Published February 1974
In the first supplement (October 1969) to Report No. 19, a third process for HDPE was evaluated. The process uses a metal oxide catalyst to produce the polymer in particle form. The modified Phillips catalyst used had sufficiently high activity and productivity that the low concentration remaining in the polymer particle eliminated the need for catalyst removal.
This was an important technological advance because the complex and expensive facilities for removing catalyst residues could now be omitted. The Phillips particle-form process was thus the first in what has turned out to be a second generation of linear polyethylene processes. These new processes, as well as a new gas-phase process for polypropylene, are the subjects of this second supplement to Report No. 19. In line with recent construction of larger units, these evaluations have all been made on the basis of producing 120 million lb/yr; the economics also have been calculated for producing both half and twice this quantity of product.
