New molecular sieve can separate 99.97% pure propylene

The Zhejiang University team has developed an ultra-fast adsorption kinetic molecular sieve ZU-609. By adjusting the pore size and pore size, it can achieve precise screening of propylene and propane and increase the diffusion rate of propylene. From equimolar propylene Propylene with a purity of 99.97% was separated from the propane mixture. The relevant research results were published online in the international journal “Science” on the 15th.

According to the official website of Zhejiang University, a team of Professor Xing Huabin and Researcher Yang Lifeng from the School of Chemical Engineering and Bioengineering of Zhejiang University and the Hangzhou International Science and Technology Innovation Center have developed a fast, efficient, and low-carbon molecular sieve material ZU-609 through precise control. Through precise control of the pores, this new molecular sieve material only allows propylene molecules to enter and blocks the passage of propane molecules, achieving rapid and accurate identification.

Propylene and propane are refined from petroleum and coexist with each other. They look like “twins”, differing only by two hydrogen atoms, and their sizes are very close. It is extremely challenging to separate propylene and propane accurately and quickly.

In order to make the separation process faster, researchers from Zhejiang University used a screening channel with “small ends and a large middle”. There are “isolation piers” at the entrance and exit of the channel to block propane molecules. After propylene enters, it can be separated in a “wide middle” “It passes quickly through the pores, and the diffusion coefficient is increased by 1-2 orders of magnitude compared to previous molecular sieve materials.

The high efficiency of separation is reflected in the fact that through ZU-609 molecular sieve, 99.97% pure propylene can be separated from an equal molar propylene-propane mixture. At the same time, the material also shows excellent desorption and regeneration capabilities. The material can be completely regenerated by nitrogen purging or vacuum reduction at room temperature.

Pressure swing adsorption calculation results show that ZU-609 propylene separation energy consumption is reduced by 2 times compared with previously reported screening materials, and propylene production efficiency is increased by 2 times.

This research provides new ideas for the core issue of chemical engineering, which is micropore diffusion mass transfer enhancement, lays a foundation for the development of low-carbon separation technology, and is also conducive to the localized preparation of ultra-high-purity electronic chemicals.