Thermal performance analysis of optimized biomass conversion in developing organic waste biorefinery to achieve sustainable development goals

To make energy sector sustainable, biomass-based energy system is need to be integrated in bio refinery model. According to the International Energy Agency (IEA), the lack of renewable energy and environmental degradation are the major pressing problems confronting the global community. However, in south Asian regions, the situation escalates as a result of severe dependency on conventional energy sources, coupled with the limitations and challenges involved in maintaining a green environment and Waste-to-Energy (WtE) strategies. In this region, energy majorly relies on imported conventional fuel. In addition to harming the environment, imported fossil fuel has also increased the risk of geopolitical unrest. Accordingly, the present study focuses on reforming the energy mix for a clean and green environment. Rice husk is a bio-organic waste that is produced in large volumes. It is a significant byproduct of agro-based biomass sector and can be considered a viable alternative to mitigate fossil fuel usage. In this research, sample composition of rice husk is demineralized in 5% hydrochloric acid (HCl) for analyzing different burning patterns in biomass conversion systems utilized in biorefinery sector. In this context, the modified thermochemical burning technique which includes pyrolysis and combustion was applied to the acidified rice husk at three different heating rates (20 °C min−1, 30 °C min−1 and 40 °C min−1) and flow rates (20 ml*min−1, 30 ml*min−1 and 40 ml*min−1) under nitrogen environment from 0 °C to 500 °C and air from 500 °C to 900 °C respectively in thermogravimetric analyzer (TGA). Proximate, thermal and kinetic analysis was used for observing the degradation patterns of demineralized rice husk. Proximate analysis revealed that the leaching of rice husk has successfully infused HCl, resulting in substantial rise in fixed carbon (FC) and calorific value (CV) by 10.53 % and 10.82 % respectively, along with decrease in the carbon footprint of about 60.55%. Thermogravimetric (TG) and derivative thermogravimetric (DTG) curves have shown decreasing behavior of conversion efficiency to the increase in flow rate, with the maximum drop of 12.7 % observed at 40 °C. With the use of the TGA equipment, the conversion efficiency was evaluated based on the sample's peak weight loss. The current study has reported synergistic effect of flow and heating rate on the degradation temperatures, activation energy and reactivity of acidified rice husk. Lowest activation energy 180.46 kJ*mole−1 and highest reactivity of 0.01192345 %*min °C was observed at 40 ml and 20 °C combination. Accordingly, degradation temperatures of burning profiles increased due to lower convective cooling and higher temperature gradient within the particle of rice husk sample. In addition, pre-exponential data and slopes of TG curves have validated the results of activation energy obtained from TGA experimentation. The sustainable biomass conversion approach is envisioned to significantly refine the waste bio refinery system to achieve sustainable development goals 7 and 13.