Can the small medium pressure air separation equipment with piston expander be converted to turbine expander for refrigeration?

The new small medium-pressure air separation plant adopts the turbine expander, which reduces the working pressure and saves energy consumption. Then, can the small medium pressure air separation equipment of the old type with piston expander be switched to turbine expander.
Technically, it should be feasible. However, the energy saving of new equipment is not only based on the turbine expander, but also the comprehensive effect through three aspects of transformation. Three closely linked, are indispensable. Therefore, during the transformation, three aspects should be carried out simultaneously:
1) replace the piston expansion machine with two turbine expansion machines to improve the efficiency and reduce the temperature in front of the machine to below-150℃;
2) replace the original Coil Heat Exchanger with Plate-fin Heat Exchanger to reduce the temperature difference at the Heat end from 5℃ to 2 ~ 3℃, in order to reduce the cold loss; the temperature of the extracting gas decreases from-100℃ to-150℃, matching with the turbine expander, and giving full play to the potential of the turbine expander;
3) add a set of precooling unit in front of the purifier to reduce the inlet air temperature of the purifier from 30℃ to 5 ~ 8℃. Because the operating pressure will decrease after the transformation, the moisture brought to the purifier will increase. Under the condition of not changing the purifier, the water-removing load of the purifier can be reduced through the method of low air temperature.