PRODUCTION OF FUEL PELLETS INCLUDING HEMP AND/OR KENAF WASTE BYPRODUCT

Abstract

A fuel pellet has a body made from a mixture of (a) 1-99 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 1-99 weight percent coal fines. A related method of making a fuel pellet includes the steps of: (1) mixing together (a) a hemp byproduct, a kenaf byproduct or a hemp byproduct and a kenaf byproduct and (b) coal fines to form a pelleting mixture; and (2) compressing or extruding the pelleting mixture and forming the fuel pellet in the absence of any added binder.

Claims

1. A fuel pellet, comprising: a pellet body made from a mixture of (a) 1-99 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 1-99 weight percent coal fines.

2. The fuel pellet of claim 1, wherein the pellet body is binder free.

3. The fuel pellet of claim 1, including 10-90 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 10-90 weight percent coal fines.

4. The fuel pellet of claim 1, including 20-80 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 20-80 weight percent coal fines.

5. The fuel pellet of claim 1, including 33-50 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 50-67 weight percent coal fines.

6. A fuel pellet, consisting essentially of: a pellet body made from a mixture of (a) 1-99 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 1-99 weight percent coal fines.

7. The fuel pellet of claim 6, wherein the pellet body is binder free.

8. The fuel pellet of claim 6, including 10-90 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 10-90 weight percent coal fines.

9. The fuel pellet of claim 6, including 20-80 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 20-80 weight percent coal fines.

10. The fuel pellet of claim 6, including 33-50 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 50-67 weight percent coal fines.

11. A fuel pellet, consisting of: a pellet body made from a mixture of (a) 1-99 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 1-99 weight percent coal fines.

12. The fuel pellet of claim 11, wherein the pellet body is binder free.

13. The fuel pellet of claim 11, including 10-90 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 10-90 weight percent coal fines.

14. The fuel pellet of claim 11, including 20-80 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 20-80 weight percent coal fines.

15. The fuel pellet of claim 11, including 33-50 weight percent hemp byproduct, kenaf byproduct or a combination thereof and 50-67 weight percent coal fines.

16. A method of making a binder-free fuel pellet comprising: mixing together (a) a hemp byproduct, a kenaf byproduct or a hemp byproduct and a kenaf byproduct and (b) coal fines to form a pelleting mixture; and compressing or extruding the pelleting mixture and forming the binderless fuel pellet in the absence of any added binder.

17. The method of claim 16, including using remnants from both bast fiber and shive remaining following fiber processing of hemp as the hemp byproduct.

18. The method of claim 16, including using coal fines less than 2.54 cm in size and having a moisture content of between 2.5 and 20 weight percent.

19. The method of claim 16, including using waste hemp byproduct following extraction of a cannabinoid oil from hemp.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0018] The accompanying drawing FIGURES incorporated herein and forming a part of the patent specification, illustrate several aspects of the fuel pellet and the method and together with the description serve to explain certain principles thereof.

[0019] FIG. 1 is a perspective view of the new and improved fuel pellet.

DETAILED DESCRIPTION

[0020] Reference is now made to FIG. 1 which illustrates the new and improved fuel pellet 10. As will become apparent from the following description, the fuel pellet 10 is a binder-free fuel pellet: that is a fuel pellet free from the addition of any fuel pellet binder of a type known to those skilled in the art. This substantially reduces the cost of producing the fuel pellet thereby making the fuel pellet a more cost effective substitute for coal.

[0021] The fuel pellet 10 also has the structural integrity to be fed into the firebox of a boiler by the existing equipment used to feed coal. As such, it should be appreciated that the fuel pellet 10 is characterized by a number of advantages that make it a commercially competitive product as an alternative fuel source.

[0022] The fuel pellet 10 includes a pellet body 12 made from a mixture of: (a) 10-90 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 10-90 weight percent coal fines. For purposes of this document, hemp byproduct includes, but is not necessarily limited to, waste that remains following fiber processing, including remnants from both the bast fiber (outer, stingy material) and the shive or hurd fiber (inner woody, pithy material) and the solid waste that remains following extraction of cannabidiol (CBD) or other cannabinoid oils or a combination thereof. For purposes of this document, kenaf byproduct includes, but is not necessarily limited to, waste that remains following fiber processing of the harvested kenaf stalks. It can include remnants from both the bast fiber (outer, stringy material) and the shive or hurd fiber (inner woody, pithy material).

[0023] In some embodiments, the pellet body is made from a mixture of: (a) 20-80 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 20-80 weight percent coal fines. In still some other embodiments, the pellet body is made from a mixture of: (a) 33-50 weight percent hemp byproduct, kenaf byproduct or a combination thereof and (b) 50-67 weight percent coal fines.

[0024] In at least one possible embodiment of the fuel pellet 10, coal fines includes coal fines of less than 2.54 cm (1.0 inch) in size and having a moisture content of between 2.5 and 20 weight percent. In some embodiments, the coal fines have a moisture content of between 5 and 20 weight percent. In still other embodiments, the coal fines have a moisture content between 10 and 20 weight percent. In yet other embodiments, the coal fines have a moisture content between 15 and 20 weight percent.

[0025] Significantly, the pellet body may be binder free: meaning no pellet binder of a type known in the art to be useful in the production of fuel pellets needs to be added to the fuel pellet 10 in order for it to have the desired structural integrity to be shipped, stored or fed into a combustor or firebox of a utility boiler by the same equipment used to feed coal.

[0026] In one or more of the many possible embodiments, the fuel pellet 10 consists essentially of the physical properties and characteristics noted above. By this, it is meant that the fuel pellet includes all of the ingredients specifically noted above (i.e. hemp byproduct and/or kenaf byproduct and coal fines) with any other components known to be useful in fuel pellets, all in the absence of any addition of a fuel pellet binder of a type known to be used for such purpose.

[0027] A method for making the fuel pellet 10 includes the steps of: (1) mixing together (a) a hemp byproduct, a kenaf byproduct or a hemp byproduct and a kenaf byproduct and (b) coal fines to form a pelleting mixture and (2) compressing or extruding the pelleting mixture and forming the binder-free fuel pellet in the absence of any added binder. The pressure applied generally exceeds 100 psi.

[0028] In one or more of the many possible embodiments, the method may include using remnants from both bast fiber and shive remaining following fiber processing of hemp as the hemp byproduct. In one particularly useful embodiment, the method includes using waste hemp byproduct following extraction of CBD oil or other cannabinoids from hemp. Significantly, raw hemp subjected to the harsh conditions for supercritical extraction of CBD oil at high temperatures and pressures results in a hemp byproduct having unexpected binder-like properties when mixed with coal fines.

[0029] In one or more of the many possible embodiments of the method, the method 30 also includes using coal fines less than 2.54 cm in size and having a moisture content of between 2.5 and 20 weight percent. In some embodiments, those coal fines have a moisture content between 5-20 weight percent. In some embodiments, those coal fines have a moisture content between 10-20 weight percent. In some embodiments, those coal fines have a moisture content between 15-20 weight percent.

Experimental Examples

[0030]

TABLE-US-00001 Hemp Air-dried.sup.a As received.sup.b Blend byproduct coal fines coal fines moisture Run # wt % wt % wt % wt % 36-4  100% 8.4% 30-3 50.0% 50.0% 7.3% 31-2 33.3% 66.7% 11.0% .sup.amoisture—2.75% .sup.bmoisture = 10.52%

[0031] The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.