I am actually recrystallizing sucrose using simple boiling and evaporation method (boiling of a saturated solution at 115 degrees and crystallizing at 40 degrees). However i am getting some lumps with fine crystals. how can I reduce the formation of this conglomerates?
Dear colleague,
Try other solvents shifting to non-polarity starting from ethanol to normal hexane or toluene taking into consideration the boiling point of each solvent. The boiling point of ethanol is 78-80 C, while that of normal hexane is 60-70 C. I expect you to get fine and even crystals without conglomerates.
Regards
try changing the solvents (mixtures etc) and then, if you gain single crystals for XRD, compare the theoretical patterns with ecperimental PXRD
As one working in a Sugar Research Institute I assume you are dealing with water based sugar solutions. If so, it is a very bad idea to do the boling at 115 C. It should be done at normal vacuum pan conditions (70-75 C at most). The reason why you have fines and lumps (conglomerates) is that you have very high supersaturation. Crystallization should be done under control of supersaturation in order to keep it safely below the nucleation limit level. There is no single instrument being able to measure supersaturation on-line, it can only be calculated taking into account several parameters of the process. The SeedMaster Instrument (SM-3) manufactured by K-PATENTS Oy, Finland can solve the problem and is being used in quite many sugar mills and refineries in the world. For more information you can contact me ([email protected])
Rgeards
Lajos Rozsa
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