Thermal Behavior and Power Efficiency Comparison of AC vs. DC Electrical Heating in a Distillation Column Using Infrared Thermography Analysis

Infrared thermography (IRT) is a widely used non-contact technique for quantifying thermal performance in industrial heating systems. This study employs IRT to analyze and compare the thermal behavior and electrical power efficiency of a heating resistor within a distillation column boiler under alternating current (AC) and direct current (DC) power supply. Experiments were conducted using a distillation pilot plant, which included a 130 W heating resistor powered by an AC (60 Hz) source and an equivalent DC source considering different voltage-current configurations. Thermal dynamics were captured using a calibrated mid-wave IR camera (7.5 to 13 µm spectral range), in parallel with electrical power measurements from a data-acquisition card embedded system. The proposed methodology establishes an IRT protocol for quantifying thermal responses via IRT images, allowing for mapping 2D temperature heterogeneity through emissivity-corrected thermograms. Power efficiency analyses showed DC reduced Joule losses while AC exhibited superior thermal stability during prolonged operation. This IRT-integrated approach provides actionable insights for optimizing distillation energy systems and aligns with industrial electrification initiatives. The protocol is scalable for infrared-based monitoring of thermo-electric processes in chemical, pharmaceutical, and renewable energy applications.