Preparation of carbon nanotubes (CNTs) by catalytic chemical vapor deposition (CCVD) was conducted using a nano-agglomerate bed of quartz with 44mm inner diameter and 1000mm height in the temperature range 500-6501C. Ethylene and propylene were used as carbon source materials, and four kinds of catalysts containing oxides of Fe, Cu, and Ni, prepared by co-precipitation method, were used. Effect of catalyst composition on morphology of CNTs was studied by transmission electron microscopy (TEM). It shows that better quality CNTs can be achieved with Fecatalysts, and carbon nano-fibers were produced at high carbon yield with Ni-catalysts.

A new catalyst loading method, in which catalyst particles are packed in a reactor with a novel internal, has been studied by measuring pressure drop, RTD, liquid holdup and mass transfer. It can be inferred from experimental results that the internal changes the conventional gas and liquid counter-current 3ow into a new cross-current 3ow, so the problems of excessive pressure drop and "3ooding" are avoided. When pressure drop, liquid holdup, RTD and mass transfer coe6cient are similar, the catalyst loading fraction of the new method is much higher than that of conventional methods. Furthermore, the reactive distillation reactor with the novel internal has advantages such as simple structure, low operating cost, and convenience for installation and removal of the catalyst.

For the alkylation of benzene with long-chain olefins, H -zeolite catalyst not only has the advantages of high selectivity to 2-phenyl isomers with no corrosive or environmental problems, but it also can be regenerated repeatedly. The characterization of the coke shows that the deactivation of catalysts is caused by a jam of bulkier molecules, such as naphthalene, indane and linear alkylbenzenes, which are too big to move quickly in the intracrystalline pores of the catalysts. These bulkier molecules deposit in intracrystalline pores and then in larger pores. The aromatic compounds in raw olefins must be removed because they can deactivate the catalyst quickly; the moisture in the reactants should be 20-30ppm. The deactivated catalyst can be regenerated by benzenewashing at higher temperature. Newspecies, such as alkylbenzene with short chains, naphthalene, indane, biphenyl, condensed ring compounds and unsaturated compounds, are formed by cracking and cyclization in the regeneration process.

An integrated hydrodynamic mathematical model is established from experimental results and a more rigorous definition is proposed for the uniformity of the axial gas distribution in a radial flow moving-bed reactor (RFMBR). A new iteration strategy is provided for the solution of the model. Simulations show the influence of the flow structure, the reactor dimension, the design of the axial gas distributor and the operation conditions on the axial uniformity of the gas distribution. This work provides a theoretical basis and useful method for the optimum design and operation of RFMBRs.

Several models for the daughter bubble/droplet size distribution are reviewed and a detailed discussion is given to get a better understanding of the daughter size distribution. A novel theoretical breakup kernel function for bubbles/droplets in a turbulent (ow, based on an eddy-bubble/droplet collision method, is developed. It takes into account the energy distribution of turbulent eddies, e5ect of capillary pressure and surface energy increase during bubble/droplet breakup. An increase in the mother bubble/droplet size and energy dissipation rate increases the probability of unequal breakup. The model prediction is in good agreement with experimental results and the underlying physical situation.

Bubble sizes, interfacial areas and volumetric mass transfer coefficients in a slurry bubble column are measured experimentally and used to determine the two parameters of a mass transfer model. The mass transfer coefficients kL between the gas and liquid phases in a slurry bubble column under different operating conditions are simulated. Calculated results show very good agreement with experimental measurements. The mass transfer model proposed can predict well the mass transfer rate in slurry bubble systems.

A gas-liquid mass transfer model for slurry bubble systems is established. It is based on the dynamic film mass transfer theory for a single bubble. The concentration in the liquid film is considered as a function of timet and radial position r. The analytical solution is obtained by Laplace transformation and the use of Danckwerts's age distribution function. The mass transfer coefficient kL is deduced from the analytical solution. The influence of the model parameters: the surface renewal rate s and the thickness of the liquid film δ on the mass transfer coefficient kL is simulated. The two parameters are correlated with the operating conditions such as temperature, pressure, superficial gas velocity and solid concentration to allow the model to be used to predict the interfacial mass transfer rate for slurry bubble systems.

The gas-liquid-solid three-phase circulating fluidized bed (TPCFB) is a novel multiphase reactor with outstanding performance in hydrodynamics, heat transfer, mass transfer and catalyst treatment. The object of this work is to study the bubble behavior in TPCFBs for better understanding of the hydrodynamics of the reactor. The local gas holdup, bubble size distribution, and bubble rise velocity in different radial positions are measured using a fiber optic probe, and the effects of operating conditions on bubble rise velocity are also investigated. Moreover, the bubble rise velocity and its distribution are compared with the data from gas-liquid two-phase external loop airlift reactors and gas-liquid-solid three phase fluidized beds without external circulation of liquid and particles.

For a reactive distillation column with a novel internal which is made of several structured porous passages, the models of pressure drop and liquid holdup are developed. The simulation from the models shows that the internal can make more than 70% gas contact liquid in cross-current instead of counter-current, so that excessive pressure drop is avoided. In addition, below the load point, only superficial liquid velocity and the volume fraction of the internals have evident effects on the liquid holdup; above the load point, both superficial gas and liquid velocities have great effects on the liquid holdup, and so do the parameters of the internal because they can affect gas flow behavior.

Complexity issues in the ecological aspects of chemical engineering are of two kinds: the mutual interactions of many multi-scale systems and the lack of consilience in the objectives of di6erent disciplines that consider the economic, philosophical, cultural, and scienti7c and engineering aspects, respectively. This paper discusses the second kind of complexity and the ecological issues in the di6erent disciplines. Economic value, as expressed by market price, depends on whether limits on resources and the Earth's services due to the scale of human technological activities are taken into account. Human activities relative to the Earth's ecology require sustainability consideration. Two important stands on sustainability are discussed. Mainstream sustainability is a stand for continued economic growth to foster advances in technology to overcome the limits of the Earth. It requires technological activities to follow green chemistry and green engineering principles to develop innovations that are ecologically considerate. Environmental sustainability is a stand to stay within forecasted limits in the resources and renewability capacity of the Earth. The technology for this further includes using the principles of industrial ecology to locate ways to use wastes and recycle products as source materials for other processes to make and close material cycles. Chemical engineering innovations for increased atomic utilization of reactants, e=ciency in energy use, dematerialization, non-toxicity, recyclability, and creative systemic cycling of materials for waste management are good for the ecology. Case studies are given showing the utility of following the principles developed for good ecological practice.