Preparation of large agglomerates of high voidage from charcoal particles for liquid absorption and release

In order to involve the amount of liquid as much as possible, the preparation of large agglomerates of high voidage was experimentally investigated with charcoal powders using a polyvinyl alcohol binder by means of a high-shear mixer type of agitation granulator. It was found that a moderately short granulation time is preferable to prepare large and high voidage agglomerates. Although the binder is necessary to produce agglomerates of certain strength, a lower concentration yields a wider oversize distribution or higher fraction of large agglomerates. There exists a suitable intermediate speed of agitator to prepare large and high voidage agglomerates. Further, although the weight fraction of absorbed liquid decreases slightly with increasing agglomerate diameter and with granulation time, the release rate of liquid from agglomerates is mainly related to agglomerate sizes—the smaller the agglomerate, the faster the release rate of liquid.