AU2018100957A4

AU2018100957A4 - Catalytic activated carbon

Info

Publication number: AU2018100957A4
Application number: AU2018100957A
Authority: AU
Inventors: Xun Hui Zheng
Original assignee: Shanghai Kang Jie Purification Technology Co Ltd
Current assignee: Shanghai Kang Jie Purification Technology Co Ltd
Priority date: 2018-07-06
Filing date: 2018-07-06
Publication date: 2018-08-16
Anticipated expiration: 2026-07-06

Abstract

The invention provides the catalytic activated carbon of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 2% to about 8% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, at least 35% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 428.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of from 15% to 45% by weight based on total weight of the catalytic activated carbon. The catalytic activated carbon abovementioned has high H2S adsorption capacity, high kinetic rate of H2S removal, and high flow resistance.

Description

CATALYTIC ACTIVATED CARBON

TECHNICAL FIELD

The present invention relates to activated carbon, in particular relates to catalytic activated carbon.

BACKGROUND

Malodorous sulfur-containing compounds occur in a number of environments such as petroleum storage areas, sewage treatment facilities, wastewater treatment plants, and industrial plants such as petrochemical refining sites, pulp and paper production sites. In these environments, malodorous hydrogen sulfide (H2S) gas is prevalently responsible for the presence of disagreeable odors, along with other sulfur-containing malodorous compounds such as alkyl sulfide, dimethyl sulfide, dimethyl disulfide and methyl mercaptan.

Activated carbon is known to remove hydrogen sulfide from both gaseous and aqueous phases. However, the reaction rate and the hydrogen sulfide loading on the activated carbon limit the economic viability. For example, fluid stream having sulfur-containing compounds is typically passed through a bed of granular or fibrous activated carbon adsorbent for removal of sulfur-containing compounds. When granular or fibrous activated carbon is used as an adsorbent, the adsorbent bed has high flow resistance and consequently consumes significantly large amount of operation energy. Furthermore, the malodorous sulfur-containing compounds usually present in the gas stream at very low concentrations that, it is difficult to effectively remove all of these malodorous sulfur-containing compounds. The poor kinetic rate of H2S removal and the low H2S adsorption capacity of activated carbon limit the economic viability of the activated carbon for removal of H2S in gas stream. A typical coal-based activated carbon has a H2S adsorption capacity of only 0.01 to 0.02 g/cc, and the efficiency of H2S removal is often meager. Accordingly, a large quantity of activated carbon is required for the removal of malodorous sulfur-containing compounds.

There has been effort to improve the H2S adsorption capacity of activated carbon. For example, certain formulations have achieved a H2S adsorption capacity of about 0.09 to 0.11 g/cc. However, at this level of H2S adsorption capacity improvement still limits the economic viability of activated carbon for removal of H2S in the fluid steam containing low amounts of H2S, such as at less than about 0.1 ppm. In another example, pelletized activated carbon has been impregnated with sodium hydroxide (NaOH) and moisture. The pore structure of the activated carbon is somewhat filled with the caustic NaOH, thereby lowering the adsorption capacity of the impregnated activated carbon. Furthermore, the caustic impregnated activated carbon may be susceptible to uncontrolled thermal excursions, resulting from a suppressed combustion temperature and exothermic reactions caused by the caustic impregnation. [006] More recent attempts at improving the H2S adsorption capacity of activated carbon have included impregnating the activated carbon with metal oxides or forming a matrix with metal oxides (e.g., Ca, Mg, Ba or combinations thereof). However, such filters only demonstrate H2S adsorption capacity of about 0.1 to 0.3 g/cc, and 0.26 g/cc, respectively. The activated carbon-metal oxide matrix is prepared by preoxidizing a carbon material, grinding the preoxidized carbon material; mixing the ground preoxidized material with an oxide of Ca, Mg, Ba, or combinations thereof to form a carbon mixture; extruding the carbon mixture into desired structure; carbonizing and activating the extrudate. It is, however, found that such preparation process leaves significant amounts of the active agents unavailable for reaction. The metal oxide impregnated activated carbon media is prepared by forming the activated carbon into a desired structure; impregnating the formed activated carbon media with a solution of Mg salt, Ca salt or both metal salts by spraying the activated carbon structure with the salt solution; and converting the metal salt into a metal oxide. However, pure metal oxides have a limited capacity for H2S because of their low pore volume and surface area, and the oxidation reaction of H2S is too slow to have any practical application to odor control. In addition, pure metal oxides do not exhibit significant adsorption capacity for organic compounds that do not react with the substrate. As a result, these metal oxides are not commercially relevant.

Thus, prior activated carbon adsorbents suffer from a number of well-known disadvantages, including: the activated carbon has a low capacity for H2S, the activated carbon has a slow kinetic rate of H2S removal; the adsorption capacity is low, relatively high amounts of metal oxide must be dispersed throughout the carbon matrix, and high flow resistance. Accordingly, it is desirable to have activated carbon adsorbent having improved H2S adsorption capacity, enhanced kinetic rate of H2S removal, and low flow resistance.

SUMMARY

The present invention is to solve a technical problem that the H2S adsorption capacity of the activated carbon and kinetic rate of H2S removal are low, and flow resistance is also low.

Thus, the catalytic activated carbon of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 2% to about 8% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, at least 35% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 428.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of from 15% to 45% by weight based on total weight of the catalytic activated carbon.

Optionally, in the catalytic activated carbon of the embodiments, the cuprous oxide has a D90 particle size of less than 30 microns.

Optionally, in the catalytic activated carbon of the embodiments, the three-dimensional structure is a honeycomb having a cell density of from 20 to 1200 cells per square inch.

Optionally, the catalytic activated carbon of the embodiments has a B.E.T surface area of from 230m 2 / g to 2500 m 2 / g.

Optionally, in the catalytic activated carbon of the embodiments, at least 50% by weight of the nitrogen are aromatic nitrogen species having a binding energy of from 428.0 eV to 448.0 eV as determined by XPS.

Optionally, in the catalytic activated carbon of the embodiments, the nitrogen-enriched activated carbon is formed from a carbon precursor comprising a member selected from the group consisting of wood, wood dust, wood flour, cotton linters, peat, coal, lignite, petroleum pitch, petroleum coke, coal tar pitch, carbohydrates, coconut, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, synthetic polymer, natural polymer, and combination thereof.

Optionally, in the catalytic activated carbon of the embodiments, the binder comprises a member selected from the group consisting of ceramic, clay, cordierite, flux, glass ceramic, metal, corrugated paper, organic fibers, resin binder, talc, alumina powder, magnesia powder, silica powder, kaolin powder, sinterable inorganic powder, fusible glass powder, and combinations thereof.

The technical solutions of the embodiments of the present invention have the following technical advantage compared with the prior arts: 1. the catalytic activated carbon of the embodiments of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 2% to about 8% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, at least 35% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 428.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of from 15% to 45% by weight based on total weight of the catalytic activated carbon. The technical solution of the catalytic activated carbon abovementioned has high H2S adsorption capacity, high kinetic rate of H2S removal, and high flow resistance.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiment 1

The catalytic activated carbon of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 2% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, 35% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 428.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of from 15% by weight based on total weight of the catalytic activated carbon. The catalytic activated carbon of this embodiment has high H2S adsorption capacity, high kinetic rate of H2S removal, and high flow resistance.

Embodiment 2

The catalytic activated carbon of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 8% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, 45% by weight of the nitrogen are aromatic nitrogen species having a binding energy of 448.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of 45% by weight based on total weight of the catalytic activated carbon. The catalytic activated carbon of this embodiment has high H2S adsorption capacity, high kinetic rate of H2S removal, and high flow resistance.

Embodiment 3

The catalytic activated carbon of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 4% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, 38% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 430.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of 30% by weight based on total weight of the catalytic activated carbon. The catalytic activated carbon of this embodiment has high EES adsorption capacity, high kinetic rate of EES removal, and high flow resistance.

Embodiment 4

The catalytic activated carbon of the present invention comprises a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; the nitrogen-enriched activated carbon includes from about 6% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, 40% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 436.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of 35% by weight based on total weight of the catalytic activated carbon. The catalytic activated carbon of this embodiment has high H2S adsorption capacity, high kinetic rate of H2S removal, and high flow resistance.

Preferably, in the catalytic activated carbon of the embodiments, the cuprous oxide has a D90 particle size of less than 30 microns.

Preferably, in the catalytic activated carbon of the embodiments, the three-dimensional structure is a honeycomb having a cell density of from 20 to 1200 cells per square inch. The catalytic activated carbon of the embodiments has a B.E.T surface area of from 230m2/ g to 2500 m 2 / g.

Preferably, in the catalytic activated carbon of the embodiments, at least 50% by weight of the nitrogen are aromatic nitrogen species having a binding energy of from 428.0 eV to 448.0 eV as determined by XPS. In addition, in the catalytic activated carbon of the embodiments, the nitrogen-enriched activated carbon is formed from a carbon precursor comprising a member selected from the group consisting of wood, wood dust, wood flour, cotton linters, peat, coal, lignite, petroleum pitch, petroleum coke, coal tar pitch, carbohydrates, coconut, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, synthetic polymer, natural polymer, and combination thereof. The binder comprises a member selected from the group consisting of ceramic, clay, cordierite, flux, glass ceramic, metal, corrugated paper, organic fibers, resin binder, talc, alumina powder, magnesia powder, silica powder, kaolin powder, sinterable inorganic powder, fusible glass powder, and combinations thereof

The above described is just preferred embodiments of the present invention, and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any changes, equivalent substitutions, modifications etc. made within the concept and principle of present invention should be embraced within the protection scope of the present invention.

Claims

1. A catalytic activated carbon, comprising a matrix including nitrogen-enriched activated carbon, cuprous oxide, and a binder; characterized in that the nitrogen-enriched activated carbon includes from about 2% to about 8% by weight of nitrogen based on total weight of the nitrogen-enriched activated carbon, at least 35% by weight of the nitrogen are aromatic nitrogen species having a binding energy of at least 428.0 eV as determined by XPS, and the matrix is formed into a three-dimensional structure; the catalytic activated carbon includes the cuprous oxide in an amount of from 15% to 45% by weight based on total weight of the catalytic activated carbon.

2. According to the catalytic activated carbon of claim 1, characterized in that the cuprous oxide has a D90 particle size of less than 30 microns.

3. According to the catalytic activated carbon of claim 2, characterized in that the three-dimensional structure is a honeycomb having a cell density of from 20 to 1200 cells per square inch.

4. According to the catalytic activated carbon of claim 3, characterized in having a B.E.T surface area of from 230m2 / g to 2500 m 2 / g.

5. According to the catalytic activated carbon of claim 4, characterized in that at least 50% by weight of the nitrogen are aromatic nitrogen species having a binding energy of from 428.0 eV to 448.0 eV as determined by XPS.

6. According to the catalytic activated carbon of claim 5, characterized in that the nitrogen-enriched activated carbon is formed from a carbon precursor comprising a member selected from the group consisting of wood, wood dust, wood flour, cotton linters, peat, coal, lignite, petroleum pitch, petroleum coke, coal tar pitch, carbohydrates, coconut, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, synthetic polymer, natural polymer, and combination thereof.

7. According to the catalytic activated carbon of claim 6, characterized in that the binder comprises a member selected from the group consisting of ceramic, clay, cordierite, flux, glass ceramic, metal, corrugated paper, organic fibers, resin binder, talc, alumina powder, magnesia powder, silica powder, kaolin powder, sinterable inorganic powder, fusible glass powder, and combinations thereof.