Minimizing the energy consumption of glass melters is crucial in the current economic and environmental context. We present a combined approach of experimental analysis, theoretical calculations, and energy balance modeling to help the glass industry make impactful choices toward energy savings and CO2 emission reduction.

The main part of the energy provided by combustion and electric boosting is consumed by the heat demand of the melting process, which is the sum of the energy required to heat the batch, the glass, and the flue gases, and to ensure the conversion of the mineral batch into a melt.

A unique experimental setup was developed with a consortium of glass-related companies to determine the heat demand of the melting process. It is based on the drop calorimetry principle, and it allows the measurement to be performed on a representative quantity (about 200 grams) of batch, with full-size cullet. Experimental results are shown and compared with theoretical calculations for validation based on the work of Conradt. The positive effect of some raw materials such as burned lime, cullet, or dry boron carriers on the heat demand of the melting process is clearly evidenced.

The measured or theoretical data are indispensable inputs to calculate an overall energy balance of a full-scale industrial furnace. The effect of using alternative raw materials on the entire melting process (including emissions, regenerator efficiency, crown hot spot temperatures, overall energy consumption, total CO2, and cost savings) can be evaluated. The potential of the combination of these methods will be demonstrated.