Caustic Soda Plant Process Flow Diagram. Nuberg is a global EPC & LSTK company for Caustic Soda Plant. Nuberg has set up more than 14 greenfield caustic soda / chlor alkali plants worldwide with latest bipolar membrane electrolysis cell technology. The company partners world leaders for various technologies and procurement to give best quality service to its global customers. Nuberg's state-of-the-art in-house fabrication facility and team of 750+ engineering professionals gives an edge over other caustic soda / caustic chlorine plant technology suppliers in very competitive global market for lump-sum turnkey projects.