INCORPORATION OF A COPROCESSING ADDITIVE INTO COAL/OIL AGGLOMERATES

摘要

One method of coprocessing coal and heavy oil uses iron sulphate as a catalyst precursor which, upon decomposition to elemental iron and subsequent transformation to pyrite/pyrotite, assists hydrogenation of the slurry and suppresses coke formation. For high process performance the iron sulphate should be dispersed as finely as possible throughout the reactant mixture. In the present invention, the iron sulfate is added in the form of an aqueous wash solution to coal agglomerates after separation of ash from the agglomerated coal. As the agglomerates remain in a continuous water phase, a good dispersion of the iron sulfate solution throughout the agglomerate matrix occurs. At this stage an unexpectedly strong adsorption of FeII ions onto the coal surfaces occurs without any adverse effects on agglomerate integrity and the ability to separate it selectively by floatation. Furthermore, this good dispersion also results in over 94% of the iron sulfate in the wash solution being transferred to the agglomerates. This manner of addition of iron sulphate to coal has been shown to elevate advantageously the lowest temperature at which coke formation occurs during coprocessing.