Adsorbent material with anisotropic layering
In at least one embodiment, a compressed gaseous fuel storage pellet is provided comprising a gas adsorbent material and a thermally conductive material extending substantially an entire dimension of the pellet and having a thermal conductivity of at least 75 W/mK. The pellet may include at least two layers of gas adsorbent material spaced apart along a compression direction of the pellet and a substantially continuous layer of the thermally conductive material disposed between the at least two layers of gas adsorbent material. The pellet may further include thermally conductive projections which intersect the layer(s) of thermally conductive material.
1. A gas storage tank containing a compressed gaseous fuel storage pellet comprising:
a gas adsorbent material; and
a thermally conductive material extending substantially an entire dimension of the pellet and having a thermal conductivity of at least 75 W/mK.
2. The gas storage tank of claim 1 , wherein the pellet further comprises at least two layers of gas adsorbent material spaced apart along a compression direction of the pellet; and
a substantially continuous layer of the thermally conductive material disposed between the at least two layers of gas adsorbent material.
3. The gas storage tank of claim 2 , wherein the pellet further comprises a plurality of layers of gas adsorbent material and a plurality of layers of thermally conductive material, wherein the layers of gas adsorbent material and thermally conductive material are in an alternating pattern.
4. The gas storage tank of claim 3 , wherein the layers of gas adsorbent material are equally spaced.
5. The gas storage tank of claim 3 , wherein the layers of thermally conductive material are equally spaced.
6. The gas storage tank of claim 3 , wherein a ratio of a thickness of the layers of thermally conductive material to a thickness of the layers of the gas adsorbent material is from 1:15 to 1:3.
7. The gas storage tank of claim 3 , wherein a ratio of a thickness of the layers of thermally conductive material to a thickness of the layers of the gas adsorbent material is from 1:12 to 1:4.
8. The gas storage tank of claim 2 , wherein the pellet further comprises a plurality of thermally conductive projections extending substantially an entire height of the pellet parallel to the compression direction of the pellet.
9. The gas storage tank of claim 8 , wherein the plurality of projections extend from a base disposed at one end of the pellet.
10. The gas storage tank of claim 8 , wherein the plurality of projections are formed of metal.
11. The gas storage tank of claim 1 , wherein the thermally conductive material is expanded natural graphite (ENG).
12. The gas storage tank of claim 1 , wherein the gas adsorbent material includes a metal-organic framework (MOF), an activated carbon, or a covalent-organic framework (COF).
13. The gas storage tank of claim 1 , wherein the pellet has a thermal conductivity of at least 0.75 W/mK in a direction parallel to the thermally conductive material.
14. The storage tank of claim 1 , wherein the pellet has a gas permeability in a direction substantially perpendicular to a compression direction that is at least 200% greater than in the compression direction.
15. A method of forming a compressed gaseous fuel storage pellet comprising:
layering alternating layers of a gas adsorbent material powder and a high thermal conductivity (HTC) additive, the HTC additive having a thermal conductivity of at least 75 W/mK;
compressing the gas adsorbent material powder and HTC additive in a direction substantially perpendicular to the layers to form a compressed pellet; and
placing the compressed pellet in a gas storage tank.
16. The method of claim 15 , wherein the HTC additive is expanded natural graphite (ENG).
17. The method of claim 15 , wherein the gas adsorbent material powder is a metal-organic framework (MOF), an activated carbon, or a covalent-organic framework (COF).
18. The method of claim 15 , wherein the alternating layers of the gas adsorbent material powder and the high thermal conductivity (HTC) additive are layered in a die.
19. The method of claim 18 further comprising inserting a plurality of thermally conductive projections into the die prior to the layering step such that the alternating layers are formed around the projections.
20. A gas storage tank containing a compressed gaseous fuel storage pellet comprising:
at least three layers of a metal-organic framework (MOF) material spaced apart along a compression direction of the pellet; and
a substantially continuous layer of expanded natural graphite (ENG) disposed in each space between the at least three spaced apart layers of MOF material.