Physiochemical characteristics of bio-char derived from pyrolysis of rice straw under different temperatures

The byproduct "bio-char" produced by the pyrolysis process was characterized to investigate the properties and its appropriateness for energy application. The pyrolysis reaction was carried out at 300, 350, 400, and 450 degrees C and 1-h reaction holding time. The analytical techniques TGA/DTG, FT-IR, XRD, SEM, CHNS, and BET were used for the characterization of the different bio-char properties. Results showed that the carbon content in rice straw bio-char increased from 42.20 to 45.33%, with increasing pyrolysis temperatures from 300 to 450 degrees C. CHNS, XRD, FT-IR, and TGA analysis showed that the bio-char aromatic structure was rich in carbon and it demonstrated higher bio-char carbon stability at 450 degrees C. With increase in temperature from 300 to 450 degrees C, the specific surface area of the bio-chars was enhanced (1.17 to 6.60 m(2)/g). At higher temperatures, biomass macromolecules decomposed completely and bio-char became more porous in nature with voids created within the bio-char matrix. During the pyrolysis of the rice straw biomass, the sharp peaks of the crystalline structure were destroyed and less intensity broader peak appeared in the pyrolysis derived bio-chars. The atomic ratio of H/C and O/C decreased with increase in pyrolysis temperature from 300 to 450 degrees C. These low values indicate that the reaction temperature promoted the loss of oxygen and hydrogen.