US 12,448,349 B2
Process for the production of urea formaldehyde concentrate
Marcus Symreng, Malmö (SE); Pat A. Han, Smørum (DK); and Christian Henrik Speth, Lynge (DK)
Assigned to Topsoe A/S, Kgs. Lyngby (DK)
Appl. No. 17/420,028
Filed by Haldor Topsøe A/S, Kgs. Lyngby (DK)
PCT Filed Mar. 5, 2020, PCT No. PCT/EP2020/055865
§ 371(c)(1), (2) Date Jun. 30, 2021,
PCT Pub. No. WO2020/187585, PCT Pub. Date Sep. 24, 2020.
Claims priority of application No. PA 2019 00322 (DK), filed on Mar. 15, 2019.
Prior Publication US 2022/0048854 A1, Feb. 17, 2022
Int. Cl. C07C 273/10 (2006.01); C01B 3/02 (2006.01); C01B 3/38 (2006.01); C01C 1/04 (2006.01); C07C 29/151 (2006.01); C07C 45/38 (2006.01)
CPC C07C 273/10 (2013.01) [C01B 3/025 (2013.01); C01B 3/382 (2013.01); C01C 1/0488 (2013.01); C07C 29/1518 (2013.01); C07C 45/38 (2013.01); C01B 2203/0244 (2013.01); C01B 2203/0288 (2013.01); C01B 2203/0415 (2013.01); C01B 2203/0445 (2013.01); C01B 2203/0475 (2013.01); C01B 2203/061 (2013.01); C01B 2203/068 (2013.01); C01B 2203/1241 (2013.01); C01B 2203/1247 (2013.01); C01B 2203/142 (2013.01)] 4 Claims
 
1. A process for the production of a urea formaldehyde concentrate from a hydrocarbon feedstock, the process comprising:
(a) producing a synthesis gas containing hydrogen, carbon monoxide, and carbon dioxide and not containing nitrogen by partial combustion and steam reforming the hydrocarbon feedstock in an autothermal reforming stage with oxygen as an oxidant, wherein a steam to carbon ratio is between 0.4:1.0 and 1.0:1.0;
(b) splitting the synthesis gas from step (a) into a first synthesis gas and a second synthesis gas;
(c) subjecting the second synthesis gas from step (b) in series to a high temperature water gas shift and a medium temperature water gas shift conversion;
(d) removing at least part of the carbon dioxide from the second synthesis gas from step (c) to obtain a carbon dioxide depleted second synthesis gas;
(e) adding nitrogen into the carbon dioxide depleted second synthesis gas in an amount to obtain a molar ratio of hydrogen to nitrogen of from 2.8:1.0 to 3.2:1.0 to obtain a purified second synthesis gas;
(f) catalytically converting the nitrogen and hydrogen in the purified second synthesis gas from step (e) in an inert free ammonia synthesis stage and withdrawing an effluent containing ammonia;
(g) passing at least part of the effluent containing ammonia to a urea synthesis stage, converting the ammonia in the effluent to a urea product by reaction with at least part of the carbon dioxide being removed from the synthesis gas in step (d), and preparing an aqueous urea solution from the urea product;
(h) catalytically converting the carbon monoxide, carbon dioxide, and hydrogen of the first synthesis gas from step (b) in a once through methanol synthesis stage and withdrawing an effluent containing raw methanol and an effluent containing unconverted first synthesis gas;
(i) recycling the effluent containing the unconverted first synthesis gas to the medium temperature water gas shift conversion in step (c);
(j) subjecting the effluent containing raw methanol to distillation and withdrawing purified methanol from the distillation;
(k) oxidizing at least a part of the purified methanol from step (j) to formaldehyde; and
(l) absorbing the formaldehyde from step (k) in water and the aqueous urea solution prepared from the urea product in step (g) to obtain the urea formaldehyde concentrate.