New Process for Organic Solvent Separation

The combined extraction rectification process jointly developed
by Tsinghua University and Beijing Tsinghuatech Co., Ltd. uses
a special extracting agent to separate and recycle acetone and
tetrahydrofuran. The recycle rate of these two products is
increased from 80% to 95%. The technology has conducted
successful application in enterprises.
   Acetone/tetrahydrofuran mixed water solution is generated in
the cephalosporin production. Acetone and tetrahydrofuran have
azeotropic components and the traditional CS2 azeotropic
process is therefore used for their separation and recycle. As
CS2 is a substance with acute toxicity and easy decomposition,
it causes serious corrosion to equipment. The operation is
complicated and the solvent recycle rate is low.
   The combined extraction rectification process developed
recently has solved problems in the separation and recycle of
acetone and tetrahydrofuran and reduce the solvent cost in the
medicine production. It can also be used in other mixed systems
in the cephalosporin production.