Mitsumasa Osada

TL;DR: In this paper, lignin and cellulose were gasified at 400 °C with gas yields of 30% and 70%, respectively, in supercritical water with a ruthenium catalyst.

TL;DR: In this article, the catalytic effect of NaOH and ZrO2 on partial oxidation of n-hexadecane and organosolv-lignin was examined by use of a batch type reactor in supercritical water: 673 K, 0.52 K, and 0.3 K, respectively.

TL;DR: In this paper, a review of the literature in biomass gasification with subcritical and supercritical water is presented, which is a low-temperature gasification technique that can be carried out from 473 to 973 K.

Abstract: We evaluated the stability of several supported ruthenium catalysts, on titania (Ru/TiO2), on γ-alumina (Ru/γ-A2O3), and on activated carbon (Ru/C), for lignin gasification in supercritical water. The initial activity of the catalysts was in the order of Ru/TiO2 > Ru/γ-A2O3 > Ru/C. The Ru/TiO2 catalyst maintained high gasification activities for three subseqent uses in supercritical water. The Ru/C catalyst showed the high gasification activity for the first run; however, the activity decreased gradually after repetitive use because of its decreasing surface area during the gasification. The Ru/γ-A2O3 catalyst also showed a high activity at the initial stage; however, it lost its activity fast because of the change in its structure from gamma- to alpha-phase and dissolution of active ruthenium speacies into supercritical water.

TL;DR: In this paper, the authors studied the gasification of lignin and 4-propylphenol over supported metal catalysts in supercritical water at 673 K. The results indicated that the first step (decomposition to low-molecular weight compounds) was enhanced by increasing the water density.