An empirical model of heat-treated straw bulks’ thermal conductivity based on changes in mass and chemical composition

Abstract An empirical model was developed to estimate the thermal conductivity of heat-treated straw bulks based on laboratory experiments. During measurements, two different types were investigated, barley and wheat. Barley used composing our define influencing parameters, wheat for validation. Both straws in a dry oxidative ambient five temperature steps from 60 180 °C. The measured at 120 kg m −3 bulk density after every treatment cycle. In addition, we looking most suitable measurement methods detect changes material structure related range relatively low-temperature treatments. Thermogravimetric conducted, mass loss elemental composition measurements showed that percentage ratio carbon increased, oxygen decreased investigated range. We identified separated following parameters model, which can relative stem bulks: residual mass, content content. divided into parts, creating simpler but worse approximation (the required this are much easier perform) slightly more complex better approximation. After validation, achieved good agreement with conductivities calculated by conductivities.