利用非线性规划技术的固定床反应器在线过程辨识

提出了基于非线性规划的在线过程辨识的一般性方法．辨识器对动态测量数据采用了移动水平法,并把具有不同采样速率的测量值统一考虑在辨识公式中,同时还可以处理具有时滞和约束的情况．概率解释说明,在一定的情况下最小二乘估计与最大似然估计具有一致性．本文以壁冷式固定床反应器为例,从仿真和实验两方面考察了所提出的在线过程辨识器的性能,并研究了各辨识器参数的影响．结果表明,该辨识器具有很好的收敛性能和鲁棒性,同时在计算速度上也能满足在线要求．     

La1-xLixMnO3钙钛矿催化剂同时消除NO和碳烟催化性能

采用溶剂热法制备La_1-xLi_xMnO₃ (x=0,0.05,0.15,0.25) 钙钛矿型复合金属氧化物催化剂。通过XRD、FT-IR、XPS、H₂-TPR和NO-TPD等手段对催化剂进行表征,在固定床微型反应器中评价催化剂同时消除NO和碳烟催化性能。结果表明,溶剂热法制备的La_1-xLi_xMnO₃催化剂具有单一的钙钛矿结构,催化剂中Mn物种以Mn³⁺和Mn⁴⁺的形式存在。Li⁺部分取代LaMnO₃中La³⁺后,La_1-xLi_xMnO₃催化剂上Mn⁴⁺数量和氧空位增加,促进更多活性氧物种和氮氧化物的吸附与活化,提高氧化还原性能,改善催化活性。Li⁺取代量为0.15,即La_0.85Li_0.15MnO₃催化剂催化活性较好,T_max和T_ig分别为463℃和327℃,NO最大转化率X_{\mathrm{N}\mathrm{O}}^{\mathrm{m}\mathrm{a}\mathrm{x}}为42.1%,反应温度T_{\mathrm{N}\mathrm{O}}^{\mathrm{m}\mathrm{a}\mathrm{x}}为383℃。     

异形催化剂床层中Sabatier反应的微-介尺度模拟

采用离散元方法（DEM）建立随机堆积球形、柱形催化剂床层,计算流体力学（CFD）方法模拟Sabatier反应床层介尺度和催化剂微尺度的温度和物质浓度分布,并探讨了催化剂形状、壁温和入口条件对反应特征的影响。结果表明：床层中会出现球形热点区,并随反应进行向出口移动,催化剂外层反应物浓度比内层高且呈环状分布。柱形催化剂单颗粒中心CO₂转化率较球形高,但棱角和床层壁面会出现低转化率区,床层流体会出现回流、滞留和沟流现象,最终导致CO₂转化率为球形>柱形（径高比=1.3）>柱形（径高比=1）。球形催化剂床层中,时间t=200s时,CO₂转化率达到峰值26%,若此时将壁温降低50K,时间t=500s时,较降温前CO₂转化率增大2%、热点温度降低10K;增加惰性球层、减小入口流速和温度,能提高催化剂内CO₂转化率。     

Validation of pressure drop prediction and bed generation of fixed-beds with complex particle shapes using discrete element method and computational fluid dynamics

Catalytic fixed-bed reactors with a low tube-to-particle diameter ratio are widely used in industrial applications. The heterogeneous packing morphology in this reactor type causes local flow phenomena that significantly affect the reactor performance. Particle-resolved computational fluid dynamics has become a predictive numerical method to analyze the flow, temperature, and species field, as well as local reaction rates spatially and may, therefore, be used as a design tool to develop new improved catalyst shapes. Most validation studies which have been presented in the past were limited to simple particle shapes. More complex catalyst shapes are supposed to increase the reactor performance. A workflow for the simulation of fixed-bed reactors filled with various industrially relevant complex particle shapes is presented and validated against experimental data in terms of bed voidage and pressure drop. Industrially relevant loading strategies are numerically replicated and their impact on particle orientation and bed voidage is investigated.     

RFT-2固定床费托合成催化剂中试应用研究

对RFT-2固定床费托合成催化剂进行中试应用研究,对其反应性能和运转稳定性能进行考察。结果表明,在合成气空速750～800h-1、原料气转化率93%左右的工况下,C3＋烃类选择性达90%以上,C5＋液体烃选择性达86%以上,催化剂具有较好的反应性能;在超过1 000 h的稳定性运转考察过程中,催化剂活性、选择性未见明显...     

造气炉水夹套失效原因分析

通过分析与试验,发现造气炉夹套失效的原因是由于空程尺寸过大.     

固定床煤气炉不可能被淘汰 应继续发展

介绍固定床煤气化技术的优势,对该技术目前认识上存在的一些误区,就煤气炉的操作控制、配套的工艺设备设置提出了看法.     

煤气化方法的比较及分析

分析比较了固定床、流化床、气流床3种气化方式中各典型工艺的工艺流程、优缺点及工业化应用。     

Recovery of rare-earth metals from aqueous solutions by bio/adsorption using non-conventional materials:a review with recent studies and promising approaches in column applications

The recovery of rare-earth metals(REMs) is of great economic and environmental interest,because of their high market prices and various industrial applications.Recently,with the increasing demand for high-purity rare-earth compounds,the separation and purification of these elements have gained considerable attention.The bio/adsorption process has been considered an alternative to recover these elements,by its simplicity,low cost and efficiency for recovery of REMs at low concentrations.This review article presents the recent progress regarding REM bio/adsorption published literature in batch system by different non-conventional bio/adsorbents,as well as a critical analysis of the technological challenges to be faced and future prospects.For this purpose,the best application model(isotherm,kinetics),thermodynamic quantities and selection of eluents for desorption studies are also discussed.Additionally,in this review,the application of different bio/adsorbent materials were reviewed extensively in terms of the removal and recovery of REMs in continuous fixed-bed adsorption and regeneration cycles.Finally,future aspects in bio/adsorption research and prospects for commercial applications were discussed.     

协庄矿煤常压固定床气化特性的研究

分析了协庄矿煤的煤质特性,在内径100mm固定床中进行了不同空气鼓风强度、不同富氧浓度的常压气化试验研究,总结出协庄矿煤常压固定床气化的气化特性。