Issues with Aspen’s custom sulfonic acid groups
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Recently, I was calculating a distillation process that involved p-benzenesulfonic acid, whose CAS number is 104-15-4 and molecular formula is… Since Aspen only has partial data on p-benzenesulfonic acid, it was necessary to use UNIFC to estimate the missing data. However, Aspen cannot recognize the sulfonic acid group –SO3H, which results in an error message. To solve this problem, my idea is to define the sulfonic acid group as a new group, labeled 5555. Then, the UNIFC q/r parameters can be calculated using software; meanwhile, p-benzenesulfonic acid can be considered as a methyl group, a phenyl group, and the newly defined sulfonic acid group 5555
Continuing from above, but using this method it is still not possible to estimate all the properties required for the p-toluenesulfonic acid. So I have a few questions: 1. Is my approach correct? Why can’t I get all the parameters for this mesylic acid? (Meets the requirements for distillation calculations) 2. Why does my custom functional group not yield any results for the estimation of p-toluenesulfonic acid? Can’t see the UNIFC q/r parameter values? 3. Are there any other ways to handle materials with incomplete database data of this kind?
BKP simulation file, version V9.0; please provide your guidance. @llbear @tdl522