Taiyo Nippon Sanso Corporation (TNSC) has successfully developed a trace moisture analyser in nitrogen using properties from a metal organic framework (MOF) with optical characteristics that change depending on absorption and desorption of moisture.
TNSC conducted the research jointly with Associate Professor Shin-Ichi Ohira of the Faculty of Advanced Science and Technology at Kumamoto University.
The analyser traces moisture in nitrogen using an MOF with a porous structure as a moisture-sensitive agent that fulfils a response speed of less than five minutes and lower detection limit of 10 vol. ppb at a cost of less than \1 million.
TNSC plans to move forward with testing at its related plants, and progress to public sales within the fiscal year ending 2021 (from April 2020 to March 2021) through long-term field testing in actual environments.
The company will also move ahead on technological development and commercialisation for application with other types of gases and greater sensitivity.
TNSC explained the process: “MOF is a porous agent group formed through a coordinate bond between metal ions and organic ligands and is a next-generation functional material expected to be used in applications such as gas storage, separation, or catalyst.”
“Cu-BTC is an MOF formed by divalent copper ion (Cu2+) and benzene-1,3,5-tricarboxylate (BTC) that absorbs and desorbs moisture molecules at room temperature and specific wavelength absorbance changes in conjunction with that (Fig. 1, above).”
“The analyser’s basic principle is to detect the absorbance change and convert that to moisture concentration.”
“In trace amounts, changes in moisture concentration have a rapid and high correlation with changes in absorbance, so showing this enables highly reliable measurements of high sensitivity and rapid responsiveness.”
“As shown in the measurement example in Fig. 2 (see below), the indicated values rose immediately after the introduction of nitrogen gas containing trace amounts of moisture, confirming that the analyser responds faster than conventional general-purpose analysers and solidifying that it can be used as a moisture impurity concentration control device in processes with extreme moisture aversion.”