Method for forming an acid-treated fly ash activated carbon

Patent metadata

Field	Value
Publication number	US-9757709-B1
Application number	US-201715650168-A
Country	US
Kind code	B1
Filing date	Jul 14, 2017
Priority date	Oct 22, 2015
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A process for making a modified, mesoporous activated carbon material from waste oil fly ash. The process involves a physicochemical treatment of a raw waste oil fly ash sample, where the sample is initially refluxed in an acid solution, then activated at about 1000° C. and in the presence of carbon dioxide. The activated carbon may be further functionalized with carboxylic and/or amine groups by refluxing the activated carbon in a second acid solution and/or an ammonia solution. The activated carbon, as prepared, has a BET surface area of 30-400 m 2 /g, a total pore volume of 0.25-0.50 cm 3 /g and an average pore size of 40-100 Å. A method for removing hydrogen sulfide from natural gas with the modified activated carbon is also provided.

First claim

The invention claimed is:

1. A process for preparing an acid-treated activated carbon material, comprising:
refluxing a waste oil fly ash powder with a first acid solution comprising at least one acid selected from the group consisting of sulfuric acid, nitric acid and phosphoric acid to form a solid residue;
rinsing the solid residue with water until the water has a pH of at least 6; and
heating the solid residue at 900-1050° C.; and
purging the solid residue in a flow of carbon dioxide to from the activated carbon material.

2. The process of claim 1 , wherein the first acid solution comprises two acids selected from the group consisting of sulfuric acid, nitric acid and phosphoric acid at a volume ratio of 1-13:1-13.

3. The process of claim 1 , wherein the first acid solution comprises sulfuric acid, nitric acid and phosphoric acid at a volume ratio of 1-8.5:1-8.5:1-8.5.

4. The process of claim 1 , wherein the refluxing is carried at 100-150° C. for 3-6 h and at a concentration of 10-100 g of the waste oil fly ash powder per liter of the first acid solution.

5. The process of claim 1 , wherein the heating is carried out for 30-90 min.

6. The process of claim 1 , wherein the purging is carried out for 15-45 min, at 1-5 bar and at a carbon dioxide flow rate of 0.5-2.0 L/min.

7. The process of claim 1 , further comprising:
contacting and refluxing the activated carbon material with an ammonia solution.

8. The process of claim 7 , wherein the contacting and the refluxing are carried out at 80-120° C. for 3-6 h and at a concentration of 50-200 g of the activated carbon material per liter of the ammonia solution.

9. The process of claim 1 , wherein the refluxing, the heating and the purging increase the BET surface area of the activated carbon material, increase the total pore volume of the activated carbon material and reduce the average pore size of the activated carbon material.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Shawabkeh Reyad Awwad
• Hussein Ibnelwaleed Ali
• ASLAM Hafiz Muhammad Zaheer
• Al-Baghli Nadhir H

Classifications

• B01D53/02

  by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)} · CPC title

• B01J20/28059

  being less than 100 m2/g · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · CPC title

• B01J20/20 Primary

  comprising free carbon; comprising carbon obtained by carbonising processes · CPC title

• C01B31/081

  Chemistry & Metallurgy · mapped topic