# US 8,539,957 B2 · Cigarettes and cigarette filters including activated carbon for removing nitric oxide

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- Number: US 8,539,957 B2
- Document ID: US8539957B2
- Status: Granted
- Kind: B2
- Application number: 11/305,338
- Filed: 2005-12-19
- Published: 2006-09-14
- Granted: 2013-09-24
- Earliest claimed: 2005-01-14
- Assignees: Philip Morris USA Inc.
- Applicants: Wei-Jun Zhang; Mark Zhuang; Shahryar Rabiei; Firooz Rasouli
- Inventors: Wei-Jun Zhang; Mark Zhuang; Shahryar Rabiei; Firooz Rasouli
- Web page: https://patentgrep.com/patent/US8539957B2

## CPC

- A24D 3/067: {characterised by functional properties}
- A24D 3/0287: {for composite filters}
- A24D 3/163: {Carbon}
- B01D 24/001: {Making filter elements not provided for elsewhere}
- A24D: CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

Filters and cigarettes include an activated carbon sorbent capable of selectively removing nitric oxide from mainstream tobacco smoke. Methods for making cigarette filters and cigarettes using the activated carbon sorbent and methods for treating mainstream tobacco smoke produced by smoking a cigarette comprising the sorbent are also provided.

## Claims

### Claim 1

A cigarette filter comprising an activated carbon sorbent, wherein a majority of the pores of the activated carbon sorbent have a size of less than about 30 Å, the activated carbon sorbent contains pores having a D-R micropore volume of from about 0.2 cm3/g to about 1.0 cm3/g in the pore size range of from about 5 Å to about 10 Å and pores having a D-R micropore volume of from 0.33 cm3/g to 0.61 cm3/g in the pore size range of from 10 Å to 20 Å, and the activated carbon sorbent is capable of removing nitric oxide from mainstream tobacco smoke, wherein the activated carbon sorbent is in the form of spherical beads.

### Claim 2 (depends on 1)

The cigarette filter of claim 1, wherein (a) a majority of the pores of the activated carbon sorbent have a size of from about 5 Å to about 20 Å; (b) the activated carbon sorbent has a BET surface area of from about 1000 m2/g to about 3,000 m2/g; or (c) the pores of the activated carbon sorbent that have a pore size of from about 5 Å to about 10 Å have a D-R micropore volume of from 0.3 cm3/g to about 1.0 cm3/g, and the activated carbon sorbent has a specific surface area of about 1000 m2/g to about 2,000 m2/g.

### Claim 3 (depends on 1)

The cigarette filter of claim 1, wherein (a) the beads have a substantially uniform diameter; or (b) the beads are of at least two different size fractions.

### Claim 4 (depends on 1)

A cigarette comprising a cigarette filter according to claim 1.

### Claim 5 (depends on 4)

The cigarette of claim 4, which is a non-traditional cigarette.

### Claim 6 (depends on 1)

The cigarette filter of claim 1, further comprising catalyst material capable of catalyzing the reaction of nitric oxide to N2 and O2 and/or to NO2.

### Claim 7 (depends on 6)

The cigarette filter of claim 6, wherein (a) the catalyst is Fe2O3 and/or Fe3O4; (b) the catalyst is nano-sized; (c) the catalyst is provided on the activated carbon sorbent; or (d) the activated carbon sorbent and the catalyst are in a physical mixture.

### Claim 8 (depends on 6)

A cigarette comprising a cigarette filter according to claim 6.

### Claim 9 (depends on 1)

The cigarette filter of claim 1, wherein the beads are of at least two different size fractions.

### Claim 10 (depends on 1)

The cigarette filter of claim 1, wherein the activated carbon sorbent contains pores having a D-R micropore volume of from about 0.2 cm3/g to about 0.31 cm3/g in the pore size range of from about 5 Å to about 10 Å.