FIELD: chemistry.
SUBSTANCE: tetrafluoroethylene is obtained by pyrolysis of difluorochlormethane in presence of water vapour and fraction of pyrolysis products with boiling temperature at atmospheric pressure minus 42÷0°C, containing difluorochlormethane, hexafluoropropylene, octafluorocyclobutane and tetrafluorochlorethane. Process includes hardening of pyrolysis products, separation of by-product hydrogen chloride, obtaining hydrochloric acid; neutralisation; comprimation; condensation of pyrolysis products and multi-step rectification with separation of target product fraction and fraction with boiling temperature at atmospheric pressure minus 42÷0°C, part of which is separated by absorption with water, absorbed difluorochlormethane and tetrafluorochlorethane are desorbed (combined with remaining part of fraction with boiling temperature at atmospheric pressure minus 42÷0°C) and returned to pyrolysis, non-sorbed gases are subjected to rectification with release of hexafluoropropylene and octafluorocyclobutane.
EFFECT: increase of tetrafluorochlorethane output and reduction of concentration of toxic perfluorisobutylene in pyrolysis products.
3 cl, 6 ex, 1 tbl
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