Coal hydrotreatment with coal-derived solvents to produce carbon product precursors

It is known that many specialty carbon products can be produced from coal. Direct liquefaction (hydrotreatment) is one of the most promising processes for coal conversion. In this present work, liquefaction of Marfork coal was examined at 350°C, 400°C and 450°C and an initial pressure of 500 psig of Nitrogen or Hydrogen using coal-derived solvents Carbon Black Base (CBB) and Heavy Creosote Oil (HCO) and their hydrogenated forms. Unlike model solvents such as Tetralin, coal-derived solvents are cheaper, readily available and recoverable. The solvents were first hydrogenated using unconverted residue from coal hydrotreatment and NiO/MoO3 on alumina as catalysts. Coal hydrotreatment experiments were conducted to determine the effectiveness of the solvents as hydrogen donors. The products obtained are exhaustively extracted in Tetrahydrofuran (THF), filtered to separate THF insolubles (unconverted coal), and after THF removal, vacuum distilled to separate pitch material (distillation bottom) and recycle solvent (overhead). It was observed that the coal conversion increased when hydrogenated solvent was used. (Abstract shortened by UMI.)