Gerd Collin

A review of the significance of polycyclic aromatic chemistry for pitch science

Abstract As polycyclic aromatic hydrocarbons (PAHs) and structurally related hetero-aromatic systems are the main constituents of pitches, there are many relations between polycyclic aromatic chemistry and pitch science. Examples are discussed in this overview, which deals inter alia with more recent observations and considerations regarding the composition and compositional complexity of coal-tar pitch, the underlying principles of structure-property relations of PAHs, the mechanism of PAH carbonization, a quantitative relation between molecular topology and carbonization rates of PAHs, solid-state carbonization of PAHs, and inadequacies of solvent fractionation as a pitch characterization method.

Co-coking of coal with pitches and waste plastics

Abstract Liquid-phase co-thermolysis of waste plastics (e.g. polystyrene, polycarbonate, polyurethane, polyvinyl chloride, tire rubber, unsaturated polyester resin, melamine-phenol formaldehyde resin, polyethylene, polyamide, polyethylene terephthalate, phenol formaldehyde resin) with coal-tar pitch at temperatures up to 400°C yielded gases, pyrolysis oils, and high-melting pitches (reaction pitches). Thermogravimetric analysis of these pitches showed that they were thermally stable up to the plastic temperature range of coals. Hence, the reaction pitches could be used as reactive additives for weak-coking coals to improve their coking properties.

Co-carbonization of pitches with coal mixtures for the production of metallurgical cokes

Abstract This study is concerned with the co-carbonization of coal-tar pitch with weak-coking coal mixtures for the production of high-strength metallurgical cokes for the blast furnace process. Several lab-scale testing methods have been applied to the pitch/coal blends including coking tests, dilatometry, Gieseler plastometry, and measuring strength and anisotropy of the obtained cokes and semi-cokes. These lab-scale tests and full-scale coke oven tests showed that the addition of, for example, 5–7% coal-tar pitch and 5% coke breeze to Polish coal blends improve their coking properties. Similar improvements can be achieved by the addition of reactive pitches from liquid-phase co-thermolysis of scrap plastics with coal-tar pitch.