Production and characterization of carbon foam

In this study, carbon foam production from biomass was carried out using two different methods. In the first part of the study, solvolytic liquefaction of biomass was investigated, and in the second part, foaming of biopitch in a high temperature/pressure reactor was examined. In the solvolytic liquidation process, the effects of the biomass:solvent ratio (1:3 and 1:5), solvent type (phenol and phenol+tar mixture) and surfactant amount were studied. To investigate the solvent type effect, liquid products were obtained from slow pyrolysis of different biomass (spruce sawdust and walnut shell) and used in the solvolytic liquefaction reaction. In the second method, biopitch was produced from liquid products by vacuum distillation method and used as carbon foam precursor in high temperature/pressure reactor. Besides, the structures of the foams produced in the high temperature/pressure reactor were investigated by means of potassium hydroxide activation. Methods such as elemental analysis, thermogravimetric analysis, x-ray diffraction, nitrogen sorption and scanning electron microscopy were used for the characterization of carbon foams, compression strength, density and thermal conductivity measurements were also performed. The results were compared with those of the pitch-based and resin-based carbon foams specified in the literature. Given the fact that carbon foam production from fossil fuel-derived pitches requires high pressure and high temperature applications, it is predicted that carbon foam with adjustable structural properties can be obtained by means of liquefaction and pyrolysis of the biomass through easier and more economical methods.