重油加氢催化剂用于中/低温煤焦油加氢改质的中试研究

在3×400 mL固定床加氢中试装置上评价了重油固定床加氢催化剂（包括重油加氢保护剂、重油加氢精制催化剂和芳烃饱和催化剂）用于中/低温煤焦油加氢改质的效果。中试条件为：原料体积空速0.8 h-1（按加氢精制催化剂计算）,反应压力12.0 MPa和13.5 MPa,氢油比1 200∶1,保护剂床层平均反应温度270℃,精制催化剂床层平均反应温度350℃,芳烃饱和催化剂床层平均反应温度360℃,在2个操作压力下各运转120 h。结果表明：提高煤焦油加氢改质反应压力,有利于杂原子的脱除。煤焦油经过加氢改质后,残炭、杂原子、芳烃含量大大降低,各馏分产品性质明显改善。产物中石脑油馏分含量增加,芳烃潜含量高,可作为优质的催化重整原料;柴油馏分含量基本不变,硫、氮含量低,凝点低,可作为优质的柴油调合组分;蜡油馏分含量明显降低,残炭和金属含量少,可作为优质的催化裂化原料。上述结果表明将重油固定床加氢催化剂用于煤焦油加氢改质在技术上是可行的。     

块煤焦固定层造气中氮改小氮流程的实践

中氮改小氮是当前的热点，改造后的实际效果却从未见到过有说服力的报道。本文对我公司造气系统中氮改小氮流程的实践进行了定性和定量评价，意为未改者提供改造依据，为已改者提供进一步完善的思路。     

固定床反应器MgO／BaCO_3甲烷氧化偶联催化剂的稳定性

报道在催化剂装量３０ｍｌ的环形固定床和直管固定床两种反应器上，ＭｇＯ／ＢａＣＯ３催化剂甲烷氧化偶联反应的５００ｈ稳定性试验结果。采用甲烷和纯氧为原料气，水蒸汽为稀释剂的共进料模式。试验结果表明，ＭｇＯ／ＢａＣＯ３催化剂在５００ｈ稳定性试验中一直保持着较高的催化活性，在直管固定床反应器上，Ｃ２烃收率１６．３％，Ｃ２烃选择性６５．０％。在环形固定床反应器上，Ｃ２烃的收率１７．３％，Ｃ２烃选择性６７．０％。为了控制反应速度，水蒸汽作为稀释气引入到反应中。水蒸汽在反应中可分散和带走催化剂床层过多的反应热，减小床层温差。ＸＲＤ结果表明，反应后的催化剂与新鲜催化剂的结构基本一致，说明催化剂具有稳定的催化活性的原因，应归属于其结构的稳定性和具有一定的抗水蒸汽性能。还考察了不同甲烷空速、反应器管壁温度、水蒸汽含量对反应性能的影响。     

Synthesis, characterization and performance of CuO/La2O3 composite catalyst for ammonia catalytic oxidation

This work considers the oxidation of ammonia (NH₃) by selective catalytic oxidation (SCO) over a CuO/La₂O₃ composite catalyst at temperatures between 150 and 400 °C. A CuO/La₂O₃ composite catalyst was prepared by co-precipitation of copper nitrate and lanthanum nitrate at various molar concentrations. This study also considers how the concentration of influent NH₃ (C₀ = 1000 ppm), the space velocity (GHSV = 92,000 l/h), the relative humidity (RH = 12%) and the concentration of oxygen (O₂ = 4%) affect the operational stability and the capacity for removing NH₃. The catalysts that were characterized using FTIR, XRD, UV-Vis, BET and PSA, have shown that the catalytic behavior is related to the copper (II) oxide, while lanthanum (III) oxide may serve only to provide active sites for the reaction during a catalyzed oxidation run. The experimental results show that the extent of conversion of ammonia by SCO in the presence of the CuO/La₂O₃ composite catalyst was a function of the molar ratio. The ammonia was removed by oxidation in the absence of CuO/La₂O₃ composite catalyst, and around 93.0% NH₃ reduction was achieved during catalytic oxidation over the CuO/La₂O₃ (8:2, molar/molar) catalyst at 400 °C with an oxygen content of 4.0%. Moreover, the effect of the reaction temperature on the removal of NH₃ in the gaseous phase was also monitored at a gas hourly space velocity of under 92,000 h^− 1.     

Trace element behaviour in the Sasol-Lurgi MK IV FBDB gasifier. Part 2 - The semi-volatile elements: Cu, Mo, Ni and Zn

Gasification is a coal conversion process that could be considered to be more amenable with regards to environmental impact factors when compared to combustion, as it provides minimum direct emission to the atmosphere due to the opportunity to apply a series of gas cleaning processes. Emissions could be in the form of the well known trace elements labelled as toxic present in feed coal. Due to the minimal literature available on coal gasification when compared to coal combustion, a large amount of inference to coal combustion has been applied in discussing the partitioning behaviour of trace elements during coal utilization. Conducting mass balance calculations of trace elements around gasification processes have proven to be a challenging task. This is due to the limitation of the analytical techniques employed to quantify at the parts per million levels at which trace elements exist. The other challenge is analyzing for trace elements in all the different stream phases that occur after gasification. The availability of thermodynamic equilibrium packages i.e. Fact-Sage to perform high temperature calculations, at the same time handling all phases of material involved has simplified the challenges. Results obtained from such calculations have also proved to be close to reality, but have not been related to the fixed-bed counter-current gasification reactor operating on lump coal.The focus of this paper is to discuss more recent environmentally-focused research developments by Sasol, where trace element simulation and validation of model predictions have been undertaken for the gasification process. Fact-Sage thermodynamic equilibrium modelling was used to simulate the semi-volatile trace elements (Cu, Mo, Ni and Zn) gas phase and ash phase partitioning and speciation behaviour occurring in a fixed-bed pressurized gasifier. A Sasol-Lurgi Mark IV FBDB gasifier was mined via turn-out sampling in order to determine the trace element changes through the gasifier, results being used to validate the modelled results.The semi-volatile elements: Cu, Mo, Ni and Zn all showed limited (5% in the case of Zn) de-volatilization behaviour in the drying and pyrolysis zone of the fixed-bed gasifier. Predictions revealed that within the reduction zone of the fixed-bed gasifier that they are all highly volatile, producing gaseous species with an increase in temperature, varying in the order: Zn > Mo > Cu > Ni, which is contrary to what was found from the experimental results. This could imply that thermodynamic equilibrium conditions do not necessarily prevail in a fixed-bed gasifier operating on lump coal, since in reality mass and heat transfer limitations across coarse coal particles apply and the reactions are therefore more kinetically limited. Over-balances of Ni and Mo partitioning to the solid ash fraction, was found for the measured results. This anomaly was found to not be caused by erosion of the gasifier internals, but rather possibly be ascribed to accumulation and contamination caused by likely condensation and vaporisation of these species during the gasifier sampling campaign, as well as by the particle size reduction processes utilized prior to elemental analyses. Leaching tests conducted on the bottom ash collected from the gasifier have shown that the trace elements studied are firmly bound into the ash matrix and therefore would not be released during later disposal. The relative enrichment in trace element content observed for Ni and Mo within the gasifier should be further investigated.     

常压固定床间歇煤气炉系统增产降耗分析

分析了常压固定床间歇煤气炉工艺指标、设备配置和操作方法对增产降耗的影响,并根据实际情况,给出了适宜的工艺指标、设备配置方案和操作方法。     

列管反应器中环形分布器内流体均布的探讨

利用动量守恒原理,推导出列管反应器中环形分布器内流体流动的修正动量方程,并在与前人实验结果比较和分析的基础上,提出了与环形分布管相适应的分流和合流动量交换系数式。研究结果表明,环形分布器内流体流动符合变质量流动规律,可采用环形分布器修正动量方程描述分流和集流的静压变化;通过直管分布器实验获得的动量交换系数对环形流道分布器也是适用的,其计算值与实验值的相对误差小于10%,可满足工程设计要求。     

催化裂化汽油烯烃转化增产丙烯工艺研究

在装有条形ZRP催化剂的固定床反应器上,考察了催化裂化汽油在ZRP稀土改性催化剂上的反应性能,反应温度、空速、原料中水油比等工艺条件对催化裂化汽油烯烃转化率和低碳烯烃收率、选择性的影响。实验结果表明：ZRP稀土改性催化剂可选择性地将催化裂化汽油中C5～C8烯烃催化裂解,提高催化裂化汽油烯烃的转化率和丙烯的收率;反应的适宜温度为550-580℃;在保证烯烃转化率的条件下,适当提高反应空速可以获得较高的丙烯、乙烯收率;引入适量的水蒸气可以起到稀释作用,能够使反应平衡向丙烯方向移动。     

Investigating effects of temperature on fuel properties of torrefied biomass for bio-energy systems

Torrefaction of selected agro-residues (rice straw and cotton stalk) was successfully carried out on indirectly heated, batch-type fixed-bed reactor under different reactor temperatures (200–300°C) at a fixed heating rate of 10°C/min. Our preliminary results demonstrated that the rice straw, torrefied at 275°C, exhibited higher mass yield (64%) and energy yield (84%) with better fuel properties, i.e. lower moisture content (1.2%), volatile matters (54.7%), higher fixed carbon (24.8%), and higher heating value (HHV) 18.7 MJ/kg. On the other hand, cotton stalk showed a slightly lower mass yield (56.3%) and energy yield (74.4%) compared to rice star with very high HHV 22.5 MJ/kg torrefied at a relatively lower temperature of 250°C. Interestingly, the lignocellulosic composition showed a drastic increase in the lignin content of rice straw and cotton stalk, torrefied at 275°C and 250°C, respectively, which indicates good binding ability of bio-fuel leading to improved energy density. Our present work gives an insight that the torrefied rice straw and cotton stalk could be a promising biomass feedstock for bio-energy based systems such as biomass pyrolsyis and gasification.     

N2和CO2气氛下辽河稠油热解过程及产物性质

利用热重分析仪（TGA）和固定床反应器对辽河Q块稠油在N₂和CO₂气氛下的热解过程及产物性质进行了研究。TGA实验结果表明,2种气氛下的稠油热解过程均可划分为轻组分与水分挥发、组分较弱化学键断裂和重组分裂解产油成焦3个阶段,热解曲线总体变化趋势类似。固定床反应器热解实验结果表明,随温度升高,2种气氛下的液体产物产率均升高,热解气和残余物产率均降低,CO₂气氛下650 ℃液体产物最大产率为61.53%。不同温度下热解所得液体产物和稠油的红外谱图显示,随热解温度升高,甲基含量增多、亚甲基含量减少。对液体产物的氧化过程进行TGA分析发现,随热解温度升高,其失重曲线向高温区明显偏移且失重程度减弱,CO₂热解所得液体产物的氧化失重比N₂快。