THE SCALE-UP OF CRIOPURA VIA A MORE SUSTAINABLE STRATEGY

The aim of this work was to scale up the synthesis of CrioPurA, a proof of concept chelating material for the removal of toxic metal ions, in more sustainable and costsaving ways. The scaling up was referred to functionalization of the 4-vinyl-benzyl chloride with N-methyl-D-glucamine to form 4-vinyl-benzyl-N-methyl-D-glucamine (VbNMDG) monomer. Also, its polymerization to produce the adsorbent cryogel, was achieved on a bench-scale, to obtain up to 1 kg of production for the cycle. Specifically, methanol used as a solvent for monomer synthesis was recycled with a loss of 10%, whereas the purification protocol of VbNMDG performed by crystallization in CHCl3 and used in a lab-scale, was modified to avoid both environmental concerns and high production costs [1, 2]. The scale-up process was performed in three different steps (350 gr, 750 gr, 1 Kg), obtaining a yield of 80% for each of them. Using this new approach, the crude monomer contains also a di-substituted N-methyl- D-glucamine compound that was exploited as a crosslinking agent during the cryogelation. Since intrinsically sustainable (water is used as a solvent), the latter process was addressed to reduce the cost of production in terms of energy consumption. Furthermore, the use of CriopurA under different pH and flux conditions were also tested comparing it with similar competitors.