Combustion characteristics of briquette fuels from sorghum panicle–pearl millets using cassava starch binder

The utilization of agricultural wastes is an attractive and viable option to reduce the environmental pollution and reverse the over-exploitation of fossil fuels. Now-a-days, the usage of fossil fuels has increased manifold causing twin serious problems such as depletion of limited source of fossil fuels and increase in environmental pollution with major consequences. In this study, briquettes were produced using sorghum panicles (SP) and pearl millet (PM) with different ratios (100:0, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10 and 0:100) using cassava starch as a binder with a planned compacting pressure level (200 kN) by exploring hydraulic compression method. The proximate parameters such as water content, level of fixed carbon, ash and volatile matter were determined using American Society for Testing and Materials (ASTM) standard procedures. The elemental analyses (SEM/EDAX) which include carbon (C), oxygen (O), potassium (K), calcium (Ca), chlorine (Cl), sulphur (S), phosphorus (P), aluminium (Al), silicon (Si), magnesium (Mg), cobalt (Co), iron (Fe), zinc (Zn) and sodium (K) were determined in all the briquette samples. Weight loss and optimum heating values of the samples were measured by adopting differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. In addition to that, the density and compressive strength of all the produced briquettes were determined. In comparison with pongamia–tamarind shell, sorghum panicle–pearl millet briquettes have better fuel properties. The pongamia–tamarind shell fuel has nitrogen and hydrogen whereas sorghum panicle–pearl millet has no identities on both nitrogen and hydrogen content. The occurrence of nitrogen absence is due to non-availability of NOx emissions during combustion. By the cause of more fixed carbon composition, there exists lack in hydrogen content. The sorghum panicle–pearl millet briquettes have better calorific value than pongamia–tamarind shells, and they produce better heating values. Hence, the prepared biomass briquettes are potentially good fuels that derived from agro wastes. Likewise, the determined parameters are compared with the other biomass briquettes.