リグニン構造の改質によるオイルパームシェル廃棄物のガス化反応促進の試み

抄録

We presented a new oxidative degradation method to separate the oil palm shell waste into hemicellulose, cellulose, and lignin fractions under mild conditions. It is also meaningful and useful to find another methods to utilize the water-soluble compounds (WSL) that are obtained in 48% yield as intermediates from the oil palm shell. Since the water-soluble organic compounds consist of partly oxidized lignin, their gasification rate is expected to be larger than the gasification rate of the original shell. We examined the possibility to utilize the water-soluble compounds as a feedstock for the gasification by comparing the gasification rates among WSL, the original oil palm shell (OPS) and the shell pretreated by hot water (HTS) using the so-called temperature-programmed reaction (TPR) method in a helium and oxygen gas mixture.
The gasification of OPS and HTS proceeded in two steps. It is supposed that the first stage and the second stage gasifications correspond to the gasifications of cellulose and lignin, respectively. On the other hand, WSL was rapidly gasified below 340°C. From the in-situ FTIR measurements it was found that the lignin decomposed into crosslinked structure before being gasified for HTS. On the other hand, WSL was gasified without the cross-linking reaction developing aromatic ring structure. The gasification rate of WSL increased with the progress of conversion and was 500 times larger than that of the oil palm shell at the conversion of 0.9 . This presented the possibility to utilize the lignin fraction as a feed stock for the gasification.