1 Quality standard The quality of finished anhydrous ethanol is mainly determined by its water content, another major factor influencing product quality is the feedstuff for production. Production anhydrous ethanol with the dehydration technology & equipments supplied by our company can meet the National-standard(GB/T678-2008)demands for high-class ethanol. Produced anhydrous ethanol with addition of denaturant is called fuel ethanol. 2 Technique Flow There are kinds of ethanol dehydration technologies. Through years of R&D and practice, our company can supply customers with two kinds of mature technologies for ethanol dehydration, namely Three-element Azeotropic Method and Molecular-siever Technology. 1) Three-element Azeotropic Technology After addition of cyclohexane into the alcohol liquid, a kind of three-element azeotropic substance will form in the mixture of alcohol, water and cyclohexane. This three-element azeotropic substance has a lowest boiling point, and it contents more water than binary azeotropic substance of alcohol and water. According to this principle, water will be taken away by this three-element azeotropic substances during the process of distillation, thus achieving the purpose of dehydration. The production process is showed as the diagram follows: The device is composed of a dehydration tower and a recovery tower, working under different pressures. Alcohol steam on the top of the recovery tower heats the dehydration tower. The finished products content water of lower than 0.05%. 2) Molecular Sieving Technology The principle of molecular sieving technology for ethanol dehydration is based on the effective absorption and deviation of water holes of zeolites. The most advanced automation control is applied in production and the operation is in alternate absorption by multi-towers, thus it is able to achieve successive dehydration and online process. When the alcoholic steam is heated to a certain temperature. It goes into molecular sieve absorption tower. The water molecules in the alcoholic steam is selectively absorbed by the holes of the siever and heat is released at the same time. Thus dehydration is achieved in this way. After being condensed &cooled, the alcoholic steam out of the dehydration devices becomes anhydrous ethanol with a high concentration of 99.5%-99.98%. When temperature reaches designed degree, monitor system can control the switches of valves. The absorption tower is switched from absorbing state to deabsorbing negative-pressure state, and the absorption stops when it reaches one certain temperature. It enters the next circle of absorption process through continous valve swiches. In this process, there are several sets of molecular-sieving dehydration equipments operated in turn. While one set of equipment is working on dehydration, the other set is on regeneration. The process flow is shown as the under diagram;
