(8e) Development of Hitz Zeolite Membrane for Acetic Acid Dehydration

Kentaro SHINOYA, Masanobu. AIZAWA, Suguru FUJITA, Yoshinobu TAKAKI, Kazuhiro YANO, Takehiro SHIMIZU, Yoshihiro ASARI, Jun YANO, Takaharu YAGI and Ken-ichi SAWAMURA

Hitachi Zosen Corporation, 2-11, Funamachi 2-Chome, Taisho-ku, Osaka 551-0022, JAPAN

Acetic acid (AcOH) is one of the important chemical products. However its aqueous solution as an intermediate in the production process possesses azeotropic characteristic and the separation of water/AcOH by distillation requires a large amount of heat energy due to the low relative volatility of them. Membrane dehydration process with high acid resistance would be most candidate to solve the problem and especially mordenite type zeolite (MOR) has been studied for the acid dehydration purpose, because MOR with high Si/Al ratio in the chemical formula is expected to possess high acid resistance. In this background, MOR membrane has been developed in Hitz using a secondary-growth method. As for the substrate, α-Al2O3 porous tube whose size of 16 mm in diameter and 60 mm in length has been adopted. It was found that Hitz MOR membrane exhibited high separation performance, the permeation flux was ca. 2.0 kg m^-2 h^-1 for the feed of AcOH (80 wt%) / H2O (20 wt%) mixture and the separation factor exceed 1000 at 75 degree centigrade in PV condition.