To guide catalyst system design in CXLs at increased temperatures, a Jurgeson-type view cell has been fitted in a high temperature oven (in conjunction with a high-pressure, high-temperature viscometer) and used for CO2 expansion studies and related catalyst component solubility studies (previous studies were limited by the temperature bath in which the cell was placed). Although pressures are relatively high, expansions approaching one-to-one volume ratios of CO2 to acetic acid are readily achieved.
This rare instrumentation allows CEBC researchers to determine conditions under which the Mid-Century process to produce terephthalic acid (TPA) can be operated in CXLs. Initial results show that at temperatures as high as 120 °C, CXLs composed of 50% (volume) CO2 can be approached and good catalyst solubilities are available.
In a related project, Prof. Scurto's group has acquired valuable data on volumetric expansion by CO2 of 1-olefin hydroformylation reaction mixtures and critical phase behavior measurements in a newly-constructed constant-volume view cell. As part of the ionic liquids (ILs) research program, Prof. Scurto's group is also investigating ILs as possible reaction media for hydroformylation. During the past year, they delineated the importance of understanding phase behavior and mass transfer effects when employing CO2-enhanced ILs as reaction media.