Process intensification in gas/liquid/solid reaction in trickle bed reactors: A review

As an important form of reactors for gas/liquid/solid catalytic reaction,trickle bed reactors (TBRs) are widely applied in petroleum industry,biochemical,fine chemical and pharmaceutical industries because of their flexibility,simplicity of operation and high throughput.However,TBRs also show inefficient production and hot pots caused by non-uniform fluid distribution and incomplete wetting of the catalyst,which limit their further application in chemical industry.Also,process intensification in TBRs is necessary as the decrease in quality of processed crude oil,caused by increased exploitation depths,and more restrictive environmental regulations and emission standards for industry,caused by increased environment protection consciousness.In recent years,lots of strategies for process intensification in TBRs have been proposed to improve reaction performance to meet the current and future demands of chemical industry from the environmental and economic perspective.This article summarizes the recent progress in techniques for intensifying gas/liquid/solid reaction in TBRs and application of intensified TBRs in petroleum industry.

Experimental study on the desulfurization and evaporation characteristics of Ca(OH)_(2) droplets

The experiments were conducted to focus on the desulfurization and evaporation characteristics of lime slurry droplets at 298-383 K. We designed an evaporation-reaction chamber with quartz glass windows.The monodisperse slurry droplet stream was injected into the evaporation reaction chamber, and the inlet gas components(air, air + SO_(2)) were introduced into the chamber. We applied the magnified digital in-line holography to measure the droplet parameters and calculated the evaporation rate. The effects of temperature, droplet concentration, and SO_(2) concentration on the evaporation rate of Ca(OH)_(2) droplets were discussed. Moreover, the Ca(OH)_(2) droplets under different experimental conditions were sampled,and the droplets were observed and analyzed using an off-line microscope. The evaporation rate of the Ca(OH)_(2) droplet increased at first, and then decreased during the falling process, and remained constant at last. The average evaporation rate of the Ca(OH)_(2) droplets increased significantly with the temperature increasing.

Kinetics of hot metal desulfurization by bottom blowing magnesium vapor

To solve the technical problems of hot metal desulfurization by injecting magnesium particulate,a new idea of hot metal desulfurization by bottom-blowing magnesium vapor was put forward.The reaction mechanism of hot metal desulfurization with magnesium vapor injection was analyzed,and the kinetic model of the desulfurization rate during the process of hot metal desulfurization with magnesium vapor injection was established.The dimensionless equation of the gas–liquid mass transfer coefficient under the injection conditions was obtained by the dimensional analysis method.And the theoretical calculation results were in good agreement with the experimental measurements.The results show that the diameter of the bubbles and the viscosity of the melt significantly affect the desulfurization rate of hot metal injected with magnesium vapor.When the temperature is 1573 K and the gas flow rate is 3 L/min,the desulfurization rate can reach 79%and the utilization rate of magnesium can reach 83%.