Pelletizing and briquetting of coal fines using binders produced by liquefaction of biomass

• US 5,916,826 A
• Filed: 12/05/1997
• Issued: 06/29/1999
• Est. Priority Date: 12/05/1997
• Status: Expired due to Fees

• Current Assignee: Waste Technology Transfer, Inc.
• Original Assignee: Waste Technology Transfer, Inc.
• Inventors: White, Donald H.
• Primary Examiner(s): MEDLEY, MARGARET B
• Application Number:
  US08/985,399
• Time in Patent Office: 571 Days
• Field of Search: 44/593, 44/552, 44/564, 44/553, 44/567, 44/569, 44/551, 44/578, 44/596
• US Class Current: 44/551
• CPC Class Codes: C10L 5/14 with organic binders

Abstract

A coal agglomerate is produced by the combination of coal fines with a binder obtained by the direct liquefaction of biomass material. The direct liquefaction is carried out in the absence of oxygen at typical temperatures between about 450 and 700° F. and typical pressures between 200 and 3,000 psi, according to known liquefaction processes. The liquefied bio-binder base is mixed with additives, if desired, such as fast pyrolysis tars and petroleum asphalt, in order to modify its characteristics to meet specific needs of particular applications, and the resulting mixture is sprayed on coal fines preheated to at least 250° F. and allowed to react at about 300-400° F. Combustible extenders and fillers; reinforcing fibers; and cross-linking agents may be mixed with the coal prior to combination with the binder to provide additional specific properties to the mixture. The resulting well mixed mass is then pelletized by the application of pressure in conventional equipment.

Claims

1. A coal pellet mixture comprising:

(a) a bio-binder base obtained from direct liquefaction of biomass material; and

(b) coal fines

wherein the bio-binder base is about three to thirty weight percent of the mixture,

wherein the bio-binder base is produced by the direct liquefaction of cellulosic bio-material in the absence of oxygen.

12. The mixture of claim 1, further comprising combustible reinforcing fibers selected from the group consisting of natural polymeric fibers, synthetic polymeric fibers, and mixtures thereof.

13. The mixture of claim 1, further comprising combustible cross-linking agents.

14. The mixture of claim 1, wherein said bio-binder base also comprises a fast pyrolysis tar.

15. The mixture of claim 1, wherein said bio-binder base also comprises a petroleum asphalt.

16. The mixture of claim 1, wherein said bio-binder base also comprises a fast pyrolysis tar and a petroleum asphalt.

17. The mixture of claim 1, further comprising combustible extenders or fillers selected from the group consisting of shredded newsprint, cardboard, pine needles, tree bark, tannins, lignins, oat hulls, wheat straws, wheat flours, corn flours, partially-degraded lignite coal, partially-degraded peat, waste organic sludges, and mixtures thereof.

2. A process for producing a coal pellet from coal fines comprising the following steps:

(a) preparing a mixture comprising liquefied bio-binder base and coal fines, wherein the liquefied bio-binder base is about three to thirty weight percent of the mixture;

(b) blending the mixture at a temperature between about 60°

C. and 260°

C. to produce a bonding reaction between the liquefied bio-binder base and the coal fines, thereby yielding a substantially uniform blend; and

(c) compressively agglomerating the blend obtained from step (b) to produce a coal pellet,

wherein the bio-binder base is produced by the direct liquefaction of cellulosic bio-material in the absence of oxygen.

3. The process of claim 2, further comprising the step of modifying the bio-binder base by adding a fast pyrolysis tar to the liquefied bio-binder base prior to carrying out step (a).

4. The process of claim 2, further comprising the step of modifying the bio-binder base by adding a petroleum asphalt to the liquefied bio-binder base prior to carrying out step (a).

5. The process of claim 2, further comprising the step of modifying the bio-binder base by adding a fast pyrolysis tar and a petroleum asphalt to the liquefied bio-binder base prior to carrying out step (a).

6. The process of claim 2, wherein step (a) is carried out by spraying the liquefied bio-binder base on the coal fines.

7. The process of claim 2, further comprising the step of adding combustible extenders or fillers to the coal fines prior to carrying out step (a), wherein said combustible extenders or fillers are selected from the group consisting of shredded newsprint, cardboard, pine needles, tree bark, tannins, lignins, oat hulls, wheat straws, wheat flours, corn flours, partially-degraded lignite coal, partially-degraded peat, waste organic sludges, and mixtures thereof.

8. The process of claim 2, further comprising the step of adding combustible reinforcing fibers to the coal fines prior to carrying out step (a), wherein said combustible reinforcing fibers are selected from the group consisting of natural polymeric fibers, synthetic polymeric fibers, and mixtures thereof.

9. The process of claim 2, further comprising the step of adding combustible cross-linking agents to the coal fines prior to carrying out step (a).

10. A coal pellet produced by the process of claim 2.

11. A coal pellet produced by the process of claim 6.