Liquefaction Pressure
From an electrical energy and cost perspective, there is a moderate
effect on increasing the liquefaction pressure, as shown in Figure 3d
and Figure S13a, respectively. This increase is primarily due
to the increase in the size of the compressor used for liquefaction. The
increase is slightly reduced as the liquefaction pressure approaches the
separator operating pressure due to the necessity for less work in the
recycle compressor. The primary effect of the choice of liquefaction
pressure is on the temperature the liquefaction column requires for the
90% CO2 recovery condition set as a requirement for the
process. These temperature effects across a wide range of separation
performance (purity) conditions, are given in Figure S13c. This choice,
therefore, has considerable effects on the design of the final heat
exchanger network, as well as the ability of the plant to utilize the
process’ available heat removal with a reasonable temperature approach.