Selection of separation processes and equipment
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Evaporated solution 1: Aqueous solution 1. Liquid: Water (5% ammonia solution, pH around 10). 2. Solid: Amino acids (readily soluble in water); the concentration of amino acids before evaporation is about 2%. The amino acid concentration after steaming is about 20%. Water recovery – Evaporation liquid 2: Organic solution. 1. Liquid: Toluene. 2. Solid: Organics (amino acid derivatives). Recovery of organic solvents: There is a large difference in boiling points between the two. Evaporation liquid 3: Organic solution. 1. Liquid: Butyl acetate. 2. Solid: Organics (amino acid derivatives). Recovery of organic solvents: Again, there is a significant difference in boiling points between the two. Note: The amount of organic solvent used per day is small, around 10 tons; it is desired to evaporate as much of this solvent as possible to obtain solids. I am not familiar with evaporators, and I’m not sure whether they can be used for this purpose I would like to ask everyone for any good methods for separation; thank you all!
As requested by the original poster, I think it would be better to use a closed-frame filter press for filtration first and then carry out evaporation, right?
For Evaporate Liquid 1, which falls under the concept of evaporation-based concentration, this is straightforward to handle, as amino acids have high solubility in water; basically, no solids will precipitate at 20% concentration. Simple evaporation equipment is sufficient for this purpose. Considering production costs and energy consumption, it is recommended to use a thin-film evaporator under vacuum conditions, as this method offers faster processing speeds and lower energy usage. For evaporates 2 and 3, it is recommended to use a small distillation tower to achieve complete separation of the two. We have experience with similar solvent separations, and the results are very good; however, when separating different solvents, it is necessary to properly control the process parameters of the distillation tower. Of course, before entering the tower, it is necessary to pass through a filtration unit to remove solids; either a centrifuge or a plate and frame filter can be used for this purpose.
Thank you. For the evaporated liquids 2 and 3, it is recommended to use a small distillation tower to achieve complete separation of the two. After the solvents are separated, the amino acids turn into a solid form; what methods can be used to remove this solid?
For evaporates 2 and 3, due to their small quantities, a jacketed evaporator can be used for batch operation: the feed is evaporated under reduced pressure until it reaches a certain temperature, after which it is removed; water is passed through it for cooling while stirring, followed by sealed filtration, with the filtrate being returned to the evaporator for reuse. The material is a toxic and flammable substance; it is essential to take proper safety precautions!
If the boiling point difference is large, vacuum distillation can also be used, which is simpler
With a processing capacity of 10 tons per day, and considering that toluene is a toxic substance, the feasibility of carrying out such operations is quite low. Thank you for your suggestions; are there any better methods that would allow for the removal of the solvent and the recovery of a solid product?
I suggest sending it to an incineration plant for burning!