A simplified approach to the model development and scale-up of a packed bubble column reactor from pilot semi-batch mode to continuous commercial operation has been presented. This is illustrated by choosing the reaction of ethynylation of formaldehyde to 1,4-butynediol for which correct reaction mechanism is difficult to postulate in the compelling safety limitations. The apparent reaction kin...

In this paper the results of a leaching kinetics study of bauxite ore with sodium hydroxide are presented. The effect of ore particle size, sodium hydroxide concentration and reaction temperature on the Al2O3 extraction rate was determined. The results obtained showed that 99% of Al2O3 was leached out using -200+270 mesh ore particle size at a reaction temperature of 105 °C for 60 min reaction ...

We propose coupled evolution equations for the thickness of a liquid film and the density of an adsorbate layer on a partially wetting solid substrate. Therein, running droplets are studied assuming a chemical reaction underneath the droplets that induces a wettability gradient on the substrate and provides the driving force for droplet motion. Two different regimes for moving droplets--reactio...

[60]Fullerene-fused pyrazolines 1 were prepared by the reaction of C60 with alky diazoacetates under the solid-state high-speed vibration milling conditions as well as in toluene solution. Pyrazolines 1 were stable in refluxing toluene and its thermolysis process in 1,2-dichlorobenzene was investigated, the decomposition rates and activation energies of pyrazolines 1 were obtained. The current ...

Platinum extraction from different secondary sources has been experimentally tested by many researchers. In this article, dissolution of platinum in aqua-regia solution from two types of spent catalysts (reforming and nitric acid production) was kinetically studied. A variety of kinetic models for heterogeneous solid-liquid reactions, including homogeneous diffusion model, shrinking core model,...

The process of dehydration of glucose to 5-hydroxymethylfurfural (HMF), using caprolactam-lithium chloride (CPL/LiCl) as a solvent, was investigated. Dual-wavelength ultraviolet spectrophotometry provides a new approach for the determination of glucose conversion rate and yield of HMF. Experiments were performed to demonstrate the accuracy and precision of this method. Various reaction paramete...

An equilibrium Y-Si-0-N melt was infiltrated to eliminate the open porosity of reaction-bonded silicon nitride at 16001800°C. This oxynitride melt contained two equilibrium phases, a P-Si,N, solid phase and a liquid phase at high temperatures. Before infiltration, porous reaction-bonded silicon nitride compacts were heat-treated to completely transform to the P-Si3N, phase. After infiltration, ...

An experimental study was conducted to determine the effects of the leaching parameters on impurity ion concentrations of the liquid phase in ulexite leaching. Powdered ulexite ore was leached in an aqueous medium with sulfur dioxide. The Taguchi experimental design approach and statistical methods were used to evaluate the effects of the leaching parameters (solid/liquid ratio, temperature...

in vitro propagation of plant has played a very important role in rapidmultiplication of cultivars with desirable traits and production of healthy and disease-free plants. in the present investigation, the objectives were to optimize the micropropagation of rose hybrid ‘black baccarat’ cultivar. in proliferation step, the nodal segments (1.5 cm) was cultured on both liquid and solid media (ms, ...