Slurry phase polymerisation process
US8202950B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2008 |
| Grant date | Jun 19, 2012 |
| Priority date | — |
| Expiry date | Jan 8, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2308/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Process for producing a multimodal polyethylene in at least two loop reactors connected in series. In the process 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor, one polymer being made in the presence of the other in either order. The ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr)/[ethylene concentration in the reactor (mol %)×residence time in the reactor (hours)×feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr), and the volumes of the two reactors differ by less than 10%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.