转晶剂对磷石膏制备无水硫酸钙影响的研究

磷石膏(PG)产生量大、资源化利用困难,严重影响磷化工行业的发展。为提高PG应用附加值,以除杂后的PG为原料,以NaCl和乙二胺四乙酸二钠(EDTA-2Na)为转晶剂,采用常压盐溶液法制备高白度无水CaSO₄。通过SEM、XRD、FT-IR、粒度分析仪等分析方法研究转晶剂对无水CaSO₄制备的影响。结果表明：当NaCl质量分数为15%、EDTA-2Na质量分数为0.5%时,PG结晶水脱水时间由120 min缩短至40 min,脱水效果显著;同时,无水CaSO₄晶体粒度分布均匀,颗粒表面完整,D₅₀为5.26μm,白度值为92.5%,P₂O₅质量分数仅为0.045%。这主要是因为非晶格Na⁺降低了体系中水的活度,促进PG脱水转晶及杂质脱除;EDTA-2Na中羧基基团与石膏晶体表面的Ca²⁺发生配位形成的配位离子层可调控无水CaSO₄晶体生长,修饰晶面。     

添加剂抑制CaSO4高温分解的TG-FTIR研究(Ⅱ)碳酸盐系列

如何提高固硫产物 Ca SO4高温的热稳定性 ,从而提高以钙基固硫剂为主固硫剂的高温固硫率 ,成为燃中固硫的关键问题 .采用 TG- FTIR联用技术 ,在线测定了各种碳酸盐添加剂对固硫产物 Ca SO4在高温下 ( 1 0 0 0℃～ 1 45 0℃ )热稳定性的影响规律 .结果表明 ,添加一定比例的Na2 CO3 ,Ba CO3 ,Sr CO3 和 Mg CO3 对固硫产物 Ca SO4晶体在高温下的分解有明显的抑制作用 .     

酸性废水体系中硫酸钙反应结晶过程研究(英文)

The present work focused on the recycle of the sulfate and the metal ions from acidic wastewater dis charged by nonferrous metallurgical industry. The effects of the temperature, the reactant concentration, the stirring speed and the metal ions on the reactive crystallization process of calcium sulfate between sulfuric acid and lime were systematically investigated. The morphology of the precipitated crystals evolved from plateletlike and nee dlelike shape to rodlike shape when the temperature was increased from 25 to 70 ℃. An increase in the agglom.     

添加剂抑制CaSO4高温分解的 TG-FTIR研究 (Ⅲ)固硫效果定性和定量分析

在氧化物系列高温固硫剂和碳酸盐系列高温固硫剂研究的基础上,利用TG-FTIR联用技术和ZCL自动定硫仪,把一定量的分析煤样与氧化物系列高温固硫剂和碳酸盐系列高温固硫剂分别以3∶1的Ca/S比充分混和,对燃煤的实际固硫效果进行了定性和定量检测.结果表明,两种系列固硫剂均使CaSO4高温分解推迟到1200℃以后,SrCO3在高温时的固硫率高达96.7%,而BaCO3也达92.2%.     

一种基于含噪时序结构独立元分析的过程监控方法(英文)

Conventional process monitoring method based on fast independent component analysis (FastICA) cannot take the ubiquitous measurement noises into account and may exhibit degraded monitoring performance under the adverse effects of the measurement noises. In this paper, a new process monitoring approach based on noisy time structure ICA (NoisyTSICA) is proposed to solve such problem. A NoisyTSICA algorithm which can consider the measurement noises explicitly is firstly developed to estimate the mixing matrix and extract the independent components (ICs). Subsequently, a monitoring statistic is built to detect process faults on the basis of the recur-sive kurtosis estimations of the dominant ICs. Lastly, a contribution plot for the monitoring statistic is constructed to identify the fault variables based on the sensitivity analysis. Simulation studies on the continuous stirred tank reactor system demonstrate that the proposed NoisyTSICA-based monitoring method outperforms the conven-tional FastICA-based monitoring method.     

基于Aspen Plus的气流床煤气化炉三段平衡模型(英文)

A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiers based on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification temperature. The model is divided into three stages including pyrolysis and combustion stage, char gas reaction stage, and gas phase reaction stage. Part of the water produced in the pyrolysis and combustion stage is assumed to be involved in the second stage to react with the unburned carbon. Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature. And the gas product compositions are calculated from gas phase reactions in the third stage. The simulation results are consistent with published experimental data.     

氧基电解质La_(10-x)V_x(SiO_4)_6O_(3+x)的制备及性能测试(英文)

Apatite-lanthanum silicate has attracted considerable interest in recent years due to its high oxide ion conductivity.In this paper,V-doped samples La10-xVx(SiO4) 6O3+x(0≤x≤1.5) were prepared by sol-gel method and the influences of V-dopant content on calcining temperature and conductivity were reported.The samples were characterized by thermal analysis(TG-DSC) ,X-ray diffraction(XRD) and scanning electron micrograph(SEM) . The apatite was obtained at 800°C,a relatively low temperature in comparison to 1500°C with the conventional solid-state method.The ceramic pellets sintered at 1200°C for 5 h showed a higher relative density than La9.33Si6O26 pellets sintered at 1400°C for 20 h.The conductivities of samples were measured by electrochemical impedance spectroscopy.The conductivity was improved with the increase of V-dopant content on La site.     

基于CoFe2O4载氧体的生物质化学链气化反应特性

在热重分析仪和固定床反应器上对基于CoFe₂O₄载氧体的生物质化学链气化反应特性进行了研究，考察了载氧体与生物质质量比、水蒸气、反应温度对生物质化学链气化反应特性的影响，同时也对载氧体的循环反应性能进行了研究。通过XRD及SEM对新制备的和反应后的载氧体进行了表征。热重结果表明：CoFe₂O₄能够提供晶格氧，有效促进生物质气化。当CoFe₂O₄与生物质质量比为0.8，水蒸气体积分数为50%，温度为900 ℃时，气化反应效果最好。5次循环反应后，仍能获得较高品质的合成气，载氧体能够循环再生且未出现明显烧结团聚。     

基于符号有向图与定性趋势分析的化工过程故障诊断方法(英文)

In the past 30 years, signed directed graph (SDG), one of the qualitative simulation technologies, has been widely applied for chemical fault diagnosis. However, SDG based fault diagnosis, as any other qualitative method, has poor diagnostic resolution. In this paper, a new method that combines SDG with qualitative trend analysis (QTA) is presented to improve the resolution. In the method, a bidirectional inference algorithm based on assumption and verification is used to find all the possible fault causes and their corresponding consistent paths in the SDG model. Then an improved QTA algorithm is used to extract and analyze the trends of nodes on the consistent paths found in the previous step. New consistency rules based on qualitative trends are used to find the real causes from the candidate causes. The resolution can be improved. This method combines the completeness feature of SDG with the good diagnostic resolution feature of QTA. The implementation of SDG-QTA based fault diagnosis is done using the integrated SDG modeling, inference and post-processing software platform. Its application is illustrated on an atmospheric distillation tower unit of a simulation platform. The result shows its good applicability and efficiency.     

基于分片化MPCA模型的多阶段批次过程阶段分析与阶段辨识方法(英文)

Multi-way principal component analysis (MPCA) is the most widely utilized multivariate statistical process control method for batch processes. Previous research on MPCA has commonly agreed that it is not a suitable method for multiphase batch process analysis. In this paper, abundant phase information is revealed by way of partitioning MPCA model, and a new phase identification method based on global dynamic information is proposed. The application to injection molding shows that it is a feasible and effective method for multiphase batch process knowledge understanding, phase division and process monitoring.     

煤/钙基载氧体化学链燃烧操作参数分析

化学链燃烧作为一种新颖的燃烧技术,在化石燃料燃烧释放能量的同时能够有效分离CO2。今以CO2为气化剂气化煤炭,基于Aspen Plus流程模拟软件,研究了煤/钙基载氧体化学链燃烧过程。结果表明,以CO2为煤气化剂,各反应器含水分少,可减少热损失。CaSO4载氧体具有载氧能力大以及反应活性良好等优点。气化炉中CO+H2含量随二氧化碳煤比增大逐渐增加后下降;随温度升高其含量先增加,后趋于平稳。燃料反应器中CO2+H2O含量随载氧体煤比增大,呈现先增大后减小的趋势;随温度升高其含量逐渐下降。空气反应器中CaSO4含量随空载比增大先增加后趋于平稳,随温度升高其含量趋于平稳后下降。气化炉中硫化物和氮化物含量随温度升高而下降,而燃料反应器和空气反应器中硫化物含量随温度升高增加趋势明显,氮化物含量变化不明显。最后确定了关键反应器操作参数:气化炉的二氧化碳煤比为1.8;燃料反应器的载氧体煤比为4.5;空气反应器的空载比为10.5和三反应器的操作温度分别为950、1000和1100℃。     

铁基化学链法调节合成气氢碳比及联产氢气的实验研究

利用固定床反应器考察了实验参数对调节用于费托合成的合成气中H2/CO及产氢的影响. 结果表明,500~800℃条件下,合成气(H2/CO为0.5)经过固定床反应器时,出口H2/CO可达0.87~0.53;通过在还原阶段通入适量水蒸汽,可有效提高调节H2/CO的能力,且能增加氧化阶段的产氢量. 此外,还原阶段加入水蒸汽还能有效抑制积碳生成,所制H2纯度接近100%. 在载氧体颗粒中加入石墨作为扩孔剂,可增强颗粒反应活性和稳定性,经过6个循环后,实际产氢量仍保持在理论产氢量的40%以上(不加石墨仅为20%)且仍保持一定的孔结构,而未加石墨的颗粒几乎完全烧结.