What are the main types of gas compressors?

Dynamic compressors: Centrifugal (high flow, moderate pressure ratio, oil-free option), Axial (very high flow, lower pressure ratio, multi-stage). Positive displacement: Reciprocating (high pressure, lower flow, pulsating output), Rotary screw (continuous flow, oil-injected or dry), and Rotary vane (lower pressure applications). Selection depends on flow rate, pressure ratio, gas properties, and service continuity. Centrifugal dominates large continuous processes; reciprocating for high pressure or smaller intermittent duty.