Abstract
This paper describes the elution behavior of metals during hydrothermal decomposition of rice hulls at 200°C using a percolation type reactor. Through that treatment, the rice hulls were converted to solubilized products at 45.9wt% yield. The solubilized products were mainly arabinose, xylose, and xylooligosaccharides derived from hemicellulose. While, cellulose was not decomposed in this treatment. Results showed that the elution behavior of metals with hydrothermal treatment is classifiable into two patterns. First, alkali metals, phosphorus, boron, and aluminum elution did not depend upon the temperature, but rather on the treatment time. On the other hand, elution of heavy metals, alkaline earth metals, and arsenic depends upon temperature. That is to say, raising the purity of organic matter might be possible by lengthening the time of the 1st fraction and inducing full elution to obtain high-quality organic matter with few metals in the 4th and the 5th fraction.
