In terms of the total CAPEX the optimum number of stages is four (ignoring the infeasible optima for the highest inter-stage pressure drop due to too high discharge temperature). From this point, and with increasing number of stages, the number of equipment needed increases i.e., more coolers and more inter-stage scrubbers/coalescers are needed, driving up the CAPEX despite the compression power and hence the CAPEX for the rotating machinery alone decreases. When looking at the aggregate number of LCOCC which factors in both CAPEX and power (via OPEX), it is seen that there is a similar trend as for power: the higher the pressure drop, the less stages are required for minimal LCOCC. It is worth noting that the minimal LCOCC is found at a lower stage number than the minimal power due to the CAPEX generally being optimal at 4 stages. As an example, the LCOCC optimal number of stages, even with no pressure drop applied, is 8 compression stages, even though power minimisation requires more stages.