Multistage compressor-expander turbomachine configuration

A turbomachine comprising:

• a casing arrangement;
• a shaft supported for rotation in said casing arrangement;
• at least a first bearing unit and a second bearing unit adapted to rotatingly support the shaft in the casing arrangement;
• a first compressor section and a second compressor section in said casing arrangement, the first compressor section comprising at least a first compressor impeller mounted on said shaft for rotation therewith, and the second compressor section comprising at least a second compressor impeller mounted on said shaft for rotation therewith;
• and
• a first turboexpander and a second turboexpander mounted on the shaft for rotation therewith in said casing arrangement, adapted to generate mechanical power by expanding a gaseous flow therethrough and drive the first compressor section and the second compressor section.