Changes pressure and recover energy

[rc4]

The idea is to use 4 cases, with different pressure inside. The image shows all steps, from left to right. I consider PV like theoretical value for remove pressure but if I use the formula P0V0*ln(P0/P1), I find this system can give more energy than it receive.

It's possible to try with others values like 4-4-1-1 for example. The best is 1-1-0-0 in theory.

It's not easy to create small pressure, but it's possible to create cases with small pressure, for example for pass from 0.5 to 0.1, I can create 5 cases with 0.1 from one case, I use later these 4 cases. Energy needed for 5 cases is 0.7*4=2.8 PV and it's possible to do 5 cycles with 0.725 Pv won in each cycle, so it's 5*0.725=3.625 PV and recover energy from cases where there is 0.5 P in it. So like this in theory, the sum is not 0.

[rc4]

I done a mistake but the sum is not 0 too, so the cycle can be done in reverse mode ?