US Patent 7767183 Production of carbon foam from coals

Methods for the production of carbon foam from swelling coals that do not require the use of high process pressures, oxidized coal, devolatized coal, or high-strength, foam expansion confining molds are described. In some embodiments, a comminuted swelling bituminous coal is heated to a first elevated temperature sufficient to result in the coal particles softening and melting together to form a substantially homogeneous open cell plastic carbon material. The substantially homogeneous open cell plastic carbon material may then be heated to a second elevated temperature at a slow rate to form carbon foam. In some embodiments, the resulting carbon foam may be heated to a higher third elevated temperature. The resulting carbon foam may be subsequently heated to elevated temperatures as great as 3200° C. or more.