Chemical Engineers from Rensselaer Polytechnic Institute have developed a highly effective separation membrane for converting carbon dioxide (CO2) into methanol.
Methanol is an efficient and versatile chemical that is a very useful product used for fuel, CO2, on the other hand, is a harmful greenhouse gas. The challenge faced by scientists is to separate or filter out the water because it restricts the continued reaction. So, they set out to figure out how to do this without losing other essential gas molecules.
The research team was led by Miao Yu, a Chair Professor of Chemical and Biological Engineering and a member of the Center for Biotechnology and Interdisciplinary Studies (CBIS) at Rensselaer.
The researchers created a membrane that was able to quickly permeate water through small pores made up of sodium ions and zeolite crystals. Together these makeup water-conduction nanochannels that do not lose gas molecules.
Yu explains the process:
The sodium can actually regulate, or tune, gas permeation. It’s like the sodium ions are standing at the gate and only allow water to go through. When the inert gas comes in, the ions will block the gas.
He goes on to say that in the past this type of membrane was susceptible to gas molecules leaking out. He and his team created a way to optimize the assembly of the crystals, thus eliminating the defects or leaks.
The researchers called this discovery a breakthrough that could improve many industrial processes which depend on chemical reactions where water is a byproduct.
The team was able to remove water from the reaction process, Huazheng Li, a postdoctoral researcher at Rensselaer and first author on the research explains: “When we can remove the water, the equilibrium shifts, which means more CO2 will be converted and more methanol will be produced.”
Next, the team is working to make a scalable version of the process along with a start-up company that would allow for this to be used in commercial applications for producing high purity methanol.
The Director of CBIS, Deepak Vashishth speaks about the work the team is doing:
This research is a prime example of the significant contributions Professor Yu and his team are making to address interdisciplinary challenges in the area of water, energy, and the environment. Development and deployment of such tailored membranes by Professor Yu’s group promise to be highly effective and practical.
In closing, Yu talked about how they would like to use this membrane to improve other reactions.
“In industry, there are so many reactions limited by water,” Yu said. “This is the only membrane that can work highly efficiently under harsh reaction conditions.”
