Process history

Univation announced launch of UNIGILITY™ Tubular High Pressure PE Process as a licensed manufacturing platform for flexible production of LDPE and EVA resins in June 2024, which is based on Dow’s tubular high pressure PE manufacturing platform^[1]. The UNIGILITY™ Tubular High Pressure PE Process Technology page is claiming 80⁺ years high-pressure LDPE operational excellence^[2], which likely refers to Union Carbide Corporation (UCC) acquiring the autoclave high-pressure process as part of a war-time agreement with the inventors of polyethylene, ICI^[3]. Later, UCC developed the high-pressure ethylene polymerization tubular reactor process described in US Patent 4,000,357^[4]. Prior to The Dow Chemical Company (TDCC) acquiring all of the shares of UCC stock, and UCC becoming a wholly owned subsidiary of TDCC in February 2001^[5], patents filed by Dow mention high-pressure polymerization of ethylene in an autoclave reactor and a tubular reactor connected in series with said autoclave reactor in that sequential order^[6]. It is only after acquisition of UCC that Dow filed patents related to the high pressure ethylene polymerization tubular reactor process^[7]. Furthermore, the Dow Chemical / UCC European merger procedure from  May 2000 establishes that Dow does not license its high pressure technology (which at the time presumably was an autoclave process with a tubular reactor tail^[6]) to third parties, whereas UCC is active only in the licensing of high pressure tubular process technology^[8]. 

Process characteristics

• Operating capacity: 350 KTA
• Design Capacities up to 500 KTA
• Reference plant in USA^[2]

Product Portfolio

Process Flow Diagram

Attached illustration is a schematic of a polymerization flow scheme^[7g]. As seen in the illustration, the notations are as follows^[7f]:

• fresh ethylene is fed through line 1;
• discharge of Primary A compressor is sent through line 2;
• discharge of Primary B compressor is sent through line 3;
• 4 and 5 are each a line feed to the Hyper compressor;
• fresh Chain Transfer Agent (CTA) is fed through each of lines 6 and 7
• 8 is a line feed to feed lines 20 and 21, each to the side of the reactor;
• 9 is a line feed from the Hyper compressor to the front of the reactor;
• 10 is a line feed from the reactor to the HPS (High Pressure Separator);
• 11 is a line feed from the High Pressure Separator (HPS) to the Low Pressure Separator (LPS);
• 12 is a discharge line from the LPS;
• 13 is a line feed from the LPS to the Booster;
• 14 is a discharge feed from the Booster;
• 15 is a recycle feed line from the HPS to lines 16 and 17;
• 16 is a purge line;
• 17 is a recycle line;
• 18 and 19 are recycled lines to the Hyper compressor.

References

1. Univation Technologies > News and Events > 16^th Jun 2024: Univation announces launch of the UNIGILITY™ Tubular High Pressure PE Process as a licensed advantaged manufacturing platform for flexible production of LDPE and EVA resins.
2. Univation Technologies > Tubular LDPE Process > UNIGILITY™ Tubular High Pressure PE Process Technology: Advanced Licensed Technology for LDPE & EVA Resin Production. (accessed 9^th February 2025)
3. Plastics Historical Society > Union Carbide Corporation. (accessed 9^th Feb 2025)
4. John P. Marano, Jr., Priority Date: 29^th Aug 1974, US4000357A, Assigned to: Union Carbide Corp., Status: Expired - Lifetime.
5. DOW > Corporate Home > About Dow > Company > Issues & challenges > Bhopal > Dow & Bhopal Tragedy > The Dow Chemical Company and Union Carbide. (accessed 9^th Feb 2024)
6. a. US4496698A, b. WO2006049783A1.
7. a. EP3098262B1, b. WO2013095969A1, c.US8912297B2; d. US9228036B2, e. US20140303309A1, f. US9334348B2, g. US10975179B2.
8. The Commission of the European Communities, Case No COMP/M.1671 – DOW CHEMICAL / UNION CARBIDE, Regulation (ECC) N° 4064/89, Merger Procedure,  Article 8(2) Decision, Date: 03/05/2000.