Membrane is a selective barrier between two phases. Generally speaking,↔ it is a kind of polymer, which can selectively separate feed liquid through the effect of p↔ressure difference. The separation process through it is called membrane separation. It is >different from the traditional filter in that the membrane can separate materials in ✘molecular sizes, and this process is a physical process without pha♣se change and additional additives. The thickness of the membra♠ne is generally in micron scale. According to filter precision, the membrane can be divided into m♠icrofiltration membrane, ultrafiltration membrane, nanofiltration membrane and reve↕rse osmosis membrane. The separation and retention performance of various membranes in cross flow membrane process is distinguished by the pore size and molecular weight cut-off ★of the membrane. The following figure shows the se>paration patterns of four kinds of membranes with dif✔ferent precision (the reflection of the arrow indicates t↓he retained substances which cannot pass through the membrane).
Fig. 1 Membrane Separation & Filtration Illustration
In the traditional glucose production process, the₩ saccharified liquid after saccharification is usually fil∞tered by plate-frame or rotary drum. In this process, a certain amou←nt of filter aid is to be added. With membrane separation technolo∏gy, there is no need to add any filter aid in the filtration unit, the quality of the filt₩rate is better than that of the traditional filtration method, in additio≤n, the by-product protein can be obtained as animal feed. In recent years, with the continuous de↓velopment and maturity of the membrane separation technology, the cost of the technology has gr adually decreased. Thus the application of membrane separation technology in the production o↑f glucose will also show good economic benefits. In addition to the a→ssurance of the product quality, in realizing automatic control and clean production, and in reduc≤ing production cost, the membrane separation process also >shows its unique advantages: Membrane separation technolo✔gy can be used to remove grease, macromolecular protein, pigment and other impurities in the saccharified liquid. The saccharified l♦iquid filtered by the membrane is clear and transparent, which can not only save the d♦ecolorization process of activated carbon in the traditional process, but also gre₹atly reduce the amount of diatomite in the front end. Due to the removal of protein and faΩt, the load of the subsequent process is reduced, thus the efficiency and life£ of the ion exchange resin is extended.
Fig. 2 Process Flow of Glucose and Its Derivatives
The traditional glucose production process is that the saccharified liquid is₽ to be filtered by plate-frame, then be separated by fixed bed, and≈ finally be crystallized and recrystallized to improve the pu™rity of glucose to obtain high-quality glucose. This process has many ≠disadvantages, such as backward process, high cost, huge pollution, incon'venient operation, unstable product quality, which cσannot meet the quality requirements of customers. Therefore, in recent years, new t÷echnologies and processes for innovation and transformation has continuously been introduced ∑in the industry. Guo Chu Technology (Xiamen) Co., Ltd. is committed to the research and deve>lopment of this process, and has developed and formed a brand-new process: Membran≈e Filtration for Saccharified Liquid → Contin♣uous Ion-Exchange Desalination → Nanofiltration Purification, which achieves the 24-hour ↔continuous operation of the whole process, and has the fol☆lowing advantages: advanced technology, low cost, little pollution, full au©tomation, and with the product quality which is not only stable, but also could reach the ∑highest level in the industry at present.
The benefits of continuous ion-exchange and nanofi✘ltration purification are obvious, thus it is easy to be× compared with the traditional technology and recognized by c>ustomers. But things are totally different in saccharified liquid↑ filtration field. Since there is no clear and scientific inspection ind♣ex in the industry, it is difficult to directly compare t♣he economic benefits, thus the promotion of membrane filtration process is slow du e to customers' doubts. However, in recent years, due to the influence ∑of Coca-Cola's high-quality syrup requirements, the fructose industry has accepted the membrane filtration process, and theβ comprehensive benefits after adopting membrane technology are obvious. Therefore, the ✔new projects all adopt membrane filtration process, such as Shandong Xiangchi J←ianyuan, COFCO Biochemical Energy (Gongzhuling, Wuhan, Chengdu, Shanghai, Hengs≥hui), Cargill (Songyuan, Luohe), Suzhou Gaofeng Sugar, Yihai Kerry, Zhejiang Tianzi€ Fruits, Dongguan Sugar Factory, Guangzhou Shuangqiao, Shanghai →Haocheng, and so on.
At present, membrane filtration technology has been used in saccharified liquid filtration indu→stry. The main indicator of filtrate is transmittanc☆e ≥ 96%. With this technology, the subsequent decolorization process can <be saved.
Fig. 3 Process Flow of Saccharified Liquid Filtration
by Connecting Membrane and
High Pressure Plate-Frame in Series
To sum up, there are following advantages by adopting membrane technology for filtration and impurity removal of saccharified liquid:
1、By adopting membrane technology, macromolecular protein, fat and macromolecular heterosaccharide can be removed, which greatly improved the quality of filtrate. Th↔e quality indexes of syrup clarified by membrane sepδaration technology are much higher than those obtained by traditional filtratio$n method.
2、The amount of diatomite used in the front end is greatly reduced, thus the cost is saved.
3、It replaces the traditional activated carbon decolorization, thus the₩ investment is saved and the working environment is i☆mproved.
4、The removal of macromolecular protein and other •impurities greatly reduces the pollution of the subsequent ion-exchange resin, thus the service ¶life of the resin is extended.
5、The system is highly automatic, thus it is easy to operate and main★tain.
6、The system is compact in design, thus it has a small footprint.
7、The environmental investment and operating costs are reduced.
Under the preconditions that the annual output of dry glucose (inc↔luding mother liquor) being 100,000 tons, the annual working days b×eing 300 days and the dry base concentration of saccharified liεquid being 35%, we can see that compared with the traditional p₹rocess technology, the one-time investment of membrane technology will increase, but the operating cost will be greatly reduce↓d. Besides, the return period of investment of membrane tech"nology will be less than 2 years.
In addition, due to the adoption of membrane technology in fil♥tration process, the quality of filtrate has been gΩreatly improved compared with the traditional filtration technology, which not onπly promotes the quality of follow-up products, but also reduces the amount of activated carbon and acid & alkali used for regeneration resin §in the subsequent activated carbon decolorization and ion-exchange i→mpurity removal process. In addition, compared with the♥ traditional filtration technology, the operating temperature of the membrane te→chnology is lower, and the liquid is in a closed system, basically isolated from the ou©tside environment, which reduces the interaction betw₩een the outside world and the liquid, and also reduces the degree of color dee≠pening of the liquid in the filtration unit. By adopting membrane t echnology, the process can be made into fully automatic control mode, which greatly reduced the∞ labor intensity and the cost.
Guo Chu Technology (Xiamen) Co., Ltd. is a high-tech enterprise, which focuses on membrane separation technology and is comm↕itted to the promotion of new separation technology. It provides c♥omprehensive filtration and purification solutions for &many industries, such as bio-pharmaceuticals, food & beverage, fermentation, agricultural deep-processing, plant extraction, oilα and petrochemical industry, environmental water treatment, air de-dusting, <chemical industry etc to meet the diversified demand¶s of different customers, and is a well-known integrated₽ service provider of new separation technology.
