	US 12,226,734 B2
	Filter medium for separating nitrogen oxides
Simon Zapf, Bamberg (DE); Volkmar Chowanietz, Bayreuth (DE); and Christoph Hitzke, Bamberg (DE)
Assigned to MANN+HUMMEL GmbH, Ludwigsburg (DE)
Filed by MANN+HUMMEL GmbH, Ludwigsburg (DE)
Filed on Aug. 16, 2021, as Appl. No. 17/403,308.
Application 17/403,308 is a continuation of application No. PCT/EP2020/054222, filed on Feb. 18, 2020.
Claims priority of application No. 10 2019 104 148.1 (DE), filed on Feb. 19, 2019.
Prior Publication US 2022/0032232 A1, Feb. 3, 2022
Int. Cl. B01D 53/82 (2006.01); B01D 39/16 (2006.01); B01D 39/20 (2006.01); B01D 53/44 (2006.01); B01D 53/56 (2006.01); B01J 20/04 (2006.01); B01J 20/08 (2006.01); B01J 20/20 (2006.01); B01J 20/26 (2006.01); B01J 20/28 (2006.01)

CPC B01D 53/82 (2013.01) [B01D 39/1623 (2013.01); B01D 39/2062 (2013.01); B01D 39/2079 (2013.01); B01D 53/44 (2013.01); B01D 53/565 (2013.01); B01J 20/041 (2013.01); B01J 20/08 (2013.01); B01J 20/20 (2013.01); B01J 20/261 (2013.01); B01J 20/262 (2013.01); B01J 20/28035 (2013.01); B01J 20/28038 (2013.01); B01J 20/28061 (2013.01); B01J 20/28064 (2013.01); B01J 20/28066 (2013.01); B01D 2239/0407 (2013.01); B01D 2239/0464 (2013.01); B01D 2239/0618 (2013.01); B01D 2239/065 (2013.01); B01D 2239/083 (2013.01); B01D 2239/10 (2013.01); B01D 2239/1241 (2013.01); B01D 2239/1291 (2013.01); B01D 2253/102 (2013.01); B01D 2253/25 (2013.01); B01D 2253/304 (2013.01); B01D 2253/306 (2013.01); B01D 2257/404 (2013.01); B01D 2257/708 (2013.01)]

18 Claims

1. A filter medium comprising:

a layer (A) comprising non-impregnated active carbon,

a layer (B) comprising a solid carrier material that is impregnated with a permanganate salt;

a layer (C) comprising alkaline impregnated active carbon;

wherein the layer (B) and the layer (C) are arranged such that a gas flowing through the filter medium flows through the layer (B) before flowing through the layer (C);

wherein the layer (A) is arranged such that the gas flowing through the filter medium flows through the layer (A) before flowing through the layer (B) or the gas flowing through the filter medium flows through the layer (A) after flowing through the layer (C); and

wherein the solid carrier material of the layer (B) is aluminum oxide (Al₂O₃).