Upgrading the Rice Husk Biochar Characteristics Through Microwave Assisted Phosphoric Acid Pretreatment Followed by Copyrolysis with Ldpe

In the present study, an attempt was made to upgrade the characteristics of rice husk biochar through a combination of two strategies: i) microwave assisted phosphoric acid pretreatment of rice husk (MAPP) followed by, ii) non-catalytic copyrolysis of pretreated rice husk with LDPE. The analysis of pretreated rice husk through biochemical composition, proximate analysis, ultimate analysis, TGA and XRD showed that MAPP significantly improved the properties of rice husk. The pretreated rice husk had higher fixed carbon and volatile matter as compared to untreated rice husk (19.65% v/s 13.35% and 66.24% v/s 61.93%) while, it’s ash content was lower than untreated rice husk due to partial removal of lignin and minerals (9.75% v/s 16.85%). TGA analysis showed that MAPP improved thermal stability of rice husk. At 719.650C, the residual masses of rice husk and pretreated rice husks were 13.76% and 23.75% respectively. An analysis of properties of biochars revealed that, biochar produced through combined mode has highest carbon (86.14%), least ash content (1.29%), least H/C and O/C values (0.29 and 0.09), and highest BET surface area (35.022 m2/g). Raman spectroscopy and XRD results showed that the biochar had a more orderly structure and less structural defects as compared to biochar produced from rice husk alone, while the FTIR spectra showed the aromatic C-H peaks at 790 cm-1, which was due to conversion of aliphatic carbon to aromatic carbon, indicating the development of condensed aromatic rings in biochar.