Densification of water hyacinth — basic data

The briquette-forming ability of water hyacinth (WH), a plant with prolific growth, to produce a fuel wood substitute or for further processing has been investigated. Compared to straw and sawdust, WH can undergo binderless briquetting. Pressure, water content and temperature have a strong influence on the briquette-forming ability of WH. Laboratory trials showed that optimal conditions are achieved between compaction pressures of 80 and 200 MPa, temperatures between 70 and 80 °C and water contents between 8 and 12 wt%. Die ram-extrusion and pellet-mill briquetting presses allow the compaction of WH with acceptable throughputs and with a specific energy consumption of 180 MJ t^?1. The produced briquettes, with a density of 1400kg m^?3 and a compression rate of 1:14, proved to be abrasive-resistant and showed an acceptable compressive strength. The re-expansion behaviour of the briquettes was moderate. The extractable matter of WH does not contribute to the briquette strength. No experimental indication of lignin softening could be found.