生物流化床处理废水的研究进展

生物流化床技术因具有处理效率高、容积负荷大、传质速度快、应用范围广等优点受到了广泛的关注。介绍了近年来国内外生物流化床技术在废水处理中的应用研究情况,并指出了生物流化床技术目前存在的主要问题及今后的发展方向。     

三相复合生物流化床反应器处理废水性能研究

提出和设计了一种新型的自充氧式复合生物流化床反应器,将该反应器应用于合成废水的处理,考察了反应器的挂膜以及停留时间、气水比,容积负荷等对COD去除率的影响,研究结果表明,该反应器在处理废水时,停留时间可达2h和1．5h,COD容积负荷提高到8．56和12．63kg/d.m^3,效率比同类反应器高1倍以上,气水比也有所下降,仅为32－34,具有停留时间短,能耗低,是一种高效的新型生物流化床反应器。     

多层三相流化床流动特性的研究

针对多层三相流化床进行冷模试验,以饱和KCl溶液为示踪剂,采用电导法测定不同液速、气速和固相浓度条件下液相流体在床内的停留时间分布曲线、平均停留时间。采用多釜串联模型得到模拟参数以及其返混特性随着各操作参数变化的情况。结果表明：液相速度对平均停留时间影响显著,随液速增大而急剧减小;气速和载体对平均停留时间影响较小,随着气速和载体量增加平均停留时间均呈下降趋势。液相返混程度随气相速度增加而增加,随液相速度和载体含量的增加而减小。     

3万t/a苯胺流化床反应器的设计

介绍了3万t/a苯胺流化床反应器整体结构,重点介绍了设备直径、高度的确定,内构件设计和分离段旋风分离器的设计,此设备已成功应用到生产中并稳定运行多年。     

苎麻污水处理工艺设计

作者介绍了采用三相生物流经床工艺处理苎麻污水的实例,处理后水中的ＣＯＤ和ＢＯＤ浓度均低于《污水综合排标准》ＧＢ８９７８－８８。该工艺流程简单,投资规模小,无二次污染。实践证明：这一方法用于苎麻污水处理是非常成功的,有很主的实用价值。     

Efficient synthesis of iron nanoparticles by self‐agglomeration in a fluidized bed

A two‐stage, fluidized reduction route is proposed to synthesize iron nanoparticles (NPs), with the aim of enhancing the quality of fluidization and preventing sintering activity. At both low and high temperatures, the degree of metallization η is approximately 80% due to the defluidization. Defluidization is mainly caused by the rapid sintering of the newly formed Fe NPs. The proposed two‐stage fluidization approach successfully resolves the defluidization problem through the self‐agglomeration of nanoparticles cultivated at low temperatures. These self‐agglomerated NPs showed an improved resistance to sintering at high temperatures. The high‐purity Fe NPs prepared by this approach exhibited excellent combustion activity, indicative of the potential as oxygen carriers in chemical looping combustion systems. © 2016 American Institute of Chemical Engineers AIChE J, 63: 459–468, 2017     

膜法SBR三相外循环流化床反应器

本文分析了以多孔高分子载体为固相的三相外循环流化床反应器的优点,通过与膜法SBR工艺相结合,在处理COD浓度范围为600～1400mg/L,容积负荷范围为1.78～4.15kgCOD/m3.d的有机废水,其COD去除率能高达90.0%以上,NH4 -N的去除率能高达70.0%以上。结果还表明,该工艺具有处理较高浓度废水的潜力。     

磁稳流化床研究与应用进展

磁稳流化床（MSFB）作为一种新型反应器,兼具固定床和流化床的众多优点,具有巨大的应用前景。本文综述了MSFB近年来在基础研究和应用上取得的进展。基础研究方面主要介绍了磁场强度和液相流速对床层结构的影响,以及床层空隙率、操作稳定性和传递特性等研究情况;应用方面介绍了MSFB在生物化工、能源和环境工程等领域的应用。最后分析了MSFB目前存在的不足,如对于一定的反应体系未找到相应合适的磁性催化剂、操作温度高于磁性载体的居里温度时,MSFB将无法操作、磁场发生装置释放出大量的热量对磁性载体和反应过程产生影响、难以确定稳定操作区域。并指出其今后的主要研究方向为磁性载体催化剂的研究与开发及对MSFB的稳定性判据、传热、传质、强化反应过程机理、反应器放大规律、工业化应用装置设计等方面的研究。     

复合载氧体磨损规律的研究

载氧体的研究是化学链燃烧技术研究的关键,制备载氧体的方法有很多,本文用浸渍法制备复合载氧体(活性组分CaSO4,惰性组分Al2O3,助剂Fe2O3)。载氧体的性能对化学链燃烧技术的应用非常关键,机械强度是评价载氧体的主要指标之一。采用冷态流化床磨损测试方法研究了复合载氧体的磨损规律。磨损的发展过程符合Gwyn磨损动力学方程,不同颗粒磨损规律的差别可由Gwyn方程的各参数来描述。     

Formulation and manufacture of pharmaceuticals by fluidized‐bed impregnation of active pharmaceutical ingredients onto porous carriers

A manufacturing method is presented for solid dosage forms using fluidized‐bed impregnation, which could eliminate many of the challenges during solid dosage manufacturing. The main difference between impregnation and dry blending is the placement of the active pharmaceutical ingredient (API) inside a porous carrier. This makes the final material flow properties independent of the physical properties of the API. The method consists of spraying an API solution in appropriate solvent onto a carefully chosen porous excipient in a fluidized state. The solution penetrates the porous carrier due to capillary forces and the solvent is evaporated soon after that. Impregnation and drying occur simultaneously, which makes this impregnation method suitable for continuous implementation. Carefully choosing the operating conditions allows impregnation to occur without introducing spray drying or spray coating of the API. The method is shown to generate an impregnated excipient with very high degree of homogeneity independent of the API loading. It is also shown that mild milling further improves blend uniformity to RSD levels below 1%, which are challenging to achieve using conventional techniques. On impregnation, the final physical properties of the material are seen to be mainly unchanged from the initial excipient properties. A study of this one‐step manufacturing method is described, using acetaminophen as the model drug and anhydrous calcium phosphate dibasic as the porous excipient. The experimental work presented establishes a proof of concept and investigates in detail blend uniformity, physical state of impregnated API, final physical properties of impregnated material, compressibility during tableting, capsule filling, and release profile of the final capsule formulation. It also discusses potential ways for drug release control and improvements using impregnation. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4538–4552, 2013     

煤热解多联产技术述评

集燃烧和热解工艺于一体的煤热解多联产技术是我国煤资源的有效利用方式之一。介绍了煤热解多联产技术的工作原理;论述并对比了以流化床、移动床、焦热载体为热解基础的煤热解多联产典型工艺技术特点;指出:煤热解多联产工艺技术更适合于挥发性高的低阶煤种,该技术已建有小型工业化生产示范装置,具备商业化生产应用的技术基础。     

高速气固流化床局部瞬态行为混沌分析

在内径 1 86mm、高 9m的提升管中 ,通过改变操作气速获得湍动流化床、快速流化床和稀相输送典型的操作状态 ,使用光纤密度探头在轴向不同截面的不同径向位置处测得密度脉动时间序列 ,以反映不同流型下 ,不同浓、稀相区的瞬态动力学行为 .利用确定性混沌理论分析了局部密度脉动信息 ,以Kolmogorov熵定量地表征系统的动力学特征 .实验结果表明 ,Kolmogorov熵随流型的变化能正确地反映相应流型的特点 ,可用来描述不同流型下的流动结构 .在忽略壁面附近行为的条件下 ,对 3种流型、不同的浓稀相区 ,局部熵值随局部固含率变化可分为两个区 :当局部固含率高于 0 0 5时 ,熵几乎不随局部固含率的变化而变化 ;当局部固含率低于 0 0 5时 ,熵随局部固含率的减小而急剧增大 .这说明系统的混沌特征与局部固含率关系密切 ,局部固含率对系统局部动态行为起控制作用 .     

大颗粒尿素技术与工艺流程比较

阐述了大颗粒尿素的特点及当今世界上生产大颗粒尿素的主要造粒工艺,对海德鲁、东洋工程公司造粒工艺与双转鼓流化工艺大颗粒尿素技术进行了比较,对大颗粒尿素的前景进行了展望。     

铁基凹凸棒载氧体制备及煤化学链燃烧性能研究

以Fe(NO3)3·9H2O、Fe2O3和Fe3O4为前驱体,凹凸棒(ATP)为惰性载体制备了系列Fe2O3/ATP载氧体。在流化床反应器内,以水蒸气作为气化-流化介质,900℃为还原温度,研究了载氧体与神木煤的反应活性及循环反应性能,同时考察了载氧体的抗磨损性能。实验结果表明:以Fe(NO3)3·9H2O为前驱体制备的Fe4ATP6(N)载氧体具有很高的反应活性和抗磨损能力。对其进行的10次还原/氧化循环实验表明:尾气中CO2平均含量先下降后升高,但都保持在95%以上,停留时间t95从14.8 min增加到16.1 min。SEM分析表明随着循环反应的进行载氧体表面小颗粒变成大颗粒,发生轻微烧结。     

昭通褐煤气化扩大试验研究

针对昭通褐煤的特点 ,在气化煤量为 0 .3t/h的焦载热流化床气化扩大试验装置上进行了试验研究 .研究结果表明 ,煤气中焦油量很小 ,有利于煤气生产的后期处理 ;与移动床气化和普通流化床气化相比 ,煤气热值和气化产率都有较大增加 ,煤气热值已接近城市煤气的要求 ;加大气化煤量可增加提升段燃烧的易燃成分 ,从而提高了燃烧温度和气化温度 ;气化煤量的变化对褐煤气化产率和产量的影响较大 .对于开发昭通褐煤资源来说 ,采用本工艺技术生产城市煤气是一个较佳的方案 .     

Operation of Fixed‐bed Bioreactor for Polluted Surface Water Treatment

Abstract

Dissolved organic matters and ammonia nitrogen are serious contaminants of surface water in Taiwan. These contaminants can interfere with the water treatment process and cause biological instability in the finished water. One solution is to employ a biological treatment stage prior to the conventional water treatment process. A continuous flow biological filter packed with reticulated PU foam was used to remove ammonia nitrogen and organic materials before the conventional water treatment practice. The effect of its operation mode, namely, empty bed contact time (EBCT) and backwash, on the removal efficiencies of ammonia and organic matter was examined. The results suggested that ammonia nitrogen and organic nitrogen can be effectively removed by controlling the operation mode of the biological fixed bed. Efficient ammonia nitrogen removal was achieved upon the combination of the backwash mode with short EBCT or extended EBCT without the backwash. Efficient organic nitrogen and DOC removals were observed at short EBCT without the backwash. This study provides insights into the function of biofiltration, which benefits the design of a fixed‐bed bioreactor for the treatment of polluted surface water.     

流化床煤燃烧过程不同气氛下的气态氮释放特征

利用微型流化床反应装置,结合快速过程质谱仪,在850~940℃操作温度下,研究了三种不同粒度分布烟煤和无烟煤在热解、气化和燃烧反应条件下四种主要气态氮产物HCN、NH₃、NO和NO₂的释放规律。结果表明,微型流化床可以实时检测挥发分氮和焦炭氮的动态释放序和类型,热解、气化和燃烧反应气氛的改变主要影响HCN和NH₃的释放量。热解产物的气态氮主要是来自于挥发分,燃烧反应的HCN和NH₃的释放量与温度有明显关系,而气化反应的各类气态氮释放量随温度变化波动不大。煤颗粒尺寸和温度变化对烟煤和无烟煤中各类气态氮释放量产生影响比较复杂,其中NH₃的释放特性是区分挥发分N释放和半焦N释放的重要特征。