Evaluation of physiochemical, thermal and kinetic properties of wheat straw by demineralising with leaching reagents for energy applications

Abstract

The augmented concerns towards greenhouse emissions have stimulated the innovative technologies to reduce the carbon footprints and lessen the usage of fossil fuel by replacing them with biomass. Wheat straw is a biowaste and has a great potential for energy-production. However, the inorganic contents in the wheat straw cause operational problems such as low heat transfer and ash-deposition in combustion chamber leading to high maintenance requirements. Demineralization of wheat straw with various basic and acidic leaching reagents (NaOH, HCl, HNO3) was investigated in this study. The concentrations of leachants was varied from 0.6, 0.4 and 0.2M to study their effect on physical, chemical, thermal and kinetic behavior of the biomass. The 0.6 M HCl solution reduced the maximum ash content up to 92.71 % and raised the heating value to 3.98 % than raw wheat straw. The kinetic study of the samples treated with 0.6M HCl demonstrated the superior ignition and the activation-energy than other samples. On other hand NaOH damaged the structure of the wheat straw and had adverse effects on their physical and chemical properties. The results of the current study suggested that HCl treated wheat straw can provide a cost effective and eco-friendly solution for energy generation.