PURPOSE: In preparing the titled substance by reacting a tertiary olefin with a primary alcohol, using crystalline aluminosilicate having a specific molar ratio of silica to alumina and diffraction lines with a specific angles of diffraction as a catalyst.
CONSTITUTION: In preparing a tertiary ether (e.g., methyl-t-butyl ether) by reacting a tertiary olefin (e.g., isobutene) with a primary alcohol (e.g., methanol), aluminosilicate having ≥10mol ratio of silica to alumina and diffraction lines at angles of diffraction (2θ) of 7.9°±0.3°, 8.8°±0.3°, 23.3°±0.3°, 23.9°±0.3° and 24.4°± 0.3° in the diffraction X-ray diagram is used as a catalyst.
EFFECT: The catalyst has high catalytic activity, high heat resistance, good handleability, long life, and strong acidity.
USE: An improver for octane value. Separating isobutene from 4C fraction.