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