Preparation Of Ge-ZSM-5 Zeolite Membrane For Separating Water From Acetic Acid-Water System

Acetic acid has a very wide range of applications in industrial production and daily life.Reactions of high purity acid production process will produce a certain amount of water, the method of removing the water often use the distillation method, while the boiling point of acetic acid and water are very closed to each other. Common industrial method of distillation separating of acetic acid and water cost a high energy and high cost and not conducive to the environmental protection. The pervaporation as a new membrane separation technology,with low power consumption,high performance,environmentally friendl, and has many other advantages. Compared with the organic film inorganic membrane swelling resistance,good stability,acid characteristics are very suitable for pervaporation of acetic acid in a small amount of water component. ZSM-5 zeolite membranes can balanced both in terms of acid resistance and silica alumina ratio to coordination acid and hydrophilic.In this paper,large and small seed coated with a seed crystal of the way, large seed modified carrier,small seeds induced deposition. Template-free formulations on a commercially available cheap macroporous α-Al2O3 ceramic carrier synthesized a thickness of about 0.25μm of Ge-ZSM-5 zeolite membrane. During the experiment examined the effects on membrane performance and synthetic silica to alumina ratio experiment,the seed concentration,aging time. This paper mainly examines the silica alumina ratio,seed crystal concentration,aging time,the influence of synthesis conditions on membrane performance. Determines the silica alumina ratio of 26,seed liquid concentration is 2.5 wt.%,optimum reaction conditions of aging time of 12 h.In 192 hours of pervaporation experiments and eight days of the acidic environment of the test,Ge-ZSM-5 zeolite membrane showed excellent performance. Flux from the initial 2100 g·m-·2h-1 beginning eventually stabilize at 600 g·m-2·h-1,the permeate side of the water retention concentrations are maintained at more than 99.95wt.%. Individual test points on the permeate side water concentration can reach 100%, the theoretical separation factor reaches infinity.In this paper, the success of the stable operating time Ge-ZSM-5 zeolite membrane from the current literature of 25 h to 196 h, throughput was increased from 200 g·m-2·h-1 to 600 g·m-2·h-1. Further experiments investigated the effects of Ge-ZSM-5 Zeolite Membranes performance process operating temperature and feed concentration. When the operating temperature from 75℃ to 99℃, membrane flux more than doubled, with the increase of raw material concentration (concentration increased from 88wt.% To 99wt.%), The flux decreased by about 30%, but the selectivity remains high separation factor (≥1000). Permeate side of the water concentration were more than 99.94wt.%, With certain industrial applications.