Sulfur analysis of Bolu-Mengen lignite before and after microbiological treatment using reductive pyrolysis and gas chromatography/mass spectrometry

Atmospheric pressure-temperature programmed reduction coupled with on-line mass spectrometry (AP-TPR/MS) is used for the first time on microbiologically treated coal samples as a technique to monitor the degree of desulfurization of the various sulfur functionalities. The experimental procedure enables the identification of both organic and inorganic sulfur species present in the coal matrix. A better insight in the degradation of the coal matrix and the accompanying processes during the AP-TPR experiment is obtained by a quantitative differentiation of the sulfur. The determination of the sulfur balance for the reductive pyrolysis gives an overview of the side reactions and their relative contribution in the total process. The volatile sulfur species are unambiguously identified using AP-TPR off-line coupled with gas chromatography/mass spectrometry (GC/MS). In this way, fundamental mechanisms and reactions that occur during the reductive pyrolysis could be quantified, explaining the differences in AP-TPR recoveries. Therefore, this study gives a clearer view on the possibilities and limitations of AP-TPR as a technique to monitor sulfur functionalities in coal

Co-firing of biomass with coals Part 1. Thermogravimetric kinetic analysis of combustion of fir (abies bornmulleriana) wood

The chemical composition and reactivity of fir (Abies bornmulleriana) wood under non-isothermal thermogravimetric (TG) conditions were studied. Oxidation of the wood sample at temperatures near 600 A degrees C caused the loss of aliphatics from the structure of the wood and created a char heavily containing C-O functionalities and of highly aromatic character. On-line FTIR recordings of the combustion of wood indicated the oxidation of carbonaceous and hydrogen content of the wood and release of some hydrocarbons due to pyrolysis reactions that occurred during combustion of the wood. TG analysis was used to study combustion of fir wood. Non-isothermal TG data were used to evaluate the kinetics of the combustion of this carbonaceous material. The article reports application of Ozawa-Flynn-Wall model to deal with non-isothermal TG data for the evaluation of the activation energy corresponding to the combustion of the fir wood. The average activation energy related to fir wood combustion was 128.9 kJ/mol, and the average reaction order for the combustion of wood was calculated as 0.30

Change of the structure of coals from the Kozlu K20 G borehole of Zonguldak basin with burial depth - 1. Chemical structure

The present paper is a part of the studies on the structure and properties of the Zonguldak bituminous coal samples, from the Kozlu K20 G borehole. The changes in the values of parameters characterizing the properties of the tested coals with an increase in the degree of coalification at increasingly greater depths in the borehole were reported. Changes in elemental and proximate analyses results, calorific value, FTIR aromatic bands, ESR values, and aromaticity of the samples were described

Change of the Structure of Coals from the Kozlu K20 G Borehole of Zonguldak Basin with Burial Depth

The present paper is a part of the studies on the structure and properties of the Zonguldak bituminous coal samples, from the Kozlu K20 G borehole. The changes in the values of parameters characterizing the properties of the tested coals with an increase in the degree of coalification at increasingly greater depths in the borehole were reported. Changes in elemental and proximate analyses results, calorific value, FTIR aromatic bands, ESR values, and aromaticity of the samples were described