Methodologies of activation barrier measurements for reactions with deactivation were theoretically analyzed. Reforming of ethane with CO2 was introduced as an example for reactions with deactivation to experimentally evaluate these methodologies. Both the theoretical and experimental results showed that due to catalyst deactivation, the conventional method would inevitably lead to a much lower activation barrier, compared to the intrinsic value, even though heat and mass transport limitations were excluded. In this work, an optimal method was identified in order to provide a reliable and efficient activation barrier measurement for reactions with deactivation.

•Evaporation and crystallization characteristics of the droplets of desulfurization wastewater.•TGA and DSC methods were used to investigate the evaporation and crystallization processes.•Evaporation and crystallization rates increase with the increase of temperature increasing rate.•Increasing volume of the droplet increases the evaporation rate, but decreases the crystallization rate.•Structure of the crystals changes significantly when the temperature increasing rate and the volume of the droplet change.Relationship between evaporation and crystallization characteristics of a droplet of desulfurization wastewater from a coal-fired power plant and some operating conditions was studied experimentally using a thermogravimetric analyzer (TGA) with differential scanning calorimetry (DSC) function and a scanning electron microscope (SEM). The results shows that, between 15 °C/min and 45 °C/min, a higher temperature increasing rate leads to higher evaporation and crystallization rates. The increment in the evaporation rate, caused by the same increment of temperature increasing rate, is larger, when the temperature increasing rate is lower. In addition, the final temperatures, ranging from 90 °C to 150 °C, have little impact on the evaporation and crystallization rates of the 0.5 μL droplet. Ultimately, for the droplets, ranging from 0.2 μL to 2.5 μL, evaporation rate increases with increasing volumes of the droplets, but the crystallization rate decreases. From the SEM results, it can be observed that the quantity of cracks on the surface of the crystals also declines with the increase in volumes. Furthermore, the Stefan flow becomes a significant and unneglectable factor in order to decrease the evaporation rate at the end of the evaporation period.

We report here the ash sintering characteristics of LLI lignite with added bauxite during K2CO3-catalyzed steam gasification. The ash samples were prepared using a catalytic gasification system at 1123 K under a steam atmosphere with a carrier gas of N2. The ash sintering temperature was determined using a pressure-drop sintering device in inert N2. The ash mineralogy and morphology were determined by X-ray diffraction and energy-dispersive X-ray spectrometry-scanning electron microscopy. The K2CO3 catalyst decreased the sintering temperature of the ash samples and increased the amount of melting of the ash. The presence of kaliophilite facilitated the formation of the liquid phases and triggered the start of sintering, resulting in a lower ash sintering temperature. The addition of bauxite reduced the degree of melting of the ash and led to a higher ash sintering temperature. The main reason for this is that bauxite containing sufficient SiO2 and Al2O3 reacts with other minerals to generate more refractory silicon oxide and decreases the amount of arcanite (which acts a flux) and amorphous material in the ash. The addition of bauxite also decreased the rate of gasification of lignite by reacting with K to generate water-insoluble kaliophilite, which deactivated the K catalyst.

Low-concentration coal bed methane combustion tests were carried out in a bubbling fluidized-bed reactor with a mixture of limestone and crushed catalyst as bed material. The effects of bed temperature (723−923 K), inlet methane concentration (0.15−3 vol %), and superficial velocity (0.1−0.25 m/s) on methane conversion were studied. Gas was sampled from the bed and the freeboard to analyze the axial profiles of methane in the reactor. With kinetic parameters obtained in a fixed-bed microreactor, predictions from a two-phase model were compared to the experimental data from the fluidized bed. The results showed that bed temperature greatly affected the conversion, with a higher methane conversion obtained by increasing the temperature, reducing the inlet methane concentration, and decreasing the superficial gas velocity.

Sorbents with their components CaO/MgO and CaO/Ca9Al6O18 were produced from calcium d-gluconate monohydrate, magnesium d-gluconate hydrate, and aluminum l-lactate hydrate as precursors with a simple wet mixing method. The effects of sorbents type, mass proportion, SO2 concentration, and calcination temperature on sorbent capability were studied. The results show that CaO/MgO (75:25%, w/w) kept the best CO2-capture capability, while CaO/Ca9Al6O18 (75:25%, w/w) kept the best cyclic stability. The CO2-capture process is drastically blocked when SO2 exists. The CO2-capture capacity drops quickly when the SO2 concentration is promoted. However, the cumulative SO2-capture capacity increases at the same time. The total calcium use rises tenderly after many cycles, and the tendency becomes more obvious with an increasing SO2 concentration. The effect of the calcination temperature on CaO/MgO and CaO/Ca9Al6O18 absorption characteristics shows little difference.

•URANS simulations of multi-cylinders with PTC in FIM agree well with experiments.•Simulations predict well FIM response as well as VIV branches and galloping.•Vortex patterns of multiple cylinders in VIV and galloping are predicted accurately.Two-dimensional Unsteady Reynolds-Average Navier–Stokes equations with the Spalart–Allmaras turbulence model are used to simulate the flow induced motions of multiple circular cylinders with passive turbulence control (PTC) in steady uniform flow. Four configurations with 1, 2, 3, and 4 cylinders in tandem are simulated and studied at a series of Reynolds numbers in the range of 30 000