About the removal of water from solvents
Thread Content
I would like to ask about the removal of trace amounts of water in the liquid. Originally, the water content in the liquid is about 1000ppm (10 minus 6 power). After dehydration, it is required to be 10-20ppm. Currently we use 4A/5A molecular sieves for dehydration. In addition to molecular sieve dehydration, are there any other methods to remove trace amounts of water? Thanks
It depends on what solvent it is. Generally speaking, trace amounts of water can be removed by distillation.
May I ask why the owner should consider other methods? Generally, when the moisture content is low, molecular sieves are used in industry. The results are good, the process is mature, and they are cheap and reliable. Other methods have defects in different aspects when implemented in industry.
Desiccant Materials suitable for drying Materials not suitable for drying Water absorption (g/g) Activation temperature Barium oxide organic base, alcohol, aldehyde, amine acidic substance, carbon dioxide 0.1 Magnesium oxide hydrocarbon, aldehyde, alcohol, alkaline gas, amine acidic substance 0.5 800℃ Calcium oxide alcohol, amine, ammonia acidic substance, ester 0.3 1000℃ Calcium sulfate most organic substances 0.066 235℃ Copper sulfate ester, alcohol, (especially suitable for drying benzene and toluene) 0.6 200℃ Sodium sulfate chlorinated alkanes, chlorinated aromatics, aldehydes, acid 1.2 150℃ Magnesium sulfate acid, aldehydes, esters, nitriles acid-sensitive substances 0.2-0.8 200℃ Calcium chloride chlorinated alkanes, chlorinated aromatics, esters, saturated aromatic hydrocarbons, aromatic hydrocarbons, Ether alcohols, amines, phenols, aldehydes, amides, amino acids, certain esters and the same 0.2(1H2O)0.3(2H2O) 250℃ Zinc chloride hydrocarbon ammonia, amine, alcohol 0.2 110℃ Potassium amine hydroxide, organic alkaline acid, phenol, ester, amide, acid gas, aldehyde sodium hydroxide amino acid, phenol, ester, amide potassium carbonate alcohol, nitrile, Homo, ester, amino acid, phenol 0.2 300℃ Metal sodium saturated aliphatic and aromatic hydrocarbons, ether acids, alcohols, aldehydes, homo, amines, esters, chlorinated organic compounds, substances with excessive water content, diphosphine pentoxide alkanes, aromatic hydrocarbons, ethers, chlorinated alkanes, chlorinated aromatic hydrocarbons, nitriles, acid anhydrides, nitriles, ester alcohols, acids, amines, homo, Hydrogen fluoride and hydrogen chloride 0.5 Silica gel (6-16 mesh) Most organic substances Hydrogen fluoride 0.2 200-350℃ This post was last edited by maogenfu on 2008-1-22 08:34 ]
The very trace amount of water on the second floor is difficult to remove through distillation, especially the water below 200ppm. Currently, all our solvents are dehydrated using molecular sieves. However, there is currently a solvent that decomposes after dehydration through molecular sieves and the purity decreases, so molecular sieve dehydration cannot be used.
Can you start from the reaction aspect? Is there a water-alkali washing process?
Reply to the 6th floor: There is no water-alkali washing process, it is just a seemingly simple dehydration process.
It is a problem of water removal in the oil. Maybe we can consider using a coalescer to deal with it. We can discuss this and see if we can do it. We seem to be able to remove water from the oil to 5PPM.
It is very good to use pervaporation membrane device in industry.
Hero, I am looking for a device for dehydrating NMP using molecular sieves. It can reach 100-200ppm. It is an industrial grade device. I will buy it from you. Reply 13928899363
Oil dehydration distillation tower, dehydration can reach <0.5ppm