(589i) The Temperature Dependence of BaSO4 Surface Precipitation Kinetics

The negative effect of scale formation is seen in multiple industries, and manifests as a decreased performance of heat exchangers, flow assurance complication in transport pipelines, and lowered equipment lifetime in geothermal wells.

Scaling mitigation includes chemical dissolution or mechanical scrubbing. BaSO₄ scaling poses as a particularly complicated scaling agent, as it has low solubility in most chemicals, and is mechanically very tough. Therefore, to predict the BaSO₄ formation, it is important to know the rate at which it forms. Currently, few published studies address the actual surface deposition kinetics in a wide temperature range. In this work, we aim to fill this gap and to give insight to surface formation through novel analysis techniques.

The experimental campaign consisted of growth studies performed in a custom-built once-through flow setup. The supersaturation and temperature were varied and the scale deposits were investigated by both volumetric and gravimetric analysis. The gravimetric analysis was performed by comparing the weight difference of the cells. The volumetric analysis was performed through micro X-ray computed tomographies. The reconstructed tomographies were further treated with a novel Python code, enabling surface texture analysis of the grown crystals.

Our work has two main objectives. First, we create novel kinetic data for BaSO4 surface precipitation under controlled temperature and supersaturation. Second, we propose a novel method for surface characterization of crystal growth.

These results will help in understanding the phenomena of scaling and reduce the associated complications experienced in multiple industries. Furthermore, it will broaden the current ways of investigating crystal growth.