Adsorbent for removing sulfur compounds from fuel gases and removal method

• US 6,875,410 B2
• Filed: 05/05/2003
• Issued: 04/05/2005
• Est. Priority Date: 02/01/2000
• Status: Expired due to Term

• Current Assignee: Tokyo Gas Company Limited
• Original Assignee: Tokyo Gas Company Limited
• Inventors: Satokawa, Shigeo, Kobayashi, Yuji
• Primary Examiner(s): Silverman, Stanley S.
• Assistant Examiner(s): Hertzog, Ardith E
• Application Number:
  US10/429,913
• Publication Number:
  US 20040057890A1
• Time in Patent Office: 701 Days
• Field of Search: 423/230, 423/244.11, 423/244.1, 423/244.04, 423/244.05, 423/244.06, 481/273, 481/97.FM, 481/983, 208/247, 585/820
• US Class Current: 423/244.1
• CPC Class Codes: B01D 2253/10 Inorganic adsorbents
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2253/1085 characterized by a silicon-aluminium ratio
• CPC Class Codes: B01D 2257/30 Sulfur compounds
• CPC Class Codes: B01D 2257/306 Organic sulfur compounds, e.g. mercaptans
• CPC Class Codes: B01D 2258/018 Natural gas engines
• CPC Class Codes: B01D 2259/40084 by exchanging used adsorbents with fresh adsorbents
• CPC Class Codes: B01D 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: B01D 53/0454 Controlling adsorption controlling temperature swing adsorption B01D53/0462, controlling pressure swing adsorption B01D53/047
• CPC Class Codes: B01J 20/186 Chemical treatments in view of modifying the properties of the sieve, e.g. increasing the stability or the activity, also decreasing the activity
• CPC Class Codes: C10L 3/12 Liquefied petroleum gas liquefying by pressure and cold treatment F25J

Abstract

An adsorbent for removing sulfur compounds from sulfur compounds-containing fuel gas contains a zeolite ion-exchanged with Ag and has an excellent performance when used to remove sulfur compounds from the fuel gas, irrespective of the moisture concentration in the fuel gas, and a method for removing sulfur compounds from sulfur compounds-containing fuel gas by use of an adsorbent of the above-mentioned type. The zeolite is a Na—+Y type zeolite.

Claims

1. A method of removing sulfur compounds from a fuel gas comprising at least one sulfur compound selected from the group consisting of thiophenes, sulfides and mercaptans comprising the steps of:

depositing silver in an amount of 13-21 wt % on a Na—

Y zeolite having a SiO₂/Al₂O₃ molar ratio of from 4.8-6.0 by ion exchange and passing the fuel gas through an adsorbent comprising the silver-deposited zeolite to remove the sulfur compounds therefrom.

2. The method of claim 1, wherein the silver-deposited zeolite has a silver content of from 15-20 wt %.

3. The method of claim 1, wherein the fuel gas is selected from the group consisting of a city gas, a natural gas and a liquefied petroleum gas.

4. The method of claim 1, wherein the fuel gas has a residual sulfur compound concentration of no greater than 7 ppb after passing through the adsorbent.

5. The method of claim 1, wherein the sulfur compounds are removed at room temperature.

6. The method of claim 1, additionally comprising the step of determining the life of the adsorbent based on a color change thereof.