US 11,655,228 B2
Process for preparing dioxolane
Thomas Heitz, Ludwigshafen am Rhein (DE); Marvin Kramp, Ludwigshafen am Rhein (DE); Manfred Heilig, Ludwigshafen am Rhein (DE); HyunSoo Chang, Gimcheon (KR); JongMoon Kim, Gimcheon (KR); and In Gi Cho, Gimcheon (KR)
Assigned to BASF SE, Ludwigshafen am Rhein (DE); and Kolon Plastics Inc., Gwacheon-Si (KR)
Appl. No. 17/56,741
Filed by BASF SE, Ludwigshafen am Rhein (DE); and Kolon Plastics Inc., Gwacheon-Si (KR)
PCT Filed May 8, 2019, PCT No. PCT/EP2019/061773
§ 371(c)(1), (2) Date Nov. 18, 2020,
PCT Pub. No. WO2019/219468, PCT Pub. Date Nov. 21, 2019.
Claims priority of application No. 18173076 (EP), filed on May 18, 2018.
Prior Publication US 2021/0403447 A1, Dec. 30, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. C07D 317/12 (2006.01)
CPC C07D 317/12 (2013.01) 9 Claims
 
1. A process for preparing dioxolane comprising the steps of
a) feeding a first feed stream (1) containing ethylene glycol and a second feed stream (2) containing formaldehyde and methanol in aqueous solution to a reaction distillation device (10) and reacting ethylene glycol and formaldehyde in aqueous solution in the presence of at least one catalyst to obtain a raw product which comprises water, dioxolane and methanol,
b) transferring a distillate stream (11) containing raw product from the top of the reaction distillation device (10) to a phase separation unit (20), wherein an organic extracting agent is present in the phase separation unit (20), wherein the mass fraction of methanol in the distillate stream (11) from the reaction distillation device (10) is from 0.02% to 5%,
c) transferring an organic fraction stream (21) from the phase separation unit (20) to an upper part of a purification column (30), withdrawing a bottom product stream (31) containing dioxolane from the purification column (30), and recycling a distillate stream (32) from the purification column (30) to the phase separation unit (20), wherein the mass fraction of methanol in the bottom product stream (31) of the purification column (30) is less than 0.5%,
d) transferring an aqueous fraction stream (22) from the phase separation unit (20) to a waste water column (40), withdrawing a waste water stream (41) from the bottom of the waste water column (40), withdrawing a side stream (42) from a stage between the feed stage and the reflux stage of the waste water column (40) and recycling this stream (42) to the phase separation unit (20), and withdrawing a distillate stream (43) containing methanol from the waste water column (40).