UASB反应器处理垃圾渗滤液的快速启动方法

研究了UASB反应器处理生活垃圾渗滤液时快速启动的条件,结果表明:在夏季的室内水温(25～30℃)时,采用未经驯化的城市生活污水厂(传统活性污泥法)的剩余污泥接种,经逐步培养法,通过控制较低的液体上升流速(3.0m/d),可以在50d的时间里完成UASB反应器处理垃圾渗滤液的启动,使其有机负荷(以CODCr计)达到10kg/(m3·d),且CODCr的去除率高达70%以上(较常规启动少用1～4个月的时间),进而在90d里完成污泥的颗粒化。     

Granulation rate processes in the kneading elements of a twin screw granulator

To characterize the granulation rate processes in the kneading section of the twin screw granulator, separate experiments were conducted using exclusively conveying elements as the baseline in addition to different configurations of kneading elements. The configuration parameters examined were the length of the kneading section, the advance angle, and the angle direction. Granule size, shape and liquid distribution were measured. Two main rate processes were observed (1) breakage and layering, and (2) Shear elongation and layering. Breakage was dominant in the 90° configuration while shear elongation dominated in the 30° reverse configurations, with other configurations giving some combination of the two rate processes. The distinct three‐dimensional (3‐D) shape characteristics of granules obtained from each configuration were crucial in elucidating the dominant granulation rate process in each case. The proposed granulation mechanisms explain the events leading to particular granule attributes, but more importantly provide insight into future optimization of twin screw granulation process. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4100–4115, 2013     

UASB反应器中颗粒污泥形成的影响因素

综述了UASB反应器中颗粒污泥形成的影响因素 ,包括环境因素、废水特征及操作条件 ,并就这一研究提出了其新的发展方向。     

工程建设项目的开车/开车服务管理

介绍工程公司在化工,石化或医药工程项目设计,采购,施工,开车及生产验收各阶段的开车／开车服务管理的工作职责,主要工作内容和方法以及所依据的标准／规范和作用文件。     

25%吡唑醚菌酯水分散粒剂挤压造粒配方研究

通过对不同类型的润湿剂、分散剂、崩解剂、填料等组分的筛选和研究,确定了挤压造粒工艺的25%吡唑醚菌酯水分散粒剂最佳配方。该配方组成为:吡唑醚菌酯25%,SXC3%,2020 3%,D908 3%,消泡剂0.5%,可溶性玉米淀粉20%,轻质碳酸钙补足至100%。该制剂分析试验表明,产品各项指标符合水分散粒剂的要求。     

The internal architecture of anaerobic sludge granules

The structural characteristics of well-formed anaerobic granular sludges were examined using scanning electron microscopy and light microscopy of thin sections. Transverse sections were found to consist of randomly orientated filaments of Methanothrix soehngenii. These were tightly packed with little space between the individual filament sheaths, revealing a ‘honeycomb’ appearance. Sections cut from wax-embedded granules were stained using a number of histochemical procedures. Detailed examination of the overall structure of the granules was possible, revealing the presence of filamentous bundles of Methanothrix surrounded by a matrix found to be carbohydrate in nature. Interpretation of serial sections through the depth of the granule allowed for the construction of a diagrammatic illustration of the internal structure. A relationship between the measured diameter of these microcolonies of Methanothrix and the distance from the centre of the granule was established. Together these results enabled a proposal to be made as to the possible mechanisms involved in the growth of granules. This supports previous suggestions relating to the involvement of Methanothrix and bacterial polymers.     

干熄焦系统烘炉开工制度的确定

介绍了马钢第1套国产化干熄焦系统开工前后操作数据的制定及工艺参数的确定，对操作要点及操作中需注意的问题进行了详述。同时为国内其他在建的干熄焦工程提供了参考。     

CO2 methanation: Optimal start‐up control of a fixed‐bed reactor for power‐to‐gas applications

Utilizing volatile renewable energy sources (e.g., solar, wind) for chemical production systems requires a deeper understanding of their dynamic operation modes. Taking the example of a methanation reactor in the context of power‐to‐gas applications, a dynamic optimization approach is used to identify control trajectories for a time optimal reactor start‐up avoiding distinct hot spot formation. For the optimization, we develop a dynamic, two‐dimensional model of a fixed‐bed tube reactor for carbon dioxide methanation which is based on the reaction scheme of the underlying exothermic Sabatier reaction mechanism. While controlling dynamic hot spot formation inside the catalyst bed, we prove the applicability of our methodology and investigate the feasibility of dynamic carbon dioxide methanation. © 2016 American Institute of Chemical Engineers AIChE J, 63: 23–31, 2017     

Packed‐bed reactor for short time gas phase olefin polymerization: Heat transfer study and reactor optimization

A specially conceived packed‐bed stopped flow minireactor (3 mL) suitable for short gas phase catalytic reactions has been used to study the start‐up of ethylene homopolymerization with a supported metallocene catalyst. Focus has been put on the heat transfer characteristics of the supported catalysts and on understanding the relationship between the initial rate and the relative gas/particle velocities and the influence of particle parameters in the packed bed. We performed a comprehensive study on the influence of various physical parameters on the heat transfer regime at start up conditions. The catalyst activity as well as the polymer morphology is shown to be dependent on heat transfer regime. The knowledge thus obtained is applicable to industrial problems like catalyst injection in fluidized beds and helps preventing experimental artifacts due to overheating in following studies. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Dynamic analysis and open‐loop start‐up of an integrated radiant syngas cooler and steam methane reformer

The transient performance of an integrated radiant syngas cooler (RSC) of an entrained‐bed gasifier and steam methane reformer (SMR) is investigated. Base‐case designs using either co‐current or counter‐current configurations are subjected to operating transients to evaluate the feasibility to transition to new steady states. Each system, under open loop, is subjected to changes in key variables of the SMR feed on the tube side and disturbances to variables of the coal‐derived syngas on the RSC side to determine the dynamics and stability of the integrated system. The results indicate that the co‐current configuration is flexible to move to new operating steady states and more safe than the counter‐current configuration, although it provides less cooling and has poorer methane conversion. The variables likely to violate the design limit in the event of a disturbance are identified. A start‐up procedure is also established based on industrial practices employed for entrained‐bed gasifiers and methane reformers. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1602–1619, 2017     

Dynamic properties of a continuous stirred tank biofilm bioreactor for aerobic processes

A dynamic analysis of a continuous stirred tank bioreactor with biofilm was performed. The existence of gas, liquid, and biofilm were taken into account. The proposed heterogeneous model of such bioreactor takes into account dynamic biofilm growth and interphase transfer of substrates and biomass for a double‐substrate aerobic process. Simulations were performed to investigate the influence of important process parameters, i.e., toxic substrate concentration in the feed stream, detachment rate coefficient, mean residence time of the liquid and aeration intensity, on dynamic properties of the bioreactor. Dynamic behavior at conditions of anoxia of microorganisms were shown. A method was proposed to reduce bioreactor start‐up time significantly. The paper presents a mathematical model of the bioreactor that uses a discrete model of biofilm growth based on the theory of cellular automata. Dynamics of the bioreactor based on the continuous and discrete biofilm model was compared. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1818–1829, 2017     

湖南金迪聚酯投料试车及试生产

介绍该装置的试车过程和 2年来的运行状况。吸纳了专利公司的许多改进之处 ,形成本装置的工艺条件、设备特点。一次投料试车成功 ,目前装置在 12 5 %负荷下平稳运行 ,各项指标优于合同值。在 12 0 %负荷下 ,PTA、EG、电的单耗分别为85 8、334、81。经过论证 ,在 5釜不做大的改动的情况下 ,可扩容至 2 80t d     

流化床大颗粒尿素造粒装置的改进

流化床大颗粒尿素造粒装置自1996年10月投产成功以来,运行时间已超过5年,在装置运行过程中,对不利于装置稳定运行的环节进行改进,为稳定装置运行和提高产品质量起到良好作用.     

On the small composite granules formed in a continuous rotating conical vessel containing grinding media: effect of the methods of feeding powder on the size and structure of binary composite granules

To investigate the effect of the methods of feeding SiC and CaCO₃ powders on the size and structure of binary composite granules made of the powders, experiments were performed by a simultaneous operation of granulation, grinding and separation in a continuous rotating conical vessel using two kinds of methods for feeding the binary powder. The structure of a composite granule was characterized by comparing the granule size with the size of the SiC-agglomerates contained in the granule.

It was found that (i) by feeding dry SiC with CaCO₃ powders, it was difficult to obtain composite granules smaller than 0.3 mm in size, and that (ii) by feeding SiC-powder with binder in a slurry state, it was possible to make composite granules of larger than at least 0.13 mm, though the structure of composite granules depended on the concentration of SiC-powder in the slurry.