大谷石"みそ"からのゼオライトの合成およびその触媒特性

概要

論文の詳細を見る
Hydrothermal synthesis of zeolite has been attempted using "Miso" (altered pumice debris) from "Ohya-ishi", a Miocene dacitic-rhyolitic tuff distributed in Tochigi Prefecture, as the starting material. The sample of "Miso" used contained a smectite mineral, clinoptilolite, and quartz as the principal minerals. The synthesis was carried out for 1 to 3 days in an autoclave kept at 175℃ and about 9.1 atm. Two sets of starting composition, (0-15) Na_2O-Al_2O_3-(10-38) SiO_2-750H_2O (inorganic system) and 1.5 (OB)_2O-3.5Na_2O-Al_2O_3-33SiO_2-750H_2O (organic system), were prepared by mixing the "Miso" with appropriate amounts of sodium hydroxide and/or organic bases (OB) and amorphous, precipitated silica. The kind of zeolites formed from the inorganic system was dependent on the Na_2O/Al_2O_3 or SiO_2/Al_2O_3 ratio of the starting composition : at the SiO_2/Al_2O_3 ratio = 23,mordenite was the main product in the range of Na_1O/Al_2O_3 ratio <5 and analcime, in the range of the ratio > 5. When the Na_2O/Al_2,O_3 Was kept at 5,analcime with some clinoptilolite was the main product in the range of SiO_2/Al_2O_3 ratio < 23,and in the range of the ratio > 23,mordenite and clinoptilolite coexisted as the main components. Replacement of a part (30 mol%) of the Na_2O in the organic systems by organic bases, such as alkylamines and alkylammoniums, was found to be efective in obtaining ZSM-5,an artificial zeolite of high catalytic activity. The mordenite-containing product obtained by 3 days' treatment showed a strong acidity and a high catalytic activity in methylation of toluene, which were comparable to those of ZSM-5. The Product containing ZSM-5 and clinoptilolite, obtained from the organic system in this study, showed a high selectivity for p-xylene in the methylation of toluene.
日本粘土学会の論文
1988-04-10

大谷石"みそ"からのゼオライトの合成およびその触媒特性

スポンサーリンク

概要

著者

関連論文

スポンサーリンク