After supplying the monopolar type electrolyzer DCM for more than 100 projects worldwide, thyssenkrupp Uhde Chlorine Engineers (Japan) Ltd. has supplied the filterpress bipolar ion-exchange membrane process electrolyzer - BiTAC - for more than 200 projects since 1994.
The first generation of the BiTAC Family, BiTAC®, was developed to attain the highest current density operation at the lowest possible power consumption while minimizing mechanical damage to the ion exchange membranes, which tend to be more vulnerable to damage in a zero-gap environment.
The design philosophy of the BiTAC family has been maintained throughout the development of each generation – BiTAC®, n-BiTAC and nx-BiTAC, each contributing to an improvement in performance, reliability and maintainability compared with the previous generation. Also to be noted is the interchangeability of elements which makes it possible for users to upgrade their plant by simply replacing older generation elements with new ones.
To achieve higher performances compared with the previous generation, R&D efforts focused on creating a smoother anode surface, improving the gas/liquid separation mechanism and the spring mechanism on the cathode side that creates the zero-gap effect, which makes the largest contribution to reducing power consumption and enhancing the electrical conductivity of the elements.
While the robust and highly reliable monopolar solution – DCM – was well received by users around the world, in the first 10 years alone the first generation BiTAC was selected for more than 40 projects, including Bayer in Baytown TX USA (now Covestro) and other major chlor alkali manufacturers around the world. The second generation, n-BiTAC, introduced to the market in 2005, was even more successful than its predecessor.
Our latest generation, nx-BiTAC, was introduced to the market in 2013 and has attained record sales of 20 projects worldwide in the first 3 years, with its exceptional performance of 2,010 kWh/t-2,025 kWh/t (6kA/m2) (expected), compared with the 2,200 kWh/t (6kA/m2) offered to our clients by the first generation back the in 1990s.
Since the introduction of nx-BiTAC in 2013, tkUCE has made significant R&D efforts to optimize the structure of its latest filterpress technology. After a series of lab-scale, full-scale tests and commercial operations to confirm its performance, mechanical strengths and design integrity, tkUCE introduced the latest of BiTAC family in 2017, further optimizing the structure from the perspectives of stability in operation.
nx-BiTAC plus has pursued stability in operation by adopting a newly designed MWX spring, replacing the coil cushion which was used in the previous model.
Very strenuous R&D programs involving numerous trial and errors, brought tkUCE to another success of finding and developing an optimum spring system which brings about advantages in realizing evenly distributed surface pressure and minimizing fluctuation in the surface pressure at all levels of spring compression.
Since the new spring system MWX is fixed in position and can better maintain suitable power level of pressure at all levels of compression, nx-BiTAC plus assures gentler contact of cathode mesh to the membrane and then the membrane to the anode surface of the adjacent bipolar element. This gentler contact contributes to reducing the mechanical stress in the membranes which is one of the most difficult challenges in zero-gap technology.
Then, in 2020 e-BiTAC v7 started commercial operation, pushing energy consumption to a new record low of 1979 kWh/t NaOH at 6 kA/m2.