Catalysts and polymerization processes have evolved over the years. Such significant developments have allowed producers to broaden the range of polymer microstructure and process productivity, thereby making it possible to offer a wide range of end-use properties at a reasonably low cost. However, these advantages in catalyst performance and reactor operation require that we understand as much as possible about reactor operation in the broadest sense. In addition to the fundamental experimental study of polymer chemistry, this means that one needs to develop complete, robust process models. The present paper provides a rapid overview of recent developments in various gas phase propylene (co)polymerization reactors in use today, concentrating on multizone gas phase polypropylene reactors: i.e.,

Powder technology has already extended its scope of interest to nanoparticles with novel properties and functionalities. Since the establishment of the National Nanotechnology Center (NANOTEC) in 2003, research activities in nanotechnology have shot up remarkably, including the production of nanoparticles via physical, chemical and biological methods. This article reviews and introduces recent works on nanoparticle production in Thailand, especially NANOTEC and her nation-wide network of Centers of Excellence. The categories of nanoparticles of interest extend from metal and zinc oxide nanoparticles to carbon nanoparticles and titanate nanostructures. However, thin films and nanofilms lie beyond the scope of this review.

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A steady state model of co-current spray evaporator and air (de)humidifier for non-isothermal droplets has been developed to investigate the effect of polydispersity of droplet size on performance. The model is validated by comparison with results of Dickinson and Marshall (1968, AICHE J.14,541). It reveals that their ideal assumption of constant droplet temperature leads to significant error when the droplet size distribution is strongly polydisperse. Numerous simulation cases of the spray evaporator show that the average droplet diameter and droplet size distribution of water spray significantly affect the change in the air properties and the size, velocity and temperature of water droplets. For polydisperse droplets, a narrower droplet size distribution ( σ =0.2) shows a more rapid decrease in the diameter of the droplets, thus causing a more rapid temperature decrease and humidity increase of the air than the case of a broader droplet size distribution ( σ =0.4) with the same volume-averaged diameter.