Around 70 per cent of all chemical products use chlorine in their manufacturing process. At the same time, the production of this important base chemical is one of the most energy-intensive processes in the chemical industry. In order to change that, thyssenkrupp is offering the NaCl-ODC electrolysis technology (ODC = oxygen depolarised cathode) which lowers power consumption and indirect CO2 emissions by up to 25 per cent compared to standard production processes.
Engineers from thyssenkrupp have now been able to develop the technology even further: By raising the current density of the electrolyzer from 4 to 6 kilo amperes, output was increased by 50 per cent. Electrolyzers with the same output capacity can now be built about one third smaller, resulting in significantly lower total cost of ownership. Plant operators profit from a smaller plant footprint, lower maintenance and from the generally high efficiency that comes with the NaCl-ODC electrolysis process.
thyssenkrupp’s cooperation partner Covestro will be the first to utilise the advanced ODC electrolysis for a new chlor-alkali plant in Tarragona, Spain. “Three factors played a vital role in choosing the technology for our process: sustainability, energy efficiency, and increasing our site’s competitiveness”, states Dr Klaus Schäfer, Chief Technology Officer at Covestro.
Energy consumption makes up roughly one third of the operating expenses of a chlor-alkali production plant. Thus, the advanced NaCl-ODC technology helps to significantly reduce energy costs. Compared with the conventional single-element design, it will cut CO2 emissions of the Tarragona plant by around 22,000 metric tons per year. That’s roughly the amount produced by 15,000 cars in one year. Implementation of NaCl-ODC electrolysis as standard technology for chlorine production around the world would mean an energy saving potential of 35 million megawatt hours per year.
