When procuring a caustic soda plant, the primary focus should be on the Ion-Exchange Membrane technology, which is the current global standard for energy efficiency and purity. You must verify the current density (typically 4.0-6.0 kA/m²) and the specific energy consumption (aim for <2,100 kWh/t on a 100% NaOH basis). Additionally, ensure the evaporation system is multi-effect to minimize steam consumption and that the rectifier system offers high conversion efficiency with minimal harmonic distortion.