Production of Shaped Activated Carbon Granules Using Binder Derived from Heavy Petroleum Tar

Abstract

A method is proposed for producing carbon adsorbent as an extrudate based on heavy petroleum tar and various carbon fillers. To obtain sorbent granules, a heavy tar suspension is dissolved in excess heptane. With continuous mixing, filler is added to the solution, followed by concentrated sulfuric acid. After the formation of binder from the tar, the solid product is isolated. Green granules are extruded from the paste and then carbonized, with subsequent activation by steam. The proportions corresponding to carbon granules with the best specific surface (up to 900 m²/g) and mechanical strength are as follows: a 0.5 : 1 ratio of tar and filler; and a 1 : 1 ratio of acid and tar (by mass in both cases).When using two different fillers—walnut shell and coke from heavy tar—differences are noted in the micropore and mesopore structure of the carbon granules after activation: the samples based on coke have a more uniform micropore structure, with fewer mesopores. Since the parameters—the tar properties and the component ratios—may be closely controlled in the course of production, carbon granules with stable characteristics (specific surface, mechanical strength) may be produced.