Computerized thermogravimetric reactor with video microscopy imaging system for coal pyrolysis and combustion studies

We present the development of a novel thermogravimetric reactor with in situ video microscopy imaging capabilities (TGA/VMI) and discuss its use for studying coal pyrolysis and combustion. Our design combines a long working distance optical microscope and video recording equipment with a computer-automated microbalance reactor. The TGA/VMI apparatus allows for simultaneous thermogravimetric measurement of reaction rates and direct viewing or video taping of structural transformations that may accompany the heterogeneous reactions. Reactor temperature is controlled by a digital algorithm combining feedback with model-based feedforward control. With its computer control and custom-built furnace, our reactor can achieve high heating rates (up to 50 °C/s) and temperatures (1000 °C) with excellent accuracy, stability, and reproducibility. We present some experimental results from our studies on coal pyrolysis and gasification to demonstrate the capabilities of the apparatus and suggest other potential applications.