Particle fluidization by a plasma jet using polypropylene particles was examined in order to understand the plasma behavior and particle behavior in a spouted bed plasma reactor. In the experiment, a two-dimensional spouted bed plasma reactor was used to evaluate the effects of plasma and fluidization conditions such as applied voltage, gas flow rate, and amount of filling particles on the plasma brightness and particle velocity in the plasma reactor. The effect of applied voltage on plasma brightness and apparent gas flow rate was also evaluated using a one-dimensional tube plasma reactor. It was clarified that the plasma brightness and the particle behavior in the spouted bed varied greatly depending on the plasma and fluidization conditions. When the applied voltage was higher than 5 kV, the plasma brightness increased proportionally regardless of the presence or absence of particles. However, further increase of the plasma brightness was observed when the particles were fluidized in the spouted bed. The plasma brightness varied greatly depending on the fluidization state and amount of packed particles, and the plasma brightness in the bed increased significantly at the minimum spouting velocity (U_ms). On the other hand, the fluidization state in the bed was greatly changed by the plasma jet, the pressure loss in the bed was decreased, and the Ums was decreased due to the plasma jet. The experiment with the one-dimensional tube plasma reactor suggested that the increase of the apparent gas flow rate due to the plasmaization of Ar gas is one reason for the decrease of U_ms in the spouted bed.

A horizontal rotating cylinder reactor with a new simple internal spiral transport mechanism was proposed for its application to biomass gasification. In this rotary reactor, the gasification chamber and the combustion chamber are separated by the spiral transport mechanism. And, solid particles move between two chambers through the transport mechanism. However, the gases in the chambers hardly mix because the transport mechanism is filled with solid particles, which act as gas seal. By applying this to a gasifier, high/middle calorie fuel gas is expected to be produced by using air without indirect heating. In the present study, a basic examination on particle behavior was carried out by using the cold model to develop a new rotary kiln gasification process. As the results, the followings were elucidated. The transfer rate of the particles as heat charrier through the mechanism is increased with the increased exit diameter of the mechanism, while, it is necessary to reduce the ratio of the exit size to the entrance size and have a flow path with a constant width of at least 1 turn to form the gas seal. Therefore, it is desirable to design the exit diameter widely within the range where the gas seal can be formed.

A novel rotating coil-shaped spiral gas–solid contacting device was proposed. A cold model of 1.5-cycle spiral structure was made by combining 180° elbows of half-octagonal shape using ID 24 mm transparent plastic tubing. Spherical adsorbent (zeolite) particles were packed in the spiral. CO₂ was pulse-injected in a nitrogen stream to measure the removal efficiency of CO₂ by adsorption. The same procedure was conducted with a uniformly packed bed in a vertical tube of the same diameter. Adsorption kinetics was determined from the removal of CO₂ observed in the uniformly packed bed. The fraction of CO₂ removed in the spiral reactor was lower than that in the uniformly packed bed under the same solid volume/gas feed rate conditions. The difference was attributed to the non-uniform shape of the packed bed in the spiral; a shortcut in the gas stream was formed in the spiral. A model to estimate the pressure drop in the spiral proposed by the present authors was applied to estimate the removal of CO₂. The model agreed with the experimental results or slightly underestimated CO₂ removal in the spiral.

A new method was proposed for calculating reaction rates using the Weibull distribution, which represents the reliability of items in reliability engineering. First, the Weibull distribution was linearized, and parameters were determined by the least squares method. Next, to obtain a reaction rate, the equation obtained by multiplying the Weibull distribution by the initial concentration of the reactant was differentiated with respect to the reaction time. This method was applied to the hydrolysis of ethyl acetate and the hydrolysis of sucrose using a typical pseudo-primary reaction with an acid catalyst. It was found that the coefficient of determination of the regression equation between the logarithm of the reaction rate and the logarithm of the concentration of the reactant calculated by the method was close to 1, indicating high linearity. Furthermore, the order of the reaction determined from the regression analysis was between 0.973 and 1.05, which was close to 1. The reaction rate calculation method using the Weibull distribution is therefore effective for pseudo-primary reactions.

This paper proposes a design of PID-level controllers in chemical plants based on IMC principles. Controller parameters of a common simple PID controller are given. This method is also applicable to integrating systems with time delay. Unlike most IMC-based design studies, this study also proposes a method for determination of the IMC filter time constant based on statistical analysis of about 200 level controllers in actual chemical plants. The proposed controller design method is applied to a typical integrating system to demonstrate its effectiveness. The design method is finally applied to level controllers in actual plants. The result shows significant improvement both in the deviation of the control variables and the fluctuation of the manipulation variables.