日本ゼオライト学会　刊行物 Publication of Japan Zeolite Association

Vapor permeation (VP) properties of commercially available zeolite membranes (dimensions of 12 mm o.d., 9 mm i.d. and 800 mm length) were examined in the water/ethanol systems, which were distilled by lab-scale column, before equipments to produce anhydrous bio-ethanol were designed. The membranes displayed extremely excellent water-permselective performance for the water/ethanol systems in VP. The repeated experiment of ethanol dehydration by VP with a zeolite NaA membrane was carried out using bio-ethanol liquid which was distilled by lab-scale column. The distilled ethanol hardly influenced the NaA membrane performance in VP. The dehydration equipment which can dehydrate 60,000 kg day⁻¹ of ethanol at less than 0.2 wt% water from 84.8 wt% ethanol at 135°C was designed for bio-ethanol production plant in Lithuania. This equipment was consisting of 6 long tubular type modules, which was composed of 550 zeolite membranes. In the initial operation result at 125°C in March, 2005, the ethanol was dehydrated over the designed value of 135°C. By the lowering of membrane performance by the fouling included in the feed vapor, the operating temperature of the plant was raised to 145°C in September, 2006, and then the plant was operated until December, 2006. Membranes in stage 1 (No.1 and 2 modules) were replaced in December, 2006. T-type membranes were applied near the entrance nozzle and NaA membranes were used except for there. Then anhydrous bio-ethanol in this plant has been produced without a hitch up to the present.