US 12,331,017 B2
Process for starting up and shutting down a plant for removing isobutene from a C4-hydrocarbon mixture
Hans-Guenter Wagner, Ludwigshafen am Rhein (DE); Suman Thotla, Ludwigshafen am Rhein (DE); Gerrit Waters, Ludwigshafen am Rhein (DE); Michael Huebner, Freeport, TX (US); Markus Neudert, Ludwigshafen am Rhein (DE); Randolph Hugo, Ludwigshafen am Rhein (DE); and Thomas Roussiere, Ludwigshafen am Rhein (DE)
Assigned to BASF SE, Ludwigshafen Am Rhein (DE)
Appl. No. 18/280,688
Filed by BASF SE, Ludwigshafen am Rhein (DE)
PCT Filed Mar. 1, 2022, PCT No. PCT/EP2022/055185
§ 371(c)(1), (2) Date Sep. 7, 2023,
PCT Pub. No. WO2022/189217, PCT Pub. Date Sep. 15, 2022.
Claims priority of application No. 21161187 (EP), filed on Mar. 8, 2021.
Prior Publication US 2024/0140887 A1, May 2, 2024
Int. Cl. C07C 7/04 (2006.01); B01D 3/14 (2006.01); C07C 1/24 (2006.01); C07C 41/09 (2006.01)
CPC C07C 7/04 (2013.01) [B01D 3/143 (2013.01); C07C 1/24 (2013.01); C07C 41/09 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A process for starting up a plant for removing isobutene from an isobutene-containing C4-hydrocarbon mixture, the plant comprising an etherification unit containing moist acidic ion exchange resin, a first distillation unit, an ether cleavage unit, and a second distillation unit, the process comprising
(a) filling the etherification unit with isobutanol;
(b) filling the first distillation unit with C4-hydrocarbon and/or isobutanol, and operating the first distillation unit with total reflux;
(c) filling the second distillation unit with C4-hydrocarbon and/or isobutanol, and operating the second distillation unit with total reflux;
(d) withdrawing a bottom product of the second distillation unit, removing water from the bottom product and directing the bottom product to the etherification unit;
(e) directing a discharge of the etherification unit to the first distillation unit;
(f) directing a bottom product of the first distillation unit to the second distillation unit while bypassing the ether cleavage unit;
(g) after the bottom product of the second distillation unit is essentially free of water, providing a flow of isobutene-containing C4-hydrocarbon mixture into the etherification unit and reacting the isobutene-containing C4-hydrocarbon mixture with isobutanol to form a mixture of IBTBE and unconverted hydrocarbons;
(h) directing the mixture of IBTBE, unconverted hydrocarbons and unreacted isobutanol from the etherification unit to the first distillation unit and distilling the mixture to obtain a top product comprising the unconverted hydrocarbons, and a bottom product comprising IBTBE and unreacted isobutanol;
(i) after IBTBE in the bottom product of the first distillation unit has reached a predetermined concentration, directing the bottom product of the first distillation unit to the ether cleavage unit to decompose the IBTBE to obtain isobutene and isobutanol;
(j) directing the mixture of isobutene and isobutanol produced in step (i) to the second distillation unit and distilling the mixture of isobutene and isobutanol to obtain a top product comprising isobutene, and a bottom product comprising isobutanol and;
(k) recycling the bottom product obtained in step (j) at least partially to the etherification unit.