Patent ID: 6899852

Claim:
A tubular polymerization reactor apparatus comprising: (a) a source of fresh monomer; (b) first and second compressor stages for compressing monomer; (c) a reactor tube; (d) multiple feeds, spaced lengthwise along the reactor tube for supplying monomer to the reactor; (e) multiple free-radical or catalyst injection positions spaced lengthwise along the tubular reactor for causing monomer to be converted into polymer inside the tubular reactor; (f) separators for receiving a monomer-polymer mixture from the reactor tube and separating said mixture into a volatile monomer-rich phase and molten polymerization phase; (g) conduits for recycling the monomer-rich phase to the first and/or second compressor stages for recycling unreacted monomer to the reactor tube; and (h) a source of transfer agent for modifying the molecular weight of the polymer for compression and feeding to the reactor tube; wherein compressor means is provided for compressing a transfer agent rich stream separately from a transfer agent-poor monomer stream and means is provided for feeding the compressed transfer agent rich stream to a polymerization reaction zone upstream of at least one reaction zone receiving the transfer agent-poor stream.