Touchstone Research Laboratory, Ltd.

Touchstone Research Lab.

Darren Kenneth Rogers

Janusz Wladyslaw Plucinski

Thomas M Matviya

Brian E Joseph

According to the present invention there is provided coal-based cellular or porous products, also referred to herein as 'carbon foams', having a density of preferably between about 0.1 g/cmand about 0.8 g/cmand most preferably between about 0.3 and about 0.4 g/cmthat are produced by the controlled heating of coal particulate preferably up to &#xbc; inch in diameter in a 'mold' and under a non-oxidizing atmosphere. The coal-based cellular or porous products of the present invention have ash contents typically greater than about 1%. More typically these coal-based cellular or porous products have ash contents greater than about 3%, with ash contents in the range of about 7% to 15% being most typical. The ash residue remaining after essentially complete combustion/oxidation of these coal-based cellular or porous products is predominately composed of oxides of aluminum and silicon. Additionally, the cellular coal-based products of the present invention have relatively low overall B.E.T. surface areas. Such surface areas are typically less than about 5 m/g and are commonly in the range of about 1 m/g to about 2 m/g.

Cellular coal products

According to the present invention there is provided a porous coal-based material having a density of between about 0.1 g/cmand about 0.6 g/cmthat is produced by the controlled heating of small coal particulate in a 'mold' and under a non-oxidizing atmosphere. The coal starting material preferably exhibits a free swell index of between about 3.5 and about 5.0 and most preferably between about 4.0 and about 4.5. The porous product thereby produced can be machined, adhered and otherwise fabricated to produce a wide variety of low cost, low density products, or used in its preformed shape as a filter, heat or electrical insulator etc. Such porous products, without further treatment exhibit compressive strengths of up to about 6000 psi. Further treatment by carbonization or graphitization yields products that can be used as electrical or heat conductors. Methods for the production of these coal-based cellular products are also described.

Cellular coal products and processes

According to the present invention there is provided a coal-based carbon foam having a density of between about 0.1 g/cmand about 0.8 g/cm, preferably between about 0.2 g/cmand about 0.6 g/cmand most preferably between about 0.3 g/cmand about 0.4 g/cmthat is produced by the controlled heating of high volatile bituminous coal particulate in a 'mold' and under a non-oxidizing atmosphere. The high volatile bituminous coal starting material preferably exhibits a free swell Index of between about 3.5 and about 5.0 and most preferably between about 3.75 and about 4.5. A number of additional highly desirable characteristics of the high volatile bituminous coal starting material are also described. The carbon foam product thereby produced can be machined, adhered and otherwise fabricated to produce a wide variety of low cost, low density products, or used in its preformed shape as a filter, beat or electrical insulator etc. Such carbon foams, without further treatment exhibit compressive strengths of up to about 6000 psi. Further treatment by carbonization or graphitization yields products that can be used as electrical or heat conductors. Methods for the production of these coal-based cellular products are also described.

An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the 'dirty' and friable particulate activated carbon foam materials of the prior art.

Activated, coal-based carbon foam

The incorporation or blending of from about 1 to about 10% by volume of a 'carbide precursor' powder, preferably on the order of &#x3c;100 microns in size, with a coal particulate starting material and the subsequent production of carbon foam in accordance with the method described herein, results in a carbon foam that exhibits significantly enhanced abrasive characteristics typical of those required in the polishing of, for example glass, in the manufacture of cathode ray tubes.

Carbon foam abrasives

Coal-based cellular products that can be custom designed to have integral stiffeners or load paths, directed heat transfer paths, and/or directed mass transfer paths and methods for their production are described. Such design and production is made possible by the appropriate selection of: starting materials, thermal treatment conditions and/or mold materials combined in at least some instances with segregation of different starting materials in different regions of a forming mold and/or the use of fibrous carbonaceous layers to obtain selected reinforcement to enhance bending and/or impact resistance. Carbon foams of a homogeneous composition comprising at least fibrous carbonaceous mat as a reinforcing element are also described.

Reinforced designed cellular coal

Coal based carbon foams that are produced by the controlled heating of coal particulate in a mold and under a non-oxidizing atmosphere and subsequently graphitized have been found to provide excellent electrode materials for electrochemical cell applications.

Electrochemical cell electrodes

Coal-based cellular products that can be custom designed to have integral stiffeners or load paths, directed heat transfer paths, and/or directed mass transfer paths and methods for their production are described. Such design and production is made possible by the appropriate selection of starting materials, thermal treatment conditions and mold materials combined in at least some instances with segregation of different starting materials in different regions of a forming mold.

Designed cellular coal

Carbon foams exhibiting a dielectric constant of from about 2 to about 6 and simultaneously an electrical resistivity in the range of between about 1.Eohm-cm and about 1.Eohm-cm, demonstrate excellent radar emission absorptivity in the megahertz and gigahertz ranges.

Stealth foam and production method

Coal based carbon foams that are produced by the controlled beating of coal particulate in a mold and under a non-oxidizing atmosphere and subsequently graphitized have been found to provide excellent electrode materials for electrochemical cell applications.

Growing community of inventors

Wheeling, WV, United States of America

Darren Kenneth Rogers