Analysis of Interactions Occurring during the Pyrolysis of Lignocellulosic Biomass.

This paper presents a review of the recent advances in research on the interactions between the components of lignocellulosic biomass. The literature reports on the effects of interaction between lignocellulosic biomass components, such as cellulose-lignin, lignin-hemicellulose, and hemicellulose-cellulose, were discussed. The results obtained by other researchers were analyzed from the viewpoint of the interactions between the pyrolysis products formed along with the impact effects of the organic and inorganic components present or added to the biomass with regard to the yield and composition of the pyrolysis products. Disagreements about some statements were noted along with the lack of an unequivocal opinion about the directivity of interactions occurring during biomass pyrolysis. Based on the data in the scientific literature, it was suggested that the course of the pyrolysis process of biomass blends can be appropriately directed by changes in the ratio of basic biomass components or by additions of inorganic or organic substances.

The Influence of Coal Tar Pitches on Thermal Behaviour of a High-Volatile Bituminous Polish Coal.

The influence of three coal tar pitches (CTPs), having softening points at 86, 94, and 103 °C, on the thermal behaviour of a defrosted high-volatile coal during co-carbonization and co-pyrolysis was studied. The following research techniques were used: X-raying of the coked charge, TG/FT-IR, ATR and UV spectroscopies, extraction, SEM, STEM, and XRD. It was determined that CTP additives change the structure of the coal plastic layer, the thickness of its zones, and the ordering degree of the structure of semi-cokes to a different extent and independently from their softening points. The softening points of CTPs do not influence the composition and yield of volatile products emitted from blends with pitch as well as the composition, structural-chemical parameters, and topological structure of material extracted from coal blends. It is suggested that such a lack of existence of any correlation between the softening points of CTPs and the degree of their influence on the thermal behaviour of coal was caused by the presence of the atoms of metals (Fe and Zn) in the CTPs. These atoms change the course of the carbonization of the CTPs themselves and their influence on organic substance of coal in blends with CTPs.

Chromatographic methods and techniques used in studies of coals, their progenitors and coal-derived materials.

The use of chromatography in studies of coals, their progenitors and coal-related products was reviewed. The specificity of the coal structure was discussed. The use of extraction in preparing study samples was discussed paying special attention to the occurrence of undesirable phenomena such as aggregation of coal derivate molecules, resulting from the formation of their dimers and trimers, and degradation of polar solvents at temperatures above 350 °C. The following ways of fractionating samples of coal materials were considered: thermal, solvent, column with the use of preparative size exclusive chromatography and preparative thin layer chromatography as well as membrane separation. The use of chromatography coupled with experimental techniques such as mass spectrometry, infrared spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and pyrolysis was analysed.