So I think I've found a way to extract noble gases.
step 1.Fill an empty airtight container with air.
step 2.Fill it with hydrogen very slowly with platinum as a catalyst and it the hydrogen with convert the oxygen into water and the nitrogen into ammonia
step 3.Extract the air and what will remain is noble gases
At first I thought it'd be more energy intensive, but not really because cooling air to sub freezing temperatures probably requires a lot of energy.
The only drawback I can think of is that it'd be a mixture of noble gases instead of each individual gas.