Purifying ethanol with molecular sieve has been highlighted in the ethanol or alcohol industry. Choosing an effective type of molecular sieve, and building a workable operation process are equally important. Here let us share solutions from SNOWPEAK.
Technique Principle: Different Adsorption Kinetics
One or more adsorbents such as molecular sieves need to be filled in a fixed adsorption bed. And the separation of the ethanol mixtures is achieved in the bed.
When the ethanol mixtures enter the adsorption bed under a certain pressure, different components form their enrichment zones in different positions of the bed due to their different adsorption kinetics.
The strongest adsorbed component is enriched at the inlet end of the bed, the weakest adsorbed component is enriched at the outlet end of the bed, and the enrichment zones of the remaining components are distributed in the middle of the bed with different adsorption strengths.
This ethanol dehydration technique called adsorption method, using molecular sieves to adsorb and desorb water from the ethanol mixtures.
Desorption Process: Pressure Release and Vacuum
After the adsorption bed completes the adsorption process under a certain pressure, the adsorbed component is desorbed by pressure release (usually close to atmospheric pressure). Note that, the natural pressure release is limited, the adsorbed components cannot be fully desorbed, and the adsorbent regeneration is incomplete.
When the pressure of the adsorption bed is released to the atmospheric level, in order to further reduce the partial pressure of the adsorbed components, and drop the bed pressure to a vacuum state, vacuuming process is needed, so that the adsorbed components can be fully desorbed.
Molecular Sieve: High Exchange Rate Zeolite Powder
Type 3A molecular sieve is considered as the most effective type to dry ethanol. SNOWPEAK 3A molecular sieves are made of specialty raw materials.
High Exchange Rate Zeolite Powder: SNOWPEAK self synthesized zeolite powder is of different exchange rate. High exchange rate ensures that the molecular sieve only adsorbs water, and the adsorption capacity is large, and almost no adsorption of ethanol or carbon dioxide etc.
High Viscosity Binder: SNOWPEAK fully considers the strength requirements of 3A molecular sieve used in ethanol dehydration. Therefore, a binder with high viscosity is selected, to make the molecular sieve high in strength and not easy to pulverize.
In SNOWPEAK’s application cases, 3A molecular sieve designed for ethanol dehydration, always performs well in adsorpion kinetics, which improves production capacity and reduces energy costs.
