A review of the multi-component utilisation of coal fly ash

Biomass thermochemical processes result in a common byproduct char. The char is also called biochar particularly when it is used as a soil amendment for soil health improvement. Effective utilization of biochar is critical for improving economic viability and environmental sustainability of biomass thermochemical technologies. Application of biochar for both agricultural and environmental benefits has been studied and reviewed extensively. However, there are limited reviews on other biochar applications, such as for catalysis and adsorption. This paper provides an overview of recent advances in several biochar utilizations including its use as catalyst, soil amendment, fuel cell, contaminant adsorbent, gas storage and activated carbon. Discussions on biochar production methods, properties and advanced characterization techniques are also provided. Biochar is a valuable resource, however, its effective utilization require further investigation of its structure and properties, and methods to modify those.

Recent advances in utilization of biochar

FTIR and Raman spectroscopy characterization of functional groups in various rank coals

Comparing the porosity and surface areas of coal as measured by gas adsorption, mercury intrusion and SAXS techniques

A review of the alumina recovery from coal fly ash, with a focus in China

The advances in the characterization of amorphous carbons by Raman spectroscopy over the last four decades are of interest to many industries, especially those involving the combustion, gasification and pyrolysis of coal. Many researchers report on the Raman character of the natural organic matter in carbon-containing compounds, such as coal, and relate the Raman bands to the structural order of the amorphous carbons. The basis of most of these studies evolved around the assignment of the G (graphitic, ∼1580 cm−1) band to crystalline graphite and any other bands, called D bands, (disorder, various from 1100 to 1500 cm−1) to any type of structural disorder in the graphitic structure. Concerning coal analysis, the information gained by Raman investigations has been used to describe char evolution as a function of temperature, the presence of catalysts and different gasification conditions. In addition, researchers looked at maturation, grade, doppleritization and many more aspects of interest. One aspect that has, however, not been addressed by most of the researchers is the natural inorganic matter (NIM) in the carbon-containing compounds. Micro-Raman spectroscopy (MRS) has many advantages over other characterization tools, i.e. in situ analysis, nondestructive, no sample preparation, low detection limit, micrometer-scale characterization, versatility and sensitivity to many amorphous compounds. With the distinct advantages it has over that of other molecular characterization tools, such as powder X-ray diffraction (PXRD), Fourier-transform infrared spectrometry (FT-IR) and scanning electron microscopy with X-ray detection (SEM/EDS), it is surprising that it has not yet been fully exploited up to this point for the characterization of the NIM in coal and other amorphous carbons. This paper reviews the work published on the Raman characterization of the natural organic matter (NOM) of coals and reports on preliminary results of the NIM character of various South African coals, whereby various inorganic compounds and minerals in the coal have been characterized. Copyright © 2010 John Wiley & Sons, Ltd.

Raman spectroscopy for the analysis of coal: a review

Extraction of alumina from coal fly ash generated from a selected low rank bituminous South African coal

https://archives.datapages.com/data/meta/tsop/TSOPv23_2006/saghafi02_firstpage.pdf

Co2 storage potential of south african coals and gas entrapment enhancement due to igneous intrusions

The application of machine vision systems to measure particle size distributions has among other things been driven by sophisticated control systems used to monitor and control mills and other ore-processing systems. Machine vision is nonintrusive and offers reliable online measurements in potentially harsh environments. Although considerable advances have been made over the last decade, reliability of measurements with segmentation algorithms is still an issue, particularly where lighting conditions may vary, fines are present, or heterogeneous particle surfaces may result in irregular reflection of light. In practice the alternative to online measurement of particle size distributions is sieve analysis, which is slow and tedious and not suitable for control purposes. The efficient preparation and quality control of coal are important for stable and effective operation of the Sasol® FBDB™ Gasification Process. The operation of these gasifiers depend among other on melting properties and composition of th...

J.H.P. van Heerden

Papers

Raman spectroscopy for the analysis of coal: a review

Extraction of alumina from coal fly ash generated from a selected low rank bituminous South African coal

Co2 storage potential of south african coals and gas entrapment enhancement due to igneous intrusions

Online Analysis of Coal on A Conveyor Belt by use of Machine Vision and Kernel Methods

Chemical fractionation tests on South African coal sources to obtain species-specific information on ash fusion temperatures (AFT)