US 12,145,900 B2
Process for filtering 2-acrylamido-2-methylpropane sulfonic acid
Cédrick Favero, Andrezieux Boutheon (FR); Raphaël Doudin, Andrezieux Boutheon (FR); Johann Kieffer, Andrezieux Boutheon (FR); and Benoît Legras, Andrezieux Boutheon (FR)
Assigned to SNF Group
Appl. No. 17/609,173
Filed by SPCM SA
PCT Filed May 7, 2020, PCT No. PCT/FR2020/050758
§ 371(c)(1), (2) Date Nov. 5, 2021,
PCT Pub. No. WO2020/229757, PCT Pub. Date Nov. 19, 2020.
Claims priority of application No. 1905037 (FR), filed on May 15, 2019.
Prior Publication US 2022/0227704 A1, Jul. 21, 2022
Int. Cl. C07C 309/15 (2006.01); B01D 33/073 (2006.01); B01D 33/46 (2006.01); B01D 33/60 (2006.01); B01D 33/62 (2006.01); C07C 303/44 (2006.01); C08F 20/58 (2006.01); C09K 8/035 (2006.01)
CPC C07C 309/15 (2013.01) [B01D 33/073 (2013.01); B01D 33/466 (2013.01); B01D 33/60 (2013.01); B01D 33/62 (2013.01); C07C 303/44 (2013.01); C08F 20/58 (2013.01); C09K 8/035 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A continuous process for filtering a suspension of 2-acrylamido-2-methylpropane sulfonic acid crystals by means of a rotary pressure filter equipped with a drum, a surface of which is provided with cells covered with a filter medium, said drum rotating within a fixed concentric cylinder comprising at least three zones sealed from each other, respectively a filtration zone, a washing zone and a discharge zone, each zone opening onto the cells, the process comprising the following steps:
a) supplying the filtration zone with a suspension of 2-acrylamido-2-methylpropane sulfonic acid crystals and filtering said suspension in the cells until a cake is formed,
b) supplying the washing zone with a washing solution and washing the cake formed in the cells,
c) discharging the washed cakes from the cells at the discharge zone; and
wherein, a depth of the cells covering the filter medium is between 6 and 150 mm and in that a pressure of between 1 and 10 bars is applied in the filtration and washing zones.