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Now showing items 11-20 of 46
The effect of carbon dioxide partial pressure on the gasification rate and pore development of Highveld coal chars at elevated pressures
(Elsevier, 2018)
Char structural changes occurring during gasification are normally only related to conversion and few data is published on the effect of carbon dioxide partial pressure on the extent of pore development. In this study, the ...
Transformation of nitrogen functional forms and the accompanying chemical-structural properties emanating from pyrolysis of bituminous coals
(Elsevier, 2018)
Characterisation of simultaneous changes in nitrogen functionalities and condensed aromatic crystallites during pyrolysis of bituminous coals was conducted. X-ray photoelectron spectroscopy (XPS) was utilised to determine ...
A modelling evaluation of an ammonia-fuelled microchannel reformer for hydrogen generation
(Elsevier, 2014)
Hydrogen production from an ammonia-fuelled microchannel reactor is simulated in a three-dimensional (3D) model implemented via Comsol Multiphysics™. The work described in this paper endeavours to obtain a mathematical ...
Mineralogy and petrology of chars produced by South African caking coals and density-separated fractions during pyrolysis and their effects on caking propensity
(ACS, 2019)
Thermochemical processes use low-rank bituminous coal to produce steam and synthetic gas. Caking coal particles can soften, swell, and coalesce in the South African boilers and fixed-bed gasifiers during pyrolysis and have ...
SO2 solubility in 50 wt % H2SO4 at elevated temperatures and pressures
(ACS, 2014)
The SO2 solubility at various temperatures and pressures was evaluated to
determine the SO2 content in a 50 wt % H2SO4 acid solution adding new experimental
solubility data for the SO2−H2SO4 binary system currently ...
Density functional theory molecular modelling and experimental particle kinetics for CO2-char gasification
(Elsevier, 2015)
Experimental measurements and DFT atomistic modelling were conducted to elucidate the mechanisms for gasification chemistry of char with CO2 gas. The molecular models used were based on experimental representations of coal ...
Influence of potassium carbonate on the swelling propensity of South African large coal particles
(ACS, 2015)
The swelling propensity of some coals may restrict their use in fixed- and fluidized-bed gasification operations, and effective reduction of swelling can widen the applicability of these coals. Extensive research has been ...
Structural and chemical modifications of typical South African biomasses during torrefaction
(Elsevier, 2016)
Torrefaction experiments were carried out for three typical South African biomass samples (softwood chips, hardwood chips and sweet sorghum bagasse) to a weight loss of 30 wt.%. During torrefaction, moisture, non-structural ...
Influence of maceral composition on the structure, properties and behaviour of chars derived from South African coals
(Elsevier, 2015)
The generation of coal chars is an important intermediate step in coal conversion processes such as combustion and gasification. The char structure impacts their behaviour in these processes. Detailed investigations on ...
The characterisation of slow-heated inertinite- and vitrinite-rich coals from the South African coalfields
(Elsevier, 2015)
The development of coal char structures with pyrolysis has been extensively investigated but has traditionally been focused on the carboniferous coals in the northern Hemisphere. In this investigation, the properties of ...