Fabrication of thermoelectric generator using local minerals at Loei Province, Thailand

Abstract

Local Thermoelectric mineral specimens at Loei Province, in the northeastern part of Thailand, were prepared as powders and bulk solids form by crushing, calcination and annealing, pressure and sintering, cutting
and polishing. Mineral samples were used to analyze the composition and phase, determine the thermoelectric property and efficiency, design and construct a thermoelectric generator. Chemical composition and phase
identification of powder samples were analyzed by the x-ray fluorescence (XRF) and x-ray diffraction (XRD), respectively. XRF and XRD results indicated that the mineral samples comprised the Fe2O3-SO3-SiO2-others, and
Fe 2O3-SiO2-CuO-others. From the thermoelectric property and efficiency determinations, the p-Fe2O3-SO3-SiO2- others and n-Fe
2O3-SiO2-CuO-others bulks were found to exhibit the thermoelectric figure of merit in orders of 1011 and 1013 K1, respectively. A fabricated thermoelectric generator made from twenty pairs of p-Fe2O3-SO3-
SiO 2-others and n-Fe2O3-SiO2-CuO-others legs that can be provided the open circuit voltage and short circuit current up to 71.7 mV and 0.08 A for a temperature difference of 38 K at room temperature, respectively.