Thermoelectric heat recovery from glass melt processes

Thermoelectric energy recovery from waste heat in glass melting process is investigated without any detrimental design or process changes. Melting glass pellets require a furnace with temperature over 1500 degrees C for downstream glass shaping processes and hence a large amount of exergy is available but currently destroyed. Due to high temperature gradients, parasitic losses are investigated in conjunction with the optimum thermoelectric design for maximum power output and the lowest cost. Among variations of thermal paths, the fireports are identified as the best potential for lowest cost. By partially replacing the refractory wall in thickness with a thermoelectric generator, heat loss is kept at the current 9 kW/m(2). High temperature gradients across the thermoelectric generator requires a water cooling heat sink. The cost of the heat sink is included in the overall energy and cost analysis. Based on a typical thermoelectric figure-of-merit (ZT = 1), optimally designed thermoelectric integrated system generates 55.6 kW of electricity with efficiency of over 15% from a 500 ton/day (5.8 kg/s) scale glass production at an additional cost of $ 1-2/W. This technology can provide 1.37 billion kWh of primary energy savings annually, if it is implemented throughout the whole glass industry in U.S. (C) 2016 Elsevier Ltd. All rights reserved.