiW1VNbN不锈钢硬度随回火温度的升高先下降后升高,在回火温度为695℃处最低.     

柴油超深度加氢脱硫非负载型Ni-Mo-W催化剂的研究

采用化学合成法制备了多孔金属固溶体,以此固溶体为前驱体制备了非负载型Ni-Mo-W加氢催化剂,采用XRD、TEM方法对硫化态非负载型催化剂进行表征,并以大庆低硫FCC柴油、中东高硫柴油为原料对非负载型催化剂进行深度加氢脱硫性能试验。结果表明,非负载型硫化态Ni-Mo-W催化剂中活性相形态主要为Ni3S2和MoS2/WS2,其中MoS2/WS2堆叠层数为3～8,远高于普通负载型催化剂。该非负载型Ni-Mo-W催化剂,对国内外低硫和高硫柴油加氢脱硫反应均表现出较高的活性和稳定性。     

桦甸页岩油柴油馏分中氮化物的加氢反应性能

采用硫化态NiMoW/Al2O3催化剂、在微型固定床加氢反应装置上,考察了反应温度、反应压力、停留时间和氢油体积比对桦甸页岩油柴油馏分中氮化物脱除率的影响,计算了加氢脱氮反应的表观动力学常数。实验结果表明,升高反应温度和反应压力或延长停留时间都能使碱性氮、非碱性氮及总氮的脱除率增加,但三者的增幅不同;增大氢油体积比使碱性氮、非碱性氮及总氮的脱除率先显著增加后略有减小。碱性氮、非碱性氮及总氮的加氢反应均符合拟一级反应动力学方程,在较低温度(340℃)下,总氮的脱除速率由碱性氮的脱除速率决定;而在较高温度(380℃)下,总氮的脱除速率由非碱性氮的脱除速率决定。NiMoW/Al2O3催化剂可有效降低加氢脱氮反应的表观活化能,具有较高的加氢脱氮活性。     

Creep property prediction of the high chromium ferritic steel 1Cr10NiMoW2VNbN at 600°C

Abstract

High chromium (Cr) ferritic steel 1Cr10NiMoW2VNbN was the first material developed in China for ultra-supercritical power stations. The creep property of high Cr ferritic steel 1Cr10NiMoW2VNbN has been studied under constant loading conditions at 600°C. The Theta projection concept applied to the creep curves was found to yield accurate predictions when interpolating and predicting creep data under service conditions. Four Theta parameters were obtained by Theta projection concept from the creep curves. The shape of the creep curves, as well as the minimum creep rate, the time to reach a limiting strain, and the time to rupture were considered with a wide range of stresses at 600°C of the high Cr ferritic steel.     

柴油在硅藻土分散 NiMoW硫化催化剂上深度加氢脱硫研究

Diatomite-dispersed NiMoW catalyst was prepared and characterized, and the activity of catalyst samples was tested during the HDS reaction of FCC diesel. Sulfur compounds in the feedstock and the hydrogenated products obtained over different catalysts were determined by GC-PFPD. The test results showed that the diatomite-dispersed NiMoW catalyst had high hydrodesulfurization activity for FCC diesel, which could be contributed to the excellent hydrogenation perfor- mance of the said catalyst. Characterization of catalyst by TEM and XRD indicated that the diatomite-dispersed NiMoW catalyst possessed higher layer stacking, larger curvature of MoS2 or WS2, and segregated Ni3S2 crystals relative to the sup- ported catalyst. This kind of structure leads to high hydrogenation activity of the diatomite-dispersed NiMoW catalyst.     

Hybrid plasma-sono-coprecipitation dispersion of NiMo nanocatalyst over functionalized multiwall carbon nanotube used in hydrodesulfurization of thiophene

To evaluate the effect of non-thermal plasma and ultrasound treatment on the catalytic physicochemical properties and hydrodesulfurization activity, a series of NiMoW/FMWCNT nanocatalysts (4%NiO, 12%MoO₃, and 6% WO₃) were prepared via co-precipitation method. The co-precipitated and treated by ultrasound or plasma-ultrasound nanocatalysts were characterized using XRD, FESEM, EDX dot-mapping, BET and FTIR techniques. The XRD data confirmed the formation of NiO, WO_3, and Mo₂C as the crystalline phase on carbon support. The results indicated ultrasound irradiation and non-thermal plasma treatment have significant influences on phase structure, morphology, and surface area. The optimum amount of applied voltage of plasma was found to be 500?V in which the maximum surface area and well-dispersion of the active phase were found. Further applied plasma voltage led to a decrease in catalytic activity due to the higher support-metal interaction and unpleasant distribution of the particles on nanocatalyst surface. The plasma–ultrasound hybrid synthesis method was able to eliminate 100% of sulfur in the initial solution of thiophene during hydrodesulfurization process.     

非负载型NiMoW加氢催化剂的制备、表征和性能评价

以NiMoW复合氧化物为前躯体制备高活性非负载型NiMoW加氢催化剂,考察了制备过程中黏结剂、胶溶剂、熟化处理等因素对催化剂性能的影响。采用BET、XRD、SEM、TEM、强度测定、堆密度测定等手段对催化剂进行表征,采用模拟柴油体系和真实柴油为原料对催化剂进行活性评价。结果表明,选择合适的黏结剂、胶溶剂以及适宜的熟化处理方法,不但可以保持催化剂原有活性相结构,而且能减小催化剂颗粒度,增大比表面积及孔容、孔径,提高催化剂的机械强度。在345℃、7.0 MPa、空速2.0 h^-1条件下,采用熟化处理制备的NiMoW-H催化剂,可将柴油中的硫质量分数由3690 μg/g降低到9 μg/g,而NiMoP/Al₂O₃参比催化剂仅降低到103 μg/g。