Sensitivity of Operating Conditions
Four important operating conditions that will affect material selection and performance were identified: the primary separator feed pressure, the primary separator vacuum pressure, the primary separator operating temperature, and the liquefaction pressure. Exploring the effects of varying these process parameters gives insight into the desired properties of the separation unit as well as performance tradeoffs that exist. The effects of the primary separator performance when operating conditions are held constant are discussed in detail in following section (Sub-ambient Pressure Swing Adsorption for CO2Capture). Since the pressure driven separation could be achieved with either a membrane or adsorption system, discussion of the economics of the primary separator itself is carried out separately.
The sensitivity of these four process conditions was examined with the other three held constant at the baseline levels listed in Table 1. Heat balance of the plant and pinch analysis were not optimized in this analysis except for the baseline case, as these considerations are best meant for optimization cases requiring knowledge regarding the specific separation modality. The effects of purity as it related to the cost of the separation unit are discussed in more detail in later discussions but are also considered for all of these variables as well in S3 of the Supporting Information. In cases where the purity had a non-linear interaction with other variables on the energetics or economics, such effects are also discussed herein. Table 1 also gives the relevant performance parameters of the primary separator.
Table 1. Base case parameters used in the sensitivity analysis