	US 12,281,191 B2
	Devolatilization of plastomer pellets
Abolfazl Noorjahan, Calgary (CA); Stephen Brown, Calgary (CA); Lawrence Van Asseldonk, Sarnia (CA); Robert Van Asseldonk, Airdrie (CA); Jeffrey Cahill, Calgary (CA); Carlos Duque, Calgary (CA); and William Oberg, Red Deer (CA)
Assigned to NOVA Chemicals (International) S.A., Fribourg (CH)
Appl. No. 17/436,046
Filed by NOVA Chemicals (International) S.A., Fribourg (CH)
PCT Filed Feb. 27, 2020, PCT No. PCT/IB2020/051678 § 371(c)(1), (2) Date Sep. 2, 2021, PCT Pub. No. WO2020/178679, PCT Pub. Date Sep. 10, 2020.
Claims priority of provisional application 62/814,985, filed on Mar. 7, 2019.
Prior Publication US 2022/0169758 A1, Jun. 2, 2022
Int. Cl. C08F 6/00 (2006.01); C08F 210/16 (2006.01)

CPC C08F 6/005 (2013.01) [C08F 210/16 (2013.01)]

15 Claims

1. A process for the production of devolatilized ethylene-alpha olefin copolymer having a density of about 0.880 to 0.905 g/cc and a melt index, I₂, of 0.3 to 30 g/10 minutes as measured by ASTM D1238 at a temperature of 190° C. using a 2.16 kg load, said process comprising:

i) providing raw pellets of ethylene-alpha olefin copolymer to a devolatilization bin, wherein said raw pellets are characterized by containing volatile hydrocarbon;

ii) providing nitrogen gas to said devolatilization bin, wherein said nitrogen gas is provided to said devolatilization bin at a temperature of 40° C. to 85° C.;

iii) discharging devolatilized pellets from said devolatilization bin, wherein said devolatilized pellets contain a lower level of said volatile hydrocarbon than said raw pellets;

iv) recovering mixed stripper gas comprising a mixture of nitrogen and hydrocarbon from an overhead portion of said devolatilization bin;

v) directing said mixed stripper gas to a hydrocarbon extraction vessel;

vi) recovering purified nitrogen from said hydrocarbon extraction vessel; and

vii) recycling said purified nitrogen to said devolatilization bin.