# US 12,005,421 B1 · Method of preparing adsorbent from sugarcane bagasse and polyolefin waste

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- Number: US 12,005,421 B1
- Document ID: US12005421B1
- Status: Granted
- Kind: B1
- Application number: 18/377,888
- Filed: 2023-10-09
- Granted: 2024-06-11
- Earliest claimed: 2023-10-09
- Assignees: King Faisal University
- Applicants: King Faisal University
- Inventors: Junaid Saleem; SK Safdar Hossain; Zubair Khalid Baig Moghal; Gordon McKay
- Web page: https://patentgrep.com/patent/US12005421B1

## CPC

- B01J 20/24: Naturally occurring macromolecular compounds, e.g. humic acids or their derivatives
- B01J 20/20: comprising free carbon; comprising carbon obtained by carbonising processes
- B01J 20/28004: {Sorbent size or size distribution, e.g. particle size}
- B01J 20/28014: {characterised by their form}
- B01J 20/28061: {being in the range 100-500 m2/g}
- B01J 20/28083: {being in the range 2-50 nm, i.e. mesopores}
- B01J 20/3021: {Milling, crushing or grinding}
- B01J 20/3028: {Granulating, agglomerating or aggregating}
- B01J 20/305: {Addition of material, later completely removed, e.g. as result of heat treatment, leaching or washing, e.g. for forming pores}
- B01J 20/3078: {Thermal treatment, e.g. calcining or pyrolizing}
- C02F 1/286: {using natural organic sorbents or derivatives thereof}
- C02F 2101/308: {Dyes; Colorants; Fluorescent agents}
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)

## Abstract

A method of preparing an adsorbent can include pyrolyzing sugarcane bagasse to provide a bagasse char, activating the bagasse char, dissolving polyolefin waste in an organic solvent to obtain a solution, dispersing the bagasse char in the solution to provide a mixture, extracting the organic solvent from the mixture to provide a composite, and annealing the composite to provide the adsorbent. The adsorbent can be porous.

## Claims

### Claim 1

A method for preparing an adsorbent from sugarcane bagasse and a polyolefin, the method comprising:
obtaining sugarcane bagasse;
pyrolyzing the sugarcane bagasse to provide a sugarcane bagasse char;
activating the sugarcane bagasse char to provide an activated sugarcane bagasse char;
dissolving a polyolefin in an organic solvent to obtain a polyolefin solution;
dispersing the activated sugarcane bagasse char in the polyolefin solution to provide a mixture;
extracting the organic solvent from the mixture to provide a composite;
annealing the composite to provide the adsorbent; and
cutting the adsorbent to provide adsorbent flakes,
wherein the adsorbent flakes have sizes ranging from about 3 mm to about 30 mm.

### Claim 2 (depends on 1)

The method of claim 1, wherein the polyolefin is waste polyolefin.

### Claim 3 (depends on 1)

The method of claim 1, wherein the polyolefin is selected from the group consisting of polyethylene, low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), ultrahigh molecular weight polyethylene, polypropylene, and combinations thereof.

### Claim 4 (depends on 1)

The method of claim 1, wherein the organic solvent is selected from the group consisting of p-xylene, o-xylene, m-xylene, an isomeric mixture of xylenes, p-cymene, o-cymene, m-cymene, limonene, toluene, mesitylene, other aromatic hydrocarbons, and mixtures thereof.

### Claim 5 (depends on 4)

The method of claim 4, wherein the organic solvent is p-cymene.

### Claim 6 (depends on 1)

The method of claim 1, wherein a surface area of the adsorbent flakes ranges from about 370 m2/g to about 430 m2/g.

### Claim 7 (depends on 1)

The method of claim 1, wherein an average pore size of the adsorbent flakes is about 3 nm.

### Claim 8 (depends on 1)

The method of claim 1, wherein the sugarcane bagasse is pyrolyzed at a temperature ranging from about 200° C. to about 1000° C. and the residence time ranges from about 30 minutes to about 5 hours.

### Claim 9 (depends on 1)

The method of claim 1, wherein the sugarcane bagasse char is activated by immersing the sugarcane bagasse char in a solution including 2N H2SO4.

### Claim 10 (depends on 1)

The method of claim 1, wherein dissolving the polyolefin in the organic solvent comprises:
heating the polyolefin solution to a temperature ranging from about 130° C. to about 150° C.; and
stirring the polyolefin solution for about 20 minutes to about 40 minutes.

### Claim 11 (depends on 1)

The method of claim 1, wherein the annealing comprises heating of the composite at a temperature ranging from about 110° C. to about 180° C. for a period of time ranging from about 2 minutes to about one hour.

### Claim 12 (depends on 1)

The method of claim 1, wherein the sugarcane bagasse is cut and dried prior to the pyrolyzing step.

### Claim 13 (depends on 1)

A method of removing a pollutant from an aqueous solution, comprising contacting the adsorbent as prepared in claim 1 with the aqueous solution.

### Claim 14 (depends on 13)

The method of claim 13, wherein the aqueous solution comprises wastewater.

### Claim 15 (depends on 13)

The method of claim 13, wherein the pollutant comprises organic dyes.

### Claim 16 (depends on 15)

The method of claim 15, wherein the organic dyes are selected from the group consisting of Alizarin red and Indigo carmine.