Solvent and diluent recovery for re-use - esp. in polymer prodn., processing or moulding, e.g. spinning

摘要

A process for recovery and reuse of chemical solvent and diluent liqs. involves (a) introducing fresh solvent and fresh diluent into a processing plant; (b) introducing process materials into a treatment appts. of the plant; (c) discharging products from the plant; (d) feeding the used mixt. of solvent, diluent and residues to a solvent recovery unit; (e) separating the mixt. into a solvent fraction opt. contg. a small amount of diluent, a diluent fraction opt. contg. a small amount of solvent, and a residue; (f) returning the solvent and diluent fractions to the processing plant for reuse; and (g) discharging the residues. Also claimed is appts. for carrying out chemical reaction and/or processing of materials using solvent and diluent. USE/ADVANTAGE - For recovery of organic polar and aprotic solvent (esp. N-methyl pyrrolidone, N,N-dimethyl formamide, N,N-dimethyl acetamide and dimethyl sulphoxide) and diluent (esp. water) from chemical processes such as polymerisation, polycondensation, polyaddition, solvent cleaning, and polymer moulding from soln. (e.g. by wet spinning or dry-wet spinning). The process provides at least partial recycling of solvent and diluent to reduce their consumption, has minimal energy requirements and produces minimal waste. D14