A comparison of the energy consumption for CO₂ compression process alternatives

The efficient transportation of large volumes of CO₂ generally requires pipelines that will operate above the critical pressure of CO₂. Since most capture processes release CO₂ at low pressure, compression of CO₂ from the point of capture to pipeline will generally be required. The compression duty can be achieved using conventional multi-stage compressors or using newer shockwave type compressors. Pumping could also be used if CO₂ is condensed below its critical point. This paper presents a comparison the energy consumption associated with these compression process alternatives. The focus of the review is on the clarity of the comparison and the careful optimisation of each of the scheme considered. The main finding is that the performance advantages claimed for improved CO₂ compression process schemes are often optimistic because the based-line scheme compared against is not well optimized.