Hi everyone, my business project is going well as all thanks to all who've recently responded to my questions so far, however like always we have been running into issues and this time i'd appreciate some sources. Our current issue is that we have air inflow stagnation issues which means we need to find a way to slow down ambient air going into a device and as it goes in, we need to maxmimize the amount of different gases that might be coming as part of the inflow specifically methane and nitrogen. Based on the paper attached, the amount of air separation we get using a cellulose acetate membrane is about 17.5% which is too low for the idea im working with, an alternative to this would be using an impermable membrane however that stands to cause an issue by providing a low energy yield. All answers with well documented sources are very well appreciated.