Single system with integrated compressor and pump and method

A system configured to compress a fluid in a gas phase and to pump the fluid in a dense phase, the system comprising:

• a compressor part comprising at least one impeller configured to compress the fluid in the gas phase;
• a compressor part inlet connected to the compressor part and configured to receive the fluid in the gas phase and to provide the fluid to the at least one impeller;
• a compressor part outlet configured to provide the fluid in the gas phase at a density equal to or larger than a predetermined density;
• a temperature changing device connected to the compressor part outlet and configured to change the fluid to the dense phase;
• a pump part comprising at least one impeller configured to pump the fluid in the dense phase;
• a pump part inlet configured to receive the fluid in the dense phase from the compressor part outlet;
• a pump part outlet configured to output the fluid in the dense phase from the system;
• a single bull gear configured to rotate around an axial axis with a predetermined speed;
• plural pinions contacting the single gear bull and configured to rotate with predetermined speeds, different from each other, each pinion being configured to activate a corresponding compressor part impeller;
• and
• a pump shaft extending from the pump part and configured to engage the single bull gear to rotate the at least one impeller of the pump part,
• wherein the at least one impeller of the compressor part has a different speed than the at least one impeller of the pump part, and the dense phase is defined by the fluid having a density larger than the predetermined density.