Combustion of an Illinois No. 6 coal char simulated using an atomistic char representation and the ReaxFF reactive force field

Current state of fine mineral tailings treatment: A critical review on theory and practice

Along with the development of industry and the improvement of people’s living standards, peoples’ demand on resources has greatly increased, causing energy crises and environmental pollution. In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally-friendly, and sustainable technology, and it has become a hot research topic. However, current photocatalytic technology cannot meet industrial requirements. The biggest challenge in the industrialization of photocatalyst technology is the development of an ideal photocatalyst, which should possess four features, including a high photocatalytic efficiency, a large specific surface area, a full utilization of sunlight, and recyclability. In this review, starting from the photocatalytic reaction mechanism and the preparation of the photocatalyst, we review the classification of current photocatalysts and the methods for improving photocatalytic performance; we also further discuss the potential industrial usage of photocatalytic technology. This review also aims to provide basic and comprehensive information on the industrialization of photocatalysis technology.

https://www.mdpi.com/2076-3417/9/12/2489/pdf

Recent Advances and Applications of Semiconductor Photocatalytic Technology

The knowledge of biomass char gasification kinetics has considerable importance in the design of advanced biomass gasifiers, some of which operate at high pressure. The char gasification kinetics themselves are influenced by char structure. In this study, the effects of pyrolysis pressure and heating rate on the char structure were investigated using scanning electron microscopy (SEM) analysis, digital cinematography, and surface area analysis. Char samples were prepared at pressures between 1 and 20 bar, temperatures ranging from 800 to 1000 °C, and heating rates between 20 and 500 °C/s. Our results indicate that pyrolysis conditions have a notable impact on the biomass char morphology. Pyrolysis pressure, in particular, was found to influence the size and the shape of char particles while high heating rates led to plastic deformation of particles (i.e. melting) resulting in smooth surfaces and large cavities. The global gasification reactivities of char samples were also determined using thermogravimetric analysis (TGA) technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure.

Effect of pyrolysis pressure and heating rate on radiata pine char structure and apparent gasification reactivity | NOVA. The University of Newcastle's Digital Repository

The present state of the methods commonly used for inorganic and mineral matter characterization in coal is described and summarized. The application of various separation procedures, macroscopic observations, reflected and transmitted optical microscopy, scanning and transmission electron microscopy, X-ray diffraction, differential thermal and thermogravimetric analyses, Mossbauer spectroscopy, infrared spectroscopy, and chemical analyses are briefly discussed. A short critical overview on the advantages and limitations of the above listed methods as well as some recommendations during their utilization are also presented.

Juan Barraza

Papers

Energy barrier of aggregates coal particle–bubble through the extended DLVO theory

Flotation of a refuse tailing fine coal slurry

A pilot-scale flotation column to produce beneficiated coal fractions having high concentration of vitrinite maceral

Effect of temperature, solvent/coal ratio and beneficiation on conversion and product distribution from direct coal liquefaction

A proposed biomass char classification system